/* ==========================================================================
   音乐课堂互动系统 · 全站样式
   视觉规范照客户选定稿（SPEC 第 2 节），色值与字号阶梯不得擅自改
   ========================================================================== */

:root {
    --canvas: #DBEFED;
    --surface: #EDF7F8;
    --alt: #E9F8F5;
    --ink: #3C5B5D;
    --muted: #587476;
    --primary: #71D4D1;
    --deep: #62B2B1;
    --border: #C3D2D3;
    --attention: #D66A58;
    --positive: #2C6751;
    --gold: #E7B95D;

    --g1: #71D4D1;
    --g2: #E7B95D;
    --g3: #8FA7E1;
    --g4: #D66A58;

    --r-card: 14px;
    --r-btn: 10px;
    --shadow: 0 1px 2px rgba(60, 91, 93, .06);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    font-family: ui-sans-serif, system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
    font-size: 15px;
    line-height: 1.55;
    background-color: var(--canvas);
    -webkit-tap-highlight-color: transparent;
}

body.bg-custom {
    background-size: cover;
    background-position: center top;
    background-attachment: fixed;
    background-repeat: no-repeat;
}

body.theme-mint  { --canvas: #DBEFED; --surface: #EDF7F8; --alt: #E9F8F5; }
body.theme-dawn  { --canvas: #FFF4E8; --surface: #FFFDF8; --alt: #FFF0E5; --ink: #5D4B45; --muted: #8A7972; --border: #E9CBB4; --primary: #F6B36A; --deep: #E58D42; }
body.theme-orange{ --canvas: #EAF1FB; --surface: #FFFFFF; --alt: #FFF5E7; --ink: #24476B; --muted: #5B7A99; --border: #C3D5EA; --primary: #F5A442; --deep: #3273B8; }
body.theme-stage { --canvas: #20283F; --surface: #2D3856; --alt: #394766; --ink: #F6F1E5; --muted: #B9C3D8; --border: #5A6B91; --primary: #D9B45D; --deep: #8FA7E1; }

/* ---------------------------------------------------------- 字号阶梯 8 档 */
.fs-12 { font-size: 12px; }
.fs-13 { font-size: 13px; }
.fs-15 { font-size: 15px; }
.fs-17 { font-size: 17px; }
.fs-21 { font-size: 21px; }
.fs-28 { font-size: 28px; }
.fs-40 { font-size: 40px; }
.fs-56 { font-size: 56px; }

.muted { color: var(--muted); }
.ink   { color: var(--ink); }
.hidden { display: none !important; }

/* ---------------------------------------------------------- 布局骨架 */
.shell {
    max-width: 1440px;
    margin: 0 auto;
    padding: 24px clamp(14px, 3vw, 44px) 96px;
}

.panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    padding: clamp(16px, 2vw, 26px);
    margin-bottom: 16px;
    box-shadow: var(--shadow);
}

.panel > h2 {
    font-size: 21px;
    margin: 0 0 4px;
    font-weight: 800;
    letter-spacing: .01em;
}

.panel > h3 {
    font-size: 17px;
    margin: 24px 0 10px;
    font-weight: 800;
}

.panel .lead {
    margin: 0 0 16px;
    color: var(--muted);
    font-size: 15px;
}

.section-title {
    font-size: 28px;
    font-weight: 800;
    margin: 0 0 4px;
    letter-spacing: .01em;
}

.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.row.between { justify-content: space-between; }
.spacer { flex: 1 1 auto; }
.grid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.grid4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }

@media (max-width: 1100px) {
    .grid4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 720px) {
    .grid2, .grid4 { grid-template-columns: 1fr; }
}

/* ---------------------------------------------------------- 按钮 */
button, .btn {
    font: inherit;
    min-height: 46px;
    padding: 10px 16px;
    border-radius: var(--r-btn);
    border: 1px solid var(--deep);
    background: var(--primary);
    color: #12302f;
    font-weight: 700;
    cursor: pointer;
    touch-action: manipulation;
    transition: filter .12s ease, transform .12s ease;
}

button:hover:not(:disabled) { filter: brightness(1.04); }
button:active:not(:disabled) { transform: translateY(1px); }
button:disabled { opacity: .5; cursor: not-allowed; }

button.secondary { background: var(--alt); color: var(--ink); border-color: var(--border); }
button.ghost { background: transparent; border-color: var(--border); color: var(--ink); }
button.danger { background: var(--attention); border-color: var(--attention); color: #fff; }
button.on { background: var(--deep); color: #fff; border-color: var(--deep); }
button.big { min-height: 64px; font-size: 17px; padding: 14px 24px; }
button.huge { min-height: 88px; font-size: 21px; padding: 18px 28px; }
button.icon { min-width: 46px; padding: 8px; }

/* ---------------------------------------------------------- 表单 */
input[type="text"], input[type="password"], input[type="url"], textarea, select {
    font: inherit;
    width: 100%;
    min-height: 46px;
    padding: 10px 12px;
    border-radius: var(--r-btn);
    border: 1px solid var(--border);
    background: #fff;
    color: var(--ink);
}

body.theme-stage input, body.theme-stage textarea, body.theme-stage select { background: #232C45; }

textarea { min-height: 88px; resize: vertical; line-height: 1.55; }

input:focus, textarea:focus, select:focus {
    outline: 2px solid var(--deep);
    outline-offset: 1px;
}

.field { margin-bottom: 12px; }
.field > label {
    display: block;
    font-size: 13px;
    font-weight: 700;
    color: var(--muted);
    margin-bottom: 6px;
    letter-spacing: .02em;
}

.file-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border: 1px dashed var(--border);
    border-radius: var(--r-btn);
    background: var(--alt);
    font-size: 13px;
}

/* ---------------------------------------------------------- 顶栏 */
.topbar {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    padding: 14px clamp(14px, 3vw, 44px);
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 30;
}

.topbar .brand { font-size: 21px; font-weight: 800; letter-spacing: .02em; }

.tabs { display: flex; gap: 8px; flex-wrap: wrap; }

.tabs button { min-height: 42px; padding: 8px 16px; }

/* ---------------------------------------------------------- 组徽 */
.gbadge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    border-radius: 9px;
    font-weight: 800;
    font-size: 15px;
    color: #12302f;
    flex: 0 0 auto;
}

.g1 { background: var(--g1); }
.g2 { background: var(--g2); }
.g3 { background: var(--g3); }
.g4 { background: var(--g4); color: #fff; }

.gcard { border-left: 5px solid var(--border); }
.gcard.gc1 { border-left-color: var(--g1); }
.gcard.gc2 { border-left-color: var(--g2); }
.gcard.gc3 { border-left-color: var(--g3); }
.gcard.gc4 { border-left-color: var(--g4); }

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    padding: 16px;
    box-shadow: var(--shadow);
}

.group-head { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }
.group-head .name { font-weight: 800; font-size: 17px; }

/* ---------------------------------------------------------- 状态标记 */
.dot { width: 10px; height: 10px; border-radius: 50%; background: var(--gold); display: inline-block; flex: 0 0 auto; }
.dot.ok { background: var(--positive); }
.dot.bad { background: var(--attention); }

.pill {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--alt);
    color: var(--muted);
}
.pill.ok { color: var(--positive); border-color: var(--positive); }
.pill.wait { color: var(--gold); border-color: var(--gold); }

/* ---------------------------------------------------------- 提示条 */
.toasts {
    position: fixed;
    top: 14px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 200;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
    width: min(92vw, 460px);
}

.toast {
    padding: 12px 16px;
    border-radius: var(--r-btn);
    font-weight: 700;
    font-size: 15px;
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow: 0 6px 20px rgba(60, 91, 93, .14);
    text-align: center;
}
.toast.ok { background: var(--positive); color: #fff; border-color: var(--positive); }
.toast.bad { background: var(--attention); color: #fff; border-color: var(--attention); }

.offline-bar {
    position: fixed;
    left: 0; right: 0; bottom: 0;
    background: var(--attention);
    color: #fff;
    font-weight: 700;
    font-size: 15px;
    text-align: center;
    padding: 10px;
    z-index: 190;
    transform: translateY(110%);
    transition: transform .2s ease;
}
.offline-bar.show { transform: translateY(0); }

/* ---------------------------------------------------------- 空态 */
.empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 40px 20px;
    color: var(--muted);
    text-align: center;
    font-size: 15px;
}
.empty .mark {
    width: 52px; height: 52px;
    border-radius: 50%;
    border: 2px dashed var(--border);
    display: flex; align-items: center; justify-content: center;
}
.empty .mark svg { width: 24px; height: 24px; stroke: var(--muted); fill: none; stroke-width: 2; }

.loading-dots { display: inline-flex; gap: 5px; }
.loading-dots i {
    width: 7px; height: 7px; border-radius: 50%;
    background: var(--deep);
    animation: pulse 1.1s infinite ease-in-out;
}
.loading-dots i:nth-child(2) { animation-delay: .16s; }
.loading-dots i:nth-child(3) { animation-delay: .32s; }
@keyframes pulse { 0%, 100% { opacity: .25; transform: scale(.8); } 50% { opacity: 1; transform: scale(1); } }

/* ---------------------------------------------------------- 入口页 */
.entry {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 32px 20px;
}
.entry-card {
    width: min(880px, 100%);
    text-align: center;
}
.entry-card .eyebrow {
    font-size: 13px;
    letter-spacing: .22em;
    font-weight: 800;
    color: var(--muted);
    text-transform: uppercase;
}
.entry-card h1 {
    font-size: clamp(32px, 6vw, 56px);
    margin: 12px 0 8px;
    font-weight: 800;
    letter-spacing: .04em;
    line-height: 1.12;
}
.entry-card .sub { color: var(--muted); font-size: 17px; margin-bottom: 32px; }

.entry-groups {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin: 20px 0 12px;
}
@media (max-width: 720px) { .entry-groups { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

.entry-groups a {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 100px;
    border-radius: var(--r-card);
    border: 1px solid var(--border);
    background: var(--surface);
    text-decoration: none;
    color: var(--ink);
    font-weight: 800;
    font-size: 17px;
    box-shadow: var(--shadow);
}
.entry-groups a .bar { width: 34px; height: 5px; border-radius: 999px; }

/* ---------------------------------------------------------- 教师端 */
.stat-strip {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
    padding: 10px 14px;
    background: var(--alt);
    border: 1px solid var(--border);
    border-radius: var(--r-btn);
    font-size: 13px;
    color: var(--muted);
    margin-bottom: 16px;
}

.save-bar {
    position: fixed;
    left: 0; right: 0; bottom: 0;
    display: flex;
    gap: 12px;
    align-items: center;
    padding: 12px clamp(14px, 3vw, 44px);
    background: var(--surface);
    border-top: 1px solid var(--border);
    z-index: 60;
}
.save-bar .status { font-size: 13px; color: var(--muted); }

.list-row {
    display: flex;
    gap: 8px;
    align-items: center;
    margin-bottom: 8px;
}
.list-row input[type="text"] { flex: 1 1 auto; }

.clip-card { border-top: 4px solid var(--border); }
.clip-card .clip-progress {
    height: 6px;
    border-radius: 999px;
    background: var(--border);
    overflow: hidden;
    margin: 10px 0;
}
.clip-card .clip-progress i { display: block; height: 100%; width: 0; background: var(--deep); transition: width .2s linear; }

.toggle-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--r-btn);
    border: 1px solid var(--border);
    background: var(--alt);
    margin-bottom: 10px;
}
.toggle-row .label { font-weight: 700; font-size: 15px; flex: 1 1 auto; }

/* 打星看板 */
.starboard-row {
    display: grid;
    grid-template-columns: 100px 1fr auto;
    gap: 12px;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}
.starboard-row:last-child { border-bottom: 0; }

.starboard-detail {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    font-size: 13px;
    color: var(--muted);
}
.starboard-detail span {
    padding: 2px 8px;
    border-radius: 999px;
    background: var(--alt);
    border: 1px solid var(--border);
}

.total-bar {
    height: 12px;
    border-radius: 999px;
    background: var(--border);
    overflow: hidden;
    margin-top: 6px;
}
.total-bar i { display: block; height: 100%; width: 0; background: var(--deep); transition: width .3s ease; }

.star-btn {
    min-width: 46px;
    padding: 8px;
    font-size: 21px;
    line-height: 1;
    background: var(--alt);
    border-color: var(--border);
    color: var(--gold);
}
.star-btn.on { background: var(--gold); color: #42320d; border-color: var(--gold); }

/* ---------------------------------------------------------- 学生端 */
.stu-top {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 30;
}
.stu-top .gname { font-size: 17px; font-weight: 800; flex: 1 1 auto; }
.stu-top .gbar { width: 6px; height: 28px; border-radius: 999px; }

.stu-main { padding: 16px; max-width: 900px; margin: 0 auto; padding-bottom: 140px; }

.stu-title {
    font-size: 21px;
    font-weight: 800;
    margin: 0 0 6px;
}
.stu-sub { color: var(--muted); font-size: 13px; margin: 0 0 16px; }

.material-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    background: var(--surface);
    margin-bottom: 10px;
    cursor: pointer;
}
.material-card .num {
    width: 40px; height: 40px;
    border-radius: 10px;
    background: var(--alt);
    border: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center;
    font-weight: 800;
    flex: 0 0 auto;
}
.material-card .info { flex: 1 1 auto; min-width: 0; }
.material-card .fname {
    font-weight: 700;
    font-size: 15px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.reader-overlay {
    position: fixed;
    inset: 0;
    background: rgba(20, 32, 33, .82);
    z-index: 150;
    display: flex;
    flex-direction: column;
}
.reader-overlay .reader-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: var(--surface);
}
.reader-overlay .reader-bar .t { flex: 1 1 auto; font-weight: 800; font-size: 15px; }
.reader-overlay .reader-body { flex: 1 1 auto; background: #fff; }
.reader-overlay iframe { width: 100%; height: 100%; border: 0; display: block; }
.reader-overlay img { max-width: 100%; max-height: 100%; display: block; margin: auto; }

/* 答题：投放框与卡片池 */
.q-box {
    border: 2px dashed var(--border);
    border-radius: var(--r-card);
    background: var(--surface);
    padding: 14px;
    margin-bottom: 12px;
    transition: border-color .12s ease, background .12s ease;
}
.q-box.hot { border-color: var(--deep); background: var(--alt); }
.q-box .q-text { font-weight: 800; font-size: 15px; margin-bottom: 10px; }
.q-box .drop-area { min-height: 52px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.q-box .drop-hint { color: var(--muted); font-size: 13px; }

.answer-chip {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 9px 12px;
    border-radius: var(--r-btn);
    background: var(--primary);
    color: #12302f;
    font-weight: 700;
    font-size: 15px;
    border: 1px solid var(--deep);
    touch-action: none;
    user-select: none;
    cursor: grab;
    max-width: 100%;
}
.answer-chip.in-box { background: var(--deep); color: #fff; }
.answer-chip .x {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 22px; height: 22px;
    border-radius: 50%;
    background: rgba(0, 0, 0, .18);
    color: #fff;
    font-size: 13px;
    font-weight: 800;
    flex: 0 0 auto;
}
.answer-chip.sel { outline: 3px solid var(--gold); outline-offset: 1px; }

.chip-pool {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    background: var(--alt);
}

.drag-ghost {
    position: fixed;
    z-index: 999;
    pointer-events: none;
    opacity: .92;
    transform: translate(-50%, -50%) scale(1.04);
}

/* 学生端底部固定操作条 */
.stu-bottom {
    position: fixed;
    left: 0; right: 0; bottom: 0;
    padding: 12px 16px calc(12px + env(safe-area-inset-bottom, 0px));
    background: var(--surface);
    border-top: 1px solid var(--border);
    z-index: 60;
    display: flex;
    gap: 10px;
}
.stu-bottom button { flex: 1 1 auto; min-height: 54px; font-size: 17px; }

/* 学生端答题状态条 */
.submitted-note {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 14px;
    border-radius: var(--r-btn);
    background: var(--positive);
    color: #fff;
    font-weight: 700;
    font-size: 15px;
    margin-bottom: 14px;
}

/* 聆听选项 */
.opt-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    min-height: 64px;
    padding: 14px 16px;
    margin-bottom: 10px;
    border-radius: var(--r-card);
    border: 2px solid var(--border);
    background: var(--surface);
    color: var(--ink);
    font-size: 17px;
    font-weight: 700;
    text-align: left;
}
.opt-btn .idx {
    width: 32px; height: 32px;
    border-radius: 50%;
    background: var(--alt);
    border: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center;
    font-size: 15px;
    flex: 0 0 auto;
}
.opt-btn.on { border-color: var(--deep); background: var(--alt); }
.opt-btn.on .idx { background: var(--deep); color: #fff; border-color: var(--deep); }

/* 抢答 */
.buzz-zone { text-align: center; padding: 20px 0; }
.buzz-btn {
    width: min(76vw, 320px);
    height: min(76vw, 320px);
    border-radius: 50%;
    font-size: 28px;
    font-weight: 800;
    background: var(--attention);
    border: 6px solid #fff3f0;
    color: #fff;
    box-shadow: 0 10px 30px rgba(214, 106, 88, .35);
}
.buzz-btn:disabled { opacity: .55; }

.buzz-flag {
    font-size: 21px;
    font-weight: 800;
    color: var(--positive);
    margin-top: 18px;
}

/* 视频区 */
.video-wrap { border-radius: var(--r-card); overflow: hidden; background: #0d1b1c; }
.video-wrap video { width: 100%; display: block; max-height: 46vh; background: #0d1b1c; }

.upload-progress {
    height: 10px;
    border-radius: 999px;
    background: var(--border);
    overflow: hidden;
    margin: 12px 0 6px;
}
.upload-progress i { display: block; height: 100%; width: 0; background: var(--deep); transition: width .2s linear; }

/* 打星 */
.rate-card { margin-bottom: 12px; }
.rate-stars { display: flex; gap: 6px; flex-wrap: wrap; }
.rate-stars button {
    min-width: 52px;
    min-height: 52px;
    font-size: 21px;
    color: var(--gold);
    background: var(--alt);
    border-color: var(--border);
}
.rate-stars button.on { background: var(--gold); color: #42320d; border-color: var(--gold); }
.rate-card.mine { opacity: .62; }

/* ---------------------------------------------------------- 大屏 */
body.bigscreen { font-size: 21px; }
body.bigscreen .shell { max-width: none; padding: 20px 24px 120px; }
body.bigscreen .big-title {
    font-size: clamp(32px, 3.4vw, 56px);
    font-weight: 800;
    letter-spacing: .04em;
    margin: 0 0 4px;
}
body.bigscreen .big-sub {
    font-size: 21px;
    color: var(--muted);
    margin: 0 0 18px;
}
body.bigscreen .panel > h2 { font-size: 28px; }

.bigscreen-stars {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 18px;
}
.bigscreen-stars .bs-card {
    border-radius: var(--r-card);
    border: 1px solid var(--border);
    border-left: 6px solid var(--border);
    background: var(--surface);
    padding: 14px 16px;
}
.bigscreen-stars .bs-card .gname { font-size: 17px; font-weight: 800; }
.bigscreen-stars .bs-card .num { font-size: 40px; font-weight: 800; line-height: 1.1; }
.bigscreen-stars .bs-card .sub { font-size: 13px; color: var(--muted); }

.big-showcase {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}
.big-answer-item {
    padding: 16px 18px;
    border-radius: var(--r-card);
    background: var(--surface);
    border: 1px solid var(--border);
    border-left: 6px solid var(--deep);
    margin-bottom: 12px;
}
.big-answer-item .q { font-size: 21px; font-weight: 800; margin-bottom: 10px; }
.big-answer-item .a {
    font-size: clamp(24px, 2.4vw, 40px);
    font-weight: 800;
    letter-spacing: .02em;
}
.big-answer-item .a.none { color: var(--muted); font-size: 21px; font-weight: 700; }

.big-groups {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}
.big-group-btn {
    min-height: 72px;
    font-size: 17px;
    border-radius: var(--r-card);
    border: 2px solid var(--border);
    background: var(--surface);
    color: var(--ink);
    font-weight: 800;
}
.big-group-btn.on { border-color: var(--deep); background: var(--alt); }

.bsswitch {
    position: fixed;
    left: 0; right: 0; bottom: 0;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr)) auto;
    gap: 10px;
    padding: 12px 24px;
    background: var(--surface);
    border-top: 1px solid var(--border);
    z-index: 60;
}
.bsswitch button { min-height: 64px; font-size: 17px; }

.listen-dist { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.listen-dist .ld-card {
    border-radius: var(--r-card);
    border: 1px solid var(--border);
    background: var(--surface);
    padding: 14px;
}
.listen-dist .ld-choice {
    font-size: 28px;
    font-weight: 800;
    margin-top: 6px;
}

.buzz-rank { display: flex; gap: 12px; flex-wrap: wrap; }
.buzz-rank .br-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-radius: var(--r-card);
    border: 1px solid var(--border);
    background: var(--surface);
    font-size: 21px;
    font-weight: 800;
}
.buzz-rank .br-item .no {
    width: 40px; height: 40px;
    border-radius: 50%;
    background: var(--deep);
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 17px;
}

.big-videos { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.big-videos .bv {
    border-radius: var(--r-card);
    border: 1px solid var(--border);
    background: var(--surface);
    overflow: hidden;
}
.big-videos .bv .cap { padding: 10px 12px; font-weight: 800; font-size: 15px; }

/* ---------------------------------------------------------- 登录面板 */
.login-box {
    width: min(420px, 100%);
    margin: 12vh auto;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    padding: 28px;
    box-shadow: 0 8px 28px rgba(60, 91, 93, .1);
}