/* ============================================================
   芯启源课堂 · 全站样式
   风格：深藏青 Hero + 青绿主色 + 琥珀点缀（区别于傻牛系列）
   ============================================================ */
:root {
  --navy: #0f1b2d;
  --navy-2: #16263d;
  --teal: #0d9488;
  --teal-dark: #0b7c72;
  --teal-light: #14b8a6;
  --teal-bg: #effaf8;
  --amber: #f59e0b;
  --amber-bg: #fef3e2;
  --ink: #17223b;
  --ink-2: #4b5566;
  --ink-3: #8a93a5;
  --line: #e6eaf0;
  --bg: #f7f9fb;
  --card: #ffffff;
  --danger: #e5484d;
  --radius: 16px;
  --shadow: 0 2px 10px rgba(15, 27, 45, .06);
  --shadow-lg: 0 12px 32px rgba(15, 27, 45, .12);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--bg); color: var(--ink); line-height: 1.6;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(15, 27, 45, .92); backdrop-filter: blur(10px);
}
.nav .wrap { display: flex; align-items: center; height: 64px; gap: 36px; }
.logo { display: flex; align-items: center; gap: 10px; color: #fff; font-size: 20px; font-weight: 700; letter-spacing: 1px; }
.logo-mark {
  width: 34px; height: 34px; border-radius: 10px;
  background: linear-gradient(135deg, var(--teal-light), var(--teal));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 18px;
}
.nav-links { display: flex; gap: 28px; flex: 1; }
.nav-links a { color: #c5cddd; font-size: 15px; padding: 4px 0; border-bottom: 2px solid transparent; transition: .2s; }
.nav-links a:hover, .nav-links a.on { color: #fff; border-color: var(--teal-light); }
.nav-actions { display: flex; gap: 12px; align-items: center; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 10px 22px; border-radius: 999px; font-size: 15px; font-weight: 600;
  cursor: pointer; border: none; transition: .2s;
}
.btn-primary { background: linear-gradient(135deg, var(--teal-light), var(--teal)); color: #fff; box-shadow: 0 4px 14px rgba(13, 148, 136, .35); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(13, 148, 136, .45); }
.btn-ghost { background: transparent; color: #c5cddd; border: 1px solid rgba(255,255,255,.25); }
.btn-ghost:hover { color: #fff; border-color: #fff; }
.btn-amber { background: var(--amber); color: #fff; box-shadow: 0 4px 14px rgba(245, 158, 11, .4); }
.btn-amber:hover { filter: brightness(1.05); }
.btn-lg { padding: 14px 34px; font-size: 16px; }
.btn-outline { background: #fff; color: var(--teal); border: 1.5px solid var(--teal); }
.btn-outline:hover { background: var(--teal-bg); }

/* ---------- Hero ---------- */
.hero { background: radial-gradient(1200px 500px at 80% -10%, rgba(20,184,166,.25), transparent 60%), linear-gradient(160deg, var(--navy) 0%, var(--navy-2) 100%); color: #fff; padding: 88px 0 96px; overflow: hidden; position: relative; }
.hero .wrap { display: grid; grid-template-columns: 1.15fr .85fr; gap: 60px; align-items: center; }
.hero-kicker { display: inline-flex; align-items: center; gap: 8px; background: rgba(20,184,166,.15); border: 1px solid rgba(20,184,166,.4); color: #5eead4; font-size: 13px; padding: 6px 14px; border-radius: 999px; margin-bottom: 20px; }
.hero h1 { font-size: 44px; line-height: 1.25; font-weight: 800; margin-bottom: 18px; }
.hero h1 em { font-style: normal; color: #5eead4; position: relative; }
.hero p.sub { color: #aab7cc; font-size: 17px; margin-bottom: 34px; max-width: 520px; }
.hero-cta { display: flex; gap: 16px; margin-bottom: 40px; }
.hero-stats { display: flex; gap: 44px; }
.hero-stats .num { font-size: 26px; font-weight: 800; color: #5eead4; }
.hero-stats .lab { font-size: 13px; color: #8fa0ba; }
/* hero 卡片 */
.hero-card {
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12);
  border-radius: 20px; padding: 22px; backdrop-filter: blur(8px); box-shadow: var(--shadow-lg);
}
.hc-title { font-size: 14px; color: #9fb0c8; margin-bottom: 14px; display: flex; justify-content: space-between; }
.hc-title b { color: #5eead4; }
.mini-course { display: flex; gap: 12px; align-items: center; padding: 10px; border-radius: 12px; margin-bottom: 8px; transition: .2s; cursor: pointer; }
.mini-course:hover { background: rgba(255,255,255,.08); }
.mini-course .cover { width: 74px; height: 52px; border-radius: 8px; flex: none; display: flex; align-items: center; justify-content: center; font-size: 24px; }
.mini-course .t { font-size: 14px; font-weight: 600; color: #e8eef6; }
.mini-course .m { font-size: 12px; color: #8fa0ba; margin-top: 2px; }
.mini-course .price { margin-left: auto; color: var(--amber); font-weight: 700; font-size: 14px; }

/* ---------- 通用区块 ---------- */
.section { padding: 72px 0; }
.section.alt { background: #fff; }
.sec-head { display: flex; align-items: flex-end; justify-content: space-between; margin-bottom: 32px; }
.sec-head h2 { font-size: 28px; font-weight: 800; }
.sec-head h2 span { color: var(--teal); }
.sec-head .more { color: var(--ink-3); font-size: 14px; display: flex; align-items: center; gap: 4px; }
.sec-head .more:hover { color: var(--teal); }

/* 分类胶囊 */
.cats { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 28px; }
.cat {
  padding: 9px 20px; border-radius: 999px; background: #fff; border: 1px solid var(--line);
  font-size: 14px; color: var(--ink-2); cursor: pointer; transition: .2s;
}
.cat:hover { border-color: var(--teal); color: var(--teal); }
.cat.on { background: var(--navy); color: #fff; border-color: var(--navy); }

/* ---------- 课程卡片 ---------- */
.grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.course-card {
  background: var(--card); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow); transition: .25s; cursor: pointer; border: 1px solid var(--line);
  display: flex; flex-direction: column;
}
.course-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.cc-cover { position: relative; height: 150px; display: flex; align-items: center; justify-content: center; font-size: 44px; }
.cc-cover .tag {
  position: absolute; top: 12px; left: 12px; background: rgba(15,27,45,.75); color: #fff;
  font-size: 12px; padding: 4px 10px; border-radius: 6px; backdrop-filter: blur(4px);
}
.cc-body { padding: 16px 18px 18px; flex: 1; display: flex; flex-direction: column; }
.cc-body h3 { font-size: 16px; font-weight: 700; line-height: 1.45; margin-bottom: 8px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.cc-meta { font-size: 12.5px; color: var(--ink-3); display: flex; gap: 14px; margin-bottom: 12px; }
.cc-foot { margin-top: auto; display: flex; align-items: center; justify-content: space-between; }
.cc-price { color: var(--danger); font-weight: 800; font-size: 18px; }
.cc-price small { font-size: 12px; font-weight: 400; }
.cc-price .free { color: var(--teal); }
.cc-rate { font-size: 12px; color: var(--ink-3); }
.cc-rate b { color: var(--amber); }
/* 封面渐变色板 */
.g1 { background: linear-gradient(135deg, #ccfbf1, #7dd3c8); }
.g2 { background: linear-gradient(135deg, #e0f2fe, #93c5fd); }
.g3 { background: linear-gradient(135deg, #fef3c7, #fcd34d); }
.g4 { background: linear-gradient(135deg, #ede9fe, #c4b5fd); }
.g5 { background: linear-gradient(135deg, #fce7f3, #f9a8d4); }
.g6 { background: linear-gradient(135deg, #d1fae5, #6ee7b7); }
.g7 { background: linear-gradient(135deg, #ffe4e6, #fda4af); }
.g8 { background: linear-gradient(135deg, #dbeafe, #bfdbfe); }

/* 真实封面图片统一适配 */
.cc-cover, .buy-cover, .featured-card .thumb, .hot-item .s-thumb, .my-course .mc-cover, .tcover { position: relative; overflow: hidden; }
.cc-cover img, .buy-cover img, .featured-card .thumb img, .hot-item .s-thumb img, .my-course .mc-cover img, .tcover img {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; display: block;
}
.cc-cover .tag, .buy-cover .tag, .featured-card .thumb .tag, .hot-item .s-thumb .tag, .my-course .mc-cover .tag, .tcover .tag {
  z-index: 2;
}

/* ---------- 讲师 ---------- */
.teachers { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.teacher {
  background: var(--card); border-radius: var(--radius); padding: 28px 22px; text-align: center;
  box-shadow: var(--shadow); border: 1px solid var(--line); transition: .25s; cursor: pointer;
}
.teacher:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.avatar {
  width: 76px; height: 76px; border-radius: 50%; margin: 0 auto 14px;
  display: flex; align-items: center; justify-content: center; font-size: 30px; color: #fff; font-weight: 700;
}
.teacher h4 { font-size: 17px; margin-bottom: 4px; }
.teacher .role { color: var(--teal); font-size: 13px; margin-bottom: 10px; }
.teacher p { color: var(--ink-3); font-size: 13px; }

/* ---------- 数据条 ---------- */
.stats-bar {
  background: linear-gradient(135deg, var(--navy), #1a3549); border-radius: 20px; padding: 40px 50px;
  color: #fff; display: flex; justify-content: space-around; align-items: center;
}
.stats-bar .item { text-align: center; }
.stats-bar .num { font-size: 34px; font-weight: 800; color: #5eead4; }
.stats-bar .lab { color: #9fb0c8; font-size: 14px; margin-top: 4px; }

/* ---------- 学习步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.step { background: var(--card); border-radius: var(--radius); padding: 26px 22px; border: 1px solid var(--line); box-shadow: var(--shadow); }
.step .no { width: 40px; height: 40px; border-radius: 12px; background: var(--teal-bg); color: var(--teal); font-weight: 800; font-size: 18px; display: flex; align-items: center; justify-content: center; margin-bottom: 14px; }
.step h4 { font-size: 16px; margin-bottom: 6px; }
.step p { font-size: 13px; color: var(--ink-3); }

/* ---------- 页脚 ---------- */
.footer { background: var(--navy); color: #8fa0ba; padding: 56px 0 28px; margin-top: 72px; }
.footer .cols { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer h5 { color: #fff; font-size: 15px; margin-bottom: 14px; }
.footer a { display: block; font-size: 13.5px; margin-bottom: 9px; color: #8fa0ba; }
.footer a:hover { color: #5eead4; }
.footer .copy { border-top: 1px solid rgba(255,255,255,.08); padding-top: 22px; font-size: 12.5px; text-align: center; }

/* ---------- 面包屑 / 页头 ---------- */
.page-head { background: linear-gradient(160deg, var(--navy), var(--navy-2)); color: #fff; padding: 44px 0; }
.page-head h1 { font-size: 28px; font-weight: 800; }
.page-head .crumb { font-size: 13px; color: #8fa0ba; margin-top: 6px; }
.page-head .crumb a:hover { color: #5eead4; }

/* ---------- 筛选栏 ---------- */
.filter-bar { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 22px; margin: -34px 0 30px; position: relative; z-index: 5; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 12px; }
.filter-row { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.filter-row .fl { font-size: 13px; color: var(--ink-3); flex: none; width: 48px; }
.fitem { padding: 6px 16px; border-radius: 8px; font-size: 13.5px; color: var(--ink-2); cursor: pointer; }
.fitem:hover { color: var(--teal); }
.fitem.on { background: var(--teal-bg); color: var(--teal); font-weight: 600; }
.sorts { margin-left: auto; display: flex; gap: 18px; font-size: 13.5px; color: var(--ink-3); }
.sorts span { cursor: pointer; }
.sorts span.on { color: var(--teal); font-weight: 700; }

/* ---------- 详情页 ---------- */
.detail-hero { background: linear-gradient(160deg, var(--navy), var(--navy-2)); color: #fff; padding: 48px 0 120px; }
.detail-hero .wrap { display: grid; grid-template-columns: 1fr 400px; gap: 48px; align-items: start; }
.detail-hero h1 { font-size: 30px; font-weight: 800; margin: 12px 0 14px; }
.detail-hero .dmeta { display: flex; gap: 22px; color: #9fb0c8; font-size: 13.5px; flex-wrap: wrap; }
.detail-hero .dmeta b { color: #5eead4; }
.dtags { display: flex; gap: 8px; margin-top: 16px; }
.dtags span { background: rgba(20,184,166,.15); border: 1px solid rgba(20,184,166,.35); color: #5eead4; font-size: 12px; padding: 4px 12px; border-radius: 6px; }
/* 购买卡片 */
.buy-card {
  background: #fff; border-radius: 20px; box-shadow: var(--shadow-lg);
  margin-top: -88px; overflow: hidden; position: relative; z-index: 5;
}
.buy-cover { height: 190px; display: flex; align-items: center; justify-content: center; font-size: 64px; }
.buy-body { padding: 22px 24px; }
.buy-price { display: flex; align-items: baseline; gap: 12px; margin-bottom: 6px; }
.buy-price .now { font-size: 34px; font-weight: 800; color: var(--danger); }
.buy-price .old { color: var(--ink-3); text-decoration: line-through; font-size: 15px; }
.buy-price .off { background: var(--amber-bg); color: var(--amber); font-size: 12px; padding: 3px 10px; border-radius: 6px; font-weight: 700; }
.buy-tip { font-size: 12.5px; color: var(--ink-3); margin-bottom: 18px; }
.buy-btns { display: flex; gap: 12px; }
.buy-btns .btn { flex: 1; }
.buy-serv { display: flex; gap: 14px; margin-top: 16px; font-size: 12px; color: var(--ink-3); flex-wrap: wrap; }
.buy-serv i { color: var(--teal); font-style: normal; margin-right: 3px; }

/* 详情主体 tabs */
.detail-main { padding: 40px 0; }
.dtabs { display: flex; gap: 30px; border-bottom: 1px solid var(--line); margin-bottom: 26px; }
.dtabs a { padding: 12px 2px; font-size: 16px; color: var(--ink-2); border-bottom: 3px solid transparent; margin-bottom: -1px; }
.dtabs a.on { color: var(--teal); font-weight: 700; border-color: var(--teal); }
.chapter { background: #fff; border: 1px solid var(--line); border-radius: 14px; margin-bottom: 14px; overflow: hidden; }
.chapter .ch-head { display: flex; align-items: center; gap: 12px; padding: 15px 20px; background: var(--teal-bg); cursor: pointer; user-select: none; }
.chapter .ch-head b { font-size: 15px; }
.chapter .ch-head .cnt { margin-left: auto; font-size: 12px; color: var(--ink-3); }
.chapter .ch-head .play-ico { transition: transform .2s; }
.chapter.collapsed .ch-head .play-ico { transform: rotate(-90deg); }
.chapter.collapsed .lesson { display: none; }
.lesson { display: flex; align-items: center; gap: 12px; padding: 12px 20px; border-top: 1px solid #f1f4f8; font-size: 14px; color: var(--ink-2); cursor: pointer; transition: background .15s; }
.lesson:hover { background: #f8fafc; }
.lesson .dur { margin-left: auto; font-size: 12px; color: var(--ink-3); }
.lesson .try { background: var(--amber-bg); color: var(--amber); font-size: 11px; padding: 2px 9px; border-radius: 5px; font-weight: 700; }
.lesson .lk { color: var(--teal); }
.play-ico { width: 26px; height: 26px; border-radius: 8px; background: var(--teal-bg); color: var(--teal); display: inline-flex; align-items: center; justify-content: center; font-size: 12px; flex: none; }

/* 试看视频弹窗 */
.vmodal { position: fixed; inset: 0; background: rgba(15,27,45,.78); z-index: 1000; display: none; align-items: center; justify-content: center; padding: 20px; }
.vmodal-content { background: #fff; border-radius: 16px; width: 100%; max-width: 720px; overflow: hidden; box-shadow: 0 24px 60px rgba(0,0,0,.25); }
.vmodal-head { display: flex; align-items: center; justify-content: space-between; padding: 14px 18px; border-bottom: 1px solid var(--line); }
.vmodal-head span { font-weight: 700; font-size: 15px; }
.vmodal-head button { background: none; border: none; font-size: 22px; color: var(--ink-3); cursor: pointer; line-height: 1; }
.vmodal-body { padding: 0; background: #000; }
.vmodal-body video { display: block; width: 100%; max-height: 70vh; }

/* 评论区 */
.review { display: flex; gap: 14px; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 18px 20px; margin-bottom: 12px; }
.review .ravatar { width: 42px; height: 42px; border-radius: 50%; flex: none; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; }
.review .rt { font-size: 13px; font-weight: 700; margin-bottom: 4px; }
.review .rt .stars { color: var(--amber); font-size: 12px; margin-left: 8px; }
.review .rt time { font-weight: 400; color: var(--ink-3); margin-left: 8px; font-size: 12px; }
.review p { font-size: 13.5px; color: var(--ink-2); }

/* ---------- 公告条 ---------- */
.notice-bar { background: linear-gradient(90deg, #b45309, #f59e0b); color: #fff; font-size: 13px; }
.notice-bar .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 8px 20px; }
.notice-bar .nb-scroll { flex: 1; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
.notice-bar .nb-phone { flex: none; font-weight: 700; }

/* ---------- 课程详情：评分摘要 + 学员评价 ---------- */
.rate-sum { display: flex; gap: 28px; align-items: center; padding: 16px 18px; background: #f8fafc; border-radius: 12px; margin-bottom: 18px; }
.rate-sum .rs-score { text-align: center; flex: none; }
.rate-sum .rs-score b { display: block; font-size: 40px; line-height: 1; color: var(--amber); font-weight: 800; }
.rate-sum .rs-score span { display: block; font-size: 12px; color: var(--ink-3); margin-top: 4px; }
.rate-sum .rs-score em { display: block; font-style: normal; color: var(--amber); font-size: 13px; letter-spacing: 2px; }
.rate-sum .rs-bars { flex: 1; }
.rs-bar { display: flex; align-items: center; gap: 10px; font-size: 12px; color: var(--ink-3); margin: 4px 0; }
.rs-bar i { flex: 1; height: 8px; background: #eef2f7; border-radius: 99px; overflow: hidden; }
.rs-bar i b { display: block; height: 100%; background: var(--amber); border-radius: 99px; }
.rs-bar em { font-style: normal; width: 34px; text-align: right; }
.rv-list { display: flex; flex-direction: column; }
.rv-item { display: flex; gap: 12px; padding: 14px 0; border-top: 1px solid #f1f4f8; }
.rv-avatar { width: 40px; height: 40px; border-radius: 50%; flex: none; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: 15px; }
.rv-main { flex: 1; min-width: 0; }
.rv-top { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; font-size: 13px; }
.rv-top b { font-size: 13.5px; }
.rv-top .rv-role { color: var(--ink-3); font-size: 12px; }
.rv-top .rv-bought { background: var(--teal-bg); color: var(--teal); font-size: 11px; padding: 1px 8px; border-radius: 5px; }
.rv-top time { color: var(--ink-3); font-size: 12px; margin-left: auto; }
.rv-stars { color: var(--amber); font-size: 13px; letter-spacing: 2px; margin: 3px 0 5px; }
.rv-main p { font-size: 13.5px; color: var(--ink-2); line-height: 1.7; }

/* ---------- 课程详情：FAQ 手风琴 ---------- */
.faq-list { display: flex; flex-direction: column; }
.faq-item { border: 1px solid var(--line); border-radius: 12px; margin-bottom: 10px; overflow: hidden; }
.faq-q { display: flex; align-items: center; gap: 10px; padding: 13px 16px; font-size: 14px; font-weight: 600; cursor: pointer; user-select: none; background: #fbfcfe; }
.faq-q .mark { flex: none; width: 22px; height: 22px; border-radius: 6px; background: var(--teal-bg); color: var(--teal); display: inline-flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 800; }
.faq-q i { margin-left: auto; color: var(--ink-3); font-style: normal; transition: transform .2s; }
.faq-item.open .faq-q i { transform: rotate(180deg); }
.faq-a { display: none; padding: 12px 16px 14px 48px; font-size: 13.5px; color: var(--ink-2); line-height: 1.8; }
.faq-a .mark { color: var(--amber); font-weight: 800; margin-right: 6px; }
.faq-item.open .faq-a { display: block; }

/* ---------- 首页学员评价 ---------- */
.hp-reviews { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.hp-review { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 18px 20px; display: flex; flex-direction: column; }
.hp-rv-top { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.hp-rv-top b { display: block; font-size: 13.5px; }
.hp-rv-top time { margin-left: auto; font-size: 12px; color: var(--ink-3); }
.hp-review p { font-size: 13.5px; color: var(--ink-2); line-height: 1.8; flex: 1; }
.hp-rv-course { margin-top: 12px; font-size: 13px; color: var(--teal); font-weight: 600; }

/* ---------- 课程列表角标 ---------- */
.course-card { position: relative; }
.badge { position: absolute; top: 12px; left: 12px; z-index: 3; font-size: 11px; font-weight: 700; padding: 3px 10px; border-radius: 99px; color: #fff; box-shadow: 0 2px 8px rgba(0,0,0,.18); }
.badge-hot { background: linear-gradient(90deg, #ef4444, #f97316); }
.badge-new { background: linear-gradient(90deg, #6366f1, #8b5cf6); }

/* ---------- 登录页 ---------- */
.auth { min-height: calc(100vh - 64px); display: flex; align-items: center; justify-content: center; background: radial-gradient(900px 400px at 20% 0%, rgba(20,184,166,.12), transparent 55%), var(--bg); padding: 60px 24px; }
.auth-box { background: #fff; border-radius: 24px; box-shadow: var(--shadow-lg); padding: 44px 44px 36px; width: 420px; max-width: 100%; }
.auth-box h2 { font-size: 24px; font-weight: 800; margin-bottom: 6px; }
.auth-box .sub { color: var(--ink-3); font-size: 14px; margin-bottom: 26px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 13px; color: var(--ink-2); margin-bottom: 6px; font-weight: 600; }
.field input {
  width: 100%; padding: 12px 16px; border: 1.5px solid var(--line); border-radius: 12px;
  font-size: 15px; outline: none; transition: .2s; background: #fbfcfe;
}
.field input:focus { border-color: var(--teal); box-shadow: 0 0 0 4px rgba(13,148,136,.1); background: #fff; }
.auth-switch { text-align: center; margin-top: 18px; font-size: 13.5px; color: var(--ink-3); }
.auth-switch a { color: var(--teal); font-weight: 600; }
.auth-alt { display: flex; align-items: center; gap: 14px; margin-top: 24px; color: var(--ink-3); font-size: 12px; }
.auth-alt::before, .auth-alt::after { content: ""; flex: 1; height: 1px; background: var(--line); }

/* ---------- toast ---------- */
.toast {
  position: fixed; top: 84px; left: 50%; transform: translateX(-50%) translateY(-16px);
  background: var(--navy); color: #fff; padding: 12px 26px; border-radius: 999px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: .3s; z-index: 999;
  box-shadow: var(--shadow-lg);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .grid { grid-template-columns: repeat(2, 1fr); }
  .teachers, .steps { grid-template-columns: repeat(2, 1fr); }
  .footer .cols { grid-template-columns: 1fr 1fr; }
  .detail-hero .wrap { grid-template-columns: 1fr; }
  .stats-bar { flex-wrap: wrap; gap: 24px; }
}
@media (max-width: 560px) {
  .grid, .teachers, .steps { grid-template-columns: 1fr; }
  .hero h1 { font-size: 32px; }
  .nav-links { display: none; }
}

/* ============================================================
   酷学院风格首页扩展
   ============================================================ */
/* 白底顶部导航 */
.topbar { background: #fff; border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 100; }
.topbar .wrap { display: flex; align-items: center; height: 72px; gap: 36px; }
.topbar .logo { color: var(--ink); }
.topbar .nav-links a { color: var(--ink-2); border-bottom-color: transparent; }
.topbar .nav-links a:hover, .topbar .nav-links a.on { color: var(--teal); border-bottom-color: var(--teal); }
.topbar .phone { display: flex; align-items: center; gap: 6px; color: var(--ink-2); font-size: 14px; margin-left: auto; }
.topbar .phone i { color: var(--teal); font-style: normal; }
.topbar .btn-primary { background: linear-gradient(135deg, #6366f1, #0d9488); box-shadow: 0 4px 14px rgba(99,102,241,.35); }
.topbar .btn-ghost { color: var(--ink-2); border-color: var(--line); }
.topbar .btn-ghost:hover { color: var(--teal); border-color: var(--teal); }

/* 深色通栏 Hero */
.hero-cover {
  background: linear-gradient(rgba(15,27,45,.82), rgba(15,27,45,.88)),
              url('https://images.unsplash.com/photo-1517245386807-bb43f82c33c4?auto=format&fit=crop&w=1600&q=80') center/cover;
  background-color: var(--navy);
  color: #fff; text-align: center; padding: 120px 0 130px; position: relative;
}
.hero-cover h1 { font-size: 46px; font-weight: 800; margin-bottom: 16px; }
.hero-cover p { font-size: 18px; color: #c5d0e2; margin-bottom: 36px; }
.hero-cover .btns { display: flex; gap: 18px; justify-content: center; }
.hero-cover .btn-primary { background: linear-gradient(135deg, #6366f1, #0d9488); box-shadow: 0 6px 22px rgba(99,102,241,.4); }
.hero-cover .btn-ghost { border-color: rgba(255,255,255,.5); color: #fff; }
.hero-cover .btn-ghost:hover { background: rgba(255,255,255,.08); border-color: #fff; }

/* 区块标题居中 */
.sec-center { text-align: center; margin-bottom: 44px; }
.sec-center h2 { font-size: 30px; font-weight: 800; color: var(--ink); margin-bottom: 10px; }
.sec-center p { color: var(--ink-3); font-size: 15px; }

/* 岗位系统班 */
.track-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.track-card {
  background: linear-gradient(135deg, #0ea5e9, #6366f1); border-radius: 18px; padding: 30px; color: #fff;
  min-height: 220px; display: flex; flex-direction: column; position: relative; overflow: hidden; box-shadow: 0 10px 26px rgba(99,102,241,.2);
}
.track-card:nth-child(2) { background: linear-gradient(135deg, #8b5cf6, #ec4899); }
.track-card:nth-child(3) { background: linear-gradient(135deg, #06b6d4, #3b82f6); }
.track-card:nth-child(4) { background: linear-gradient(135deg, #10b981, #0d9488); }
.track-card:nth-child(5) { background: linear-gradient(135deg, #f59e0b, #ef4444); }
.track-card:nth-child(6) { background: linear-gradient(135deg, #6366f1, #8b5cf6); }
.track-card .ico { font-size: 48px; opacity: .22; position: absolute; right: 16px; bottom: 16px; }
.track-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 16px; z-index: 1; }
.track-card ul { list-style: none; z-index: 1; margin-top: auto; }
.track-card li { font-size: 14px; padding: 7px 0; border-bottom: 1px solid rgba(255,255,255,.15); opacity: .95; }
.track-card li:last-child { border-bottom: none; }

/* 行业专题课 */
.industry-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.industry-card {
  border-radius: 16px; height: 160px; display: flex; flex-direction: column; justify-content: flex-end; padding: 20px;
  color: #fff; position: relative; overflow: hidden; cursor: pointer; transition: .25s; box-shadow: var(--shadow);
}
.industry-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.industry-card .bg { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; font-size: 70px; opacity: .2; }
.industry-card .mask { position: absolute; inset: 0; background: linear-gradient(transparent 20%, rgba(15,27,45,.72)); }
.industry-card h4 { font-size: 16px; font-weight: 700; z-index: 1; margin-bottom: 10px; }
.industry-card .tag { z-index: 1; align-self: flex-start; background: rgba(255,255,255,.2); border: 1px solid rgba(255,255,255,.35); font-size: 12px; padding: 4px 12px; border-radius: 999px; }

/* 两栏主体 */
.mall-layout { display: grid; grid-template-columns: 1fr 340px; gap: 40px; align-items: start; }
.mall-main > .sec-head { margin-bottom: 24px; }
.mall-main > .sec-head h2 { font-size: 24px; }
.mall-main > .sec-head h2 small { font-size: 14px; color: var(--ink-3); font-weight: 400; margin-left: 12px; }

/* 精品专题课 / 方案横卡 */
.featured-card {
  display: flex; gap: 18px; background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 18px;
  margin-bottom: 18px; transition: .25s; cursor: pointer;
}
.featured-card:hover { box-shadow: var(--shadow-lg); border-color: #dbeafe; }
.featured-card .thumb { width: 140px; height: 100px; border-radius: 12px; flex: none; display: flex; align-items: center; justify-content: center; font-size: 42px; }
.featured-card .body { flex: 1; }
.featured-card h4 { font-size: 17px; font-weight: 700; margin-bottom: 8px; color: var(--ink); }
.featured-card p { font-size: 13.5px; color: var(--ink-3); line-height: 1.7; }

/* 右侧热门课程 */
.sidebar h3 { font-size: 20px; font-weight: 800; margin-bottom: 18px; color: var(--ink); }
.hot-list { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 18px; }
.hot-item { display: flex; gap: 12px; padding: 14px 0; border-bottom: 1px solid #f1f4f8; cursor: pointer; transition: .2s; }
.hot-item:last-child { border-bottom: none; }
.hot-item:hover { background: #f7f9fb; margin: 0 -18px; padding-left: 18px; padding-right: 18px; }
.hot-item .s-thumb { width: 72px; height: 52px; border-radius: 8px; flex: none; display: flex; align-items: center; justify-content: center; font-size: 24px; }
.hot-item .info { flex: 1; min-width: 0; }
.hot-item .t { font-size: 14px; font-weight: 700; color: var(--ink); line-height: 1.45; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.hot-item .m { font-size: 12px; color: var(--ink-3); margin-top: 4px; }
.hot-item .price { color: var(--danger); font-weight: 700; font-size: 13px; margin-top: 4px; }

/* 悬浮右侧咨询条 */
.float-bar {
  position: fixed; right: 0; top: 50%; transform: translateY(-50%);
  display: flex; flex-direction: column; z-index: 200;
}
.float-btn {
  width: 58px; height: 58px; display: flex; flex-direction: column; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #8b5cf6, #6366f1); color: #fff; font-size: 11px; border-bottom: 1px solid rgba(255,255,255,.15);
  cursor: pointer; transition: .2s;
}
.float-btn:first-child { border-radius: 8px 0 0 0; }
.float-btn:last-child { border-radius: 0 0 0 8px; border-bottom: none; }
.float-btn:hover { filter: brightness(1.08); }
.float-btn .ic { font-size: 18px; margin-bottom: 2px; }

@media (max-width: 960px) {
  .track-grid, .industry-grid { grid-template-columns: repeat(2, 1fr); }
  .mall-layout { grid-template-columns: 1fr; }
  .hero-cover h1 { font-size: 34px; }
  .float-bar { display: none; }
  .hp-reviews { grid-template-columns: 1fr; }
  .rate-sum { flex-direction: column; gap: 14px; }
}
@media (max-width: 560px) {
  .track-grid, .industry-grid { grid-template-columns: 1fr; }
  .hero-cover { padding: 80px 0 90px; }
  .hero-cover h1 { font-size: 28px; }
  .topbar .nav-links { display: none; }
  .topbar .phone { display: none; }
  .notice-bar .nb-phone { display: none; }
}