/* ============================================================
   鱼叔 AI 实验室 · 全站样式（主题 C · 琥珀橙）
   配色与原则见 DESIGN.md，修改前先读它
   ============================================================ */
:root {
  --ink: #2b2119;        /* 正文墨色（暖褐） */
  --ink-soft: #7a6a58;   /* 次要文字 */
  --paper: #fbf8f3;      /* 页面浅底 */
  --paper-alt: #f4ede3;  /* 交替区块底 */
  --elm: #d97706;        /* 主色 · 琥珀橙 */
  --elm-deep: #7c3a0e;   /* 深色 · 深褐 */
  --elm-light: #fef3c7;  /* 主色浅底 */
  --gold: #b45309;       /* 点缀 · 赭金（编号/时间） */
  --sun: #fde68a;        /* 高亮 · 暖黄 */
  --line: #e5dccf;       /* 描边 */
  --radius: 14px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.75;
  overflow-x: hidden;
}

/* ===== 导航 ===== */
.site-nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(251, 248, 243, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1080px; margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: flex-start; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.brand-mark {
  width: 38px; height: 38px; border-radius: 10px;
  background: var(--elm); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 700;
  transition: transform .3s;
}
.brand:hover .brand-mark { transform: rotate(-8deg) scale(1.08); }
.brand-text { font-weight: 700; font-size: 16px; line-height: 1.25; display: flex; flex-direction: column; }
.brand-text small { font-weight: 400; font-size: 10px; letter-spacing: 0.18em; color: var(--ink-soft); }
.nav-links { display: flex; align-items: center; gap: 22px; margin-left: 20px; }
.nav-links a { text-decoration: none; color: var(--ink-soft); font-size: 15px; transition: color .15s, transform .15s; display: inline-block; }
.nav-links a:hover { color: var(--elm-deep); transform: translateY(-2px); }
.nav-links a.active { color: var(--elm-deep); font-weight: 700; }
.nav-cta {
  color: var(--ink-soft) !important;
  margin-left: auto;
  font-size: 15px;
}
.nav-cta:hover { color: var(--elm-deep) !important; text-decoration: underline; }

/* ===== Hero ===== */
.hero { position: relative; padding: 64px 24px 64px; overflow: hidden; }
.hero-inner { max-width: 1080px; margin: 0 auto; position: relative; z-index: 2; }
.hero-eyebrow { color: var(--gold); font-size: 13px; letter-spacing: 0.2em; margin-bottom: 16px; }
.hero h1 { font-size: clamp(36px, 5.4vw, 60px); line-height: 1.22; letter-spacing: 0.02em; font-weight: 800; }
.hero .hl { position: relative; color: var(--elm-deep); white-space: nowrap; }
.hero .hl::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 6px; height: 12px;
  background: var(--sun); z-index: -1; border-radius: 4px;
  transform: skewX(-8deg);
}
.hero-sub { max-width: 620px; margin-top: 22px; color: var(--ink-soft); font-size: 17px; }
.hero-actions { margin-top: 32px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 13px 26px; border-radius: 999px;
  text-decoration: none; font-size: 15px; font-weight: 600;
  border: none; cursor: pointer; transition: all .15s;
}
.btn-primary { background: var(--elm); color: #fff; box-shadow: 0 6px 18px rgba(217, 119, 6, .25); }
.btn-primary:hover { background: var(--elm-deep); transform: translateY(-2px); }
.btn-ghost { border: 1px solid var(--ink); color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: #fff; transform: translateY(-2px); }
.btn-light { background: #fff; color: var(--elm-deep); }
.btn-light:hover { transform: translateY(-2px) rotate(-1deg); }
.hero-stats { display: flex; gap: 44px; margin-top: 56px; flex-wrap: wrap; }
.stat strong { display: block; font-size: 32px; color: var(--elm-deep); font-variant-numeric: tabular-nums; }
.stat span { font-size: 13px; color: var(--ink-soft); }

/* 气泡 */
.bubble {
  position: absolute; border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,.9), rgba(217,119,6,.12));
  border: 1px solid rgba(217,119,6,.15);
  animation: float 9s ease-in-out infinite;
}
.bubble-1 { width: 90px; height: 90px; right: 12%; top: 18%; }
.bubble-2 { width: 46px; height: 46px; right: 24%; top: 46%; animation-delay: -3s; }
.bubble-3 { width: 140px; height: 140px; right: 5%; top: 52%; animation-delay: -6s; }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-22px); }
}

/* ===== 通用区块 ===== */
.section { max-width: 1080px; margin: 0 auto; padding: 72px 24px; }
.section-alt { background: var(--paper-alt); max-width: none; }
.section-alt > * { max-width: 1032px; margin-left: auto; margin-right: auto; }
.section-head { margin-bottom: 36px; }
.section-head h2 { font-size: 30px; font-weight: 800; letter-spacing: 0.04em; }
.section-head p { color: var(--ink-soft); margin-top: 8px; max-width: 640px; }

/* ===== 卡片 ===== */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; display: flex; flex-direction: column; gap: 12px;
  transition: transform .18s, box-shadow .18s;
}
a.card { text-decoration: none; color: inherit; }
.card:hover { transform: translateY(-4px) rotate(-0.4deg); box-shadow: 0 14px 30px rgba(43, 33, 25, .1); }
.card h3 { font-size: 19px; }
.card p { color: var(--ink-soft); font-size: 14.5px; flex: 1; }
.card-featured { border-color: var(--elm); box-shadow: 0 8px 24px rgba(217, 119, 6, .1); }
.card-soon { opacity: .78; border-style: dashed; }
.card-link { color: var(--elm-deep); font-weight: 700; font-size: 14px; }
.tag {
  align-self: flex-start; font-size: 12px; padding: 3px 12px; border-radius: 999px;
  background: var(--paper-alt); color: var(--ink-soft); border: 1px solid var(--line);
}
.tag-live { background: var(--elm); color: #fff; border-color: var(--elm); }
.tag-done { background: var(--elm-light); color: var(--elm-deep); border-color: var(--elm-light); }

/* ===== 生存法则 ===== */
.rule { max-width: 1080px; margin: 0 auto; padding: 8px 24px 72px; }
.rule-card {
  background: linear-gradient(135deg, var(--elm) 0%, var(--elm-deep) 100%);
  color: #fff; border-radius: 20px; padding: 44px 36px; text-align: center;
  box-shadow: 0 16px 40px rgba(124, 58, 14, .25);
}
.rule-label { font-size: 13px; letter-spacing: .2em; opacity: .8; margin-bottom: 14px; }
.rule-text {
  font-size: clamp(18px, 2.6vw, 24px); font-weight: 700; line-height: 1.6;
  min-height: 2.6em; max-width: 720px; margin: 0 auto 24px;
  transition: opacity .2s, transform .2s;
}
.rule-text.swap { opacity: 0; transform: translateY(8px); }

/* ===== 读书笔记 ===== */
.note-list { display: flex; flex-direction: column; }
.note-item { display: flex; gap: 24px; padding: 22px 4px; border-bottom: 1px solid var(--line); transition: background .15s; border-radius: 8px; }
.note-item:hover { background: rgba(255, 255, 255, .6); }
.note-item:last-of-type { border-bottom: none; }
.note-item time { color: var(--gold); font-size: 13px; white-space: nowrap; padding-top: 4px; }
.note-item h3 { font-size: 17px; margin-bottom: 4px; }
.note-item p { color: var(--ink-soft); font-size: 14.5px; }
.soon-note { margin-top: 20px; font-size: 14px; color: var(--ink-soft); background: #fff; border: 1px dashed var(--line); border-radius: 10px; padding: 12px 18px; }

/* ===== 更多 ===== */
.idea-list { list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 16px; }
.idea-list li { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 22px; transition: transform .15s; }
.idea-list li:hover { transform: translateY(-3px); }
.idea-list strong { display: block; font-size: 16px; margin-bottom: 6px; color: var(--elm-deep); }
.idea-list span { color: var(--ink-soft); font-size: 14px; }

/* ===== 二维码 ===== */
.qr { background: #fff; padding: 8px; border-radius: 12px; display: flex; align-items: center; justify-content: center; box-shadow: 0 6px 20px rgba(0, 0, 0, .15); }
.qr img { width: 100%; height: 100%; object-fit: contain; border-radius: 6px; display: block; }

/* ===== 联系 ===== */
.contact-card {
  background: var(--elm-deep); color: #fbf3ea; border-radius: 20px;
  padding: 56px 40px; text-align: center;
}
.contact-card h2 { font-size: 28px; margin-bottom: 10px; }
.contact-card > p { color: rgba(251, 243, 234, .75); max-width: 560px; margin: 0 auto 32px; }
.contact-channels { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; }
.channel { display: flex; flex-direction: column; align-items: center; gap: 10px; font-size: 14px; }
.channel .qr { width: 140px; height: 140px; }

/* ===== 页脚 ===== */
.site-footer { text-align: center; padding: 32px 24px; color: var(--ink-soft); font-size: 13px; border-top: 1px solid var(--line); }

@media (max-width: 720px) {
  .nav-links { gap: 14px; font-size: 14px; }
  .nav-links a:not(.nav-cta) { display: none; }
  .hero { padding: 72px 24px 56px; }
  .hero-stats { gap: 28px; }
  .note-item { flex-direction: column; gap: 6px; }
}

/* ===== 板块速览条 ===== */
.topic-strip {
  max-width: 1032px; margin: 0 auto 16px; padding: 0 24px;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px;
}
.topic-strip a {
  display: flex; align-items: baseline; gap: 8px;
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  padding: 14px 16px; text-decoration: none; color: var(--ink);
  font-size: 15px; font-weight: 600;
  transition: transform .15s, border-color .15s;
}
.topic-strip a:hover { transform: translateY(-2px); border-color: var(--elm); }
.topic-strip b { color: var(--gold); font-size: 12px; font-variant-numeric: tabular-nums; }

/* ===== 知识词条 chips ===== */
.chip-grid { display: flex; flex-wrap: wrap; gap: 12px; }
.chip {
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 10px 20px; font-size: 14.5px; color: var(--ink);
  transition: all .15s; cursor: default;
}
.chip:hover { border-color: var(--elm); color: var(--elm-deep); transform: translateY(-2px); background: var(--elm-light); }

/* ===== 板块内页 ===== */
.page-head { max-width: 1032px; margin: 0 auto; padding: 72px 24px 8px; }
.page-eyebrow { color: var(--gold); font-size: 13px; letter-spacing: 0.2em; }
.page-head h1 { font-size: clamp(30px, 4.4vw, 46px); font-weight: 800; margin-top: 10px; letter-spacing: 0.02em; }
.page-desc { color: var(--ink-soft); max-width: 660px; margin-top: 12px; font-size: 16px; }

.empty-list { display: flex; flex-direction: column; gap: 12px; }
.empty-item {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px 24px; display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.empty-item h3 { font-size: 17px; }
.empty-item p { color: var(--ink-soft); font-size: 14px; margin-top: 2px; }
a.empty-item { text-decoration: none; color: inherit; transition: transform .15s, border-color .15s; }
a.empty-item:hover { transform: translateY(-2px); border-color: var(--elm); }
.back-home { max-width: 1032px; margin: 0 auto; padding: 0 24px 24px; font-size: 14px; }
.back-home a { color: var(--elm-deep); text-decoration: none; }
.back-home a:hover { text-decoration: underline; }

@media (max-width: 720px) {
  .empty-item { flex-direction: column; align-items: flex-start; gap: 8px; }
}
.site-footer .beian { margin-top: 6px; font-size: 12px; color: var(--ink-soft); }
.site-footer .beian a { color: var(--ink-soft); text-decoration: none; }
.site-footer .beian a:hover { color: var(--ink); }