/* ============================================================
 * 放映厅 —— 暗色，海报为主。影片主色只做一层很淡的光。
 * 颜色规则（写完不挂名字，只靠颜色认身份）：
 *   导师 = 琥珀色 + 宋体；学生 = 天蓝色 + 苹方（和琥珀一冷一暖，在黑底上都清楚）。
 *   导入语、问题、模块：按书写身份打一层淡底色；回答、批注：没有底色，文字用身份色。
 *   时间、分区标题、按钮这些都用统一的浅灰。紫色只留给知识库。
 * ============================================================ */
:root {
  --bg: #0c0c0c;
  --fg: #ece8e1;
  --fg-2: #a9a49b;
  --fg-3: #7e796f;
  --label: #9d988e;                    /* 所有标签 */
  --text: #e8e4dc;                     /* 导入语、问题、模块正文 */
  --line: rgba(236, 232, 225, .09);
  --line-2: rgba(236, 232, 225, .18);
  --kb: #8b6cf6;                       /* 知识库 */
  --kb-2: #ab91ff;
  --sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "Source Han Serif", "SimSun", serif;
  --latin: "Helvetica Neue", "Avenir Next", Arial, sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  --ease: cubic-bezier(.2, .7, .1, 1);
  --pad: clamp(16px, 2.6vw, 36px);
}
.by-mentor {
  --c: #e2b35f; --c-strong: #e2b35f; --c-ink: #ecca8c; --c-paper: #f2e4c6; --c-on: #1b1407;
  --c-bg: rgba(226, 179, 95, .11); --c-soft: rgba(226, 179, 95, .3); --c-line: rgba(226, 179, 95, .6);
  --c-font: var(--serif);
}
.by-student {
  --c: #8cbaf6; --c-strong: #74a8f0; --c-ink: #bcd7fb; --c-paper: #dbe8fb; --c-on: #07111f;
  --c-bg: rgba(116, 168, 240, .11); --c-soft: rgba(116, 168, 240, .3); --c-line: rgba(116, 168, 240, .62);
  --c-font: var(--sans);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { background: var(--bg); color: var(--fg); -webkit-font-smoothing: antialiased; overflow-x: clip; }
body { margin: 0; min-height: 100vh; display: flex; flex-direction: column; font-family: var(--sans); font-size: 15px; line-height: 1.7; font-weight: 300; }
main { flex: 1; }
main:focus { outline: none; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: 0; padding: 0; }
p, h1, h2, h3 { margin: 0; }
h1, h2, h3 { font-weight: 400; }
textarea { display: block; width: 100%; margin: 0; padding: 0; border: 0; background: none; resize: none; overflow: hidden; outline: none; }
::placeholder { color: var(--fg-3); opacity: 1; }
::selection { background: rgba(236, 232, 225, .22); }
:focus-visible { outline: 1px solid var(--fg-2); outline-offset: 3px; }
textarea:focus-visible, input:focus-visible, select:focus-visible { outline: none; }
.skip { position: absolute; left: -999px; top: 8px; z-index: 100; background: #000; padding: 6px 12px; }
.skip:focus { left: 12px; }

/* ---------------- 顶栏 ---------------- */
.bar { position: sticky; top: 0; z-index: 30; display: flex; align-items: center; gap: 36px; height: 60px; padding: 0 var(--pad);
  background: rgba(12, 12, 12, .86); -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; font-size: 15px; letter-spacing: .18em; font-weight: 400; white-space: nowrap; }
.brand i { width: 7px; height: 7px; border-radius: 50%; background: var(--fg); box-shadow: 0 0 12px rgba(236, 232, 225, .55); }
.nav { display: flex; gap: 24px; font-size: 14px; }
.nav a { color: var(--fg-3); padding: 4px 0; transition: color .2s; }
.nav a:hover, .nav a.on { color: var(--fg); }

/* ---------------- 通用 ---------------- */
.btn { display: inline-flex; align-items: center; height: 36px; padding: 0 16px; border: 1px solid var(--line-2); border-radius: 999px; font-size: 13px; white-space: nowrap; transition: .2s; }
.btn:hover { border-color: var(--fg-2); }
.btn.primary { background: var(--fg); border-color: var(--fg); color: #111; font-weight: 400; }
.btn.primary:hover { background: #fff; }
.btn.ghost { color: var(--fg-2); }
.lk { font-size: 12px; color: var(--label); transition: color .2s; }
.lk:hover { color: var(--fg); }
.label { font-size: 12px; letter-spacing: .24em; color: var(--fg-3); margin-bottom: 18px; }
.label span { margin-left: 10px; letter-spacing: 0; }
.none { padding: 18px 0; font-size: 13.5px; color: var(--fg-3); }
.poster { display: block; width: 100%; aspect-ratio: 2 / 3; object-fit: cover; border-radius: 3px; background: #1b1b1b; }
.poster-ph { display: grid; place-items: center; padding: 12px; text-align: center; font-size: 15px; color: var(--fg-2); background: linear-gradient(160deg, #262626, #121212); }
.new { flex: none; padding: 0 6px; border: 1px solid var(--line-2); border-radius: 999px; font-size: 10.5px; font-weight: 400; line-height: 16px; color: var(--fg); }
.flash { animation: flash 1.6s var(--ease); }
@keyframes flash { from { box-shadow: 0 0 0 1px var(--line-2), 0 0 44px -6px rgba(236, 232, 225, .2); } }
.pop { animation: pop .7s var(--ease); }
@keyframes pop { from { opacity: .35; transform: translateY(4px); } }

/* 身份小图标：写在输入框里，点一下切换学生 / 导师 */
.who { flex: none; display: inline-flex; align-items: center; gap: 5px; height: 26px; padding: 0 10px 0 8px; border: 1px solid var(--c-soft); border-radius: 999px;
  font-size: 12px; line-height: 1; color: var(--c); white-space: nowrap; transition: border-color .2s, background .2s; }
.who svg { width: 13px; height: 13px; fill: none; stroke: currentColor; stroke-width: 1.4; stroke-linecap: round; stroke-linejoin: round; }
.who .who-swap { width: 11px; height: 11px; margin-left: 2px; opacity: .5; transition: opacity .2s, transform .3s var(--ease); }
.who:hover { border-color: var(--c); background: var(--c-bg); }
.who:hover .who-swap { opacity: 1; transform: rotate(180deg); }

/* ---------------- 片单：左边片子，右边最近动态 ---------------- */
.home { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 44px; align-items: start; width: min(1480px, 100%); margin: 0 auto; padding: 36px var(--pad) 96px; }
.home-main { min-width: 0; }
.done { margin-top: 56px; }
/* 看过：原来那种大长卡片，一条一条往下排 */
.done-list { display: flex; flex-direction: column; gap: 16px; }
.feature { position: relative; display: grid; grid-template-columns: 196px minmax(0, 1fr); gap: 36px; padding: 28px; border: 1px solid var(--line); border-radius: 8px; overflow: hidden;
  background: radial-gradient(90% 140% at 0% 0%, color-mix(in srgb, var(--pc) 34%, transparent), transparent 62%), #111; transition: border-color .3s; }
.feature:hover { border-color: var(--line-2); }
.ft-body { display: flex; flex-direction: column; gap: 6px; min-width: 0; padding-top: 4px; }
.ft-kicker { font-size: 12px; letter-spacing: .16em; color: var(--fg-3); }
.ft-title { margin-top: 4px; font-size: 40px; font-weight: 200; letter-spacing: .06em; line-height: 1.2; }
.ft-sub { font-size: 14px; color: var(--fg-2); }
.ft-rating { margin-top: 8px; font-size: 14px; color: var(--fg-2); }
.ft-rating b { margin-left: 4px; font-family: var(--latin); font-size: 22px; font-weight: 400; color: var(--fg); }
.ft-meta { font-size: 13px; color: var(--fg-2); }
.ft-dates { display: flex; flex-wrap: wrap; gap: 4px 20px; margin-top: 4px; font-size: 12.5px; color: var(--label); }
.ft-dates b { margin-right: 4px; font-weight: 400; color: var(--c); }
.ft-new { align-self: flex-start; display: flex; align-items: center; gap: 8px; margin-top: 10px; padding: 6px 12px; border-radius: 8px; background: rgba(236, 232, 225, .06); font-size: 13px; color: var(--fg); }
.ft-new i { flex: none; width: 7px; height: 7px; border-radius: 50%; background: var(--c); }
.ft-go { margin-top: auto; padding-top: 18px; font-size: 13px; color: var(--fg-2); transition: color .2s; }
.feature:hover .ft-go { color: var(--fg); }
.dot { flex: none; width: 7px; height: 7px; border-radius: 50%; background: var(--c); }
.news i { flex: none; width: 7px; height: 7px; border-radius: 50%; background: var(--c); }

/* 最近动态：一条一行，谁 · 做了什么 · 什么时候 */
.feed { position: sticky; top: 84px; min-width: 0; }
.feed-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line); }
.ev a { position: relative; display: block; padding: 12px 0 12px 14px; border-bottom: 1px solid var(--line); transition: background .2s; }
.ev a::before { content: ''; position: absolute; left: 0; top: 19px; width: 5px; height: 5px; border-radius: 50%; background: var(--c); opacity: .85; }
.ev a:hover { background: rgba(236, 232, 225, .03); }
.ev-text { display: block; font-size: 13px; line-height: 1.65; color: var(--fg-2); }
.ev-text b { margin-right: 4px; font-weight: 400; color: var(--c); }
.ev a:hover .ev-text { color: var(--fg); }
.ev time { display: flex; align-items: center; gap: 8px; margin-top: 3px; font-size: 11px; color: var(--label); }
.ev-new { padding: 0 6px; border: 1px solid var(--line-2); border-radius: 999px; font-size: 10px; font-style: normal; line-height: 15px; color: var(--fg); }
.ev.is-new .ev-text { color: var(--fg); }
.feed-more { margin-top: 12px; font-size: 12px; color: var(--label); transition: color .2s; }
.feed-more:hover { color: var(--fg); }
.grid { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(146px, 1fr)); gap: 26px 18px; }
/* 待观影列表：按住拖动排序，右上角小 × 移出片单 */
.grid-wish li { position: relative; }
.grid-wish li[draggable=true] { cursor: grab; }
.grid-wish li[draggable=true]:active { cursor: grabbing; }
.grid-wish li.dragging { opacity: .3; }
.grid-wish li.dragging .poster { transform: none; box-shadow: none; }
.card-x { position: absolute; top: 6px; right: 6px; z-index: 2; display: grid; place-items: center; width: 24px; height: 24px; border: 1px solid rgba(236, 232, 225, .22); border-radius: 50%;
  background: rgba(12, 12, 12, .72); -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); font-size: 14px; line-height: 1; color: var(--fg-2); opacity: 0; transition: opacity .2s, color .2s, background .2s; }
.grid-wish li:hover .card-x, .card-x:focus-visible { opacity: 1; }
.card-x:hover { background: rgba(0, 0, 0, .9); color: var(--fg); }
.grid-wish li:hover .poster { transform: translateY(-4px); }
.card { display: block; width: 100%; border-radius: 4px; text-align: left; }
.card-img { position: relative; display: block; }
.card-img .poster { transition: transform .35s var(--ease), box-shadow .35s; }
.card:hover .poster { transform: translateY(-4px); box-shadow: 0 18px 40px -18px rgba(0, 0, 0, .9); }
.card .dot { position: absolute; top: 9px; left: 9px; box-shadow: 0 0 0 3px rgba(0, 0, 0, .5); }
.card-t { display: block; margin-top: 10px; font-size: 14px; font-weight: 400; }
.card-s { display: block; font-size: 12px; color: var(--fg-3); }
/* 待观影列表最后一格：添加影片 */
.add-img { position: relative; display: grid; place-items: center; aspect-ratio: 2 / 3; border: 1px dashed var(--line-2); border-radius: 3px; transition: border-color .25s, background .25s; }
.add-img i { position: relative; width: 30px; height: 30px; }
.add-img i::before, .add-img i::after { content: ''; position: absolute; left: 50%; top: 50%; background: var(--fg-3); transform: translate(-50%, -50%); transition: background .2s; }
.add-img i::before { width: 30px; height: 1px; }
.add-img i::after { width: 1px; height: 30px; }
.card-add .card-t { color: var(--fg-3); transition: color .2s; }
.card-add:hover .add-img { border-color: var(--fg-2); background: rgba(255, 255, 255, .025); }
.card-add:hover .add-img i::before, .card-add:hover .add-img i::after { background: var(--fg); }
.card-add:hover .card-t { color: var(--fg); }

/* ---------------- 影片页 ---------------- */
.film { position: relative; isolation: isolate; width: min(1180px, 100%); margin: 0 auto; padding: 24px var(--pad) 88px; }
.glow { position: absolute; top: 0; left: calc(50% - 50vw); right: calc(50% - 50vw); z-index: -1; height: 720px; pointer-events: none;
  background: radial-gradient(60% 90% at 22% 0%, color-mix(in srgb, var(--pc) 28%, transparent), transparent 72%); }
.back { display: inline-block; margin-bottom: 28px; font-size: 13px; color: var(--fg-3); }
.back:hover { color: var(--fg); }
.film-grid { display: grid; grid-template-columns: 280px minmax(0, 1fr); gap: 56px; align-items: start; }
.film-side { position: sticky; top: 88px; }
.film-poster .poster { box-shadow: 0 40px 90px -40px rgba(0, 0, 0, .95); }
.info .kicker { font-size: 12.5px; letter-spacing: .12em; color: var(--fg-3); }
.info .title { margin-top: 10px; font-size: 46px; font-weight: 200; letter-spacing: .06em; line-height: 1.2; }
.info .orig { margin-top: 4px; font-family: var(--latin); font-size: 16px; color: var(--fg-2); }
.info .meta-line { margin-top: 16px; font-size: 13.5px; color: var(--fg-2); }
.info .people { margin-top: 4px; font-size: 13.5px; color: var(--fg-2); }
.sep { display: inline-block; width: 18px; }
.db { margin-top: 16px; font-size: 14px; color: var(--fg-2); }
.db a:hover { color: var(--fg); }
.db b { margin: 0 6px 0 4px; font-family: var(--latin); font-size: 24px; font-weight: 400; color: var(--fg); }
.db span { font-size: 12.5px; color: var(--fg-3); }
.summary { max-width: 44em; margin-top: 16px; font-size: 14px; line-height: 1.9; color: var(--fg-2); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.summary.open { display: block; }
.more { margin-top: 4px; font-size: 12.5px; color: var(--fg-3); }
.more:hover { color: var(--fg); }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 24px; }
.news { display: flex; align-items: center; gap: 10px; margin-top: 28px; padding: 12px 16px; border-radius: 8px; background: rgba(236, 232, 225, .06); color: var(--fg); font-size: 14px; }

.sec { margin-top: 56px; }
.sec-t { margin-bottom: 18px; padding-bottom: 12px; border-bottom: 1px solid var(--line); font-size: 12.5px; letter-spacing: .24em; color: var(--label); }
.sec-t span { margin-left: 10px; letter-spacing: 0; }

/* 块：导入语 / 问题 / 模块。按书写身份打一层淡底色，正文用那个身份的字体 */
.bk { margin-top: 14px; scroll-margin: 90px 0 120px; }
.bk + .bk { margin-top: 26px; }
.bk-card { position: relative; display: block; width: 100%; padding: 18px 22px 12px; border-radius: 12px; background: rgba(236, 232, 225, .045); text-align: left; }
.bk-card.by-mentor { background: rgba(226, 179, 95, .1); }
.bk-card.by-student { background: rgba(116, 168, 240, .1); }
.bk-card:has(> .ed-block) { background: none; }
.bk-text { font-family: var(--c-font, var(--serif)); font-weight: 400; font-size: 15.5px; line-height: 2; color: var(--c-paper, var(--text)); white-space: pre-wrap; word-break: break-word; }
/* 左下角的小时间；鼠标移上去才出现「修改 / 删除」 */
.meta { display: flex; align-items: center; gap: 12px; min-height: 22px; margin-top: 4px; font-family: var(--sans); font-size: 11px; line-height: 1; color: var(--label); }
.meta time { opacity: .85; }
.new-dot { flex: none; width: 6px; height: 6px; margin-right: -4px; border-radius: 50%; background: var(--c, var(--fg)); }
.acts { display: flex; gap: 12px; opacity: 0; transition: opacity .2s; }
.bk-card:hover .acts, .add:hover .acts, .acts:focus-within { opacity: 1; }
.bk-question .bk-text { font-size: 18px; line-height: 1.8; }
.bk-intro .bk-text { max-width: 46em; font-size: 16px; line-height: 2.1; }
.q-n { display: inline-block; min-width: 28px; margin-right: 6px; font-family: var(--mono); font-size: 12px; font-weight: 400; color: var(--c, var(--label)); opacity: .75; vertical-align: 2px; }
.bk-empty { padding: 20px 22px; border: 1px dashed var(--line-2); background: none; font-size: 13.5px; color: var(--fg-2); cursor: pointer; transition: background .2s, color .2s, border-color .2s; }
.bk-empty:hover { border-color: var(--fg-3); background: rgba(236, 232, 225, .04); color: var(--fg); }

/* 追加（回答 / 批注）：没有线条和色块，文字用作者的身份色，下面一个小时间 */
.bk-adds { display: flex; flex-direction: column; align-items: stretch; gap: 14px; padding: 16px 0 0 22px; }
.add-text { font-family: var(--c-font); font-weight: 400; font-size: 15px; line-height: 1.95; color: var(--c-ink); white-space: pre-wrap; word-break: break-word; }
/* 批注入口：各处都一样，一个不张扬、但一看就能点的小按钮 */
.note-btn { align-self: flex-start; display: inline-flex; align-items: center; gap: 4px; height: 28px; padding: 0 13px; border: 1px solid var(--line-2); border-radius: 999px;
  font-size: 12.5px; color: var(--fg-2); transition: color .2s, border-color .2s, background .2s; }
.note-btn:hover, .note-btn:focus-visible { border-color: var(--fg-3); background: rgba(236, 232, 225, .05); color: var(--fg); }

/* 编辑框：文字、图标、按钮跟着当前身份 */
.ed { position: relative; }
.ed-in { font-family: var(--c-font); font-weight: 400; font-size: 15.5px; line-height: 1.95; color: var(--c-ink); }
.ed-foot { display: flex; align-items: center; gap: 12px; margin-top: 10px; }
.ed-state { margin-left: auto; font-size: 11.5px; color: var(--label); }
.ed-cancel { font-size: 12.5px; color: var(--label); transition: color .2s; }
.ed-cancel:hover { color: var(--fg); }
.ed-save { flex: none; height: 30px; padding: 0 18px; border-radius: 999px; background: var(--c-strong); color: var(--c-on); font-size: 13px; font-weight: 400; transition: opacity .2s, filter .2s; }
.ed-save:hover { filter: brightness(1.08); }
.ed-save:disabled { opacity: .25; cursor: default; filter: none; }
/* 在块下面写：极简，没有线框；写的时候才有一层很淡的底 */
.ed-add { margin: -8px 0 -8px -12px; padding: 8px 12px; border-radius: 10px; transition: background .2s; }
.ed-add:focus-within { background: rgba(236, 232, 225, .035); }
.ed-add .ed-in { min-height: 56px; font-size: 15px; }
.ed-answer .ed-in { min-height: 136px; }
.ed-answer:not(:focus-within):not(.has-text) .ed-foot { display: none; }
/* 在块里直接改：底色和线框跟着编辑框里选的身份，切换时当场变 */
.ed-block { margin: -18px -22px -12px; padding: 18px 22px 12px; border: 1px solid var(--c-soft); border-radius: 12px; background: var(--c-bg); transition: background .25s, border-color .25s; }
.ed-block:focus-within { border-color: var(--c-line); }
.ed-block .ed-in { color: var(--c-paper); }
.bk-question .ed-block .ed-in { font-size: 18px; line-height: 1.8; }
.bk-intro .ed-block .ed-in { font-size: 16px; line-height: 2.1; }
.ed-sm .ed-in { min-height: 0; font-size: 14px; line-height: 1.85; }
.ed-sm .ed-foot { gap: 10px; margin-top: 8px; }
.ed-sm .ed-save { height: 26px; padding: 0 14px; font-size: 12.5px; }
.ed-sm .who { height: 24px; font-size: 11.5px; }

.related { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 16px; margin-top: 40px; font-size: 13px; color: var(--label); }
.related span { letter-spacing: .2em; font-size: 12px; }
.related a { color: var(--fg-2); border-bottom: 1px solid var(--line-2); transition: .2s; }
.related a:hover { color: var(--kb-2); border-color: var(--kb); }

/* 页面下方的添加区：选身份 → 添加问题 / 添加新模块 → 写 → 发送 */
.composer { margin-top: 48px; padding: 8px 8px 8px 10px; border: 1px solid var(--c-soft); border-radius: 12px; background: rgba(236, 232, 225, .02); transition: border-color .2s; }
.composer:focus-within { border-color: var(--c-line); }
.cp-top { display: flex; align-items: center; gap: 10px; min-width: 0; }
.cp-sep { flex: none; width: 1px; height: 14px; background: var(--line-2); }
.cp-types { display: flex; gap: 2px; }
.cp-type { flex: none; height: 26px; padding: 0 12px; border-radius: 999px; font-size: 12.5px; color: var(--label); transition: color .2s, background .2s; }
.cp-type:hover { color: var(--fg); }
.cp-type[aria-checked=true] { color: var(--fg); background: rgba(236, 232, 225, .08); }
.cp-name { display: block; width: 100%; margin-top: 8px; padding: 4px 2px 6px; border: 0; border-bottom: 1px solid var(--line-2); background: none; font-size: 14px; color: var(--fg); outline: none; }
.cp-name:focus { border-bottom-color: var(--c-soft); }
.cp-row { display: flex; align-items: flex-end; gap: 8px; margin-top: 4px; }
.cp-text { flex: 1; min-width: 0; min-height: 36px; max-height: 40vh; padding: 6px 2px; overflow-y: auto !important;
  font-family: var(--c-font); font-weight: 400; font-size: 14.5px; line-height: 1.8; color: var(--c-ink); }
.cp-send { flex: none; display: grid; place-items: center; width: 30px; height: 30px; margin-bottom: 3px; border-radius: 8px; background: var(--c-strong); color: var(--c-on); transition: opacity .2s, filter .2s; }
.cp-send svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.cp-send:hover { filter: brightness(1.08); }
.cp-send:disabled { opacity: .25; cursor: default; filter: none; }

/* ---------------- 知识库（紫色只用在这里） ---------------- */
.kb { width: min(1040px, 100%); margin: 0 auto; padding: 48px var(--pad) 96px; }
.kb-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; padding-bottom: 22px;
  border-bottom: 1px solid transparent; border-image: linear-gradient(90deg, rgba(139, 108, 246, .6), var(--line) 45%, var(--line)) 1; }
.kb-head h1 { font-size: 40px; font-weight: 200; letter-spacing: .08em; line-height: 1.2; }
.legend { display: flex; gap: 18px; margin-top: 10px; font-size: 12px; color: var(--label); }
.legend span { display: inline-flex; align-items: center; gap: 7px; }
.legend i { width: 6px; height: 6px; border-radius: 50%; background: var(--c); }
.kb-list { list-style: none; display: flex; flex-direction: column; gap: 20px; margin: 28px 0 0; padding: 0; }
.kb-item { position: relative; display: grid; grid-template-columns: minmax(0, 1fr) 300px; border: 1px solid rgba(139, 108, 246, .22); border-radius: 16px; overflow: hidden; scroll-margin-top: 90px;
  background: radial-gradient(120% 90% at 0% 0%, rgba(139, 108, 246, .16), transparent 58%), #111; }
.kb-item::before { content: ''; position: absolute; left: 0; right: 0; top: 0; height: 1px; background: linear-gradient(90deg, var(--kb-2), transparent 65%); opacity: .85; }
.kb-item.editing { display: block; border: 0; overflow: visible; background: none; }
.kb-item.editing::before { display: none; }
.kb-main { padding: 30px 32px 26px; }
.kb-term { font-family: var(--serif); font-size: 30px; font-weight: 400; letter-spacing: .08em; line-height: 1.3; color: #f4efe6; }
.kb-sub { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 18px; margin-top: 14px; font-size: 12px; }
.kb-sub time { font-size: 11.5px; color: var(--label); }
.kb-film { display: inline-flex; align-items: center; gap: 3px; padding: 3px 10px 3px 4px; border: 1px solid color-mix(in srgb, var(--fc) 55%, rgba(236, 232, 225, .18)); border-radius: 999px;
  background: color-mix(in srgb, var(--fc) 16%, transparent); font-size: 12.5px; color: var(--fg); transition: background .2s; }
.kb-film:hover { background: color-mix(in srgb, var(--fc) 30%, transparent); }
.kb-thumb { flex: none; width: 16px; }
.kb-thumb .poster { border-radius: 2px; }
.kb-thumb .poster-ph { padding: 0; font-size: 0; }
.kb-text { margin-top: 20px; padding-top: 18px; border-top: 1px solid transparent; border-image: linear-gradient(90deg, rgba(139, 108, 246, .4), transparent 70%) 1;
  font-family: var(--serif); font-weight: 400; font-size: 15.5px; line-height: 2.05; color: var(--text); white-space: pre-wrap; word-break: break-word; }
.kb-acts { display: flex; gap: 16px; margin-top: 16px; opacity: 0; transition: opacity .2s; }
.kb-main:hover .kb-acts, .kb-acts:focus-within { opacity: 1; }
.kb-notes { display: flex; flex-direction: column; gap: 18px; min-width: 0; padding: 26px 24px 22px; border-left: 1px solid rgba(139, 108, 246, .16); background: rgba(0, 0, 0, .25); }
.kb-notes-t { font-size: 12px; letter-spacing: .22em; color: var(--label); }
.kb-notes-t span { margin-left: 8px; letter-spacing: 0; }
.kb-notes .add-text { font-size: 14px; line-height: 1.85; }
.kb-form { margin-top: 26px; padding: 22px 24px 16px; border: 1px solid rgba(139, 108, 246, .45); border-radius: 16px;
  background: radial-gradient(120% 100% at 0% 0%, rgba(139, 108, 246, .16), transparent 60%), #111; box-shadow: 0 0 0 4px rgba(139, 108, 246, .07); transition: border-color .2s; }
.kb-form:focus-within { border-color: var(--kb); }
.kb-form .ed-save { background: var(--kb); color: #fff; }
.kb-form-row { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 14px 24px; }
.kb-term-in { flex: 1 1 240px; min-width: 0; padding: 4px 0 8px; border: 0; border-bottom: 1px solid var(--line-2); background: none; font-family: var(--serif); font-size: 26px; font-weight: 400; letter-spacing: .06em; color: #f4efe6; outline: none; transition: border-color .2s; }
.kb-term-in:focus { border-bottom-color: var(--kb-2); }
.kb-film-in { flex: 0 1 220px; height: 34px; padding: 0 12px; border: 1px solid var(--line-2); border-radius: 999px; background: #151515; font-size: 13px; color: var(--fg-2); color-scheme: dark; outline: none; cursor: pointer; }
.kb-film-in:focus { border-color: var(--fg-2); }
.kb-text-in { min-height: 130px; margin-top: 20px; font-family: var(--serif); font-weight: 400; font-size: 15.5px; line-height: 2; color: var(--text); }

/* ---------------- 添加影片 ---------------- */
.sheet { width: min(620px, calc(100% - 28px)); max-height: calc(100vh - 60px); padding: 0; border: 1px solid var(--line-2); border-radius: 12px; background: #151515; color: var(--fg); box-shadow: 0 40px 120px -30px #000; }
.sheet::backdrop { background: rgba(0, 0, 0, .62); -webkit-backdrop-filter: blur(3px); backdrop-filter: blur(3px); }
.sheet-in { padding: 24px 28px 30px; }
.sheet-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.sheet-head h2 { font-size: 18px; letter-spacing: .08em; }
.sheet-x { font-size: 22px; line-height: 1; color: var(--fg-3); }
.sheet-x:hover { color: var(--fg); }
.nf-search input { width: 100%; padding: 10px 0; border: 0; border-bottom: 1px solid var(--line-2); background: transparent; font-size: 17px; outline: none; }
.nf-search input:focus { border-color: var(--fg-2); }
.nf-hint { margin-top: 12px; font-size: 13px; line-height: 1.9; color: var(--fg-2); }
.nf-results { list-style: none; max-height: 360px; margin: 10px 0 0; padding: 0; overflow: auto; }
.nf-item { display: flex; align-items: center; gap: 14px; width: 100%; padding: 8px; border-radius: 6px; text-align: left; }
.nf-item:hover, .nf-item:focus-visible { background: rgba(255, 255, 255, .05); }
.nf-item img, .nf-noimg { flex: none; width: 40px; height: 58px; object-fit: cover; border-radius: 2px; background: #222; }
.nf-item-t b { display: block; font-size: 15px; font-weight: 400; }
.nf-item-t i { font-style: normal; font-size: 12.5px; color: var(--fg-3); }
.nf-switch { margin-top: 14px; }
.nf-card { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 20px; }
.nf-info { display: flex; flex-direction: column; gap: 3px; font-size: 13.5px; color: var(--fg-2); }
.nf-title { font-size: 22px; font-weight: 300; color: var(--fg); }
.nf-rating b { font-family: var(--latin); font-size: 18px; font-weight: 400; color: var(--fg); }
.nf-row { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin-top: 22px; }
.nf-btn { height: 36px; padding: 0 18px; border: 1px solid var(--line-2); border-radius: 999px; font-size: 13px; }
.nf-btn:hover { border-color: var(--fg-2); }
.nf-btn.nf-primary { border-color: var(--fg); background: var(--fg); color: #111; }
.nf-link { font-size: 13px; color: var(--fg-3); }
.nf-link:hover { color: var(--fg); }
.nf-note { font-size: 13px; color: var(--fg-2); }
.nf-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px 20px; }
.nf-wide { grid-column: 1 / -1; }
.nf-field { display: flex; flex-direction: column; gap: 4px; }
.nf-label { font-size: 12px; color: var(--fg-3); }
.nf-field input { padding: 7px 0; border: 0; border-bottom: 1px solid var(--line-2); background: transparent; font-size: 14px; color: var(--fg); outline: none; }
.nf-wide input { font-size: 18px; }
.nf-field input:focus { border-color: var(--fg-2); }

/* ---------------- 页脚 / 提示 ---------------- */
.foot { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px 24px; padding: 22px var(--pad); border-top: 1px solid var(--line); font-size: 12px; color: var(--fg-3); }
.foot button:hover { color: var(--fg); }
.toast { position: fixed; left: 50%; top: 76px; z-index: 90; transform: translate(-50%, -10px); padding: 9px 18px; border-radius: 999px; background: var(--fg); color: #111; font-size: 13px; opacity: 0; pointer-events: none; transition: .3s var(--ease); }
.toast.show { opacity: 1; transform: translate(-50%, 0); }
body[data-role=mentor] .toast { background: #e2b35f; color: #1b1407; }
body[data-role=student] .toast { background: #74a8f0; color: #07111f; }

/* ---------------- 窄屏 ---------------- */
@media (max-width: 960px) {
  .home { grid-template-columns: 1fr; gap: 48px; }
  .feed { position: static; }
}
@media (max-width: 860px) {
  .feature { grid-template-columns: 110px minmax(0, 1fr); gap: 20px; padding: 18px; }
  .ft-title { font-size: 28px; }
  .film-grid { grid-template-columns: 1fr; gap: 28px; }
  .film-side { position: static; width: 180px; }
  .info .title { font-size: 34px; }
  .bk-adds { padding-left: 8px; }
  .kb-item { grid-template-columns: 1fr; }
  .kb-notes { border-left: 0; border-top: 1px solid rgba(139, 108, 246, .16); }
  .kb-main { padding: 24px 22px; }
  .nf-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .bar { gap: 24px; }
  .composer .who span { display: none; }
}
@media (hover: none) {
  .card-x { opacity: 1; }
  .acts, .kb-acts { opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}