/* ============================================================
   AI 心得 · 站点样式
   基调：暖纸色背景 + 靛蓝点缀，重中文阅读体验，自动适配暗色模式
   零外部依赖（无 CDN 字体/框架），国内访问无忧
   ============================================================ */

:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --text: #2d2c29;
  --text-2: #6a675f;
  --text-3: #96928a;
  --border: #e7e4dc;
  --accent: #4f46e5;
  --accent-strong: #4338ca;
  --code-bg: #f0eee7;
  --pre-bg: #15161b;
  --pre-text: #e8e8ec;
  --shadow: 0 1px 2px rgba(40, 35, 20, 0.04), 0 10px 28px rgba(40, 35, 20, 0.06);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC",
    sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121317;
    --surface: #1a1b20;
    --text: #e7e6e1;
    --text-2: #a5a49d;
    --text-3: #73747c;
    --border: #292a31;
    --accent: #8b93f8;
    --accent-strong: #a5abfa;
    --code-bg: #22232a;
    --pre-bg: #101116;
    --pre-text: #e6e6ea;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.25), 0 10px 28px rgba(0, 0, 0, 0.3);
  }
}

/* ---------- 基础 ---------- */

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: color-mix(in srgb, var(--accent) 24%, transparent);
}

a {
  color: var(--accent);
}

a:hover {
  color: var(--accent-strong);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

.container {
  max-width: 46rem;
  margin-inline: auto;
  padding-inline: 1.4rem;
}

.spark {
  width: 1.05rem;
  height: 1.05rem;
  flex: none;
  color: var(--accent);
}

/* 跳到正文（无障碍） */
.skip-link {
  position: fixed;
  left: 1rem;
  top: -4rem;
  z-index: 99;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  text-decoration: none;
  font-size: 0.9rem;
  transition: top 0.15s ease;
}

.skip-link:focus {
  top: 1rem;
}

/* ---------- 顶栏 ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  -webkit-backdrop-filter: blur(10px) saturate(1.3);
  backdrop-filter: blur(10px) saturate(1.3);
  border-bottom: 1px solid var(--border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 3.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  font-size: 1.02rem;
}

.brand:hover {
  color: var(--text);
}

.site-nav a {
  margin-left: 1.4rem;
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.95rem;
}

.site-nav a:hover {
  color: var(--accent);
}

.site-nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 600;
}

/* ---------- 首页 Hero ---------- */

.hero {
  padding: 4.5rem 0 3.2rem;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 1.15rem;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--accent);
}

.eyebrow .spark {
  width: 0.85rem;
  height: 0.85rem;
}

.hero h1 {
  margin: 0 0 1.15rem;
  font-size: clamp(2rem, 5.5vw, 2.9rem);
  line-height: 1.24;
  letter-spacing: 0.01em;
}

.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-sub {
  max-width: 36rem;
  margin: 0;
  color: var(--text-2);
  font-size: 1.05rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1.8rem 0 0;
}

.chip {
  padding: 0.18rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.78rem;
  color: var(--text-3);
  background: var(--surface);
}

/* ---------- 区块 ---------- */

.section {
  padding: 0.8rem 0 3rem;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 1.1rem;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--text-2);
}

.section-title::before {
  content: "";
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 3px;
  background: var(--accent);
}

/* ---------- 文章列表 ---------- */

.post-list {
  border-top: 1px solid var(--border);
}

.post {
  padding: 1.7rem 0 1.9rem;
  border-bottom: 1px solid var(--border);
}

.post-item-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.post-time {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-3);
  font-variant-numeric: tabular-nums;
}

.post h3 {
  margin: 0.45rem 0 0.55rem;
  font-size: 1.3rem;
  line-height: 1.45;
}

.post h3 a {
  color: var(--text);
  text-decoration: none;
}

.post h3 a:hover {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 5px;
}

.post-excerpt {
  margin: 0 0 0.8rem;
  color: var(--text-2);
  font-size: 0.96rem;
}

.read-more {
  font-size: 0.86rem;
  text-decoration: none;
}

.read-more::after {
  content: " →";
  display: inline-block;
  transition: transform 0.15s ease;
}

.read-more:hover::after {
  transform: translateX(3px);
}

/* 标签 */
.tag-list {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag {
  padding: 0.08rem 0.62rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.74rem;
  color: var(--text-3);
  background: var(--surface);
}

/* 首页关于卡片 */
.about-card {
  padding: 1.5rem 1.7rem;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.about-card p {
  margin: 0;
  color: var(--text-2);
}

/* ---------- 文章页 ---------- */

.post-header {
  padding: 3.1rem 0 0;
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-3);
  font-variant-numeric: tabular-nums;
}

.post-header h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.65rem, 3.6vw, 2.2rem);
  line-height: 1.32;
}

.post-lede {
  margin: 0;
  color: var(--text-2);
  font-size: 1.04rem;
}

.prose {
  padding: 2.2rem 0 1rem;
}

.prose h2 {
  margin: 2.4em 0 0.8em;
  font-size: 1.32em;
  line-height: 1.4;
}

.prose h3 {
  margin: 2em 0 0.7em;
  font-size: 1.12em;
}

.prose p {
  margin: 1.05em 0;
}

.prose a {
  text-underline-offset: 4px;
}

.prose ul,
.prose ol {
  margin: 1.05em 0;
  padding-left: 1.6em;
}

.prose li {
  margin: 0.45em 0;
}

.prose li::marker {
  color: var(--accent);
}

.prose blockquote {
  margin: 1.7em 0;
  padding: 0.85em 1.25em;
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
  background: var(--surface);
  box-shadow: var(--shadow);
  color: var(--text-2);
}

.prose blockquote p {
  margin: 0.3em 0;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--code-bg);
  padding: 0.14em 0.42em;
  border-radius: 5px;
}

.prose pre {
  margin: 1.6em 0;
  padding: 1.15rem 1.3rem;
  border-radius: 11px;
  background: var(--pre-bg);
  color: var(--pre-text);
  overflow-x: auto;
  box-shadow: var(--shadow);
}

.prose pre code {
  display: block;
  background: none;
  padding: 0;
  font-size: 0.86rem;
  line-height: 1.65;
  color: inherit;
}

.prose table {
  width: 100%;
  margin: 1.7em 0;
  border-collapse: collapse;
  font-size: 0.94em;
}

.prose th,
.prose td {
  padding: 0.6rem 0.8rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

.prose th {
  color: var(--text-2);
  font-weight: 600;
  white-space: nowrap;
}

.prose hr {
  margin: 2.8em auto;
  width: 42%;
  border: 0;
  border-top: 1px solid var(--border);
}

.post-end {
  margin: 3.2rem 0 0.6rem;
  text-align: center;
  color: var(--text-3);
  letter-spacing: 0.4em;
  font-size: 0.85rem;
}

.post-nav {
  margin: 0 0 3rem;
}

.post-nav a {
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--text-2);
}

.post-nav a:hover {
  color: var(--accent);
}

/* ---------- 404 ---------- */

.lost {
  padding: 6.5rem 0 5rem;
  text-align: center;
}

.lost-code {
  margin: 0;
  font-size: clamp(4.2rem, 12vw, 6.5rem);
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(120deg, var(--accent), #a855f7);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lost h1 {
  margin: 1.2rem 0 0.8rem;
  font-size: 1.5rem;
}

.lost p {
  color: var(--text-2);
}

/* ---------- 页脚 ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 2.6rem 0 3rem;
  font-size: 0.88rem;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.2rem;
}

.footer-desc {
  margin: 0.45rem 0 0;
  color: var(--text-3);
  font-size: 0.84rem;
}

.footer-nav {
  display: flex;
  gap: 1.3rem;
}

.footer-nav a {
  color: var(--text-2);
  text-decoration: none;
}

.footer-nav a:hover {
  color: var(--accent);
}

/* 备案信息（由 footer.js 根据 site.json 渲染） */
.beian {
  margin-top: 1.9rem;
  padding-top: 1.35rem;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-3);
  font-size: 0.8rem;
}

.beian a {
  color: var(--text-3);
  text-decoration: none;
}

.beian a:hover {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.beian-sep {
  margin: 0 0.5em;
  opacity: 0.6;
}

/* ---------- 响应式 ---------- */

@media (max-width: 560px) {
  .hero {
    padding: 3.2rem 0 2.4rem;
  }

  .site-nav a {
    margin-left: 0.95rem;
  }

  .post-item-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-top {
    flex-direction: column;
  }
}