/* ============================================
   Vibe Coding Wiki · 中国色版
   基于《中国传统色 Studio》设计哲学：
   - 暖纸基底、衬线标题、锐角无圆角
   - 中国色 palette (石青/竹青/朱砂/鎏金/玄青/黛...)
   - Editorial · paper-calm · sharp
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=M+PLUS+Rounded+1c:wght@400;500;700&family=Noto+Serif+SC:wght@500;700;900&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  /* ============ 中国色 Palette ============ */
  /* 主背景与文本（暖纸基底） */
  --c-paper: #F9F4DC;          /* 乳白 - 主背景 */
  --c-paper-deep: #F5F0E6;     /* 米白 - 次背景 */
  --c-panel: #FFFFFF;          /* 面板 */
  --c-panel-soft: #FAF6E6;     /* 凹陷面板 */
  --c-ink: #0F1A20;            /* 墨黑 - 主文字 */
  --c-ink-soft: #3B4F5C;       /* 黛色 - 次文字 */
  --c-muted: #777777;          /* 三级文字 */
  --c-line-soft: #E9E4DA;      /* 细线 */
  --c-line: #DDD6CA;           /* 中线 */
  --c-line-strong: #AAA093;    /* 强线 */

  /* 品牌主色（中国色意境） */
  --c-shihqing: #2E5D8C;       /* 石青 - 主品牌色 */
  --c-zhuqing: #00A86B;        /* 竹青 - 成功 / 正向 */
  --c-zhusha: #F43E06;         /* 朱砂 - 警示 / 风险 */
  --c-liujin: #D4AF37;         /* 鎏金 - 高亮 / 点缀 */
  --c-xuanqing: #2B3A4F;       /* 玄青 - 深邃 */
  --c-dai: #3B4F5C;            /* 黛色 - 中性 */
  --c-shui: #4F84FF;           /* 绀青 - 信息 */
  --c-qianjiang: #D9A594;      /* 浅绛 - 场景 */

  /* wash 浅色背景 */
  --c-wash-yellow: #F8DF72;    /* 麦秆黄 */
  --c-wash-green: #D7E8D0;     /* 浅绿 */
  --c-wash-red: #EAD0D1;       /* 胭脂淡 */
  --c-wash-blue: #D8E3E7;      /* 雪青淡 */

  /* ============ 8 大层级色 ============ */
  --L1-paradigm: #2B3A4F;      /* 玄青 */
  --L2-method: #4F84FF;        /* 绀青 */
  --L3-tech: #00A86B;          /* 竹青 */
  --L4-tools: #2E5D8C;         /* 石青 */
  --L5-quality: #D4AF37;       /* 鎏金 */
  --L6-risk: #F43E06;          /* 朱砂 */
  --L7-prompt: #3B4F5C;        /* 黛色 */
  --L8-scenario: #D9A594;      /* 浅绛 */

  /* ============ 系统 ============ */
  --font-title: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, serif;
  --font-body: "Avenir Next", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-rounded: "M PLUS Rounded 1c", "PingFang SC", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Menlo", monospace;

  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
  --ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);

  --content: 1240px;
  --shadow-card: 0 14px 34px rgba(17, 17, 17, 0.08);
  --shadow-soft: 0 18px 50px rgba(17, 17, 17, 0.06);
}

/* ============ Reset ============ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-margin-top: 82px;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  color: var(--c-ink);
  background: var(--c-paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

img { max-width: 100%; display: block; }

button { font-family: inherit; cursor: pointer; border: none; background: none; }

.container {
  max-width: var(--content);
  margin: 0 auto;
  padding: 0 32px;
}

/* ============ Top Nav ============ */
.topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(249, 244, 220, 0.86);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-line-soft);
}

.topnav__inner {
  display: flex;
  align-items: center;
  height: 72px;
  gap: 32px;
}

.topnav__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-ink);
  color: var(--c-paper);
  font-family: var(--font-title);
  font-weight: 900;
  font-size: 16px;
  letter-spacing: 0.02em;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-text strong {
  font-family: var(--font-title);
  font-weight: 900;
  font-size: 17px;
  color: var(--c-ink);
  letter-spacing: 0.02em;
}

.brand-text small {
  font-size: 11px;
  color: var(--c-muted);
  font-weight: 500;
  letter-spacing: 0.05em;
}

.topnav__links {
  display: flex;
  gap: 28px;
  margin-left: auto;
}

.topnav__links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--c-ink-soft);
  position: relative;
  padding: 4px 0;
  transition: color 0.2s var(--ease-out-quart);
}

.topnav__links a:hover { color: var(--c-ink); }

.topnav__links a.active {
  color: var(--c-ink);
}

.topnav__links a.active::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  background: var(--c-ink);
}

.topnav__search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--c-panel-soft);
  border: 1px solid var(--c-line-soft);
  color: var(--c-muted);
  font-size: 13px;
  transition: all 0.2s var(--ease-out-quart);
}

.topnav__search:hover {
  background: var(--c-panel);
  border-color: var(--c-line);
  color: var(--c-ink);
}

.topnav__search kbd {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 6px;
  background: var(--c-paper);
  border: 1px solid var(--c-line);
  color: var(--c-ink-soft);
}

/* ============ Hero ============ */
.hero {
  position: relative;
  padding: 88px 0 64px;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 800px 400px at 20% 0%, rgba(216, 227, 231, 0.4), transparent 60%),
    radial-gradient(ellipse 600px 300px at 90% 50%, rgba(248, 223, 114, 0.18), transparent 60%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
}

.hero__chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--c-panel);
  border: 1px solid var(--c-line-soft);
  font-size: 12px;
  font-weight: 500;
  color: var(--c-ink-soft);
  letter-spacing: 0.04em;
  margin-bottom: 24px;
}

.hero__chip .dot {
  width: 6px; height: 6px;
  background: var(--c-zhuqing);
  display: inline-block;
}

.hero__title {
  font-family: var(--font-title);
  font-size: clamp(2.4rem, 5vw, 4.2rem);
  font-weight: 900;
  line-height: 1.15;
  color: var(--c-ink);
  margin-bottom: 24px;
  text-wrap: balance;
  letter-spacing: -0.01em;
}

.hero__title .gradient {
  background: linear-gradient(135deg, var(--c-shihqing) 0%, var(--c-zhuqing) 50%, var(--c-liujin) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero__subtitle {
  font-size: 18px;
  line-height: 1.7;
  color: var(--c-ink-soft);
  max-width: 720px;
  margin-bottom: 40px;
}

.hero__metrics {
  display: flex;
  gap: 0;
  border: 1px solid var(--c-line);
  background: var(--c-panel);
  margin-bottom: 32px;
}

.metric {
  flex: 1;
  padding: 24px 28px;
  border-right: 1px solid var(--c-line-soft);
}

.metric:last-child { border-right: none; }

.metric__value {
  font-family: var(--font-rounded);
  font-weight: 700;
  font-size: 36px;
  color: var(--c-ink);
  line-height: 1;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.metric__label {
  font-size: 12px;
  color: var(--c-muted);
  letter-spacing: 0.06em;
  font-weight: 500;
  text-transform: uppercase;
}

.hero__cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.hero__hint {
  font-size: 13px;
  color: var(--c-muted);
  margin-bottom: 32px;
  font-family: var(--font-body);
}

.hero__hint kbd {
  display: inline-block;
  padding: 1px 6px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-ink);
  margin: 0 2px;
}

.hero__hint a {
  color: var(--c-shihqing);
  font-weight: 500;
}

.hero__hint a:hover {
  text-decoration: underline;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font-body);
  min-height: 46px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s var(--ease-out-quart);
  letter-spacing: 0.02em;
}

.btn:hover { transform: translateY(-1px); }

.btn--primary {
  background: var(--c-ink);
  color: var(--c-paper);
  border-color: var(--c-ink);
}

.btn--primary:hover {
  background: var(--c-zhuqing);
  border-color: var(--c-zhuqing);
}

.btn--ghost {
  background: transparent;
  color: var(--c-ink);
  border-color: var(--c-line-strong);
}

.btn--ghost:hover {
  background: var(--c-ink);
  color: var(--c-paper);
  border-color: var(--c-ink);
}

/* ============ Two Column ============ */
.two-col {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 64px;
  padding-top: 32px;
  padding-bottom: 64px;
}

.col-main { min-width: 0; }

.col-side { min-width: 0; }

.section-h2 {
  font-family: var(--font-title);
  font-size: 2rem;
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.section-lede {
  font-size: 15px;
  color: var(--c-ink-soft);
  margin-bottom: 32px;
  line-height: 1.7;
}

.block-h3 {
  font-family: var(--font-title);
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--c-ink);
  margin: 48px 0 20px;
  letter-spacing: 0.01em;
}

/* ============ Layer Grid ============ */
.layer-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border: 1px solid var(--c-line);
  background: var(--c-line);
}

.layer-card {
  display: block;
  padding: 24px;
  background: var(--c-panel);
  text-decoration: none;
  color: inherit;
  position: relative;
  border-left: 3px solid transparent;
  transition: all 0.2s var(--ease-out-quart);
}

.layer-card:hover {
  background: var(--c-paper-deep);
  border-left-width: 6px;
}

.layer-card__num {
  font-family: var(--font-rounded);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-ink);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  opacity: 0.5;
}

.layer-card__title {
  font-family: var(--font-title);
  font-size: 18px;
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: 8px;
  letter-spacing: 0.01em;
}

.layer-card__desc {
  font-size: 13px;
  color: var(--c-ink-soft);
  line-height: 1.6;
  margin-bottom: 12px;
}

.layer-card__count {
  font-family: var(--font-rounded);
  font-size: 11px;
  color: var(--c-muted);
  letter-spacing: 0.05em;
}

.layer-card--L1:hover { border-left-color: var(--L1-paradigm); }
.layer-card--L2:hover { border-left-color: var(--L2-method); }
.layer-card--L3:hover { border-left-color: var(--L3-tech); }
.layer-card--L4:hover { border-left-color: var(--L4-tools); }
.layer-card--L5:hover { border-left-color: var(--L5-quality); }
.layer-card--L6:hover { border-left-color: var(--L6-risk); }
.layer-card--L7:hover { border-left-color: var(--L7-prompt); }
.layer-card--L8:hover { border-left-color: var(--L8-scenario); }

/* ============ Scenario Strip ============ */
.scenario-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.scenario-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  font-size: 13px;
  font-weight: 500;
  color: var(--c-ink);
  transition: all 0.2s var(--ease-out-quart);
}

.scenario-chip:hover {
  background: var(--c-qianjiang);
  color: var(--c-ink);
  border-color: var(--c-qianjiang);
}

.scenario-chip .ic { font-size: 14px; }

/* ============ Side Cards ============ */
.side-card {
  padding: 24px;
  background: var(--c-panel);
  border: 1px solid var(--c-line-soft);
  margin-bottom: 20px;
}

.side-card h4 {
  font-family: var(--font-title);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: 14px;
  letter-spacing: 0.02em;
}

.side-card p {
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-ink-soft);
  margin-bottom: 10px;
}

.side-card a {
  color: var(--c-shihqing);
  font-size: 13px;
  font-weight: 600;
  border-bottom: 1px solid var(--c-shihqing);
}

.side-card--warning {
  background: var(--c-wash-red);
  border-color: var(--c-zhusha);
}

.side-card--warning h4 { color: var(--c-zhusha); }

.side-card--warning p strong { color: var(--c-ink); }

.side-card--warning a {
  color: var(--c-zhusha);
  border-bottom-color: var(--c-zhusha);
}

.quote {
  font-family: var(--font-title);
  font-size: 14px;
  font-weight: 500;
  font-style: italic;
  color: var(--c-ink);
  padding: 0 0 0 16px;
  border-left: 2px solid var(--c-zhuqing);
  line-height: 1.7;
}

.quote cite {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  font-style: normal;
  color: var(--c-muted);
  font-family: var(--font-body);
}

.kv {
  list-style: none;
  padding: 0;
}

.kv li {
  padding: 10px 0;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 13px;
}

.kv li:last-child { border-bottom: none; }

.kv strong {
  display: block;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 13px;
  color: var(--c-ink);
  margin-bottom: 4px;
}

.kv span {
  color: var(--c-ink-soft);
  line-height: 1.5;
}

.start-list {
  list-style: none;
  counter-reset: step;
  padding: 0;
}

.start-list li {
  counter-increment: step;
  padding: 8px 0 8px 32px;
  position: relative;
  font-size: 13px;
}

.start-list li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 8px;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-ink);
  color: var(--c-paper);
  font-family: var(--font-rounded);
  font-weight: 700;
  font-size: 11px;
}

.start-list a {
  color: var(--c-shihqing);
  font-weight: 600;
  border-bottom: 1px solid var(--c-shihqing);
}

/* ============ Concept Grid ============ */
.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 1px solid var(--c-line);
  background: var(--c-line);
}

.concept-card {
  display: flex;
  flex-direction: column;
  padding: 28px 24px;
  background: var(--c-panel);
  border-top: 3px solid var(--c-shihqing);
  transition: all 0.2s var(--ease-out-quart);
}

.concept-card:hover {
  background: var(--c-paper-deep);
  transform: translateY(-2px);
}

.concept-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  gap: 10px;
}

.concept-card h3 {
  font-family: var(--font-title);
  font-size: 17px;
  font-weight: 700;
  color: var(--c-ink);
  letter-spacing: 0.01em;
}

.badge {
  display: inline-block;
  padding: 3px 8px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-family: var(--font-rounded);
}

.badge--core { background: var(--c-wash-yellow); color: var(--c-ink); }
.badge--method { background: var(--c-wash-blue); color: var(--c-ink); }
.badge--tech { background: var(--c-wash-green); color: var(--c-ink); }
.badge--quality { background: #F5E6C8; color: var(--c-ink); }
.badge--risk { background: var(--c-wash-red); color: var(--c-ink); }

.concept-card p {
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-ink-soft);
  flex: 1;
  margin-bottom: 14px;
}

.concept-card footer a {
  font-size: 12px;
  font-weight: 600;
  color: var(--c-shihqing);
  border-bottom: 1px solid var(--c-shihqing);
  padding-bottom: 1px;
}

/* ============ Timeline ============ */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-left: 2px solid var(--c-line);
  padding-left: 32px;
  margin-top: 16px;
}

.timeline__item {
  position: relative;
  padding: 14px 0;
}

.timeline__item::before {
  content: '';
  position: absolute;
  left: -38px;
  top: 20px;
  width: 10px;
  height: 10px;
  background: var(--c-zhuqing);
  border: 2px solid var(--c-paper);
}

.timeline__date {
  font-family: var(--font-rounded);
  font-size: 12px;
  font-weight: 700;
  color: var(--c-shihqing);
  letter-spacing: 0.04em;
  margin-bottom: 4px;
}

.timeline__content {
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-ink);
}

.timeline__content strong { color: var(--c-zhusha); font-weight: 700; }

/* ============ Footer ============ */
.footer {
  margin-top: 80px;
  padding: 48px 0;
  border-top: 1px solid var(--c-line);
  background: var(--c-panel-soft);
}

.footer__inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 32px;
}

.footer strong {
  font-family: var(--font-title);
  font-size: 16px;
  font-weight: 700;
  display: block;
  margin-bottom: 6px;
}

.footer p {
  font-size: 13px;
  color: var(--c-muted);
  max-width: 480px;
  line-height: 1.6;
}

.footer__last-updated {
  font-size: 12px !important;
  margin-top: 8px;
  opacity: 0.8;
}

.footer__last-updated a {
  color: var(--c-shihqing);
  text-decoration: none;
  margin: 0 4px;
}

.footer__last-updated a:hover {
  text-decoration: underline;
}

.footer__links {
  display: flex;
  gap: 24px;
}

.footer__links a {
  font-size: 13px;
  color: var(--c-ink-soft);
  font-weight: 500;
  transition: color 0.2s;
}

.footer__links a:hover { color: var(--c-shihqing); }

/* ============ Search Modal ============ */
.search-modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 26, 32, 0.6);
  z-index: 1000;
  align-items: flex-start;
  justify-content: center;
  padding-top: 12vh;
}

.search-modal.open { display: flex; }

.search-modal__inner {
  width: 90%;
  max-width: 640px;
  background: var(--c-panel);
  border: 1px solid var(--c-line-strong);
  box-shadow: var(--shadow-soft);
  padding: 24px;
}

.search-modal__inner input {
  width: 100%;
  padding: 14px 16px;
  background: var(--c-paper-deep);
  border: 1px solid var(--c-line);
  font-family: var(--font-body);
  font-size: 16px;
  color: var(--c-ink);
  outline: none;
}

.search-modal__inner input:focus { border-color: var(--c-shihqing); }

.search-results {
  max-height: 50vh;
  overflow-y: auto;
  margin-top: 16px;
}

.search-result {
  padding: 12px 14px;
  border: 1px solid transparent;
  border-bottom: 1px solid var(--c-line-soft);
  cursor: pointer;
  transition: all 0.15s;
}

.search-result:hover, .search-result.active {
  background: var(--c-paper-deep);
  border-color: var(--c-shihqing);
}

.search-result h5 {
  font-family: var(--font-title);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: 4px;
}

.search-result p {
  font-size: 12px;
  color: var(--c-ink-soft);
  line-height: 1.5;
}

.search-mark {
  background: var(--c-liujin);
  color: var(--c-ink);
  padding: 0 2px;
  font-weight: 600;
  border-radius: 0;
}

.search-layer-badge {
  display: inline-block;
  padding: 3px 8px;
  font-family: var(--font-rounded);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.search-modal__hint {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--c-line-soft);
  font-size: 12px;
  color: var(--c-muted);
  text-align: center;
}

/* ============ Sections (used on other pages) ============ */
.section {
  padding: 64px 0;
}

.section + .section { border-top: 1px solid var(--c-line-soft); }

/* ============ Responsive ============ */
@media (max-width: 960px) {
  .two-col { grid-template-columns: 1fr; }
  .concept-grid { grid-template-columns: repeat(2, 1fr); }
  .layer-grid { grid-template-columns: 1fr; }
  .topnav__links { display: none; }
  .hero__metrics { flex-wrap: wrap; }
  .metric { flex-basis: 50%; border-right: none; border-bottom: 1px solid var(--c-line-soft); }
  .container { padding: 0 20px; }
}

@media (max-width: 600px) {
  .concept-grid { grid-template-columns: 1fr; }
  .hero { padding: 48px 0 32px; }
  .hero__title { font-size: 2rem; }
  .hero__subtitle { font-size: 15px; }
  .footer__inner { flex-direction: column; }
  .topnav__search { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

::selection {
  background: var(--c-liujin);
  color: var(--c-ink);
}

:focus-visible {
  outline: 3px solid var(--c-shihqing);
  outline-offset: 3px;
  border-radius: 0;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 8px;
  z-index: 9999;
  padding: 12px 20px;
  background: var(--c-ink);
  color: var(--c-paper);
  font-family: var(--font-title);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  border: 2px solid var(--c-liujin);
  transition: top 0.2s;
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 8px;
  outline: 3px solid var(--c-liujin);
  outline-offset: 2px;
}

#main-content:focus {
  outline: none;
}

/* 键盘焦点增强 */
a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--c-shihqing);
  outline-offset: 3px;
  background-color: rgba(46, 93, 140, 0.06);
}

[data-theme="dark"] a:focus-visible,
[data-theme="dark"] button:focus-visible,
[data-theme="dark"] input:focus-visible,
[data-theme="dark"] [tabindex]:focus-visible {
  outline-color: var(--c-liujin);
  background-color: rgba(240, 203, 94, 0.08);
}

/* 跳过链接面板 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* 仅屏幕阅读器可见 */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.sr-only-focusable:focus,
.sr-only-focusable:focus-within {
  position: static;
  width: auto;
  height: auto;
  overflow: visible;
  clip: auto;
  white-space: normal;
}

/* 高对比模式 */
@media (prefers-contrast: high) {
  :root {
    --c-line: #000000;
    --c-line-strong: #000000;
  }
  [data-theme="dark"] {
    --c-line: #FFFFFF;
    --c-line-strong: #FFFFFF;
  }
}