/* ===== 基础重置与变量 ===== */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#1a4480;
  --primary-dark:#0f2d57;
  --primary-light:#e8f0fc;
  --primary-tint:#f0f5ff;
  --bg:#f7f8fa;
  --surface:#ffffff;
  --surface-2:#fafbfc;
  --border:#e2e6ec;
  --border-light:#eef0f3;
  --text:#16202e;
  --text-2:#4a5568;
  --text-3:#8892a6;
  --radius:14px;
  --radius-sm:10px;
  --radius-xs:6px;
  --shadow:0 1px 3px rgba(16,32,64,.05),0 1px 2px rgba(16,32,64,.03);
  --shadow-md:0 6px 24px rgba(16,32,64,.08);
  --shadow-lg:0 16px 48px rgba(16,32,64,.14);
  --max-w:1280px;
  --serif:'Microsoft YaHei','微软雅黑','PingFang SC','Helvetica Neue',Arial,sans-serif;
  --sans:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;
  --ease-out:cubic-bezier(0.16,1,0.3,1);
  --ease-out-quart:cubic-bezier(0.25,1,0.5,1);
}
body{font-family:var(--sans);background:linear-gradient(180deg,rgba(8,16,32,0.3) 0%,rgba(8,16,32,0.45) 100%),url('../images/hero-bg.png') center/cover fixed;color:var(--text);line-height:1.65;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
img,svg{display:block;max-width:100%}

/* ===== 顶部导航 ===== */
.header{background:rgba(10,18,34,0.82);backdrop-filter:saturate(180%) blur(12px);-webkit-backdrop-filter:saturate(180%) blur(12px);border-bottom:1px solid rgba(255,255,255,0.1);position:sticky;top:0;z-index:100;box-shadow:0 4px 20px rgba(0,0,0,0.2)}
.header-inner{max-width:var(--max-w);margin:0 auto;padding:0 32px;height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.school-badge{display:flex;align-items:center;flex-shrink:0;height:44px}
.school-logo{height:44px;width:auto;object-fit:contain;border-radius:6px;transition:opacity .15s}
.school-badge:hover .school-logo{opacity:.85}
.logo{display:flex;align-items:center;gap:12px}
.logo-mark{color:#7ab5ff;display:flex}
.logo-text h1{font-family:var(--serif);font-size:18px;font-weight:700;letter-spacing:-.3px;color:#fff}
.logo-text p{font-size:12px;color:rgba(255,255,255,0.6)}
.header-actions{display:flex;align-items:center;gap:12px}
.search-box{position:relative;display:flex;align-items:center}
.search-icon{position:absolute;left:12px;color:rgba(255,255,255,0.5);pointer-events:none}
.search-box input{width:280px;padding:9px 14px 9px 36px;border:1px solid rgba(255,255,255,0.15);border-radius:var(--radius-sm);font-size:14px;outline:none;transition:all .2s;background:rgba(0,0,0,0.25);color:#fff}
.search-box input::placeholder{color:rgba(255,255,255,0.5)}
.search-box input:focus{border-color:rgba(122,181,255,0.8);box-shadow:0 0 0 3px rgba(122,181,255,0.25);background:rgba(0,0,0,0.4)}
.demo-badge{font-size:12px;font-weight:600;color:#7ab5ff;background:rgba(122,181,255,0.12);padding:4px 10px;border-radius:6px;white-space:nowrap;cursor:pointer;transition:all .15s}
.demo-badge:hover{background:rgba(122,181,255,0.2)}
.author-btn{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:600;color:#7ab5ff;background:rgba(122,181,255,0.12);padding:6px 12px;border-radius:6px;white-space:nowrap;cursor:pointer;transition:all .15s;border:none;outline:none}
.author-btn:hover{background:rgba(122,181,255,0.2);color:#9ccfff}
.feedback-btn{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:600;color:#ffc060;background:rgba(255,192,96,0.12);padding:6px 12px;border-radius:6px;white-space:nowrap;cursor:pointer;transition:all .15s;border:none;outline:none}
.feedback-btn:hover{background:rgba(255,192,96,0.2);color:#ffd680}
.admin-link{display:flex;align-items:center;justify-content:center;width:32px;height:32px;border-radius:var(--radius-sm);color:rgba(255,255,255,0.7);transition:all .15s;cursor:pointer}
.admin-link:hover{background:rgba(255,255,255,0.1);color:#7ab5ff}
.fav-link{display:flex;align-items:center;justify-content:center;width:32px;height:32px;border-radius:var(--radius-sm);color:rgba(255,255,255,0.7);transition:all .15s;cursor:pointer;position:relative;background:none;border:none}
.fav-link:hover{background:rgba(255,255,255,0.1);color:#ff6b8a}
.fav-link svg{transition:color .15s}
.fav-count{position:absolute;top:-2px;right:-4px;background:#ff6b8a;color:#fff;font-size:10px;font-weight:700;min-width:16px;height:16px;border-radius:8px;display:flex;align-items:center;justify-content:center;padding:0 4px}

/* ===== Hero 大图（全屏视口） ===== */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;background:linear-gradient(90deg,rgba(8,16,32,0.78) 0%,rgba(8,16,32,0.35) 45%,rgba(8,16,32,0.15) 100%);color:#fff;overflow:hidden}
.hero-bg{position:absolute;inset:0;color:#fff;pointer-events:none}
.hero-pattern{width:100%;height:100%;object-fit:cover}
.hero-content{position:relative;max-width:var(--max-w);margin:0 auto;padding:120px 32px 100px;width:100%;z-index:2}
.hero-tag{display:inline-block;font-size:11px;font-weight:600;letter-spacing:2.5px;color:rgba(255,255,255,0.72);margin-bottom:28px;padding:6px 16px;border:1px solid rgba(255,255,255,0.2);border-radius:20px;text-transform:uppercase;animation:heroFadeIn .8s var(--ease-out) both;background:rgba(0,0,0,0.12);backdrop-filter:blur(4px)}
.hero-title{font-family:var(--serif);font-size:clamp(32px,5.5vw,56px);font-weight:900;line-height:1.2;letter-spacing:-1px;margin-bottom:20px;animation:heroFadeIn .8s var(--ease-out) .1s both;text-shadow:0 2px 12px rgba(0,0,0,0.35)}
.hero-title-accent{color:#9ccfff;font-weight:700}
.hero-subtitle{font-size:clamp(14px,1.8vw,17px);color:rgba(255,255,255,0.82);max-width:600px;margin-bottom:36px;line-height:1.7;animation:heroFadeIn .8s var(--ease-out) .2s both;text-shadow:0 1px 8px rgba(0,0,0,0.35)}
.hero-stats{display:flex;gap:40px;margin-bottom:40px;flex-wrap:wrap;animation:heroFadeIn .8s var(--ease-out) .3s both}
.hero-stat{display:flex;flex-direction:column;gap:2px}
.hero-stat .num{font-family:var(--serif);font-size:32px;font-weight:700;line-height:1;text-shadow:0 2px 8px rgba(0,0,0,0.3)}
.hero-stat .label{font-size:13px;color:rgba(255,255,255,0.7);letter-spacing:.5px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;animation:heroFadeIn .8s var(--ease-out) .4s both}
.hero-btn{padding:12px 28px;border-radius:var(--radius-sm);font-size:15px;font-weight:600;cursor:pointer;transition:all .2s var(--ease-out);display:inline-flex;align-items:center;gap:8px;border:none}
.hero-btn-primary{background:#7ab5f0;color:#0a1525}
.hero-btn-primary:hover{background:#9ac8f5;transform:translateY(-2px);box-shadow:0 8px 24px rgba(122,181,240,0.3)}
.hero-btn-ghost{background:transparent;color:#fff;border:1px solid rgba(255,255,255,0.2)}
.hero-btn-ghost:hover{background:rgba(255,255,255,0.08);border-color:rgba(255,255,255,0.35)}
.hero-scroll-indicator{position:absolute;bottom:32px;left:50%;transform:translateX(-50%);display:flex;flex-direction:column;align-items:center;gap:8px;color:rgba(255,255,255,0.4);font-size:12px;cursor:pointer;transition:color .2s;animation:heroFadeIn .8s var(--ease-out) .6s both;z-index:2}
.hero-scroll-indicator:hover{color:rgba(255,255,255,0.7)}
.hero-scroll-indicator svg{animation:scrollBounce 2s ease-in-out infinite}

@keyframes heroFadeIn{from{opacity:0;transform:translateY(24px)}to{opacity:1;transform:translateY(0)}}
@keyframes scrollBounce{0%,100%{transform:translateY(0)}50%{transform:translateY(6px)}}

/* ===== 滚动渐入动画 ===== */
.reveal{opacity:0;transform:translateY(32px);transition:opacity .7s var(--ease-out),transform .7s var(--ease-out)}
.reveal.revealed{opacity:1;transform:translateY(0)}

/* ===== 通用 Section ===== */
.section{max-width:var(--max-w);margin:0 auto;padding:72px 32px 16px;background:transparent}
.section-books{padding-top:80px}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;margin-bottom:36px}
.section-title{font-family:var(--serif);font-size:clamp(22px,3vw,28px);font-weight:700;letter-spacing:-.3px;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,0.35)}
.section-sub{display:block;font-size:13px;color:rgba(255,255,255,0.75);margin-top:6px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
.link-btn{background:none;border:none;color:#b8d4ff;font-size:14px;font-weight:500;cursor:pointer;padding:6px 12px;border-radius:6px;transition:background .15s}
.link-btn:hover{background:rgba(255,255,255,0.12);color:#fff}

/* ===== 教材分区卡片 ===== */
.book-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.book-card{background:rgba(22,32,52,0.72);border:1px solid rgba(255,255,255,0.12);border-radius:var(--radius);cursor:pointer;transition:all .3s var(--ease-out);overflow:hidden;display:flex;flex-direction:column;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);box-shadow:0 8px 32px rgba(0,0,0,0.25)}
.book-card:hover{box-shadow:0 16px 48px rgba(0,0,0,0.35);transform:translateY(-4px);border-color:var(--book-color)}
.book-card-visual{width:100%;aspect-ratio:16/9;position:relative;overflow:hidden;background:var(--book-tint)}
.book-card-cover{width:100%;height:100%;object-fit:cover;object-position:center;transition:transform .4s var(--ease-out)}
.book-card:hover .book-card-cover{transform:scale(1.06)}
.book-card-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(0,0,0,0.05) 0%,transparent 40%,rgba(0,0,0,0.45) 100%);pointer-events:none;transition:opacity .3s}
.book-card-visual::after{content:'';position:absolute;inset:0;background:linear-gradient(180deg,transparent 60%,rgba(0,0,0,0.12) 100%);pointer-events:none}
.book-card-body{padding:20px 22px 22px;flex:1;display:flex;flex-direction:column}
.book-card-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:6px}
.book-card-name{font-family:var(--serif);font-size:17px;font-weight:700;color:#fff}
.book-card-count{font-size:12px;color:rgba(255,255,255,0.75);background:rgba(255,255,255,0.12);padding:3px 11px;border-radius:12px;white-space:nowrap}
.book-card-sub{font-size:13px;color:rgba(255,255,255,0.7);margin-bottom:14px}
.book-chapters{display:flex;flex-wrap:wrap;gap:6px;margin-top:auto}
.book-chip{font-size:12px;color:rgba(255,255,255,0.8);background:rgba(255,255,255,0.1);padding:4px 10px;border-radius:6px;transition:all .15s}
.book-card:hover .book-chip{background:var(--book-color);color:#fff}

/* ===== 筛选栏 ===== */
.filter-bar{display:flex;align-items:center;gap:12px;margin-bottom:20px;flex-wrap:wrap}
.filter-tabs{display:flex;gap:2px;background:rgba(22,32,52,0.72);padding:3px;border-radius:var(--radius-sm);border:1px solid rgba(255,255,255,0.12);backdrop-filter:blur(12px)}
.filter-tab{padding:7px 16px;border:none;background:transparent;border-radius:6px;font-size:13px;font-weight:500;cursor:pointer;color:rgba(255,255,255,0.7);transition:all .15s;display:flex;align-items:center;gap:4px}
.filter-tab.active{background:var(--primary);color:#fff}
.filter-tab:hover:not(.active){background:rgba(255,255,255,0.1);color:#fff}
.category-tabs{margin-left:4px}
.category-tabs .filter-tab{font-size:12px;padding:6px 12px}
.category-tabs .filter-tab.active{background:var(--text-2);color:#fff}
.result-count{font-size:13px;color:rgba(255,255,255,0.7)}
.back-btn{background:none;border:1px solid rgba(255,255,255,0.25);padding:7px 14px;border-radius:var(--radius-sm);font-size:13px;cursor:pointer;color:rgba(255,255,255,0.85);transition:all .15s}
.back-btn:hover{background:rgba(255,255,255,0.08);border-color:rgba(255,255,255,0.45);color:#fff}

/* ===== 资源卡片网格 ===== */
.resource-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.resource-card{background:rgba(22,32,52,0.72);border:1px solid rgba(255,255,255,0.12);border-radius:var(--radius);overflow:hidden;cursor:pointer;transition:all .25s var(--ease-out);display:flex;flex-direction:column;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);box-shadow:0 8px 32px rgba(0,0,0,0.25)}
.resource-card:hover{box-shadow:0 16px 48px rgba(0,0,0,0.35);transform:translateY(-3px);border-color:var(--card-tint,rgba(255,255,255,0.25))}
.card-thumb{width:100%;aspect-ratio:16/10;background:rgba(255,255,255,0.06);position:relative;overflow:hidden;border-bottom:1px solid rgba(255,255,255,0.08)}
.card-thumb svg{width:100%;height:100%;transition:transform .35s var(--ease-out)}
.resource-card:hover .card-thumb svg{transform:scale(1.05)}
.type-badge{position:absolute;top:8px;left:8px;padding:3px 9px;border-radius:5px;font-size:11px;font-weight:600;color:#fff;display:flex;align-items:center;gap:3px;text-shadow:0 1px 2px rgba(0,0,0,0.3)}
.type-badge.video{background:rgba(40,86,168,.85)}
.type-badge.image{background:rgba(30,110,70,.85)}
.type-badge.embed{background:rgba(251,114,153,.85)}
.platform-badge{position:absolute;top:8px;right:8px;padding:3px 9px;border-radius:5px;font-size:10px;font-weight:600;color:#fff;display:flex;align-items:center;gap:3px}
.platform-badge.bilibili{background:rgba(251,114,153,.9)}
.science-badge{position:absolute;bottom:8px;left:8px;padding:3px 9px;border-radius:5px;font-size:10px;font-weight:600;color:#fff;background:rgba(99,153,34,.9);display:flex;align-items:center;gap:3px}
.card-duration{position:absolute;bottom:8px;right:8px;background:rgba(0,0,0,.65);color:#fff;font-size:11px;padding:2px 7px;border-radius:4px}
.difficulty-badge{position:absolute;top:8px;right:8px;padding:3px 9px;border-radius:5px;font-size:10px;font-weight:600;border:1px solid rgba(255,255,255,0.35);color:rgba(255,255,255,0.85);display:flex;align-items:center;gap:2px;background:rgba(0,0,0,0.25)}
.fav-btn{position:absolute;bottom:8px;right:44px;width:28px;height:28px;border-radius:50%;background:rgba(0,0,0,0.45);border:1px solid rgba(255,255,255,0.15);display:flex;align-items:center;justify-content:center;cursor:pointer;color:rgba(255,255,255,0.8);transition:all .15s;backdrop-filter:blur(4px)}
.fav-btn:hover{color:#ff6b8a;transform:scale(1.15);border-color:rgba(255,107,138,0.5);background:rgba(0,0,0,0.6)}
.fav-btn.active{color:#ff6b8a}
.play-icon{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;opacity:0;transition:opacity .2s}
.resource-card:hover .play-icon{opacity:1}
.play-icon circle{fill:rgba(255,255,255,.85)}
.card-body{padding:12px 14px;flex:1;display:flex;flex-direction:column}
.card-title{font-size:14px;font-weight:600;margin-bottom:4px;line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;color:#fff}
.card-desc{font-size:12px;color:rgba(255,255,255,0.65);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:10px;flex:1}
.card-tags{display:flex;flex-wrap:wrap;gap:4px;margin-bottom:10px}
.card-tag{font-size:11px;padding:2px 8px;background:rgba(255,255,255,0.12);border-radius:4px;color:rgba(255,255,255,0.75)}
.card-foot{display:flex;align-items:center;justify-content:space-between;padding-top:8px;border-top:1px solid rgba(255,255,255,0.1)}
.card-chapter{font-size:11px;color:rgba(255,255,255,0.7);display:flex;align-items:center;gap:4px}
.card-chapter .dot{width:6px;height:6px;border-radius:50%;background:var(--card-color,var(--primary))}
.card-date{font-size:11px;color:rgba(255,255,255,0.5)}

/* ===== 空状态 ===== */
.empty-state{text-align:center;padding:60px 20px;color:rgba(255,255,255,0.7);text-shadow:0 1px 6px rgba(0,0,0,0.3)}
.empty-icon{display:flex;justify-content:center;margin-bottom:12px}
.empty-state h3{font-size:16px;margin-bottom:6px;color:#fff}

/* ===== 教材详情视图（知识点目录）===== */
.book-header{max-width:var(--max-w);margin:0 auto;padding:40px 32px 16px}
.book-header .ch-book{font-size:13px;color:rgba(255,255,255,0.7);margin-bottom:4px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
.book-header .ch-title{font-family:var(--serif);font-size:28px;font-weight:700;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,0.35)}
.book-header .ch-desc{font-size:14px;color:rgba(255,255,255,0.8);margin-top:6px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
#bookFilterBar{max-width:var(--max-w);margin:0 auto 20px;padding:0 32px}
.chapter-grid{max-width:var(--max-w);margin:0 auto;padding:0 32px 48px;display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.chapter-card{background:rgba(22,32,52,0.72);border:1px solid rgba(255,255,255,0.12);border-radius:var(--radius);padding:22px;cursor:pointer;transition:all .25s var(--ease-out);position:relative;overflow:hidden;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);box-shadow:0 8px 32px rgba(0,0,0,0.25)}
.chapter-card::before{content:'';position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--chapter-color)}
.chapter-card:hover{box-shadow:0 16px 48px rgba(0,0,0,0.35);transform:translateY(-3px);border-color:var(--chapter-color)}
.chapter-card-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:10px}
.chapter-card-name{font-family:var(--serif);font-size:17px;font-weight:700;color:#fff}
.chapter-card-count{font-size:12px;color:rgba(255,255,255,0.75);background:rgba(255,255,255,0.12);padding:2px 10px;border-radius:12px}
.chapter-card-quote{font-size:13px;line-height:1.6;font-style:italic;color:rgba(255,255,255,0.7);margin-bottom:14px;padding-left:12px;border-left:2px solid var(--chapter-color);-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;display:-webkit-box}
.chapter-card-topics{display:flex;flex-wrap:wrap;gap:6px}
.chapter-topic-chip{font-size:12px;color:rgba(255,255,255,0.8);background:rgba(255,255,255,0.1);padding:5px 11px;border-radius:6px;transition:all .15s}
.chapter-card:hover .chapter-topic-chip{background:var(--chapter-color);color:#fff}

/* ===== 章节详情视图 ===== */
.chapter-header{max-width:var(--max-w);margin:0 auto;padding:40px 32px 16px}
.chapter-header .ch-book{font-size:13px;color:rgba(255,255,255,0.7);margin-bottom:4px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
.chapter-header .ch-title{font-family:var(--serif);font-size:28px;font-weight:700;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,0.35)}
.chapter-header .ch-desc{font-size:14px;color:rgba(255,255,255,0.8);margin-top:6px;text-shadow:0 1px 6px rgba(0,0,0,0.3)}
#chapterView .filter-bar{max-width:var(--max-w);margin:0 auto 20px;padding:0 32px}

/* ===== 趣味物理卡片 ===== */
.fun-facts-section{max-width:var(--max-w);margin:0 auto;padding:8px 32px 24px}
.fun-facts-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.fun-fact-card{display:flex;gap:14px;padding:18px 20px;border-radius:var(--radius);background:rgba(22,32,52,0.72);border:1px solid rgba(255,255,255,0.12);border-left:4px solid var(--ff-border);backdrop-filter:blur(12px);transition:all .3s var(--ease-out);cursor:default;box-shadow:0 8px 32px rgba(0,0,0,0.25)}
.fun-fact-card:hover{transform:translateY(-2px);box-shadow:0 16px 48px rgba(0,0,0,0.35);border-left-color:var(--ff-color)}
.fun-fact-icon{flex-shrink:0;width:40px;height:40px;border-radius:10px;background:var(--ff-bg);color:var(--ff-color);display:flex;align-items:center;justify-content:center}
.fun-fact-body{flex:1;min-width:0}
.fun-fact-label{font-size:12px;font-weight:600;color:var(--ff-color);margin-bottom:4px;letter-spacing:.5px}
.fun-fact-text{font-size:13px;line-height:1.7;color:rgba(255,255,255,0.8);margin:0}
@media(max-width:768px){
  .fun-facts-grid{grid-template-columns:1fr}
  .fun-facts-section{padding:8px 16px 20px}
}

/* ===== 弹窗 ===== */
.modal-overlay{position:fixed;inset:0;background:rgba(10,16,32,.65);display:none;align-items:center;justify-content:center;z-index:1000;padding:20px;backdrop-filter:blur(4px)}
.modal-overlay.show{display:flex;animation:fadeIn .2s}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.modal{background:rgba(22,32,52,0.88);border:1px solid rgba(255,255,255,0.12);border-radius:var(--radius);width:100%;max-width:720px;max-height:90vh;display:flex;flex-direction:column;box-shadow:0 24px 64px rgba(0,0,0,0.45);animation:slideUp .3s var(--ease-out);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);color:#fff}
@keyframes slideUp{from{transform:translateY(24px);opacity:0}to{transform:translateY(0);opacity:1}}
.modal-small{max-width:480px}
.modal-detail{max-width:760px}
.modal-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid rgba(255,255,255,0.12)}
.modal-title-group{display:flex;align-items:center;gap:10px}
.modal-type-badge{font-size:11px;font-weight:600;padding:3px 9px;border-radius:5px;color:#fff}
.modal-type-badge.video{background:#2856a8}
.modal-type-badge.image{background:#1e6e46}
.modal-type-badge.embed{background:#fb7299}
.modal-header h2{font-size:16px;font-weight:600;color:#fff}
.modal-close{background:none;border:none;font-size:18px;cursor:pointer;color:rgba(255,255,255,0.7);padding:4px 8px;border-radius:4px;transition:all .15s}
.modal-close:hover{background:rgba(255,255,255,0.12);color:#fff}
.modal-body{padding:20px;overflow-y:auto;flex:1}
.modal-footer{padding:14px 20px;border-top:1px solid rgba(255,255,255,0.12);display:flex;justify-content:flex-end;gap:10px}

/* 关于作者弹窗 */
.modal-author{max-width:460px}
.author-card{display:flex;align-items:center;gap:22px;padding:10px 4px}
.author-avatar{flex-shrink:0;width:120px;height:120px;border-radius:var(--radius-sm);overflow:hidden;background:rgba(255,255,255,0.08);box-shadow:0 4px 16px rgba(0,0,0,0.2)}
.author-avatar img{width:100%;height:100%;object-fit:cover;display:block}
.author-info{display:flex;flex-direction:column;gap:6px}
.author-line{font-size:14px;color:rgba(255,255,255,0.75);line-height:1.5}
.author-name{font-size:22px;font-weight:700;color:#fff;letter-spacing:.5px;margin-top:4px}
.author-detail{margin-top:18px;padding-top:18px;border-top:0.5px solid rgba(255,255,255,0.12)}
.author-detail-line{font-size:13px;color:rgba(255,255,255,0.6);line-height:1.7;margin-bottom:6px}
.author-legal-links{margin-top:10px;font-size:12px}
.author-legal-links a{color:rgba(255,255,255,0.5);transition:color .2s}
.author-legal-links a:hover{color:rgba(255,255,255,0.85)}

/* 留言弹窗 */
.modal-feedback{max-width:480px}
.feedback-form{display:flex;flex-direction:column;gap:16px}
.feedback-form .form-group{display:flex;flex-direction:column;gap:6px}
.feedback-label{font-size:13px;font-weight:600;color:rgba(255,255,255,0.9)}
.feedback-optional{font-size:11px;color:rgba(255,255,255,0.4);font-weight:400}
.feedback-required{color:#ff6b8a}
.feedback-input{padding:10px 14px;border:1px solid rgba(255,255,255,0.15);border-radius:var(--radius-sm);font-size:14px;background:rgba(0,0,0,0.25);color:#fff;outline:none;transition:border-color .2s}
.feedback-input:focus{border-color:rgba(255,192,96,0.6);box-shadow:0 0 0 3px rgba(255,192,96,0.15)}
.feedback-textarea{padding:10px 14px;border:1px solid rgba(255,255,255,0.15);border-radius:var(--radius-sm);font-size:14px;background:rgba(0,0,0,0.25);color:#fff;outline:none;transition:border-color .2s;resize:vertical;min-height:100px;font-family:inherit;line-height:1.6}
.feedback-textarea:focus{border-color:rgba(255,192,96,0.6);box-shadow:0 0 0 3px rgba(255,192,96,0.15)}
.feedback-counter{font-size:11px;color:rgba(255,255,255,0.4);text-align:right}
.feedback-submit{padding:11px 20px;border:none;border-radius:var(--radius-sm);font-size:14px;font-weight:600;cursor:pointer;background:#ffc060;color:#1a1525;transition:all .15s}
.feedback-submit:hover{background:#ffd070;transform:translateY(-1px);box-shadow:0 4px 16px rgba(255,192,96,0.3)}
.feedback-result{font-size:13px;text-align:center;min-height:20px}
.feedback-result.success{color:#4ade80}
.feedback-result.error{color:#ff6b8a}

/* 详情弹窗内容 */
.detail-preview{border-radius:var(--radius-sm);overflow:hidden;margin-bottom:16px;min-height:200px;display:flex;align-items:center;justify-content:center;background:rgba(255,255,255,0.06)}
.detail-preview svg{width:100%;max-height:360px}
.iframe-player-wrap{width:100%;aspect-ratio:16/9;background:#000;border-radius:var(--radius-sm);overflow:hidden}
.iframe-player-wrap iframe{display:block;width:100%;height:100%;border:none}
.source-link{color:#7ab5ff;text-decoration:none;cursor:pointer}
.source-link:hover{text-decoration:underline}
.detail-meta{display:flex;flex-direction:column;gap:10px}
.detail-meta .meta-row{display:flex;gap:8px;font-size:13px}
.detail-meta .meta-label{font-weight:600;color:#fff;min-width:60px;flex-shrink:0}
.detail-meta .meta-value{color:rgba(255,255,255,0.75)}
.detail-tags{display:flex;flex-wrap:wrap;gap:6px}
.detail-tag{font-size:12px;padding:3px 10px;background:rgba(255,255,255,0.12);border-radius:4px;color:rgba(255,255,255,0.85)}
.detail-meta-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:4px}
.detail-difficulty-badge{padding:4px 12px;border-radius:6px;font-size:12px;font-weight:600;color:#fff}
.detail-fav-btn{display:flex;align-items:center;gap:5px;padding:5px 14px;border-radius:6px;font-size:13px;font-weight:500;border:1px solid rgba(255,255,255,0.15);background:rgba(255,255,255,0.08);color:rgba(255,255,255,0.8);cursor:pointer;transition:all .15s}
.detail-fav-btn:hover{border-color:#ff6b8a;color:#ff6b8a;background:rgba(255,107,138,0.1)}
.detail-fav-btn.active{background:rgba(255,107,138,0.15);border-color:#ff6b8a;color:#ff6b8a}

/* ===== 收藏夹视图 ===== */
#favoritesView .filter-bar{max-width:var(--max-w);margin:0 auto 20px;padding:0 32px}
#favoritesView .chapter-header{max-width:var(--max-w);margin:0 auto;padding:40px 32px 12px}

/* ===== 难度筛选标签 ===== */
.difficulty-tabs .filter-tab[data-difficulty="基础"]{color:#8ad29a}
.difficulty-tabs .filter-tab[data-difficulty="基础"].active{background:rgba(46,125,50,0.25);color:#8ad29a;border-color:rgba(138,210,154,0.4)}
.difficulty-tabs .filter-tab[data-difficulty="提高"]{color:#ffb380}
.difficulty-tabs .filter-tab[data-difficulty="提高"].active{background:rgba(230,81,0,0.25);color:#ffb380;border-color:rgba(255,179,128,0.4)}
.difficulty-tabs .filter-tab[data-difficulty="拓展"]{color:#d1a3e6}
.difficulty-tabs .filter-tab[data-difficulty="拓展"].active{background:rgba(123,31,162,0.25);color:#d1a3e6;border-color:rgba(209,163,230,0.4)}

/* 知识要点 */
.knowledge-points{flex-direction:column;gap:8px;padding-top:10px;border-top:1px dashed rgba(255,255,255,0.15)}
.knowledge-points .meta-label{color:#7ab5ff;font-size:13px}
.points-list{display:flex;flex-direction:column;gap:6px}
.point-item{display:flex;align-items:flex-start;gap:8px;font-size:13px;color:rgba(255,255,255,0.75);line-height:1.5}
.point-dot{width:6px;height:6px;border-radius:50%;background:var(--primary);flex-shrink:0;margin-top:7px}

/* 演示提示弹窗 */
.demo-info{text-align:center}
.demo-info p{font-size:14px;color:var(--text-2);margin-bottom:8px;line-height:1.6}
.demo-info strong{color:var(--text)}
.demo-roadmap{margin-top:20px;text-align:left;display:flex;flex-direction:column;gap:10px}
.roadmap-item{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--text-2)}
.roadmap-item .step{width:24px;height:24px;border-radius:50%;background:var(--bg);color:var(--text-3);display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:600;flex-shrink:0}
.roadmap-item .step.done{background:var(--primary);color:#fff}

/* ===== 按钮 ===== */
.btn{padding:9px 18px;border:none;border-radius:var(--radius-sm);font-size:14px;font-weight:500;cursor:pointer;transition:all .15s;display:inline-flex;align-items:center;gap:6px}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-dark)}

/* ===== Toast ===== */
.toast-container{position:fixed;bottom:24px;right:24px;z-index:2000;display:flex;flex-direction:column;gap:8px}
.toast{padding:12px 20px;border-radius:var(--radius-sm);color:#fff;font-size:14px;box-shadow:var(--shadow-lg);animation:slideIn .3s var(--ease-out)}
.toast.info{background:var(--primary)}
@keyframes slideIn{from{transform:translateX(120%)}to{transform:translateX(0)}}

/* ===== 页脚 ===== */
.footer{border-top:1px solid rgba(255,255,255,0.12);background:rgba(8,16,32,0.35);backdrop-filter:blur(8px);margin-top:64px}
.footer-inner{max-width:var(--max-w);margin:0 auto;padding:32px;text-align:center}
.footer-top{margin-bottom:16px}
.footer-brand{font-size:14px;font-weight:500;color:rgba(255,255,255,0.9)}
.footer-desc{font-size:12px;color:rgba(255,255,255,0.55);margin-top:4px}
.footer-links{margin-bottom:18px}
.footer-links a{font-size:12px;color:rgba(255,255,255,0.7);transition:color .2s}
.footer-links a:hover{color:#fff}
.footer-sep{color:rgba(255,255,255,0.3);margin:0 6px;font-size:12px}
.footer-bottom{padding-top:16px;border-top:0.5px solid rgba(255,255,255,0.08)}
.footer-org{font-size:12px;color:rgba(255,255,255,0.55)}
.footer-icp{font-size:12px;color:rgba(255,255,255,0.55);margin-top:4px}
.footer-icp a{color:rgba(255,255,255,0.55);transition:color .2s}
.footer-icp a:hover{color:rgba(255,255,255,0.85)}
.footer-copy{font-size:11px;color:rgba(255,255,255,0.4);margin-top:6px}
.beian-icon{width:14px;height:14px;vertical-align:middle;margin-right:4px;border-radius:2px}

/* ===== 响应式 ===== */
@media(max-width:960px){
  .book-grid{grid-template-columns:repeat(2,1fr)}
  .chapter-grid{grid-template-columns:repeat(2,1fr)}
  .search-box input{width:180px}
  .hero-content{padding:100px 24px 80px}
  .hero-stats{gap:24px}
  .hero-stat .num{font-size:26px}
}
@media(max-width:640px){
  .header-inner{padding:0 16px;height:56px}
  .logo-text p{display:none}
  .search-box input{width:120px;font-size:13px}
  .hero{min-height:90vh}
  .hero-content{padding:80px 16px 60px}
  .hero-tag{font-size:10px;letter-spacing:2px}
  .hero-stats{gap:20px}
  .hero-stat .num{font-size:24px}
  .hero-actions{flex-direction:column;align-items:stretch}
  .hero-btn{text-align:center;justify-content:center}
  .section{padding:48px 16px 8px}
  .book-grid{grid-template-columns:1fr}
  .chapter-grid{grid-template-columns:1fr;padding:0 16px 32px}
  .resource-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:12px}
  .filter-bar{flex-wrap:wrap}
  .chapter-header{padding:28px 16px 12px}
  .book-header{padding:28px 16px 12px}
  #bookFilterBar{padding:0 16px}
  #chapterView .filter-bar{padding:0 16px}
  #favoritesView .filter-bar{padding:0 16px}
  #favoritesView .chapter-header{padding:28px 16px 12px}
  .hero-scroll-indicator{display:none}
}