/* ===================== 设计变量 ===================== */
:root {
  --bg: #0b1020;
  --bg-soft: #11182e;
  --surface: #161f3a;
  --surface-2: #1d2848;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.16);
  --text: #eef2ff;
  --text-dim: #aab3d4;
  --text-mute: #7c86ad;

  --c1: #6a8bff;   /* 蓝 */
  --c2: #a06bff;   /* 紫 */
  --c3: #ff7a59;   /* 橙 */
  --c4: #2bd4c4;   /* 青 */
  --grad: linear-gradient(120deg, #6a8bff 0%, #a06bff 45%, #ff7a59 100%);
  --grad-soft: linear-gradient(120deg, rgba(106,139,255,.18), rgba(160,107,255,.18), rgba(255,122,89,.18));

  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 18px 50px -20px rgba(0, 0, 0, 0.6);
  --maxw: 1180px;
  --nav-h: 66px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0; font-weight: 800; letter-spacing: -0.01em; }
img { max-width: 100%; }
::selection { background: rgba(160, 107, 255, 0.4); }

/* ===================== 顶部进度条 ===================== */
.top-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: var(--grad); z-index: 200; transition: width .25s ease;
}

/* ===================== 导航 ===================== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 clamp(16px, 4vw, 40px); z-index: 100;
  background: rgba(11, 16, 32, 0.72);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 11px; font-weight: 800; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center;
  background: var(--grad); color: #fff; font-weight: 900; font-size: 18px;
  box-shadow: 0 6px 18px -6px rgba(160, 107, 255, .8);
}
.brand-text { display: flex; flex-direction: column; font-size: 15px; line-height: 1.1; }
.brand-text small { font-size: 10px; color: var(--text-mute); font-weight: 600; letter-spacing: .08em; }

.nav-links { display: flex; gap: 4px; }
.nav-links a {
  padding: 8px 14px; border-radius: 10px; font-size: 14px; color: var(--text-dim);
  font-weight: 600; transition: .2s;
}
.nav-links a:hover { color: var(--text); background: rgba(255, 255, 255, .05); }
.nav-links a.active { color: #fff; background: var(--grad-soft); }

.nav-actions { display: flex; align-items: center; gap: 12px; }
.progress-pill {
  border: 1px solid var(--line-strong); background: var(--surface);
  border-radius: 999px; padding: 5px 6px 5px 8px; cursor: pointer; display: flex; align-items: center; gap: 8px;
  color: var(--text-dim); font-size: 13px; font-weight: 700; transition: .2s;
}
.progress-pill:hover { border-color: var(--c2); color: #fff; }
.ring {
  width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(var(--c2) calc(var(--p, 0) * 1%), rgba(255,255,255,.1) 0);
  font-size: 9px; font-weight: 800; color: #fff; position: relative;
}
.ring::before { content: ""; position: absolute; inset: 3px; border-radius: 50%; background: var(--surface); }
.ring span { position: relative; z-index: 1; }

.menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.menu-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: .3s; }
.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===================== Hero ===================== */
.hero { position: relative; min-height: 100vh; display: grid; place-items: center; padding: calc(var(--nav-h) + 40px) 20px 60px; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(60% 50% at 20% 15%, rgba(106,139,255,.35), transparent 60%),
    radial-gradient(50% 50% at 85% 25%, rgba(255,122,89,.30), transparent 60%),
    radial-gradient(60% 60% at 60% 90%, rgba(160,107,255,.30), transparent 60%),
    var(--bg);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 46px 46px; mask-image: radial-gradient(circle at 50% 40%, #000, transparent 75%);
  -webkit-mask-image: radial-gradient(circle at 50% 40%, #000, transparent 75%);
}
.hero-inner { position: relative; max-width: 880px; text-align: center; z-index: 1; }
.hero-tag {
  display: inline-block; font-size: 12.5px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  color: var(--text-dim); padding: 7px 16px; border: 1px solid var(--line-strong); border-radius: 999px;
  background: rgba(255,255,255,.03); margin-bottom: 22px;
}
.hero-title { font-size: clamp(34px, 6vw, 62px); font-weight: 900; letter-spacing: -0.02em; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { color: var(--text-dim); font-size: clamp(15px, 2vw, 18px); max-width: 660px; margin: 22px auto 0; }
.hero-cta { display: flex; gap: 14px; justify-content: center; margin-top: 32px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 13px 24px; border-radius: 12px;
  font-weight: 700; font-size: 15px; cursor: pointer; border: 1px solid transparent; transition: .2s;
}
.btn-sm { padding: 9px 16px; font-size: 13px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 12px 30px -10px rgba(160,107,255,.7); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 40px -10px rgba(160,107,255,.85); }
.btn-ghost { background: rgba(255,255,255,.04); border-color: var(--line-strong); color: var(--text); }
.btn-ghost:hover { background: rgba(255,255,255,.09); }

.hero-stats { display: flex; gap: 14px; justify-content: center; margin-top: 48px; flex-wrap: wrap; }
.hero-stats .stat {
  background: rgba(255,255,255,.04); border: 1px solid var(--line); border-radius: 14px;
  padding: 16px 22px; min-width: 118px; backdrop-filter: blur(6px);
}
.hero-stats .stat b { display: block; font-size: 30px; font-weight: 900; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-stats .stat span { font-size: 12.5px; color: var(--text-mute); }

.scroll-hint { position: absolute; bottom: 22px; left: 50%; transform: translateX(-50%); font-size: 30px; color: var(--text-mute); animation: bob 1.8s infinite; text-decoration: none; }
@keyframes bob { 0%,100% { transform: translate(-50%, 0); } 50% { transform: translate(-50%, 8px); } }

/* ===================== 通用区块 ===================== */
.section { max-width: var(--maxw); margin: 0 auto; padding: clamp(60px, 9vw, 110px) clamp(16px, 4vw, 40px); }
.section-alt { max-width: none; background: linear-gradient(180deg, rgba(255,255,255,.015), transparent); border-block: 1px solid var(--line); }
.section-alt > * { max-width: var(--maxw); margin-inline: auto; }
.section-head { text-align: center; margin-bottom: 46px; }
.eyebrow { color: var(--c4); font-weight: 800; font-size: 13px; letter-spacing: .14em; text-transform: uppercase; }
.section-head h2 { font-size: clamp(26px, 4vw, 40px); margin: 12px 0 10px; }
.section-head p { color: var(--text-dim); max-width: 620px; margin: 0 auto; font-size: 15.5px; }

/* ===================== 课程学习区 ===================== */
.learn-layout { display: grid; grid-template-columns: 232px 1fr; gap: 30px; align-items: start; }
.learn-nav { position: sticky; top: calc(var(--nav-h) + 18px); display: flex; flex-direction: column; gap: 6px; }
.learn-nav button {
  display: flex; align-items: center; gap: 11px; text-align: left; padding: 12px 14px; border-radius: 12px;
  background: transparent; border: 1px solid transparent; color: var(--text-dim); font-size: 14px; font-weight: 600;
  cursor: pointer; transition: .18s; width: 100%;
}
.learn-nav button:hover { background: rgba(255,255,255,.04); color: #fff; }
.learn-nav button.active { background: var(--grad-soft); color: #fff; border-color: var(--line-strong); }
.learn-nav .ln-num {
  width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center; font-size: 12px; font-weight: 800;
  background: rgba(255,255,255,.07); flex-shrink: 0;
}
.learn-nav button.done .ln-num { background: var(--c4); color: #04241f; }
.learn-nav .ln-check { margin-left: auto; color: var(--c4); font-size: 13px; opacity: 0; }
.learn-nav button.done .ln-check { opacity: 1; }

.learn-content { min-width: 0; }
.module { display: none; animation: fade .4s ease; }
.module.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.module-card {
  background: linear-gradient(180deg, var(--surface), var(--bg-soft)); border: 1px solid var(--line);
  border-radius: var(--radius); padding: clamp(22px, 3vw, 36px); box-shadow: var(--shadow);
}
.module-tag { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; font-weight: 700; color: var(--c2); letter-spacing: .08em; text-transform: uppercase; }
.module h3 { font-size: clamp(22px, 3vw, 30px); margin: 12px 0 6px; }
.module .lede { color: var(--text-dim); margin: 0 0 22px; font-size: 15.5px; }
.module h4 { font-size: 17px; margin: 24px 0 10px; display: flex; align-items: center; gap: 9px; }
.module h4::before { content: ""; width: 8px; height: 8px; border-radius: 3px; background: var(--grad); }
.module p { color: var(--text-dim); margin: 8px 0; }
.module ul.tips { list-style: none; padding: 0; margin: 12px 0; display: grid; gap: 10px; }
.module ul.tips li { position: relative; padding: 12px 14px 12px 42px; background: rgba(255,255,255,.04); border: 1px solid var(--line); border-radius: 12px; color: var(--text); font-size: 14.5px; }
.module ul.tips li::before { content: "✓"; position: absolute; left: 13px; top: 11px; width: 20px; height: 20px; border-radius: 6px; background: rgba(43,212,196,.16); color: var(--c4); display: grid; place-items: center; font-size: 12px; font-weight: 800; }
.module .callout { border-left: 3px solid var(--c3); background: rgba(255,122,89,.08); padding: 14px 16px; border-radius: 0 12px 12px 0; color: var(--text); font-size: 14.5px; margin: 18px 0; }
.module .callout b { color: var(--c3); }

.module-foot { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-top: 26px; flex-wrap: wrap; border-top: 1px solid var(--line); padding-top: 20px; }
.module-foot .mf-info { color: var(--text-mute); font-size: 13px; }
.chk-btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 12px; border: 1px solid var(--c4); background: rgba(43,212,196,.12); color: var(--c4); font-weight: 700; cursor: pointer; transition: .2s; font-size: 14px; }
.chk-btn:hover { background: rgba(43,212,196,.22); }
.chk-btn.done { background: var(--c4); color: #04241f; border-color: var(--c4); }

/* ===================== 案例库 ===================== */
.case-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 20px; }
.case-card {
  position: relative; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; cursor: pointer; transition: .22s; overflow: hidden;
}
.case-card:hover { transform: translateY(-4px); border-color: var(--line-strong); box-shadow: var(--shadow); }
.case-badge { display: inline-flex; align-items: center; gap: 6px; font-size: 11.5px; font-weight: 700; padding: 5px 11px; border-radius: 999px; background: rgba(255,255,255,.06); color: var(--text-dim); margin-bottom: 14px; }
.case-card h3 { font-size: 18px; margin-bottom: 8px; }
.case-org { color: var(--c2); font-size: 13px; font-weight: 700; margin-bottom: 10px; }
.case-card p { color: var(--text-dim); font-size: 14px; margin: 0; }
.case-card .case-more { margin-top: 14px; color: var(--c4); font-size: 13px; font-weight: 700; }

.modal-mask { position: fixed; inset: 0; background: rgba(5,8,18,.7); backdrop-filter: blur(6px); z-index: 300; display: none; padding: 20px; }
.modal-mask.open { display: grid; place-items: center; animation: fade .25s; }
.modal { background: var(--surface); border: 1px solid var(--line-strong); border-radius: var(--radius); max-width: 640px; width: 100%; max-height: 86vh; overflow: auto; padding: 30px; box-shadow: var(--shadow); }
.modal .modal-badge { color: var(--c2); font-weight: 800; font-size: 13px; }
.modal h3 { font-size: 24px; margin: 8px 0 4px; }
.modal .modal-org { color: var(--text-mute); font-size: 14px; margin-bottom: 18px; }
.modal h4 { font-size: 15px; margin: 18px 0 8px; color: var(--c4); }
.modal p, .modal li { color: var(--text-dim); font-size: 14.5px; }
.modal ul { padding-left: 20px; margin: 8px 0; }
.modal-close { position: sticky; top: -10px; float: right; background: rgba(255,255,255,.06); border: 1px solid var(--line); color: var(--text); width: 34px; height: 34px; border-radius: 10px; cursor: pointer; font-size: 18px; }

/* ===================== 随堂测验 ===================== */
.quiz-wrap { display: grid; gap: 18px; }
.quiz-block { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.quiz-block-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 6px; flex-wrap: wrap; }
.quiz-block-head h3 { font-size: 19px; }
.quiz-score { font-size: 13px; font-weight: 800; padding: 6px 12px; border-radius: 999px; background: rgba(255,255,255,.06); color: var(--text-dim); }
.quiz-score.pass { background: rgba(43,212,196,.16); color: var(--c4); }
.quiz-score.fail { background: rgba(255,122,89,.16); color: var(--c3); }
.q-item { padding: 16px 0; border-top: 1px solid var(--line); }
.q-item:first-of-type { border-top: 0; }
.q-title { font-weight: 700; margin-bottom: 12px; font-size: 15px; }
.q-title .qtype { font-size: 11px; color: var(--text-mute); font-weight: 700; margin-left: 8px; }
.q-opts { display: grid; gap: 9px; }
.q-opt { display: flex; align-items: center; gap: 11px; padding: 11px 14px; border: 1px solid var(--line); border-radius: 11px; cursor: pointer; font-size: 14.5px; transition: .15s; background: rgba(255,255,255,.02); }
.q-opt:hover { border-color: var(--line-strong); background: rgba(255,255,255,.05); }
.q-opt input { accent-color: var(--c2); width: 16px; height: 16px; }
.q-opt.correct { border-color: var(--c4); background: rgba(43,212,196,.14); }
.q-opt.wrong { border-color: var(--c3); background: rgba(255,122,89,.12); }
.q-feedback { font-size: 13px; margin-top: 10px; color: var(--text-mute); display: none; }
.q-feedback.show { display: block; }
.q-feedback .ok { color: var(--c4); font-weight: 700; }
.q-feedback .no { color: var(--c3); font-weight: 700; }
.quiz-submit { margin-top: 16px; }
.quiz-result { margin-top: 14px; font-weight: 700; display: none; }
.quiz-result.show { display: block; }

/* ===================== 课堂讨论 ===================== */
.discuss-wrap { display: grid; grid-template-columns: 320px 1fr; gap: 26px; align-items: start; }
.discuss-form { position: sticky; top: calc(var(--nav-h) + 18px); background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.discuss-form h3 { font-size: 18px; margin-bottom: 4px; }
.discuss-form p { color: var(--text-mute); font-size: 13px; margin: 0 0 16px; }
.field { margin-bottom: 13px; }
.field label { display: block; font-size: 13px; color: var(--text-dim); font-weight: 700; margin-bottom: 6px; }
.field input, .field textarea, .field select {
  width: 100%; background: var(--bg-soft); border: 1px solid var(--line-strong); border-radius: 10px;
  color: var(--text); padding: 11px 13px; font-size: 14px; font-family: var(--font); resize: vertical;
}
.field input:focus, .field textarea:focus, .field select:focus { outline: none; border-color: var(--c2); }
.discuss-list { display: grid; gap: 14px; }
.post { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; }
.post-top { display: flex; align-items: center; gap: 11px; margin-bottom: 9px; }
.avatar { width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; font-weight: 800; color: #fff; font-size: 15px; flex-shrink: 0; }
.post-meta { line-height: 1.3; }
.post-meta .name { font-weight: 700; font-size: 14.5px; }
.post-meta .time { font-size: 12px; color: var(--text-mute); }
.post-tag { margin-left: auto; font-size: 11px; font-weight: 700; color: var(--c1); background: rgba(106,139,255,.14); padding: 4px 10px; border-radius: 999px; }
.post-body { color: var(--text); font-size: 14.5px; }
.post-actions { display: flex; gap: 16px; margin-top: 12px; }
.like-btn { display: inline-flex; align-items: center; gap: 7px; background: none; border: 0; color: var(--text-mute); cursor: pointer; font-size: 13px; font-weight: 700; padding: 0; }
.like-btn:hover { color: var(--c3); }
.like-btn.liked { color: var(--c3); }
.empty { color: var(--text-mute); text-align: center; padding: 40px 0; font-size: 14px; }

/* ===================== 作品展示 ===================== */
.works-wrap { display: grid; grid-template-columns: 320px 1fr; gap: 26px; align-items: start; }
.work-form { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.work-form h3 { font-size: 18px; margin-bottom: 4px; }
.work-form p { color: var(--text-mute); font-size: 13px; margin: 0 0 16px; }
.work-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 16px; align-content: start; }
.work-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; display: flex; flex-direction: column; }
.work-card .w-type { font-size: 11px; font-weight: 800; color: var(--c4); letter-spacing: .08em; text-transform: uppercase; }
.work-card h3 { font-size: 17px; margin: 8px 0 6px; }
.work-card .w-author { font-size: 13px; color: var(--text-mute); margin-bottom: 10px; }
.work-card .w-desc { color: var(--text-dim); font-size: 14px; flex: 1; }
.work-card .w-link { margin-top: 14px; color: var(--c1); font-weight: 700; font-size: 13.5px; }
.work-card.is-seed { border-color: color-mix(in srgb, var(--c4) 40%, var(--line)); }
.work-card .w-tag {
  align-self: flex-start; font-size: 10.5px; font-weight: 800; letter-spacing: .06em;
  color: #06222a; background: var(--c4); padding: 3px 9px; border-radius: 999px; margin-bottom: 8px;
}
.work-card .w-readmore { align-self: flex-start; margin-top: 6px; }
.work-card .w-content {
  margin-top: 12px; padding-top: 12px; border-top: 1px dashed var(--line);
  font-size: 14px; line-height: 1.85; color: var(--text-dim); max-height: 420px; overflow-y: auto;
}
.work-card .w-content p { margin: 0 0 11px; text-align: justify; }
.work-card .w-content p:last-child { margin-bottom: 0; }

/* ===================== 资源工具 ===================== */
.res-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 18px; }
.res-cat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.res-cat h3 { font-size: 17px; display: flex; align-items: center; gap: 10px; margin-bottom: 6px; }
.res-cat .res-ico { width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center; background: var(--grad-soft); font-size: 16px; }
.res-cat .res-sub { color: var(--text-mute); font-size: 13px; margin-bottom: 14px; }
.res-cat ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 9px; }
.res-cat li a { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 12px; border-radius: 10px; background: rgba(255,255,255,.03); border: 1px solid var(--line); font-size: 14px; transition: .15s; }
.res-cat li a:hover { background: rgba(255,255,255,.07); border-color: var(--line-strong); }
.res-cat li a .arrow { color: var(--text-mute); font-size: 13px; }

/* ===================== 页脚 ===================== */
.footer { border-top: 1px solid var(--line); background: var(--bg-soft); }
.footer-inner { max-width: var(--maxw); margin: 0 auto; padding: 40px clamp(16px, 4vw, 40px); display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; align-items: center; }
.footer-brand { display: flex; gap: 14px; align-items: flex-start; max-width: 460px; }
.footer-brand b { font-size: 15px; }
.footer-brand p { color: var(--text-mute); font-size: 13px; margin: 6px 0 0; }
.footer-meta { text-align: right; }
.footer-meta p { color: var(--text-mute); font-size: 13px; margin: 0 0 12px; }

/* ===================== 抽屉 ===================== */
.drawer-mask { position: fixed; inset: 0; background: rgba(5,8,18,.6); backdrop-filter: blur(4px); z-index: 250; display: none; }
.drawer-mask.open { display: block; }
.drawer { position: fixed; top: 0; right: 0; bottom: 0; width: min(380px, 90vw); background: var(--surface); border-left: 1px solid var(--line-strong); z-index: 260; transform: translateX(100%); transition: transform .3s ease; display: flex; flex-direction: column; }
.drawer.open { transform: none; }
.drawer-head { display: flex; align-items: center; justify-content: space-between; padding: 20px 22px; border-bottom: 1px solid var(--line); }
.drawer-head h3 { font-size: 18px; }
.drawer-close { background: none; border: 0; color: var(--text-dim); font-size: 26px; cursor: pointer; line-height: 1; }
.drawer-body { padding: 22px; overflow: auto; }
.d-progress-big { text-align: center; margin-bottom: 22px; }
.d-ring { width: 110px; height: 110px; border-radius: 50%; margin: 0 auto 12px; display: grid; place-items: center; background: conic-gradient(var(--c2) calc(var(--p,0)*1%), rgba(255,255,255,.08) 0); position: relative; }
.d-ring::before { content: ""; position: absolute; inset: 9px; border-radius: 50%; background: var(--surface); }
.d-ring span { position: relative; z-index: 1; font-size: 26px; font-weight: 900; }
.d-stat-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 10px; margin-bottom: 22px; }
.d-stat { background: rgba(255,255,255,.04); border: 1px solid var(--line); border-radius: 12px; padding: 14px 8px; text-align: center; }
.d-stat b { display: block; font-size: 22px; font-weight: 900; }
.d-stat span { font-size: 11px; color: var(--text-mute); }
.d-modules h4 { font-size: 14px; color: var(--text-dim); margin-bottom: 10px; }
.d-mod { display: flex; align-items: center; gap: 10px; padding: 10px 0; border-top: 1px solid var(--line); font-size: 14px; }
.d-mod .dot { width: 9px; height: 9px; border-radius: 50%; background: rgba(255,255,255,.18); flex-shrink: 0; }
.d-mod.done .dot { background: var(--c4); }
.d-mod .score { margin-left: auto; font-size: 12px; font-weight: 700; color: var(--text-mute); }

/* ===================== Toast ===================== */
.toast { position: fixed; bottom: 26px; left: 50%; transform: translateX(-50%) translateY(20px); background: var(--surface-2); border: 1px solid var(--line-strong); color: #fff; padding: 13px 22px; border-radius: 12px; font-size: 14px; font-weight: 600; box-shadow: var(--shadow); opacity: 0; pointer-events: none; transition: .3s; z-index: 400; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===================== 响应式 ===================== */
@media (max-width: 940px) {
  .learn-layout { grid-template-columns: 1fr; }
  .learn-nav { position: static; flex-direction: row; flex-wrap: wrap; gap: 8px; }
  .learn-nav button { width: auto; }
  .learn-nav .ln-check { display: none; }
  .discuss-wrap, .works-wrap { grid-template-columns: 1fr; }
  .discuss-form, .work-form { position: static; }
}
@media (max-width: 720px) {
  .nav-links { position: fixed; top: var(--nav-h); right: 0; width: 240px; height: calc(100vh - var(--nav-h)); background: var(--bg-soft); border-left: 1px solid var(--line); flex-direction: column; padding: 16px; gap: 4px; transform: translateX(100%); transition: transform .28s; }
  .nav-links.open { transform: none; }
  .menu-toggle { display: flex; }
  .hero-stats { gap: 10px; }
  .hero-stats .stat { min-width: 96px; padding: 12px 14px; }
  .footer-meta { text-align: left; }
}

/* 进场动画 */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; } html { scroll-behavior: auto; } }

/* ===================== 登录门 ===================== */
.login-gate { position: fixed; top: var(--nav-h); left: 0; right: 0; bottom: 0; z-index: 1000; display: grid; place-items: center; padding: 20px; background: radial-gradient(60% 60% at 50% 30%, rgba(106,139,255,.35), transparent 60%), radial-gradient(50% 50% at 80% 80%, rgba(160,107,255,.3), transparent 60%), rgba(5,8,18,.92); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.login-gate.hidden { display: none; }
.gate-tabs { display: flex; gap: 6px; background: rgba(255,255,255,.06); padding: 5px; border-radius: 12px; margin-bottom: 18px; }
.gate-tabs .gtab { flex: 1; border: 0; background: none; color: var(--text-mute); font-size: 14px; font-weight: 700; padding: 9px 0; border-radius: 9px; cursor: pointer; transition: .18s; }
.gate-tabs .gtab.active { background: var(--surface-2); color: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.3); }
.login-card h2 { font-size: 22px; margin: 0 0 4px; }
.login-sub { color: var(--text-mute); font-size: 13.5px; margin: 0 0 18px; }
.nav-entry { border: 1px solid var(--line-strong); background: rgba(255,255,255,.04); color: var(--text); font-size: 13.5px; font-weight: 700; padding: 8px 14px; border-radius: 10px; cursor: pointer; transition: .18s; }
.nav-entry:hover { border-color: var(--c1); color: #fff; }
.nav-entry-primary { background: var(--grad); border-color: transparent; color: #fff; }
.nav-entry-primary:hover { filter: brightness(1.08); color: #fff; }
.login-card { width: min(380px, 100%); background: var(--surface); border: 1px solid var(--line-strong); border-radius: 20px; padding: 34px 28px; text-align: center; box-shadow: var(--shadow); animation: pop .35s ease; }
@keyframes pop { from { opacity: 0; transform: translateY(16px) scale(.97); } to { opacity: 1; transform: none; } }
.login-card .brand-mark { margin: 0 auto 16px; }
.login-card h2 { font-size: 24px; }
.login-sub { color: var(--text-dim); font-size: 14px; margin: 8px 0 22px; }
.login-card .field { text-align: left; margin-bottom: 14px; }
.login-card .field label { display: block; font-size: 13px; color: var(--text-dim); font-weight: 700; margin-bottom: 6px; }
.login-card .field input { width: 100%; background: var(--bg-soft); border: 1px solid var(--line-strong); border-radius: 10px; color: var(--text); padding: 12px 14px; font-size: 15px; font-family: var(--font); }
.login-card .field input:focus { outline: none; border-color: var(--c2); }
.login-err { color: var(--c3); font-size: 13px; font-weight: 700; min-height: 18px; margin-bottom: 10px; text-align: left; }
.login-note { color: var(--text-mute); font-size: 12px; margin: 16px 0 0; line-height: 1.6; }

/* ===================== 用户徽章 ===================== */
.user-chip { display: none; align-items: center; gap: 8px; }
.user-chip.show { display: flex; }
.uc-name { font-size: 13px; font-weight: 700; color: var(--text); padding: 6px 10px; background: rgba(255,255,255,.05); border: 1px solid var(--line); border-radius: 999px; max-width: 130px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.uc-logout { background: none; border: 1px solid var(--line-strong); color: var(--text-dim); font-size: 12px; font-weight: 700; padding: 6px 10px; border-radius: 999px; cursor: pointer; transition: .2s; }
.uc-logout:hover { color: #fff; border-color: var(--c3); }

/* 心情点名浮层弹窗：z-index 高于登录门(1000)，免登录即可用 */
.rc-modal { position: fixed; inset: 0; z-index: 2100; display: flex; align-items: flex-start; justify-content: center; padding: calc(var(--nav-h) + 18px) 16px 24px; }
.rc-modal[hidden] { display: none; }
.rc-modal-mask { position: absolute; inset: 0; background: rgba(5,8,18,.78); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.rc-modal-card { position: relative; width: min(960px, 100%); max-height: calc(100vh - var(--nav-h) - 36px); overflow: auto; background: var(--bg); border: 1px solid var(--line-strong); border-radius: var(--radius); box-shadow: var(--shadow); padding: 22px clamp(18px,3vw,30px) 28px; animation: rcPop .25s ease; }
@keyframes rcPop { from { opacity: 0; transform: translateY(14px) scale(.98); } to { opacity: 1; transform: none; } }
.rc-modal-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.rc-modal-head .eyebrow { display: block; }
.rc-modal-head h2 { font-size: 22px; margin: 2px 0 0; }
.rc-modal-intro { color: var(--text-dim); font-size: 14px; margin: 10px 0 16px; }
.rc-close { flex: 0 0 auto; width: 38px; height: 38px; border-radius: 10px; border: 1px solid var(--line-strong); background: var(--surface); color: var(--text-dim); font-size: 22px; line-height: 1; cursor: pointer; transition: .2s; }
.rc-close:hover { color: #fff; border-color: var(--c3); }
body.rc-open { overflow: hidden; }
.gate-skip {
  margin-top: 14px; width: 100%; justify-content: center;
  background: rgba(255,255,255,.06); border: 1px dashed var(--line-strong); color: var(--text);
  font-size: 13px; font-weight: 700;
}
.gate-skip:hover { background: rgba(255,255,255,.12); }

/* ===================== 知识图谱 ===================== */
.graph-layout { display: grid; grid-template-columns: 1fr 300px; gap: 24px; align-items: stretch; }
.graph-canvas { background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; min-height: 540px; position: relative; }
.graph-canvas svg { width: 100%; height: 100%; display: block; cursor: grab; touch-action: none; }
.graph-canvas svg:active { cursor: grabbing; }
.graph-detail { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; min-height: 540px; overflow: auto; }
.g-hint { color: var(--text-mute); font-size: 14px; }
.g-cat { font-size: 12px; font-weight: 800; letter-spacing: .06em; text-transform: uppercase; }
.graph-detail h3 { font-size: 22px; margin: 8px 0 10px; }
.graph-detail p { color: var(--text-dim); font-size: 14.5px; margin: 0; }
.graph-detail h4 { font-size: 14px; color: var(--c4); margin: 18px 0 8px; }
.g-rels { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.g-rels li { font-size: 13.5px; color: var(--text); background: rgba(255,255,255,.03); border: 1px solid var(--line); border-radius: 10px; padding: 9px 12px; }
.g-rel { display: inline-block; font-size: 11px; font-weight: 800; color: var(--c2); background: rgba(160,107,255,.14); padding: 2px 8px; border-radius: 999px; margin-right: 8px; }
.graph-tabs { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.graph-tabs .gtab { font: inherit; font-size: 14px; font-weight: 700; color: var(--text-dim); background: var(--surface); border: 1px solid var(--line); border-radius: 999px; padding: 9px 20px; cursor: pointer; transition: all .18s; }
.graph-tabs .gtab:hover { border-color: var(--line-strong); color: #fff; transform: translateY(-1px); }
.graph-tabs .gtab.active { color: #fff; background: linear-gradient(135deg, var(--c1), var(--c4)); border-color: transparent; box-shadow: 0 6px 18px rgba(160,107,255,.28); }
.graph-legend { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-top: 22px; }
.graph-legend .lg { display: flex; align-items: center; gap: 7px; font-size: 13px; color: var(--text-dim); cursor: pointer; padding: 5px 11px; border-radius: 999px; border: 1px solid var(--line); user-select: none; }
.graph-legend .lg:hover { border-color: var(--line-strong); color: #fff; }
.graph-legend .dot { width: 12px; height: 12px; border-radius: 50%; }
.node circle { stroke: rgba(255,255,255,.55); stroke-width: 1.5; cursor: pointer; transition: opacity .2s; filter: drop-shadow(0 4px 6px rgba(0,0,0,.35)); }
.node text { fill: #fff; font-size: 12px; font-weight: 700; pointer-events: none; text-anchor: middle; paint-order: stroke; stroke: rgba(0,0,0,.55); stroke-width: 3px; stroke-linejoin: round; }
.link { stroke: rgba(255,255,255,.14); stroke-width: 1.4; transition: opacity .2s; }
@media (max-width: 860px) {
  .graph-layout { grid-template-columns: 1fr; }
  .graph-canvas, .graph-detail { min-height: 420px; }
}

/* ===================== 课程切换器 ===================== */
.course-switch { position: relative; }
.cs-btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 7px 13px; border-radius: 999px;
  background: rgba(255,255,255,.04); border: 1px solid var(--line-strong); color: var(--text);
  font-size: 13px; font-weight: 700; cursor: pointer; transition: .2s; white-space: nowrap;
}
.cs-btn:hover { border-color: var(--c2); color: #fff; }
.cs-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--c2); flex-shrink: 0; }
.cs-arrow { color: var(--text-mute); font-size: 11px; }
.cs-menu {
  position: absolute; top: calc(100% + 10px); right: 0; min-width: 248px; z-index: 120;
  background: var(--surface); border: 1px solid var(--line-strong); border-radius: 14px;
  padding: 8px; box-shadow: var(--shadow); display: none; animation: pop .18s ease;
}
.cs-menu.open { display: block; }
.cs-item {
  display: flex; align-items: center; gap: 11px; width: 100%; text-align: left; padding: 11px 12px;
  border-radius: 10px; background: none; border: 0; color: var(--text-dim); cursor: pointer; transition: .15s;
}
.cs-item:hover { background: rgba(255,255,255,.05); color: #fff; }
.cs-item .cs-dot { width: 11px; height: 11px; }
.cs-item.active { background: rgba(255,255,255,.07); color: #fff; }
.cs-item .cs-meta { display: flex; flex-direction: column; line-height: 1.25; }
.cs-item .cs-name { font-size: 14px; font-weight: 700; }
.cs-item .cs-aud { font-size: 11.5px; color: var(--text-mute); }
.cs-item .cs-check { margin-left: auto; color: var(--c4); font-weight: 800; opacity: 0; }
.cs-item.active .cs-check { opacity: 1; }

/* ===================== 课程中心 ===================== */
.course-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 22px; }
.course-card {
  --accent: #a06bff;
  position: relative; text-align: left; background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px 24px; cursor: pointer; transition: .22s; overflow: hidden;
  display: flex; flex-direction: column; gap: 10px;
}
.course-card::before {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 4px; background: var(--accent); opacity: .9;
}
.course-card:hover { transform: translateY(-5px); border-color: var(--accent); box-shadow: var(--shadow); }
.course-card.active { border-color: var(--accent); background: linear-gradient(180deg, color-mix(in srgb, var(--accent) 9%, var(--surface)), var(--surface)); }
.cc-audience { font-size: 12px; font-weight: 700; color: var(--accent); letter-spacing: .04em; }
.course-card h3 { font-size: 22px; margin: 2px 0; color: var(--text); }
.cc-tag { color: var(--text-dim); font-size: 14px; margin: 0; flex: 1; }
.cc-meta { font-size: 12.5px; color: var(--text-mute); font-weight: 600; margin-top: 4px; }
.cc-enter {
  display: inline-flex; align-items: center; gap: 6px; align-self: flex-start; margin-top: 6px;
  font-size: 13px; font-weight: 800; color: var(--accent);
  padding: 8px 14px; border-radius: 10px; border: 1px solid color-mix(in srgb, var(--accent) 45%, transparent);
  background: color-mix(in srgb, var(--accent) 12%, transparent); transition: .2s;
}
.course-card:hover .cc-enter { gap: 10px; }
.cc-ribbon { position: absolute; top: 0; right: 0; font-size: 11.5px; font-weight: 800; padding: 6px 12px; border-bottom-left-radius: 12px; background: rgba(255,255,255,.08); color: var(--text-mute); letter-spacing: .03em; }
.cc-ribbon.on { background: color-mix(in srgb, var(--accent) 22%, transparent); color: var(--accent); }
.cc-actions { display: flex; align-items: center; gap: 14px; margin-top: 8px; }
.cc-enroll { align-self: flex-start; }
.cc-drop { background: none; border: 0; color: var(--text-mute); font-size: 12.5px; font-weight: 600; cursor: pointer; text-decoration: underline; text-underline-offset: 3px; }
.cc-drop:hover { color: #ff8a8a; }
.enroll-summary { text-align: center; margin-top: 26px; color: var(--text-mute); font-size: 13.5px; font-weight: 600; }
.cs-item.cs-more { color: var(--c1); }
.cs-item.cs-more .cs-name { color: var(--c1); }

/* ===================== 选课门禁覆盖层 ===================== */
#mainContent { position: relative; }
.enroll-gate { position: absolute; inset: 0; z-index: 40; background: rgba(10,12,22,.82); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.enroll-gate[hidden] { display: none; }
.eg-card { position: sticky; top: 38vh; width: min(440px, 86vw); margin: 0 auto; text-align: center; padding: 36px 30px; background: var(--surface); border: 1px solid var(--line-strong); border-radius: 20px; box-shadow: 0 24px 70px rgba(0,0,0,.45); }
.eg-icon { font-size: 44px; line-height: 1; }
.eg-card h3 { margin: 14px 0 8px; font-size: 21px; }
.eg-card p { color: var(--text-mute); margin: 0 0 20px; font-size: 14.5px; line-height: 1.6; }

@media (max-width: 720px) {
  .cs-btn #csName { max-width: 84px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
}

/* ===================== 课件展示 ===================== */
.ppt-wrap { display: flex; flex-direction: column; gap: 18px; }
.ppt-toolbar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.ppt-toolbar .spacer { flex: 1; }
.ppt-count { font-size: 13px; color: var(--text-mute); font-weight: 600; }

/* 导入幻灯片入口（下拉菜单） */
.import-entry { position: relative; display: inline-flex; }
.import-menu {
  position: absolute; top: calc(100% + 8px); left: 0; z-index: 60;
  min-width: 220px; padding: 6px; display: flex; flex-direction: column; gap: 2px;
  background: var(--surface); border: 1px solid var(--line-strong); border-radius: 14px;
  box-shadow: 0 18px 40px rgba(0, 0, 0, .45);
}
.import-menu[hidden] { display: none; }
.import-menu button {
  text-align: left; border: 0; background: transparent; color: var(--text);
  padding: 10px 12px; border-radius: 9px; cursor: pointer; font-size: 13px; transition: background .15s; white-space: nowrap;
}
.import-menu button:hover { background: var(--surface-2); }
.import-menu .im-head { padding: 6px 12px 2px; font-size: 11px; font-weight: 700; letter-spacing: .06em; color: var(--text-mute); cursor: default; }
.import-menu .im-head:hover { background: transparent; }
.ppt-layout { display: grid; grid-template-columns: 260px 1fr; gap: 20px; align-items: start; }
.ppt-list { display: flex; flex-direction: column; gap: 10px; max-height: 560px; overflow-y: auto; padding-right: 6px; }
.ppt-thumb {
  position: relative; border-radius: 12px; padding: 16px 14px; min-height: 78px; cursor: pointer;
  border: 2px solid transparent; color: #fff; transition: .16s; overflow: hidden;
}
.ppt-thumb:hover { border-color: rgba(255,255,255,.25); }
.ppt-thumb.active { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 25%, transparent); }
.pt-no { position: absolute; top: 8px; right: 10px; font-size: 12px; font-weight: 800; opacity: .8; z-index: 1; }
.pt-title { position: relative; font-size: 14px; font-weight: 700; line-height: 1.35; text-shadow: 0 1px 3px rgba(0,0,0,.4); z-index: 1; }
.pt-img { position: absolute; bottom: 8px; left: 10px; font-size: 13px; opacity: .85; z-index: 1; }
.pt-bg {
  position: absolute; inset: 0; z-index: 0; border-radius: 12px;
  background-size: cover; background-position: center;
}
.pt-bg::after {
  content: ""; position: absolute; inset: 0; border-radius: 12px;
  background: linear-gradient(180deg, rgba(0,0,0,.52) 0%, rgba(0,0,0,.08) 42%, rgba(0,0,0,.48) 100%);
}
.ppt-editor {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; display: flex; flex-direction: column; gap: 14px;
}
.ed-head { display: flex; align-items: center; justify-content: space-between; font-weight: 800; color: var(--text); }
.ed-actions { display: flex; gap: 6px; }
.icon-btn {
  width: 34px; height: 32px; border-radius: 8px; border: 1px solid var(--line); background: var(--surface-2);
  color: var(--text-dim); cursor: pointer; font-size: 15px; transition: .15s;
}
.icon-btn:hover:not(:disabled) { color: #fff; border-color: var(--accent); }
.icon-btn:disabled { opacity: .35; cursor: not-allowed; }
.icon-btn.danger:hover:not(:disabled) { color: #fff; border-color: var(--c3); background: color-mix(in srgb, var(--c3) 18%, transparent); }
.ed-row { display: flex; gap: 16px; flex-wrap: wrap; }
.ed-row > div { display: flex; flex-direction: column; gap: 6px; }
.ed-row > div:first-child { width: 140px; }
.ed-img-col { flex: 1; }
.ed-img-row { display: flex; gap: 8px; align-items: center; }
.ed-preview-img { border-radius: 10px; overflow: hidden; border: 1px solid var(--line); background: #000; }
.ed-preview-img img { display: block; max-width: 100%; max-height: 220px; margin: 0 auto; }
.ed-live { font-size: 12.5px; color: var(--text-mute); background: rgba(255,255,255,.04); border-radius: 8px; padding: 9px 12px; }
input[type="color"] { width: 100%; height: 38px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface-2); cursor: pointer; padding: 3px; }

/* 放映遮罩（全屏） */
.ppt-presenter {
  position: fixed; inset: 0; z-index: 1000; display: none; background: #000;
  flex-direction: column; cursor: default;
}
.ppt-presenter.open { display: flex; }
.pp-stage { flex: 1; display: flex; align-items: center; justify-content: center; overflow: hidden; padding: 4vh 6vw; }
.pp-slide { width: 100%; max-width: 1100px; color: #fff; display: flex; flex-direction: column; justify-content: center; animation: ppIn .35s ease; }
@keyframes ppIn { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.pp-title { font-size: clamp(26px, 4vw, 52px); line-height: 1.18; margin-bottom: 26px; font-weight: 800; }
.pp-body { list-style: none; display: flex; flex-direction: column; gap: 18px; font-size: clamp(18px, 2.4vw, 32px); line-height: 1.4; }
.pp-body li { padding-left: 30px; position: relative; }
.pp-body li::before { content: "▍"; position: absolute; left: 0; color: var(--accent); }
.pp-title-slide { text-align: center; align-items: center; }
.pp-title-slide h1 { font-size: clamp(34px, 6vw, 84px); font-weight: 900; line-height: 1.1; }
.pp-title-slide .pp-sub { font-size: clamp(18px, 2.6vw, 34px); color: rgba(255,255,255,.78); margin-top: 22px; }
.pp-image { align-items: center; }
.pp-image img { max-width: 100%; max-height: 72vh; border-radius: 12px; box-shadow: 0 20px 60px rgba(0,0,0,.5); }
.pp-full { max-width: 100%; width: 100%; height: 100%; padding: 0; align-items: center; justify-content: center; }
.pp-full img { max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; box-shadow: none; }
.pp-bar {
  display: flex; align-items: center; gap: 12px; padding: 12px 18px; background: rgba(0,0,0,.55);
  backdrop-filter: blur(8px); border-top: 1px solid rgba(255,255,255,.08);
}
.pp-btn {
  border: 1px solid rgba(255,255,255,.2); background: rgba(255,255,255,.07); color: #fff;
  padding: 9px 16px; border-radius: 9px; cursor: pointer; font-size: 14px; font-weight: 700; transition: .15s;
}
.pp-btn:hover { background: rgba(255,255,255,.16); }
.pp-btn.pp-exit { margin-left: auto; background: rgba(229,86,122,.22); border-color: rgba(229,86,122,.5); }
.pp-count { color: rgba(255,255,255,.8); font-weight: 700; font-size: 14px; min-width: 70px; text-align: center; }

@media (max-width: 860px) {
  .ppt-layout { grid-template-columns: 1fr; }
  .ppt-list { flex-direction: row; max-height: none; overflow-x: auto; }
  .ppt-thumb { min-width: 180px; }
}

/* ===================== 讲座（教师专属 / 口令解锁） ===================== */
.lecture-lock {
  display: inline-flex; align-items: center; gap: 5px; padding: 7px 12px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface-2); color: var(--text-dim);
  font-size: 13px; font-weight: 700; cursor: pointer; transition: .15s; white-space: nowrap;
}
.lecture-lock:hover { color: #fff; border-color: var(--accent); }
body.lecture-unlocked .lecture-lock { color: #fff; border-color: var(--accent); background: color-mix(in srgb, var(--accent) 15%, transparent); }
.lecture-locked {
  display: flex; flex-direction: column; align-items: center; gap: 12px; text-align: center;
  padding: 64px 20px; border: 1px dashed var(--line); border-radius: var(--radius); background: var(--surface);
}
.lecture-locked .ll-icon { font-size: 46px; }
.lecture-locked h3 { margin: 0; color: var(--text); }
.lecture-locked p { color: var(--text-dim); max-width: 480px; margin: 0; }

/* 讲座：多讲座集合 */
.lec-collection {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px; margin-bottom: 18px;
}
.lec-collection-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; flex-wrap: wrap; }
.lec-collection-head h3 { margin: 0; font-size: 18px; color: var(--text); }
.lec-collection-head .muted { color: var(--text-dim); font-weight: 600; font-size: 14px; }
.lec-col-actions { display: flex; align-items: center; gap: 10px; }
.lec-cat-sel {
  background: var(--surface-2); color: var(--text); border: 1px solid var(--line);
  border-radius: 9px; padding: 8px 10px; font-size: 13px; font-weight: 600; cursor: pointer;
}
.lec-deck-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.lec-deck-card {
  position: relative; border: 2px solid transparent; border-radius: 14px; padding: 14px 14px 12px;
  background: linear-gradient(160deg, rgba(255,255,255,.06), rgba(255,255,255,.02));
  cursor: pointer; transition: .16s; display: flex; flex-direction: column; gap: 10px; min-height: 92px;
}
.lec-deck-card:hover { border-color: rgba(255,255,255,.22); transform: translateY(-2px); }
.lec-deck-card.active { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent); }
.lec-dc-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 8px; }
.lec-dc-title { font-size: 15px; font-weight: 800; color: #fff; line-height: 1.35; word-break: break-word; }
.lec-dc-del {
  flex: none; width: 22px; height: 22px; border-radius: 6px; border: 1px solid var(--line);
  background: rgba(255,255,255,.05); color: var(--text-dim); font-size: 12px; cursor: pointer; transition: .15s; line-height: 1;
}
.lec-dc-del:hover { color: #fff; background: rgba(229,86,122,.25); border-color: rgba(229,86,122,.5); }
.lec-dc-meta { display: flex; align-items: center; gap: 8px; }
.lec-cat-badge {
  font-size: 11px; font-weight: 700; padding: 3px 9px; border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 20%, transparent); color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, transparent);
}
.lec-deck-edit { display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin-bottom: 16px; }
.lec-deck-edit .field { margin: 0; flex: 1; min-width: 200px; }
.lec-deck-edit .lec-de-cat { max-width: 240px; }
.lec-del-deck { white-space: nowrap; margin-left: auto; }
.lec-workspace .ppt-list { max-height: 560px; }

/* ===================== 心情点名 ===================== */
.rollcall-wrap { display: grid; grid-template-columns: minmax(300px, 380px) 1fr; gap: 26px; align-items: start; }
.rc-panel, .rc-stage { display: flex; flex-direction: column; gap: 18px; }
.rc-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.rc-card h3 { font-size: 17px; margin-bottom: 4px; display: flex; align-items: center; gap: 10px; }
.rc-card .rc-sub { color: var(--text-mute); font-size: 13px; margin: 0 0 16px; }
.rc-card .field { margin-bottom: 0; }

.rc-mood-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.rc-mood-chip {
  background: rgba(255,255,255,.04); border: 1px solid var(--line); color: var(--text-dim);
  border-radius: 999px; padding: 7px 13px; font-size: 13px; font-weight: 600; cursor: pointer; transition: .15s;
}
.rc-mood-chip:hover { background: rgba(255,255,255,.09); color: #fff; border-color: var(--line-strong); }
.rc-mood-chips + .field textarea { min-height: 76px; }

.rc-roll-btn { width: 100%; justify-content: center; padding: 15px; font-size: 16px; margin-top: 14px; }

.rc-add-row { display: flex; gap: 10px; }
.rc-add-row .field { flex: 1; }
.rc-batch-hint { color: var(--text-mute); font-size: 12px; margin: 10px 0 0; }
.rc-textarea { width: 100%; background: var(--bg-soft); border: 1px solid var(--line-strong); border-radius: 10px; color: var(--text); padding: 11px 13px; font-size: 14px; font-family: var(--font); resize: vertical; min-height: 70px; }
.rc-textarea:focus { outline: none; border-color: var(--c2); }
.rc-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.rc-chips:empty::after { content: "名单为空，先添加几位同学吧"; color: var(--text-mute); font-size: 13px; }
.rc-chip { display: inline-flex; align-items: center; gap: 9px; background: rgba(255,255,255,.04); border: 1px solid var(--line); border-radius: 999px; padding: 6px 8px 6px 14px; font-size: 14px; }
.rc-chip.zero { border-color: rgba(43,212,196,.4); }
.rc-chip.zero .rc-chip-dot { background: var(--c4); }
.rc-chip-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--text-mute); }
.rc-chip button { width: 20px; height: 20px; border-radius: 50%; border: 1px solid var(--line); background: rgba(255,255,255,.06); color: var(--text-dim); cursor: pointer; font-size: 11px; line-height: 1; transition: .15s; }
.rc-chip button:hover { color: #fff; background: rgba(229,86,122,.25); border-color: rgba(229,86,122,.5); }

.rc-result { text-align: center; padding: 8px 0 2px; }
.rc-result-name { font-size: clamp(40px, 8vw, 64px); font-weight: 900; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; line-height: 1.1; min-height: 64px; display: flex; align-items: center; justify-content: center; }
.rc-result-name.landed { animation: rcPop .5s cubic-bezier(.2,1.4,.4,1); }
@keyframes rcPop { 0% { transform: scale(.6); opacity: 0; } 60% { transform: scale(1.12); } 100% { transform: scale(1); opacity: 1; } }
.rc-badge { display: inline-block; font-size: 13px; font-weight: 800; padding: 5px 14px; border-radius: 999px; background: var(--grad-soft); color: #fff; border: 1px solid var(--line-strong); }
.rc-tagline { color: var(--text-dim); font-size: 14.5px; margin: 14px auto 0; max-width: 440px; }
.rc-mood-echo { color: var(--text-mute); font-size: 13px; margin: 8px 0 0; }

.rc-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 16px; }
.rc-stat { background: rgba(255,255,255,.03); border: 1px solid var(--line); border-radius: 12px; padding: 14px 8px; text-align: center; }
.rc-stat b { display: block; font-size: 24px; font-weight: 900; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; line-height: 1.1; }
.rc-stat span { font-size: 12px; color: var(--text-mute); }

.rc-history { display: grid; gap: 10px; max-height: 340px; overflow: auto; }
.rc-hist { display: flex; align-items: center; gap: 12px; background: rgba(255,255,255,.03); border: 1px solid var(--line); border-radius: 12px; padding: 11px 14px; }
.rc-hist .rc-h-name { font-weight: 800; font-size: 15px; }
.rc-hist .rc-h-mood { color: var(--text-dim); font-size: 12.5px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 160px; }
.rc-hist .rc-h-time { color: var(--text-mute); font-size: 12px; }
.rc-hist .rc-h-mode { margin-left: auto; flex: none; font-size: 11px; font-weight: 700; color: var(--c1); background: rgba(106,139,255,.14); padding: 3px 9px; border-radius: 999px; }

.rc-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 6px; }
@media (max-width: 860px) { .rollcall-wrap { grid-template-columns: 1fr; } }

/* 心情签到 / 心情墙 / 词云 */
.rc-checkin { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.rc-field-row { margin-bottom: 14px; }
.rc-name-input { width: 100%; background: var(--bg-soft); border: 1px solid var(--line-strong); border-radius: 10px; color: var(--text); padding: 11px 13px; font-size: 14px; font-family: var(--font); }
.rc-name-input:focus { outline: none; border-color: var(--c2); }
.rc-checkin-actions { display: flex; align-items: center; gap: 14px; margin-top: 14px; flex-wrap: wrap; }
.rc-submit { justify-content: center; padding: 14px 26px; font-size: 16px; }
.rc-count { color: var(--text-mute); font-size: 13px; }
.rc-section { margin-top: 22px; }
.rc-section-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 12px; flex-wrap: wrap; }
.rc-section-head h3 { font-size: 17px; }
.rc-section-tools { display: flex; gap: 8px; }
.rc-section-sub { color: var(--text-mute); font-size: 12.5px; }
.rc-wall { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; max-height: 360px; overflow: auto; padding-right: 4px; }
.rc-wall-card { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 14px 16px; animation: rcPop .25s ease; }
.rc-wall-top { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-bottom: 6px; }
.rc-wall-top b { font-size: 15px; color: #fff; }
.rc-wall-top span { font-size: 11.5px; color: var(--text-mute); flex: none; }
.rc-wall-card p { margin: 0; color: var(--text-dim); font-size: 14px; line-height: 1.5; word-break: break-word; }
.rc-cloud-wrap { position: relative; background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px; }
#rcCloud { width: 100%; height: auto; display: block; }
.rc-cloud-empty { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; text-align: center; padding: 20px; color: var(--text-mute); font-size: 14px; }
.rc-cloud-empty[hidden] { display: none; }