@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Noto+Sans+SC:wght@400;500;700&display=swap');

/* ============================================================
   现代白色设计系统（全站统一，自适应）
   版权署名：兔子科技
   ============================================================ */

:root {
    /* M3 基准色板（Baseline） */
    --md-primary: #4f46e5;
    --md-on-primary: #ffffff;
    --md-primary-container: #e0e7ff;
    --md-on-primary-container: #312e81;
    --md-secondary: #475569;
    --md-on-secondary: #ffffff;
    --md-secondary-container: #e2e8f0;
    --md-on-secondary-container: #1e293b;
    --md-tertiary: #7d5260;
    --md-tertiary-container: #ffd8e4;
    --md-on-tertiary-container: #31111d;
    --md-error: #b3261e;
    --md-on-error: #ffffff;
    --md-error-container: #f9dedc;
    --md-on-error-container: #410e0b;
    --md-surface: #ffffff;
    --md-surface-dim: #eceef1;
    --md-surface-bright: #ffffff;
    --md-surface-container-lowest: #ffffff;
    --md-surface-container-low: #ffffff;
    --md-surface-container: #f4f5f7;
    --md-surface-container-high: #eceef1;
    --md-surface-container-highest: #e4e7eb;
    --md-on-surface: #1f2328;
    --md-on-surface-variant: #5f6368;
    --md-outline: #74777c;
    --md-outline-variant: #dde1e6;
    --md-inverse-surface: #322f35;
    --md-inverse-on-surface: #f5eff7;
    --md-success: #146c2e;
    --md-success-container: #c4eed0;
    --md-on-success-container: #072711;
    --md-online: #2e7d32;

    --md-scrim: rgba(0, 0, 0, .42);
    --md-elev-1: 0 1px 2px rgba(15, 23, 42, .04), 0 1px 3px rgba(15, 23, 42, .06);
    --md-elev-2: 0 4px 12px rgba(15, 23, 42, .08), 0 1px 2px rgba(15, 23, 42, .05);
    --md-elev-3: 0 12px 32px rgba(15, 23, 42, .14), 0 4px 12px rgba(15, 23, 42, .08);

    --md-radius-xs: 8px;
    --md-radius-sm: 12px;
    --md-radius-md: 16px;
    --md-radius-lg: 24px;
    --md-radius-full: 9999px;

    --md-font: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

    color-scheme: light;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
}

body {
    font-family: var(--md-font);
    background: var(--md-surface);
    color: var(--md-on-surface);
    font-size: 14px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--md-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { margin: 0; font-weight: 600; }

::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: var(--md-outline-variant); border-radius: 4px; }
::-webkit-scrollbar-track { background: transparent; }

/* ---------------- 按钮 ---------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 40px;
    padding: 0 24px;
    border: none;
    border-radius: var(--md-radius-full);
    font-family: inherit;
    font-size: 14px;
    font-weight: 500;
    letter-spacing: .1px;
    cursor: pointer;
    transition: box-shadow .18s ease, background-color .18s ease, transform .05s ease;
    user-select: none;
    white-space: nowrap;
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-filled { background: var(--md-primary); color: var(--md-on-primary); }
.btn-filled:hover:not(:disabled) { box-shadow: var(--md-elev-1); }
.btn-tonal { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.btn-tonal:hover:not(:disabled) { box-shadow: var(--md-elev-1); }
.btn-outlined { background: transparent; color: var(--md-primary); border: 1px solid var(--md-outline); }
.btn-text { background: transparent; color: var(--md-primary); padding: 0 12px; }
.btn-danger { background: var(--md-error); color: var(--md-on-error); }
.btn-danger-tonal { background: var(--md-error-container); color: var(--md-on-error-container); }
.btn-sm { height: 32px; padding: 0 16px; font-size: 13px; }
.btn-block { width: 100%; }
.btn-icon {
    width: 40px; height: 40px; padding: 0;
    border: none; border-radius: var(--md-radius-full);
    background: transparent; color: var(--md-on-surface-variant);
    display: inline-flex; align-items: center; justify-content: center;
    cursor: pointer; transition: background-color .15s;
    font-family: inherit;
}
.btn-icon:hover { background: var(--md-surface-container-highest); }
.btn-icon svg { width: 22px; height: 22px; }

/* ---------------- 输入框（M3 Outlined Field） ---------------- */
.field { position: relative; margin-bottom: 4px; }
.field input, .field textarea {
    width: 100%;
    background: transparent;
    border: 1px solid var(--md-outline);
    border-radius: var(--md-radius-xs);
    color: var(--md-on-surface);
    font-family: inherit;
    font-size: 15px;
    padding: 22px 14px 8px;
    outline: none;
    transition: border-color .15s;
}
.field textarea { min-height: 96px; resize: vertical; }
.field input:focus, .field textarea:focus { border-color: var(--md-primary); border-width: 2px; padding: 21px 13px 7px; }
.field label {
    position: absolute; left: 12px; top: 6px;
    font-size: 12px; color: var(--md-on-surface-variant);
    pointer-events: none;
}
.field-hint { font-size: 12px; color: var(--md-on-surface-variant); margin: 4px 14px 0; }
.field-error-text { font-size: 12px; color: var(--md-error); margin: 4px 14px 0; }

/* ---------------- 卡片 / 面板 ---------------- */
.card {
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    padding: 20px;
    box-shadow: 0 1px 2px rgba(16, 24, 40, .04);
}
.card-elevated { background: var(--md-surface-container-lowest); box-shadow: var(--md-elev-1); }
.card-title { font-size: 16px; font-weight: 600; margin-bottom: 12px; }

/* ---------------- Chip ---------------- */
.chip {
    display: inline-flex; align-items: center; gap: 6px;
    height: 28px; padding: 0 12px;
    border-radius: var(--md-radius-xs);
    border: 1px solid var(--md-outline-variant);
    background: transparent;
    color: var(--md-on-surface-variant);
    font-size: 12px; font-weight: 500;
}
.chip-tonal { background: var(--md-secondary-container); color: var(--md-on-secondary-container); border-color: transparent; }
.chip-primary { background: var(--md-primary-container); color: var(--md-on-primary-container); border-color: transparent; }
.chip-danger { background: var(--md-error-container); color: var(--md-on-error-container); border-color: transparent; }
.chip-success { background: var(--md-success-container); color: var(--md-on-success-container); border-color: transparent; }

/* ---------------- 头像 ---------------- */
.avatar {
    position: relative;
    width: 40px; height: 40px; flex: none;
    border-radius: var(--md-radius-full);
    background: var(--md-primary-container);
    color: var(--md-on-primary-container);
    display: inline-flex; align-items: center; justify-content: center;
    font-weight: 600; font-size: 16px;
    overflow: hidden;
}
.avatar-lg { width: 72px; height: 72px; font-size: 28px; }
.avatar-sm { width: 40px; height: 40px; font-size: 15px; }
.avatar-xs { width: 32px; height: 32px; font-size: 13px; }
.avatar-img { object-fit: cover; width: 100%; height: 100%; display: block; }
img.avatar { padding: 0; }
/* 当图片自身作为头像容器时，使用固定尺寸，避免 avatar-img 的 100% 撑满消息行导致超大头像 */
img.avatar.avatar-img { width: 40px; height: 40px; }
img.avatar.avatar-img.avatar-lg { width: 72px; height: 72px; }
img.avatar.avatar-img.avatar-xs { width: 32px; height: 32px; }
.avatar-clickable { cursor: pointer; transition: opacity .15s; }
.avatar-clickable:hover { opacity: .85; }
.presence-dot {
    position: absolute; right: -1px; bottom: -1px;
    width: 12px; height: 12px; border-radius: 50%;
    border: 2px solid var(--md-surface);
    background: var(--md-outline);
}
.presence-dot.on { background: var(--md-online); }
.presence-inline {
    display: inline-block; width: 8px; height: 8px; border-radius: 50%;
    background: var(--md-outline); margin-right: 6px; vertical-align: middle;
}
.presence-inline.on { background: var(--md-online); }

/* ---------------- 横幅提示 ---------------- */
.banner {
    display: flex; align-items: center; gap: 10px;
    border-radius: var(--md-radius-sm);
    padding: 12px 16px; margin-bottom: 16px;
    font-size: 14px;
}
.banner-error { background: var(--md-error-container); color: var(--md-on-error-container); }
.banner-success { background: var(--md-success-container); color: var(--md-on-success-container); }
.banner-info { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }

/* ---------------- 认证页（登录 / 注册 / 安装 / 房门） ---------------- */
.auth-page {
    min-height: 100dvh;
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    padding: 24px 16px;
    background:
        radial-gradient(1200px 600px at 10% -10%, var(--md-primary-container) 0%, transparent 55%),
        radial-gradient(1000px 500px at 110% 110%, var(--md-tertiary-container) 0%, transparent 55%),
        var(--md-surface);
}
.auth-card {
    width: 100%; max-width: 440px;
    background: var(--md-surface-container-low);
    border-radius: var(--md-radius-lg);
    box-shadow: var(--md-elev-2);
    padding: 32px 28px 24px;
}
.auth-brand {
    display: flex; align-items: center; gap: 10px;
    margin-bottom: 20px; color: var(--md-primary);
    font-weight: 700; letter-spacing: .4px; font-size: 14px;
}
.auth-brand .brand-mark {
    width: 34px; height: 34px; border-radius: 10px;
    background: var(--md-primary); color: var(--md-on-primary);
    display: inline-flex; align-items: center; justify-content: center;
}
.auth-brand .brand-mark svg { width: 20px; height: 20px; }
.auth-title { font-size: 26px; font-weight: 600; margin-bottom: 6px; }
.auth-sub { color: var(--md-on-surface-variant); margin: 0 0 22px; font-size: 14px; }
.auth-form .field { margin-bottom: 14px; }
.auth-actions { margin-top: 8px; }
.auth-links { margin-top: 18px; text-align: center; color: var(--md-on-surface-variant); font-size: 14px; }
.auth-security-note {
    margin-top: 16px; padding: 12px 14px;
    border-radius: var(--md-radius-sm);
    background: var(--md-surface-container-high);
    color: var(--md-on-surface-variant);
    font-size: 12.5px; line-height: 1.6;
}
.site-copy {
    margin-top: 22px; text-align: center;
    color: var(--md-on-surface-variant); font-size: 12px;
}
.site-copy a { color: inherit; }

/* ---------------- 认证页 4.0（M3：登录 / 注册 / 找回密码，卡片式输入） ---------------- */
.auth-page-3 {
    min-height: 100dvh;
    display: flex;
    padding: 28px 16px;
    background:
        radial-gradient(1100px 650px at 85% -5%, rgba(99, 102, 241, .08) 0%, transparent 60%),
        linear-gradient(180deg, #ffffff 0%, #fbfcff 55%, #f2f6ff 100%);
}
/* 背景装饰：白底未来科技（星点 + 透视网格地板 + 雷达环 + 扫描线 + 光斑 + 彩色流星） */
.auth-bg { position: fixed; inset: 0; pointer-events: none; overflow: hidden; z-index: 0; }
/* 星点两层尺寸，缓慢闪烁 */
.auth-bg::before {
    content: ''; position: absolute; inset: 0;
    background-image:
        radial-gradient(1.6px 1.6px at 22px 34px, rgba(99, 102, 241, .4) 50%, transparent 52%),
        radial-gradient(1.1px 1.1px at 68px 12px, rgba(139, 92, 246, .35) 50%, transparent 52%),
        radial-gradient(1.3px 1.3px at 118px 72px, rgba(14, 165, 233, .3) 50%, transparent 52%),
        radial-gradient(1px 1px at 34px 96px, rgba(99, 102, 241, .3) 50%, transparent 52%);
    background-size: 140px 110px;
    animation: auth-twinkle 5s ease-in-out infinite alternate;
}
@keyframes auth-twinkle {
    from { opacity: .35; }
    to { opacity: .8; }
}
/* 未来科技地板：透视网格向前流动 */
.auth-bg::after {
    content: ''; position: absolute;
    left: -25%; right: -25%; bottom: -12%; height: 58%;
    background-image:
        linear-gradient(rgba(99, 102, 241, .16) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, .16) 1px, transparent 1px);
    background-size: 52px 52px;
    transform: perspective(520px) rotateX(63deg);
    transform-origin: 50% 0;
    -webkit-mask-image: linear-gradient(to bottom, transparent 0%, rgba(0, 0, 0, .85) 24%, rgba(0, 0, 0, .5) 70%, transparent 100%);
    mask-image: linear-gradient(to bottom, transparent 0%, rgba(0, 0, 0, .85) 24%, rgba(0, 0, 0, .5) 70%, transparent 100%);
    animation: tech-floor-run 2.6s linear infinite;
}
@keyframes tech-floor-run {
    from { background-position: 0 0; }
    to { background-position: 0 52px; }
}
/* 雷达同心环（右上角）+ 旋转扫描 */
.auth-bg .tech-rings {
    position: absolute; top: -190px; right: -170px;
    width: 460px; height: 460px; border-radius: 50%;
    border: 1px solid rgba(99, 102, 241, .18);
    box-shadow: 0 0 0 70px rgba(99, 102, 241, .04), 0 0 0 140px rgba(99, 102, 241, .03);
}
.auth-bg .tech-rings::before {
    content: ''; position: absolute; inset: 60px;
    border-radius: 50%; border: 1px dashed rgba(99, 102, 241, .22);
}
.auth-bg .tech-rings::after {
    content: ''; position: absolute; inset: 0; border-radius: 50%;
    background: conic-gradient(from 0deg, rgba(99, 102, 241, .22), transparent 90deg);
    animation: tech-sweep 6s linear infinite;
}
@keyframes tech-sweep { to { transform: rotate(360deg); } }
/* 纵向扫描光线：横贯屏幕缓缓下移 */
.auth-bg .tech-scan {
    position: absolute; left: 0; right: 0; top: 0; height: 2px;
    background: linear-gradient(90deg, transparent 0%, rgba(14, 165, 233, .55) 35%, rgba(99, 102, 241, .65) 50%, rgba(14, 165, 233, .55) 65%, transparent 100%);
    box-shadow: 0 0 20px rgba(56, 189, 248, .5);
    opacity: 0;
    animation: tech-scan-run 8s linear infinite;
}
@keyframes tech-scan-run {
    0% { top: -2%; opacity: 0; }
    6% { opacity: .85; }
    52% { opacity: .85; }
    60%, 100% { top: 103%; opacity: 0; }
}
.auth-bg .blob {
    position: absolute; border-radius: 50%;
    filter: blur(90px); opacity: .3;
    animation: auth-drift 18s ease-in-out infinite alternate;
}
.auth-bg .blob.b1 { width: 460px; height: 460px; background: #a5b4fc; top: -140px; left: -120px; }
.auth-bg .blob.b2 { width: 380px; height: 380px; background: #c4b5fd; bottom: -140px; right: -100px; animation-delay: -6s; }
.auth-bg .blob.b3 { width: 300px; height: 300px; background: #7dd3fc; top: 40%; left: 62%; animation-delay: -12s; }
@keyframes auth-drift {
    from { transform: translate(0, 0) scale(1); }
    to { transform: translate(-30px, 26px) scale(1.08); }
}
/* 流星：多彩渐变亮尾，斜向划过，七条错峰 */
.auth-bg .meteor {
    position: absolute; top: -18%;
    width: 2px; height: 110px;
    border-radius: 2px;
    --mc: rgba(99, 102, 241, .85);
    background: linear-gradient(to bottom, transparent, var(--mc));
    box-shadow: 0 0 8px var(--mc);
    opacity: 0;
    transform: rotate(28deg);
    animation: auth-meteor 10s linear infinite;
}
.auth-bg .meteor.m1 { left: 6%;  --mc: rgba(99, 102, 241, .85);  animation-delay: 0s;   animation-duration: 9s; }
.auth-bg .meteor.m2 { left: 22%; --mc: rgba(139, 92, 246, .8);   height: 80px;  animation-delay: 1.8s; animation-duration: 11s; }
.auth-bg .meteor.m3 { left: 38%; --mc: rgba(14, 165, 233, .8);   height: 130px; animation-delay: 3.4s; animation-duration: 12s; }
.auth-bg .meteor.m4 { left: 52%; --mc: rgba(236, 72, 153, .75);  height: 90px;  animation-delay: 5s;   animation-duration: 10s; }
.auth-bg .meteor.m5 { left: 66%; --mc: rgba(16, 185, 129, .7);   height: 120px; animation-delay: 6.6s; animation-duration: 13s; }
.auth-bg .meteor.m6 { left: 80%; --mc: rgba(245, 158, 11, .7);   height: 70px;  animation-delay: 8.2s; animation-duration: 9.5s; }
.auth-bg .meteor.m7 { left: 92%; --mc: rgba(59, 130, 246, .8);   height: 140px; animation-delay: 9.6s; animation-duration: 14s; }
@keyframes auth-meteor {
    0% { transform: translate(0, 0) rotate(28deg); opacity: 0; }
    3% { opacity: 1; }
    26% { transform: translate(-300px, 560px) rotate(28deg); opacity: 1; }
    32%, 100% { transform: translate(-360px, 660px) rotate(28deg); opacity: 0; }
}

.auth-wrap {
    margin: auto;
    width: 100%; max-width: 430px;
    position: relative; z-index: 1;
    animation: auth-rise .45s cubic-bezier(.2, .8, .3, 1) both;
}
@keyframes auth-rise {
    from { opacity: 0; transform: translateY(18px); }
    to { opacity: 1; transform: translateY(0); }
}
.auth-card-3 {
    position: relative;
    transform: translateZ(0);
    background:
        linear-gradient(150deg, rgba(255, 255, 255, .68) 0%, rgba(255, 255, 255, .46) 48%, rgba(240, 246, 255, .5) 100%);
    backdrop-filter: blur(26px) saturate(1.6);
    -webkit-backdrop-filter: blur(26px) saturate(1.6);
    border: 1px solid rgba(255, 255, 255, .95);
    border-radius: 26px;
    box-shadow:
        0 30px 80px -30px rgba(79, 70, 229, .38),
        0 4px 16px rgba(15, 23, 42, .05),
        inset 0 1px 0 rgba(255, 255, 255, .95);
    padding: 34px 30px 26px;
    color: var(--md-on-surface);
    overflow: hidden;
}
/* 卡片顶部科技高光扫线（transform 动画，仅合成，不触发布局重绘） */
.auth-card-3::before {
    content: ''; position: absolute; top: 0; left: 0; width: 36%; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(99, 102, 241, .7), transparent);
    animation: auth-card-scan 3.6s ease-in-out infinite;
    will-change: transform;
}
@keyframes auth-card-scan {
    0%, 100% { transform: translateX(-110%); opacity: 0; }
    12%, 60% { transform: translateX(150%); opacity: 1; }
    88% { transform: translateX(330%); opacity: 0; }
}
.auth-card-3 > * { position: relative; }
.auth-logo {
    width: 62px; height: 62px; margin: 0 auto 14px;
    border-radius: 20px;
    background: linear-gradient(135deg, #4f46e5, #8b5cf6);
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 10px 30px -6px rgba(99, 102, 241, .6);
}
.auth-logo svg { width: 30px; height: 30px; }
.auth-headline { text-align: center; font-size: 23px; font-weight: 700; margin: 0 0 4px; letter-spacing: .2px; }
.auth-desc { text-align: center; color: var(--md-on-surface-variant); font-size: 13.5px; margin: 0 0 20px; }
.auth-card-3 .banner { margin-bottom: 14px; font-size: 13px; padding: 11px 14px; }

/* ---- 卡片式输入组：图标 + 标签/输入 + 可见切换，整体一张圆角小卡 ---- */
.auth-input-card {
    display: flex; align-items: center; gap: 12px;
    background: rgba(255, 255, 255, .85);
    border: 1.5px solid var(--md-outline-variant);
    border-radius: 16px;
    padding: 12px 14px;
    transition: border-color .18s ease, background-color .18s ease, box-shadow .18s ease;
}
.auth-input-card:focus-within {
    background: #fff;
    border-color: var(--md-primary);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, .1);
}
.auth-input-icon { width: 21px; height: 21px; flex: none; color: #8a8f98; transition: color .18s ease; }
.auth-input-card:focus-within .auth-input-icon { color: var(--md-primary); }
.auth-input-inner { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 1px; }
.auth-input-inner label {
    font-size: 11.5px; font-weight: 500; letter-spacing: .3px;
    color: #7c828c; pointer-events: none;
}
.auth-input-inner input {
    border: none; background: transparent; outline: none;
    font-family: inherit; font-size: 15.5px; line-height: 1.4;
    color: var(--md-on-surface);
    padding: 0; width: 100%; min-width: 0;
}
.auth-input-inner input::placeholder { color: #aab0bb; }
.auth-input-inner input:-webkit-autofill {
    -webkit-text-fill-color: var(--md-on-surface);
    transition: background-color 99999s ease-in-out 0s;
}
.auth-eye {
    flex: none; width: 34px; height: 34px;
    border: none; background: transparent; border-radius: 999px;
    color: #8a8f98; cursor: pointer;
    display: inline-flex; align-items: center; justify-content: center;
    transition: background-color .15s ease, color .15s ease;
}
.auth-eye:hover { background: rgba(79, 70, 229, .1); color: var(--md-primary); }
.auth-eye.active { color: var(--md-primary); }
.auth-eye svg { width: 19px; height: 19px; }
/* 表单内垂直节奏 */
.auth-form > .auth-input-card,
.auth-form > .auth-field-row { margin-bottom: 12px; }

/* 验证码行：输入卡 + 发送按钮 */
.auth-field-row { display: flex; gap: 10px; align-items: stretch; }
.auth-field-row .auth-input-card { flex: 1; }
.auth-field-row .btn { align-self: stretch; height: auto; border-radius: 15px; padding: 0 18px; font-size: 13.5px; white-space: nowrap; }

/* 分组标题 */
.auth-group-label {
    display: flex; align-items: center; gap: 8px;
    font-size: 12.5px; font-weight: 600; letter-spacing: .6px;
    color: var(--md-primary);
    margin: 18px 0 10px;
}
.auth-group-label:first-of-type { margin-top: 2px; }
.auth-group-label::after {
    content: ''; flex: 1; height: 1px;
    background: var(--md-outline-variant);
}
/* 双列（宽屏下密码/密钥并排） */
.auth-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }

/* 主按钮与链接 */
.auth-card-3 .btn-filled {
    position: relative; overflow: hidden;
    height: 50px; border-radius: 16px; font-size: 15px; font-weight: 600;
    color: #fff;
    background: linear-gradient(120deg, #38bdf8 0%, #60a5fa 35%, #818cf8 70%, #38bdf8 100%);
    box-shadow:
        0 12px 28px -10px rgba(56, 189, 248, .65),
        0 2px 8px rgba(99, 102, 241, .3),
        inset 0 1px 0 rgba(255, 255, 255, .3);
    transition: box-shadow .2s ease, transform .12s ease;
}
/* 流光：覆盖层 transform 平移，不重绘按钮文字 */
.auth-card-3 .btn-filled::after {
    content: ''; position: absolute; top: 0; bottom: 0; left: -60%; width: 40%;
    background: linear-gradient(100deg, transparent, rgba(255, 255, 255, .38), transparent);
    transform: translateX(0) skewX(-18deg);
    animation: auth-btn-sheen 5s ease-in-out infinite;
    will-change: transform;
    pointer-events: none;
}
@keyframes auth-btn-sheen {
    0%, 55% { transform: translateX(0) skewX(-18deg); }
    85%, 100% { transform: translateX(430%) skewX(-18deg); }
}
.auth-card-3 .btn-filled:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow:
        0 16px 36px -10px rgba(56, 189, 248, .8),
        0 4px 12px rgba(99, 102, 241, .35),
        inset 0 1px 0 rgba(255, 255, 255, .3);
}
.auth-card-3 .btn-filled:active { transform: translateY(0) scale(.985); }
/* 发送验证码等次级按钮：白玻璃 + 靛紫描边 */
.auth-card-3 .btn-tonal {
    background: rgba(255, 255, 255, .8);
    border: 1.5px solid rgba(99, 102, 241, .35);
    color: #4338ca;
    box-shadow: 0 2px 10px rgba(79, 70, 229, .12);
    transition: background-color .18s ease, border-color .18s ease, box-shadow .18s ease, transform .12s ease;
}
.auth-card-3 .btn-tonal:hover:not(:disabled) {
    background: #eef2ff;
    border-color: #4f46e5;
    box-shadow: 0 6px 18px -6px rgba(79, 70, 229, .45);
}
.auth-card-3 .btn-tonal:disabled { color: #9aa1ad; border-color: var(--md-outline-variant); background: rgba(255,255,255,.6); box-shadow: none; }
.auth-actions { margin-top: 6px; }
.auth-text-link { margin: 16px 0 0; text-align: center; font-size: 14px; color: var(--md-on-surface-variant); }
.auth-text-link a { font-weight: 600; }
.auth-forgot { text-align: right; margin: 10px 4px 4px; }
.auth-forgot a { font-size: 13px; color: var(--md-primary); font-weight: 500; }
.auth-footer-note {
    margin: 16px auto 0; text-align: center;
    font-size: 12px; color: var(--md-on-surface-variant);
    display: flex; align-items: center; justify-content: center; gap: 6px;
}
.auth-footer-note svg { width: 14px; height: 14px; flex: none; }
/* 折叠式重要说明（融入注册体验，默认收起） */
.auth-note {
    margin-top: 18px;
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-sm);
    background: var(--md-surface-container);
    overflow: hidden;
}
.auth-note summary {
    display: flex; align-items: center; gap: 8px;
    padding: 12px 14px; cursor: pointer;
    font-size: 13px; font-weight: 500; color: var(--md-on-surface-variant);
    list-style: none; user-select: none;
}
.auth-note summary::-webkit-details-marker { display: none; }
.auth-note summary svg { width: 18px; height: 18px; flex: none; color: var(--md-primary); }
.auth-note summary::after {
    content: ''; margin-left: auto; width: 8px; height: 8px;
    border-right: 2px solid var(--md-on-surface-variant);
    border-bottom: 2px solid var(--md-on-surface-variant);
    transform: rotate(45deg); transition: transform .18s ease;
}
.auth-note[open] summary::after { transform: rotate(-135deg); }
.auth-note-body {
    padding: 0 14px 14px; font-size: 12.5px; line-height: 1.7;
    color: var(--md-on-surface-variant);
}
.auth-note-body b { color: var(--md-on-surface); }

/* 手机 / 窄屏自适应：紧凑排版；margin:auto 保证居中且超高时可正常滚动 */
@media (max-width: 480px) {
    .auth-page-3 { padding: 12px 10px calc(12px + env(safe-area-inset-bottom, 0px)); }
    .auth-card-3 { border-radius: 22px; padding: 22px 18px 18px; }
    .auth-logo { width: 52px; height: 52px; border-radius: 16px; margin-bottom: 10px; }
    .auth-logo svg { width: 26px; height: 26px; }
    .auth-headline { font-size: 21px; margin-bottom: 2px; }
    .auth-desc { font-size: 13px; margin-bottom: 14px; }
    .auth-form > .auth-input-card,
    .auth-form > .auth-field-row { margin-bottom: 10px; }
    .auth-input-card { padding: 10px 12px; border-radius: 14px; }
    .auth-input-inner input { font-size: 16px; }
    .auth-card-3 .btn-filled { height: 48px; border-radius: 14px; }
    .auth-group-label { margin: 14px 0 9px; font-size: 12px; }
    .auth-grid-2 { grid-template-columns: 1fr; gap: 10px; margin-bottom: 10px; }
    .auth-note { margin-top: 12px; }
    .auth-note summary { padding: 10px 12px; font-size: 12.5px; }
    .auth-text-link { margin-top: 14px; font-size: 13.5px; }
    .auth-forgot { margin: 8px 4px 2px; }
    .auth-footer-note { display: none; }
    .auth-bg .blob { opacity: .35; }
}
@media (max-width: 360px) {
    .auth-card-3 { padding: 20px 14px 16px; }
    .auth-headline { font-size: 20px; }
    .auth-logo { width: 46px; height: 46px; margin-bottom: 8px; }
    .auth-field-row .btn { padding: 0 14px; }
}

/* ---------------- 应用主框架（消息/通讯录/我的） ---------------- */
.app {
    display: grid;
    grid-template-columns: 80px 340px 1fr;
    grid-template-rows: minmax(0, 1fr);
    height: 100dvh;
    overflow: hidden;
}

/* 左侧导航轨 */
.nav-rail {
    background: var(--md-surface);
    border-right: 1px solid var(--md-outline-variant);
    display: flex; flex-direction: column; align-items: center;
    padding: 12px 0; gap: 6px;
}
.nav-rail-brand {
    width: 44px; height: 44px; margin-bottom: 12px;
    border-radius: 14px;
    background: var(--md-primary); color: var(--md-on-primary);
    display: flex; align-items: center; justify-content: center;
}
.nav-rail-brand svg { width: 24px; height: 24px; }
.rail-item {
    width: 64px; padding: 6px 0 8px;
    display: flex; flex-direction: column; align-items: center; gap: 3px;
    background: none; border: none; cursor: pointer;
    color: var(--md-on-surface-variant);
    font-family: inherit; font-size: 11.5px; font-weight: 500;
    text-decoration: none; position: relative;
}
.rail-item .rail-icon {
    width: 52px; height: 30px; border-radius: var(--md-radius-full);
    display: flex; align-items: center; justify-content: center;
    transition: background-color .18s;
    position: relative;
}
.rail-item svg { width: 22px; height: 22px; }
.rail-item:hover .rail-icon { background: var(--md-surface-container-high); }
.rail-item.active { color: var(--md-on-surface); }
.rail-item.active .rail-icon { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.rail-badge {
    position: absolute; top: 0; right: 8px;
    min-width: 18px; height: 18px; padding: 0 5px;
    border-radius: 9px; background: var(--md-error); color: var(--md-on-error);
    font-size: 11px; font-weight: 600;
    display: flex; align-items: center; justify-content: center;
}
.rail-spacer { flex: 1; }

/* 会话列表面板 */
.session-pane {
    background: var(--md-surface-container-low);
    border-right: 1px solid var(--md-outline-variant);
    display: flex; flex-direction: column;
    min-width: 0;
}
.session-head {
    padding: 18px 18px 10px;
    display: flex; align-items: center; justify-content: space-between; gap: 8px;
}
.session-head h2 { font-size: 20px; font-weight: 600; }
.session-search { padding: 4px 14px 12px; }
.session-search input {
    width: 100%; height: 40px;
    border: none; border-radius: var(--md-radius-full);
    background: var(--md-surface-container-high);
    color: var(--md-on-surface);
    padding: 0 18px; font-family: inherit; font-size: 14px; outline: none;
}
.session-search input::placeholder { color: var(--md-on-surface-variant); }
.session-tabs {
    display: flex; gap: 8px; padding: 0 16px 10px;
}
.session-tab {
    flex: 1; height: 34px;
    border: none; border-radius: var(--md-radius-full);
    background: transparent; color: var(--md-on-surface-variant);
    font-family: inherit; font-size: 13px; font-weight: 500; cursor: pointer;
    position: relative;
}
.session-tab.active { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.session-tab .tab-badge {
    position: absolute; top: 2px; right: 6px;
    min-width: 16px; height: 16px; padding: 0 4px;
    border-radius: 8px; background: var(--md-error); color: var(--md-on-error);
    font-size: 10px; display: flex; align-items: center; justify-content: center;
}
.session-list { flex: 1; overflow-y: auto; padding: 0 8px 16px; }
.session-group-label {
    padding: 10px 12px 6px; font-size: 12px; font-weight: 600;
    color: var(--md-on-surface-variant); letter-spacing: .5px;
}
.session-item {
    width: 100%;
    display: flex; align-items: center; gap: 12px;
    padding: 10px 12px; margin-bottom: 2px;
    border: none; border-radius: var(--md-radius-md);
    background: transparent; cursor: pointer; text-align: left;
    font-family: inherit; color: var(--md-on-surface);
    transition: background-color .15s;
}
.session-item:hover { background: var(--md-surface-container-high); }
.session-item.active { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }
.session-item-main { flex: 1; min-width: 0; }
.session-item-top { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; }
.session-item-name {
    font-size: 14.5px; font-weight: 500;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.session-item-time { font-size: 11.5px; color: var(--md-on-surface-variant); flex: none; }
.session-item-sub {
    font-size: 12.5px; color: var(--md-on-surface-variant);
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    margin-top: 2px; display: flex; align-items: center; gap: 6px;
}
.session-empty { padding: 40px 20px; text-align: center; color: var(--md-on-surface-variant); font-size: 13.5px; }

/* 主聊天区 */
.chat-main { display: flex; flex-direction: column; min-width: 0; min-height: 0; overflow: hidden; background: var(--md-surface); position: relative; }
.chat-topbar {
    display: flex; align-items: center; gap: 12px;
    padding: 10px 18px;
    border-bottom: 1px solid var(--md-outline-variant);
    background: var(--md-surface-container-low);
    min-height: 64px;
}
.chat-topbar-info { flex: 1; min-width: 0; }
.chat-topbar-title {
    font-size: 16px; font-weight: 600;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    display: flex; align-items: center; gap: 8px;
}
.chat-topbar-sub { font-size: 12.5px; color: var(--md-on-surface-variant); margin-top: 1px; display: flex; align-items: center; gap: 6px; }
.chat-topbar-actions { display: flex; gap: 4px; }
.chat-welcome {
    flex: 1; display: flex; flex-direction: column;
    align-items: center; justify-content: center; gap: 14px;
    color: var(--md-on-surface-variant); padding: 24px; text-align: center;
}
.chat-welcome .welcome-mark {
    width: 84px; height: 84px; border-radius: 28px;
    background: var(--md-primary-container); color: var(--md-on-primary-container);
    display: flex; align-items: center; justify-content: center;
}
.chat-welcome .welcome-mark svg { width: 40px; height: 40px; }
.chat-welcome h3 { color: var(--md-on-surface); font-size: 20px; }

.broadcast-bar {
    display: flex; align-items: center; gap: 8px;
    background: var(--md-tertiary-container); color: var(--md-on-tertiary-container);
    padding: 8px 16px; font-size: 13px; overflow: hidden;
}
.broadcast-bar svg { width: 16px; height: 16px; flex: none; }
.broadcast-text { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.msg-list {
    flex: 1; min-height: 0; overflow-y: auto;
    padding: 18px 18px 8px;
    display: flex; flex-direction: column; gap: 6px;
}
.msg-day-divider {
    align-self: center; margin: 10px 0 4px;
    font-size: 12px; color: var(--md-on-surface-variant);
    background: var(--md-surface-container-high);
    padding: 3px 12px; border-radius: var(--md-radius-full);
}
/* 微信风格：头像在消息顶部（上方）对齐 */
.msg-row { display: flex; gap: 10px; max-width: 78%; align-items: flex-start; -webkit-user-select: none; user-select: none; }
.msg-row.theirs { align-self: flex-start; }
.msg-row.mine { align-self: flex-end; flex-direction: row-reverse; }
.msg-row.system { align-self: center; max-width: 90%; }
.msg-meta { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.msg-row.mine .msg-meta { align-items: flex-end; }
.msg-sender { font-size: 12px; color: var(--md-on-surface-variant); padding: 0 6px; }
.bubble {
    position: relative;
    padding: 9px 14px;
    border-radius: var(--md-radius-md);
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    color: var(--md-on-surface);
    font-size: 14.5px; line-height: 1.5;
    word-break: break-word; overflow-wrap: anywhere;
    box-shadow: 0 1px 2px rgba(16, 24, 40, .04);
}
.msg-row.mine .bubble { background: var(--md-primary-container); color: var(--md-on-primary-container); border-color: transparent; }
.msg-row.system .bubble {
    background: transparent; color: var(--md-on-surface-variant);
    font-size: 12.5px; padding: 4px 10px;
    border: none; box-shadow: none;
}
.msg-recalled { font-style: italic; color: var(--md-on-surface-variant); font-size: 13px; }
.msg-time { font-size: 11px; color: var(--md-on-surface-variant); padding: 0 6px; }
.msg-time-divider {
    align-self: center; margin: 10px 0 4px;
    font-size: 12px; color: var(--md-on-surface-variant);
    background: var(--md-surface-container-highest);
    padding: 3px 12px; border-radius: var(--md-radius-full);
}
.msg-lock {
    display: inline-flex; align-items: center; gap: 6px;
    font-family: ui-monospace, Consolas, monospace; font-size: 12.5px;
    opacity: .85;
}
.msg-lock svg { width: 14px; height: 14px; flex: none; }
.msg-cipher-preview { opacity: .6; word-break: break-all; }
.bubble .msg-img { max-width: 260px; max-height: 260px; border-radius: var(--md-radius-sm); display: block; cursor: zoom-in; }
.bubble .msg-video { max-width: 260px; max-height: 340px; border-radius: var(--md-radius-sm); display: block; background: #000; }
.bubble .msg-file {
    display: flex; align-items: center; gap: 10px;
    padding: 6px 4px; color: inherit; text-decoration: none;
}
.bubble .msg-file:hover { text-decoration: none; opacity: .85; }
.msg-file-icon {
    width: 38px; height: 38px; border-radius: 10px; flex: none;
    background: var(--md-secondary-container); color: var(--md-on-secondary-container);
    display: flex; align-items: center; justify-content: center;
}
.msg-file-icon svg { width: 20px; height: 20px; }
.msg-file-name { font-size: 13.5px; font-weight: 500; word-break: break-all; }
.bubble .msg-link { color: var(--md-primary); text-decoration: underline; text-underline-offset: 2px; word-break: break-all; }
.bubble .msg-link:hover { opacity: .82; }
.msg-voice { display: inline-flex; align-items: center; gap: 9px; min-width: 128px; cursor: pointer; }
.msg-voice-play {
    width: 34px; height: 34px; border-radius: 50%; border: none;
    background: var(--md-primary); color: var(--md-on-primary);
    display: flex; align-items: center; justify-content: center; cursor: pointer; flex: none;
}
.msg-voice-play svg { width: 16px; height: 16px; }
.msg-voice-bars { display: flex; align-items: center; gap: 2px; height: 22px; }
.msg-voice-bars i { width: 3px; border-radius: 2px; background: var(--md-on-surface-variant); }
.msg-voice-bars i:nth-child(1) { height: 8px; }
.msg-voice-bars i:nth-child(2) { height: 14px; }
.msg-voice-bars i:nth-child(3) { height: 20px; }
.msg-voice-bars i:nth-child(4) { height: 11px; }
.msg-voice-bars i:nth-child(5) { height: 16px; }
.msg-voice-dur { font-size: 12.5px; color: var(--md-on-surface-variant); white-space: nowrap; }
.msg-voice.playing .msg-voice-bars i { animation: voice-eq 1s ease-in-out infinite; }
.msg-voice.playing .msg-voice-bars i:nth-child(2) { animation-delay: .15s; }
.msg-voice.playing .msg-voice-bars i:nth-child(3) { animation-delay: .3s; }
.msg-voice.playing .msg-voice-bars i:nth-child(4) { animation-delay: .45s; }
.msg-voice.playing .msg-voice-bars i:nth-child(5) { animation-delay: .6s; }
@keyframes voice-eq { 0%, 100% { transform: scaleY(.4); } 50% { transform: scaleY(1); } }
.msg-reply-quote {
    border-left: 3px solid var(--md-outline);
    background: rgba(120, 120, 140, .10);
    border-radius: 8px; padding: 6px 10px; margin-bottom: 6px;
    font-size: 12.5px; color: var(--md-on-surface-variant);
    overflow: hidden; text-overflow: ellipsis; display: -webkit-box;
    -webkit-line-clamp: 2; -webkit-box-orient: vertical;
}
.msg-row.mine .msg-reply-quote { border-left-color: var(--md-on-primary-container); }

/* 消息操作菜单（长按弹出的底部动作面板） */
.msg-action-sheet {
    position: fixed; left: 50%; bottom: 0;
    transform: translateX(-50%);
    width: 100%; max-width: 560px;
    background: var(--md-surface-container-lowest);
    border-radius: var(--md-radius-lg) var(--md-radius-lg) 0 0;
    box-shadow: var(--md-elev-3);
    padding: 10px 12px calc(14px + env(safe-area-inset-bottom));
    animation: sheet-in .18s ease;
}
@keyframes sheet-in { from { transform: translate(-50%, 100%); } to { transform: translate(-50%, 0); } }
.msg-action-sheet-head {
    text-align: center; font-size: 12px; color: var(--md-on-surface-variant);
    padding: 6px 0 10px;
}
.msg-action-sheet-list { display: flex; flex-direction: column; gap: 2px; }
.msg-action-sheet-item {
    width: 100%; border: none; background: none; text-align: center;
    padding: 13px 0; font-family: inherit; font-size: 15.5px; font-weight: 500;
    color: var(--md-on-surface); cursor: pointer; border-radius: var(--md-radius-sm);
}
.msg-action-sheet-item:hover { background: var(--md-surface-container-high); }
.msg-action-sheet-item.danger { color: var(--md-error); }
.msg-action-sheet-cancel {
    width: 100%; margin-top: 8px; border: none;
    background: var(--md-surface-container); color: var(--md-on-surface);
    padding: 13px 0; font-family: inherit; font-size: 15.5px; font-weight: 500;
    cursor: pointer; border-radius: var(--md-radius-sm);
}
.msg-action-sheet-cancel:hover { background: var(--md-surface-container-high); }

/* E2E 标识条 */
.e2e-bar {
    display: flex; align-items: center; justify-content: center; gap: 6px;
    padding: 6px 12px; font-size: 12px;
    color: var(--md-on-surface-variant);
    background: var(--md-surface-container);
}
.e2e-bar svg { width: 13px; height: 13px; }
.e2e-bar.locked { color: var(--md-error); background: var(--md-error-container); }

/* 输入区（微信风格：白色圆角输入框 + 右侧表情/图片/附件 + 圆形发送键） */
.composer {
    border-top: 1px solid var(--md-outline-variant);
    background: var(--md-surface-container);
    padding: 10px 12px calc(10px + env(safe-area-inset-bottom));
}
.composer-reply {
    display: flex; align-items: center; gap: 8px;
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-sm);
    padding: 8px 12px; margin-bottom: 8px; font-size: 13px;
}
.composer-reply-text { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--md-on-surface-variant); }
.composer-row { display: flex; align-items: flex-end; gap: 8px; }
.composer-input {
    flex: 1; min-height: 42px; max-height: 140px;
    border: 1px solid var(--md-outline-variant); border-radius: var(--md-radius-sm);
    background: var(--md-surface-container-lowest);
    color: var(--md-on-surface);
    padding: 10px 14px; font-family: inherit; font-size: 14.5px;
    outline: none; resize: none; line-height: 1.45;
    transition: border-color .15s, box-shadow .15s;
}
.composer-input:focus { border-color: var(--md-primary); box-shadow: 0 0 0 3px rgba(79, 70, 229, .12); }
.attach-panel {
    margin-top: 10px;
    display: flex; flex-wrap: wrap; gap: 6px;
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    box-shadow: var(--md-elev-1);
    padding: 10px;
}
.attach-item {
    display: flex; flex-direction: column; align-items: center; gap: 6px;
    width: 68px; padding: 8px 4px; border: none; background: none;
    color: var(--md-on-surface); cursor: pointer; font-family: inherit;
    font-size: 12px; border-radius: var(--md-radius-sm);
    transition: background-color .15s;
}
.attach-item:hover { background: var(--md-surface-container-high); }
.attach-item-icon {
    width: 44px; height: 44px; border-radius: 12px;
    background: var(--md-surface-container-highest); color: var(--md-on-surface-variant);
    display: flex; align-items: center; justify-content: center;
}
.attach-item-icon svg { width: 22px; height: 22px; }
.voice-hold-area {
    display: flex; align-items: center; gap: 8px;
}
.voice-hold-btn {
    flex: 1; height: 42px;
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-sm);
    background: var(--md-surface-container-lowest);
    color: var(--md-on-surface);
    font-family: inherit; font-size: 14.5px; font-weight: 500;
    cursor: pointer; user-select: none; -webkit-user-select: none;
    touch-action: manipulation;
}
.voice-hold-btn.recording {
    background: var(--md-primary-container);
    color: var(--md-on-primary-container);
    border-color: transparent;
}
.composer-tool-btn {
    width: 40px; height: 40px; border: none; border-radius: var(--md-radius-full);
    background: transparent; color: var(--md-on-surface-variant);
    display: inline-flex; align-items: center; justify-content: center;
    cursor: pointer; transition: background-color .15s, color .15s;
    font-family: inherit; padding: 0;
}
.composer-tool-btn:hover { background: var(--md-surface-container-highest); color: var(--md-on-surface); }
.composer-tool-btn.active { color: var(--md-primary); background: var(--md-primary-container); }
.composer-tool-btn svg { width: 22px; height: 22px; }
.composer-send {
    width: 42px; height: 42px; border-radius: var(--md-radius-full);
    border: none; background: var(--md-primary); color: var(--md-on-primary);
    display: flex; align-items: center; justify-content: center; cursor: pointer;
    flex: none; transition: box-shadow .15s, opacity .15s;
}
.composer-send:hover { box-shadow: var(--md-elev-1); }
.composer-send:disabled { opacity: .4; cursor: not-allowed; }
.composer-send svg { width: 19px; height: 19px; }
/* 表情面板：内嵌在输入区下方展开（微信风格） */
.emoji-panel {
    margin-top: 10px;
    width: 100%; max-height: 216px; overflow-y: auto;
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    box-shadow: var(--md-elev-1);
    padding: 10px; display: grid; grid-template-columns: repeat(8, 1fr); gap: 2px;
}
.emoji-panel button {
    border: none; background: none; font-size: 22px; cursor: pointer;
    border-radius: 8px; padding: 6px 0; line-height: 1;
}
.emoji-panel button:hover { background: var(--md-surface-container-high); }
@media (max-width: 600px) {
    .emoji-panel { grid-template-columns: repeat(7, 1fr); }
}
.muted-bar {
    padding: 12px; text-align: center; color: var(--md-on-surface-variant);
    background: var(--md-surface-container); font-size: 13px;
    border-top: 1px solid var(--md-outline-variant);
}

/* ---------------- 对话框（M3 Dialog） ---------------- */
.scrim {
    position: fixed; inset: 0; background: var(--md-scrim);
    display: flex; align-items: center; justify-content: center;
    z-index: 100; padding: 20px;
}
.dialog {
    width: 100%; max-width: 420px;
    max-height: min(84dvh, 720px);
    background: var(--md-surface-container-high);
    border-radius: var(--md-radius-lg);
    box-shadow: var(--md-elev-3);
    padding: 24px;
    display: flex; flex-direction: column;
    overflow-y: auto;
}
.dialog-wide { max-width: 560px; }
.dialog-icon {
    width: 48px; height: 48px; margin: 0 auto 12px;
    border-radius: 16px;
    background: var(--md-primary-container); color: var(--md-on-primary-container);
    display: flex; align-items: center; justify-content: center;
}
.dialog-icon svg { width: 26px; height: 26px; }
.dialog h3 { font-size: 20px; text-align: center; margin-bottom: 8px; }
.dialog-body { color: var(--md-on-surface-variant); font-size: 14px; }
.dialog-body .field { margin: 12px 0; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 20px; }
.dialog-actions .btn { min-width: 88px; }

/* 全屏解锁遮罩 */
.unlock-scrim {
    position: fixed; inset: 0; z-index: 200;
    background:
        radial-gradient(1200px 600px at 15% -10%, var(--md-primary-container) 0%, transparent 55%),
        var(--md-surface);
    display: flex; align-items: center; justify-content: center; padding: 20px;
}
.unlock-card {
    width: 100%; max-width: 430px;
    background: var(--md-surface-container-low);
    border-radius: var(--md-radius-lg);
    box-shadow: var(--md-elev-3);
    padding: 32px 28px;
}
.unlock-lockmark {
    width: 64px; height: 64px; margin: 0 auto 16px;
    border-radius: 22px;
    background: var(--md-primary); color: var(--md-on-primary);
    display: flex; align-items: center; justify-content: center;
}
.unlock-lockmark svg { width: 30px; height: 30px; }

/* ---------------- Snackbar ---------------- */
.snackbar {
    position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%);
    background: var(--md-inverse-surface); color: var(--md-inverse-on-surface);
    border-radius: var(--md-radius-xs);
    padding: 12px 20px; font-size: 14px;
    box-shadow: var(--md-elev-2);
    z-index: 300; max-width: min(92vw, 480px);
    animation: snack-in .22s ease;
}
@keyframes snack-in {
    from { opacity: 0; transform: translate(-50%, 12px); }
    to { opacity: 1; transform: translate(-50%, 0); }
}

/* ---------------- 通讯录页 ---------------- */
.page-body {
    max-width: 860px; margin: 0 auto;
    padding: 24px 18px 90px;
}
.page-head { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; }
.page-head h1 { font-size: 24px; }
.page-section { margin-bottom: 26px; }
.page-section-title {
    font-size: 14px; font-weight: 600; letter-spacing: .4px;
    color: var(--md-on-surface-variant);
    margin-bottom: 10px;
    display: flex; align-items: center; gap: 8px;
}
.contact-list { display: flex; flex-direction: column; gap: 8px; }
.contact-item {
    display: flex; align-items: center; gap: 12px;
    background: var(--md-surface-container-low);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    padding: 12px 14px;
    box-shadow: 0 1px 2px rgba(16, 24, 40, .04);
}
.contact-main { flex: 1; min-width: 0; }
.contact-name { font-weight: 500; font-size: 14.5px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.contact-sub { font-size: 12.5px; color: var(--md-on-surface-variant); margin-top: 2px; }
.contact-sig {
    font-size: 12.5px; color: var(--md-on-surface-variant); margin-top: 3px;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.contact-actions { display: flex; gap: 6px; flex: none; }
.status-text { font-size: 12px; }
.status-text.on { color: var(--md-online); }
.status-text.off { color: var(--md-on-surface-variant); }

/* ---------------- 个人中心 ---------------- */
.profile-hero {
    display: flex; align-items: center; gap: 18px;
    padding: 26px 22px;
    background: var(--md-surface-container-lowest);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-lg);
    box-shadow: 0 1px 3px rgba(16, 24, 40, .06);
    margin-bottom: 18px;
}
.profile-hero .avatar-lg { background: var(--md-primary); color: var(--md-on-primary); }
.profile-hero-name { font-size: 20px; font-weight: 600; }
.profile-hero-sub { font-size: 13px; color: var(--md-on-surface-variant); margin-top: 3px; }
.profile-hero-sig { font-size: 13px; color: var(--md-on-surface-variant); margin-top: 6px; }
.profile-avatar-btn {
    position: relative; border: none; background: none; padding: 0;
    cursor: pointer; border-radius: 50%; flex: none; line-height: 0;
}
.profile-avatar-wrap { display: block; border-radius: 50%; overflow: hidden; }
.avatar-edit-hint {
    position: absolute; right: -2px; bottom: -2px;
    width: 26px; height: 26px; border-radius: 50%;
    background: var(--md-primary); color: var(--md-on-primary);
    display: flex; align-items: center; justify-content: center;
    border: 2px solid var(--md-surface-container-lowest);
}
.avatar-edit-hint svg { width: 12px; height: 12px; }
/* 群聊用户卡片 */
.usercard-head { display: flex; align-items: center; gap: 16px; margin-bottom: 6px; }
.usercard-head h3 { text-align: left; margin-bottom: 2px; font-size: 18px; }
.usercard-sub { font-size: 13px; color: var(--md-on-surface-variant); word-break: break-all; }
.profile-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.profile-section { margin-bottom: 16px; }
details.card > summary { list-style: none; }
details.card > summary::-webkit-details-marker { display: none; }
details.card[open] > summary svg { transform: rotate(180deg); }
.kv-row {
    display: flex; align-items: center; justify-content: space-between;
    padding: 11px 2px; border-bottom: 1px solid var(--md-outline-variant);
    font-size: 14px; gap: 12px;
}
.kv-row:last-child { border-bottom: none; }
.kv-key { color: var(--md-on-surface-variant); flex: none; }
.kv-val { font-weight: 500; text-align: right; word-break: break-all; font-family: ui-monospace, Consolas, monospace; font-size: 13px; }

/* ---------------- 页面框架（通讯录 / 个人中心） ---------------- */
.app.app-page { grid-template-columns: 80px 1fr; }
.app-page-main { overflow-y: auto; min-width: 0; }

/* ---------------- 底部导航（移动端） ---------------- */
.bottom-nav { display: none; }

/* ---------------- 管理后台（M3 重设计） ---------------- */
.admin-body { background: #f6f7fb; }
.admin-shell { display: grid; grid-template-columns: 264px 1fr; min-height: 100dvh; }
.admin-scrim { display: none; }
.admin-side {
    background: #ffffff;
    border-right: 1px solid var(--md-outline-variant);
    padding: 20px 14px 16px;
    display: flex; flex-direction: column; gap: 4px;
    position: sticky; top: 0; height: 100dvh;
    overflow-y: auto;
}
.admin-side-brand {
    display: flex; align-items: center; gap: 12px;
    padding: 4px 10px 20px;
}
.admin-side-brand .brand-mark {
    width: 40px; height: 40px; border-radius: 13px; flex: none;
    background: linear-gradient(135deg, #4f46e5, #8b5cf6);
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 8px 20px -6px rgba(79, 70, 229, .55);
}
.admin-side-brand .brand-mark svg { width: 21px; height: 21px; }
.admin-side-brand .brand-text { display: flex; flex-direction: column; line-height: 1.3; }
.admin-side-brand .brand-text strong { font-size: 15px; color: var(--md-on-surface); }
.admin-side-brand .brand-text small { font-size: 10.5px; color: var(--md-on-surface-variant); letter-spacing: 1px; }
.admin-nav { display: flex; flex-direction: column; gap: 3px; }
.admin-nav-label {
    font-size: 11px; font-weight: 600; letter-spacing: .8px;
    color: var(--md-on-surface-variant);
    padding: 14px 12px 6px;
}
.admin-nav-label:first-child { padding-top: 0; }
.admin-nav-item {
    display: flex; align-items: center; gap: 12px;
    padding: 11px 14px; border-radius: var(--md-radius-full);
    color: var(--md-on-surface-variant); text-decoration: none;
    font-size: 13.5px; font-weight: 500;
    transition: background-color .15s ease, color .15s ease;
}
.admin-nav-item:hover { background: var(--md-surface-container); text-decoration: none; color: var(--md-on-surface); }
.admin-nav-item.active { background: var(--md-secondary-container); color: var(--md-on-secondary-container); font-weight: 600; }
.admin-nav-item svg { width: 19px; height: 19px; flex: none; }
.admin-nav-item.danger { color: var(--md-error); }
.admin-nav-item.danger:hover { background: var(--md-error-container); color: var(--md-on-error-container); }
.admin-side-spacer { flex: 1; }
.admin-side-foot {
    border-top: 1px solid var(--md-outline-variant);
    padding-top: 10px;
    display: flex; flex-direction: column; gap: 3px;
}
.admin-body-col { min-width: 0; display: flex; flex-direction: column; }
.admin-topbar {
    position: sticky; top: 0; z-index: 40;
    display: flex; align-items: center; gap: 12px;
    padding: 12px 28px;
    background: rgba(246, 247, 251, .86);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--md-outline-variant);
}
.admin-burger {
    display: none; width: 40px; height: 40px;
    border: none; border-radius: 12px;
    background: transparent; color: var(--md-on-surface); cursor: pointer;
    align-items: center; justify-content: center;
}
.admin-burger:hover { background: var(--md-surface-container); }
.admin-burger svg { width: 20px; height: 20px; }
.admin-topbar-title { font-size: 14px; font-weight: 600; color: var(--md-on-surface-variant); }
.admin-topbar-right { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.admin-chip {
    display: inline-flex; align-items: center; gap: 7px;
    height: 34px; padding: 0 14px; border-radius: 999px;
    background: #fff; border: 1px solid var(--md-outline-variant);
    font-size: 12.5px; font-weight: 500; color: var(--md-on-surface-variant);
    text-decoration: none; white-space: nowrap;
    transition: border-color .15s ease, color .15s ease, box-shadow .15s ease;
}
.admin-chip:hover { border-color: var(--md-primary); color: var(--md-primary); text-decoration: none; box-shadow: 0 2px 10px rgba(79, 70, 229, .12); }
.admin-chip svg { width: 14px; height: 14px; flex: none; }
.admin-chip-avatar {
    width: 22px; height: 22px; border-radius: 50%; flex: none;
    background: linear-gradient(135deg, #38bdf8, #818cf8); color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 11px; font-weight: 700;
}
.admin-main { padding: 26px 28px 60px; min-width: 0; }
.admin-title { font-size: 26px; margin: 0 0 4px; font-weight: 700; letter-spacing: -.3px; }
.admin-sub { color: var(--md-on-surface-variant); margin: 0 0 22px; font-size: 13.5px; }
/* 后台内容卡片 */
.admin-main .card {
    background: #fff;
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    box-shadow: var(--md-elev-1);
}
/* 统计卡 */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-bottom: 26px; }
.stat-card {
    background: #fff;
    border-radius: var(--md-radius-md);
    padding: 18px;
    display: flex; flex-direction: column; gap: 6px;
    border: 1px solid var(--md-outline-variant);
    box-shadow: var(--md-elev-1);
    transition: transform .18s ease, box-shadow .18s ease;
    animation: admin-card-in .32s ease both;
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--md-elev-2); }
.stat-card:nth-child(2) { animation-delay: .05s; }
.stat-card:nth-child(3) { animation-delay: .1s; }
.stat-card:nth-child(4) { animation-delay: .15s; }
.stat-card:nth-child(5) { animation-delay: .2s; }
@keyframes admin-card-in {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: none; }
}
.stat-card .stat-icon {
    width: 42px; height: 42px; border-radius: 13px;
    background: var(--md-primary-container); color: var(--md-on-primary-container);
    display: flex; align-items: center; justify-content: center; margin-bottom: 6px;
}
.stat-card .stat-icon svg { width: 20px; height: 20px; }
.stat-value { font-size: 27px; font-weight: 700; letter-spacing: -.5px; }
.stat-label { font-size: 12.5px; color: var(--md-on-surface-variant); }
/* 表格卡片 */
.admin-table-wrap {
    background: #fff;
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-radius-md);
    box-shadow: var(--md-elev-1);
    overflow-x: auto;
}
.admin-table { width: 100%; border-collapse: collapse; font-size: 13.5px; min-width: 640px; }
.admin-table th {
    text-align: left; padding: 13px 16px;
    background: var(--md-surface-container);
    color: var(--md-on-surface-variant); font-weight: 600; font-size: 12px;
    letter-spacing: .3px;
    border-bottom: 1px solid var(--md-outline-variant);
    white-space: nowrap;
}
.admin-table td { padding: 12px 16px; border-bottom: 1px solid var(--md-outline-variant); vertical-align: middle; }
.admin-table tbody tr { transition: background-color .12s ease; }
.admin-table tr:last-child td { border-bottom: none; }
.admin-table tbody tr:hover td { background: var(--md-surface-container); }
.admin-checks { display: flex; flex-wrap: wrap; gap: 6px; }
.admin-actions { display: flex; gap: 6px; flex-wrap: wrap; }
.admin-note {
    display: flex; gap: 12px; align-items: flex-start;
    background: linear-gradient(135deg, #eef2ff, #e0f2fe);
    color: #312e81;
    border: 1px solid #c7d2fe;
    border-radius: var(--md-radius-sm); padding: 14px 16px; font-size: 13px; margin-bottom: 20px;
}
.admin-note svg { width: 18px; height: 18px; flex: none; margin-top: 2px; color: #4f46e5; }
/* 后台表单（设置页等）：标签在上、控件填充式，替代前台浮动标签 .field */
.admin-form { display: flex; flex-direction: column; gap: 18px; }
.admin-form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px 16px; }
.a-field { display: flex; flex-direction: column; gap: 7px; min-width: 0; }
.a-field > label { font-size: 12.5px; font-weight: 600; color: var(--md-on-surface-variant); }
.a-field input, .a-field select, .a-field textarea {
    width: 100%; height: 44px;
    padding: 0 14px;
    border: 1px solid var(--md-outline);
    border-radius: 12px;
    background: var(--md-surface-container-lowest);
    color: var(--md-on-surface);
    font-family: inherit; font-size: 14px;
    transition: border-color .15s ease, box-shadow .15s ease, background-color .15s ease;
}
.a-field textarea { height: auto; min-height: 84px; padding: 11px 14px; resize: vertical; }
.a-field input:focus, .a-field select:focus, .a-field textarea:focus {
    outline: none;
    border-color: var(--md-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, .12);
    background: #fff;
}
.a-field .a-hint { font-size: 11.5px; color: var(--md-on-surface-variant); line-height: 1.5; }
/* 复选胶囊（开关行） */
.admin-check-row { display: flex; flex-wrap: wrap; gap: 10px; }
.admin-check {
    display: inline-flex; align-items: center; gap: 9px;
    height: 38px; padding: 0 16px 0 12px;
    border: 1px solid var(--md-outline-variant);
    border-radius: 999px; background: #fff;
    font-size: 13px; color: var(--md-on-surface-variant);
    cursor: pointer; user-select: none;
    transition: border-color .15s ease, background-color .15s ease, color .15s ease, box-shadow .15s ease;
}
.admin-check:hover { border-color: var(--md-primary); }
.admin-check input {
    appearance: none; -webkit-appearance: none;
    width: 18px; height: 18px; margin: 0;
    border: 2px solid var(--md-outline); border-radius: 6px;
    background: #fff; cursor: pointer; position: relative; flex: none;
    transition: background-color .15s ease, border-color .15s ease;
}
.admin-check input:checked { background: var(--md-primary); border-color: var(--md-primary); }
.admin-check input:checked::after {
    content: ''; position: absolute; left: 4px; top: 1px;
    width: 6px; height: 10px;
    border: solid #fff; border-width: 0 2px 2px 0; transform: rotate(45deg);
}
.admin-check:has(input:checked) {
    background: var(--md-primary-container); border-color: var(--md-primary);
    color: var(--md-on-primary-container); font-weight: 500;
    box-shadow: 0 2px 10px rgba(79, 70, 229, .16);
}
/* 工具栏下拉（消息页选择房间） */
.admin-toolbar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 18px; }
.admin-select {
    height: 42px; padding: 0 38px 0 16px;
    border: 1px solid var(--md-outline);
    border-radius: 999px;
    background: #fff;
    color: var(--md-on-surface);
    font-family: inherit; font-size: 13.5px; font-weight: 500;
    cursor: pointer;
    appearance: none; -webkit-appearance: none;
    background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%235f6368' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 14px center;
    background-size: 15px;
    transition: border-color .15s ease, box-shadow .15s ease;
}
.admin-select:focus { outline: none; border-color: var(--md-primary); box-shadow: 0 0 0 3px rgba(79, 70, 229, .12); }
/* 后台遗留 .field 内的 select 兜底（浮动标签不重叠） */
.admin-main .field select {
    width: 100%; height: 46px;
    background-color: var(--md-surface-container-lowest);
    background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%235f6368' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 15px;
    border: 1px solid var(--md-outline);
    border-radius: 12px;
    color: var(--md-on-surface);
    font-family: inherit; font-size: 14px;
    padding: 18px 38px 4px 12px;
    appearance: none; -webkit-appearance: none;
    cursor: pointer;
    transition: border-color .15s ease, box-shadow .15s ease;
}
.admin-main .field select:focus {
    outline: none; border-color: var(--md-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, .12);
}
/* UA 等长字符串单元格：单行截断 + 悬停提示完整内容 */
.admin-ua {
    display: inline-block; max-width: 200px;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    vertical-align: bottom; cursor: help;
}

/* ---------------- 图片预览 ---------------- */
.image-preview-scrim {
    position: fixed; inset: 0; z-index: 220;
    background: rgba(0, 0, 0, .82);
    display: flex; align-items: center; justify-content: center;
    padding: 24px; cursor: zoom-out;
}
.image-preview-scrim img { max-width: 94vw; max-height: 92dvh; border-radius: 8px; }

/* ---------------- 工具类 ---------------- */
.hidden { display: none !important; }
.mt-12 { margin-top: 12px; }
.mt-16 { margin-top: 16px; }
.row-gap { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.spacer { flex: 1; }
.text-muted { color: var(--md-on-surface-variant); }
.mono { font-family: ui-monospace, Consolas, monospace; }

/* ---------------- 动效（点击 / 长按 / 消息进入等） ---------------- */
.msg-row { animation: msg-in .22s ease both; }
@keyframes msg-in {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}
.bubble { transition: transform .12s ease, box-shadow .12s ease; }
.msg-row:active .bubble { transform: scale(.98); }
.msg-row.system:active .bubble { transform: none; }

.composer-tool-btn { transition: background-color .15s, color .15s, transform .1s ease; }
.composer-send { transition: box-shadow .15s, opacity .15s, transform .1s ease; }
.composer-tool-btn:active, .composer-send:active { transform: scale(.9); }
.attach-item { transition: background-color .15s, transform .1s ease; }
.attach-item:active { transform: scale(.96); }
.rail-item .rail-icon { transition: background-color .18s, transform .1s ease; }
.rail-item:active .rail-icon { transform: scale(.9); }
.session-item { transition: background-color .15s, transform .1s ease; }
.session-item:active { transform: scale(.985); }
.btn { transition: box-shadow .18s ease, background-color .18s ease, transform .08s ease; }

/* 回复引用条淡入 */
.msg-reply-quote { animation: quote-in .18s ease both; }
@keyframes quote-in {
    from { opacity: 0; transform: translateY(-3px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 系统提示（撤回 / 删除 / 销毁）淡入 */
.msg-row.system .bubble { animation: sys-in .24s ease both; }
@keyframes sys-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* 在线状态点脉冲 */
.presence-dot.on { animation: presence-pulse 2.2s ease-in-out infinite; }
@keyframes presence-pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(46, 125, 50, .45); }
    50% { box-shadow: 0 0 0 5px rgba(46, 125, 50, 0); }
}

/* 遮罩与弹窗淡入 / 缩放 */
.scrim { animation: scrim-in .18s ease both; }
@keyframes scrim-in {
    from { opacity: 0; }
    to { opacity: 1; }
}
.dialog { animation: dialog-in .2s cubic-bezier(.2, .8, .3, 1) both; }
@keyframes dialog-in {
    from { opacity: 0; transform: translateY(10px) scale(.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

/* 未读角标弹跳 */
.msg-badge, .req-badge { animation: badge-pop .28s cubic-bezier(.2, .8, .3, 1) both; }
@keyframes badge-pop {
    from { transform: scale(0); }
    to { transform: scale(1); }
}

/* 头像与链接的细腻反馈 */
.avatar-img, .avatar-clickable { transition: transform .15s ease, opacity .15s ease; }
.avatar-clickable:hover .avatar-img { transform: scale(1.05); }
.bubble .msg-link { transition: color .15s ease, opacity .15s ease; }

/* 消息操作菜单项反馈 */
.msg-action-sheet-item { transition: background-color .15s ease, transform .08s ease; }
.msg-action-sheet-item:active { transform: scale(.97); }

/* 降低动效偏好：尊重系统设置，同时避免低端设备卡顿 */
@media (prefers-reduced-motion: reduce) {
    .msg-row, .msg-row.system .bubble, .msg-reply-quote, .scrim, .dialog, .msg-badge, .req-badge,
    .msg-action-sheet, .snackbar, .auth-wrap, .auth-bg .blob, .auth-bg .meteor, .auth-bg::before,
    .auth-bg::after, .auth-bg .tech-rings::after, .auth-bg .tech-scan,
    .auth-card-3::before, .auth-card-3 .btn-filled {
        animation: none !important;
    }
    .bubble, .btn, .session-item, .composer-tool-btn, .composer-send, .attach-item, .msg-action-sheet-item, .field .field-eye {
        transition: none !important;
    }
    .presence-dot.on { animation: none !important; }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 1080px) {
    .app { grid-template-columns: 80px 300px 1fr; }
}

@media (max-width: 900px) {
    .app { grid-template-columns: 1fr; grid-template-rows: 1fr auto; }
    /* 通讯录 / 个人中心页：单列铺满，修复移动端排版错位 */
    .app.app-page { grid-template-columns: 1fr; grid-template-rows: 1fr auto; }
    .app-page-main { grid-row: 1; }
    .nav-rail { display: none; }
    .bottom-nav {
        display: flex; justify-content: space-around; align-items: stretch;
        background: var(--md-surface-container-lowest);
        border-top: 1px solid var(--md-outline-variant);
        padding: 6px 8px calc(6px + env(safe-area-inset-bottom));
        grid-row: 2;
    }
    .bottom-nav .rail-item { width: auto; flex: 1; }
    .session-pane { border-right: none; grid-row: 1; }
    .page-body { padding: 16px 12px 96px; }
    .page-head { flex-wrap: wrap; gap: 10px; }
    .page-head h1 { font-size: 20px; }
    .contact-item { flex-wrap: wrap; }
    .chat-main {
        position: fixed; inset: 0; z-index: 60;
        transform: translateX(100%);
        transition: transform .22s ease;
        grid-row: auto;
    }
    .app.chat-open .chat-main { transform: translateX(0); }
    .msg-row { max-width: 88%; }
    .profile-grid { grid-template-columns: 1fr; }
    /* 后台：单列 + 抽屉侧栏 */
    .admin-shell { grid-template-columns: 1fr; }
    .admin-scrim {
        display: block; position: fixed; inset: 0; z-index: 89;
        background: var(--md-scrim); opacity: 0; pointer-events: none;
        transition: opacity .2s ease;
    }
    .admin-shell.side-open .admin-scrim { opacity: 1; pointer-events: auto; }
    .admin-side {
        position: fixed; left: 0; top: 0; bottom: 0; z-index: 90;
        width: min(82vw, 300px);
        transform: translateX(-102%); transition: transform .22s ease;
        box-shadow: var(--md-elev-3);
    }
    .admin-shell.side-open .admin-side { transform: translateX(0); }
    .admin-burger { display: inline-flex; }
    .admin-topbar { padding: 10px 14px; }
    .admin-topbar-title { display: none; }
    .admin-main { padding: 18px 14px 60px; }
    .admin-title { font-size: 21px; }
    .stat-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
    .admin-ua { max-width: 130px; }
}

@media (max-width: 480px) {
    .admin-topbar-right .admin-chip { padding: 0 10px; }
    .admin-main { padding: 14px 10px 60px; }
    .stat-card { padding: 14px; }
    .stat-value { font-size: 22px; }
    .stat-card .stat-icon { width: 36px; height: 36px; border-radius: 11px; }
    .row-gap { flex-wrap: wrap; }
    .auth-card { padding: 26px 18px 20px; border-radius: var(--md-radius-md); }
    .session-head h2 { font-size: 18px; }
    .dialog { padding: 20px 16px; }
    .profile-hero { flex-direction: column; text-align: center; }
}