/* =========================================================
   跨境大白说 · Astro 设计系统
   高端极简：近白底 / 近黑主色 / 靛蓝 accent / 微软雅黑 / 字重 600
   ========================================================= */

:root {
  /* —— 语义色（HSL，便于透明度派生）—— */
  --bg: hsl(0 0% 98%);
  --surface: hsl(0 0% 100%);
  --surface-2: hsl(0 0% 96%);
  --primary: hsl(0 0% 9%);
  --primary-foreground: hsl(0 0% 100%);
  --accent: hsl(243 75% 59%);
  --accent-soft: hsl(243 75% 59% / 0.08);
  --accent-foreground: hsl(0 0% 100%);
  --text: hsl(0 0% 12%);
  --text-secondary: hsl(0 0% 40%);
  --text-tertiary: hsl(0 0% 55%);
  --border: hsl(0 0% 90%);
  --border-strong: hsl(0 0% 82%);
  --ring: hsl(243 75% 59% / 0.35);

  /* —— 尺寸 —— */
  --sidebar-w: 240px;
  --sidebar-w-collapsed: 64px;
  --topbar-h: 60px;
  --radius: 14px;
  --radius-sm: 10px;
  --radius-lg: 20px;
  --max-width: 1100px;

  --font-sans: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB",
    system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Cascadia Code", Menlo, Monaco, monospace;

  --shadow-sm: 0 1px 2px hsl(0 0% 0% / 0.04), 0 1px 3px hsl(0 0% 0% / 0.06);
  --shadow-md: 0 4px 16px hsl(0 0% 0% / 0.06);
  --shadow-lg: 0 12px 40px hsl(0 0% 0% / 0.10);
}

[data-theme="dark"] {
  --bg: hsl(240 10% 7%);
  --surface: hsl(240 9% 11%);
  --surface-2: hsl(240 8% 14%);
  --primary: hsl(0 0% 96%);
  --primary-foreground: hsl(240 10% 9%);
  --accent: hsl(243 80% 70%);
  --accent-soft: hsl(243 75% 59% / 0.16);
  --accent-foreground: hsl(240 10% 9%);
  --text: hsl(0 0% 92%);
  --text-secondary: hsl(0 0% 66%);
  --text-tertiary: hsl(0 0% 50%);
  --border: hsl(240 6% 20%);
  --border-strong: hsl(240 6% 28%);
  --ring: hsl(243 80% 70% / 0.4);
  --shadow-sm: 0 1px 2px hsl(0 0% 0% / 0.3);
  --shadow-md: 0 4px 16px hsl(0 0% 0% / 0.4);
  --shadow-lg: 0 12px 40px hsl(0 0% 0% / 0.5);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { font-size: 16px; scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-weight: 400;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; transition: color 0.18s ease; }
a:hover { color: var(--accent); filter: brightness(0.9); }

img { max-width: 100%; height: auto; }

h1, h2, h3, h4 { font-weight: 600; line-height: 1.3; color: var(--text); letter-spacing: -0.01em; }
h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.2rem; }

::selection { background: var(--accent-soft); color: var(--accent); }

/* =========================================================
   布局骨架
   ========================================================= */
.shell { display: flex; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  transition: width 0.22s ease;
  overflow: hidden;
}
.shell--collapsed .sidebar { width: var(--sidebar-w-collapsed); }

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  height: var(--topbar-h);
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-weight: 700;
  font-size: 1.05rem;
  white-space: nowrap;
}
.sidebar-brand .brand-mark {
  width: 32px; height: 32px; border-radius: 9px;
  background: var(--accent); color: var(--accent-foreground);
  display: grid; place-items: center; font-size: 1rem; flex-shrink: 0;
}
.sidebar-brand b { color: var(--accent); }

.sidebar-nav { flex: 1; overflow-y: auto; padding: 14px 12px; }
.nav-group { margin-bottom: 18px; }
.nav-group-title {
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.08em;
  color: var(--text-tertiary); text-transform: uppercase;
  padding: 0 12px 8px; white-space: nowrap;
}
.shell--collapsed .nav-group-title { opacity: 0; height: 8px; padding: 0; }

.nav-item {
  display: flex; align-items: center; gap: 12px;
  padding: 9px 12px; border-radius: var(--radius-sm);
  color: var(--text-secondary); font-size: 0.92rem; font-weight: 500;
  white-space: nowrap; transition: background 0.16s ease, color 0.16s ease;
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-item .mono {
  width: 28px; height: 28px; border-radius: 8px; flex-shrink: 0;
  display: grid; place-items: center; font-size: 0.85rem; font-weight: 700;
  background: var(--surface-2); color: var(--text-secondary);
}
.nav-item.active .mono { background: var(--accent); color: var(--accent-foreground); }
.shell--collapsed .nav-item-label { display: none; }

.sidebar-foot { border-top: 1px solid var(--border); padding: 12px; }
.collapse-btn {
  width: 100%; display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: var(--radius-sm); border: none;
  background: transparent; color: var(--text-tertiary); cursor: pointer;
  font-family: inherit; font-size: 0.88rem; font-weight: 500;
  transition: background 0.16s ease;
}
.collapse-btn:hover { background: var(--surface-2); color: var(--text); }
.shell--collapsed .collapse-btn .label { display: none; }

.shell-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }

.topbar {
  height: var(--topbar-h); position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--surface) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; gap: 12px;
}
.topbar-left { display: flex; align-items: center; gap: 12px; min-width: 0; }
.topbar-title { font-weight: 600; font-size: 1rem; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.icon-btn {
  width: 38px; height: 38px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text-secondary); cursor: pointer;
  display: grid; place-items: center; transition: all 0.16s ease;
}
.icon-btn:hover { color: var(--text); border-color: var(--border-strong); }
.menu-toggle { display: none; }

.shell-content { flex: 1; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: 820px; margin: 0 auto; padding: 0 24px; }

.site-footer {
  border-top: 1px solid var(--border);
  padding: 36px 24px; margin-top: 72px;
  background: var(--surface);
}
.site-footer .footer-inner { max-width: var(--max-width); margin: 0 auto; }
.site-footer .footer-links { display: flex; flex-wrap: wrap; gap: 18px; margin-bottom: 14px; }
.site-footer .footer-links a { color: var(--text-secondary); font-size: 0.9rem; font-weight: 500; }
.site-footer .footer-links a:hover { color: var(--accent); }
.site-footer p { color: var(--text-tertiary); font-size: 0.85rem; line-height: 1.8; }
.site-footer .footer-disclaim { margin-top: 10px; font-size: 0.8rem; color: var(--text-tertiary); }

/* =========================================================
   通用组件
   ========================================================= */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: 24px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer; font-family: inherit;
  transition: all 0.18s ease;
}
.btn-primary { background: var(--primary); color: var(--primary-foreground); }
.btn-primary:hover { filter: brightness(1.12); color: var(--primary-foreground); }
.btn-accent { background: var(--accent); color: var(--accent-foreground); }
.btn-accent:hover { filter: brightness(1.08); color: var(--accent-foreground); }
.btn-ghost { border-color: var(--border-strong); color: var(--text); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px; transition: all 0.18s ease;
}
.card:hover { box-shadow: var(--shadow-md); border-color: var(--border-strong); }
.card-grid { display: grid; gap: 16px; }
@media (min-width: 640px) { .card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .card-grid.cols-3 { grid-template-columns: repeat(3, 1fr); } }

.section-head { margin: 8px 0 24px; }
.section-head .eyebrow {
  display: inline-block; font-size: 0.78rem; font-weight: 600; letter-spacing: 0.06em;
  color: var(--accent); text-transform: uppercase; margin-bottom: 8px;
}
.section-head h2 { font-size: 1.5rem; }
.section-head p { color: var(--text-secondary); margin-top: 8px; font-size: 0.98rem; }

.badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 3px 11px; border-radius: 20px; font-size: 0.78rem; font-weight: 600;
  background: var(--accent-soft); color: var(--accent);
}
.badge-muted { background: var(--surface-2); color: var(--text-tertiary); }
/* 分类色只用 accent 同色相（243）的深浅渐变，禁止引入独立色相 */
.badge-amazon { background: hsl(243 75% 59% / 0.10); color: hsl(243 75% 52%); }
.badge-ai { background: hsl(243 60% 42% / 0.12); color: hsl(243 60% 40%); }

.page-hero { padding: 48px 0 32px; }
.page-hero h1 { font-size: 2.2rem; letter-spacing: -0.02em; }
.page-hero h1 .accent { color: var(--accent); }
.page-hero p { color: var(--text-secondary); margin-top: 14px; font-size: 1.08rem; max-width: 640px; }

.stat-row { display: flex; flex-wrap: wrap; gap: 28px; margin-top: 26px; }
.stat .num { font-size: 1.7rem; font-weight: 700; color: var(--text); }
.stat .label { font-size: 0.85rem; color: var(--text-tertiary); }

/* =========================================================
   筛选条 + 文章卡片（博客列表页）
   ========================================================= */
.filter-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.filter-btn {
  display: inline-flex; align-items: center;
  padding: 7px 16px; border-radius: 20px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-secondary); font-size: 0.88rem; font-weight: 500;
  text-decoration: none; transition: all 0.16s ease;
}
.filter-btn:hover { border-color: var(--accent); color: var(--accent); }
.filter-btn.active { background: var(--primary); border-color: var(--primary); color: var(--primary-foreground); font-weight: 600; }
.filter-btn.active:hover { color: var(--primary-foreground); }

.post-list { display: grid; gap: 16px; }
@media (min-width: 760px) { .post-list { grid-template-columns: repeat(2, 1fr); } }

.post-card {
  display: flex; flex-direction: column;
  padding: 22px 24px; background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius);
  color: var(--text); text-decoration: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}
.post-card:hover { border-color: var(--accent); box-shadow: var(--shadow-md); transform: translateY(-2px); color: var(--text); }
.post-card-meta { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.post-card-category,
.blog-post-category {
  display: inline-flex; align-items: center;
  padding: 3px 11px; border-radius: 20px;
  font-size: 0.75rem; font-weight: 600;
  background: var(--accent-soft); color: var(--accent);
}
/* 分类区分只用 accent 同色相（243）的深浅渐变，不引入新色相 */
.post-card-category.amazon,
.blog-post-category.amazon { background: hsl(243 75% 59% / 0.10); color: hsl(243 75% 52%); }
.post-card-category.ai,
.blog-post-category.ai { background: hsl(243 60% 42% / 0.12); color: hsl(243 60% 40%); }
.post-card-date { font-size: 0.82rem; color: var(--text-tertiary); }
.post-card h3 { font-size: 1.1rem; line-height: 1.45; margin-bottom: 8px; }
.post-card p { font-size: 0.93rem; color: var(--text-secondary); line-height: 1.65; }
.post-card-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; padding-top: 12px; border-top: 1px solid var(--border); }
.post-card-tag { font-size: 0.75rem; color: var(--text-tertiary); }

/* =========================================================
   博客详情页（正文排版）
   ========================================================= */
/* 位于 .blog-layout 网格内，左右间距由外层 container 提供 */
.blog-post { padding: 8px 0; min-width: 0; }
.blog-post-header { margin-bottom: 32px; }
.blog-post-header h1 { font-size: 2rem; line-height: 1.3; letter-spacing: -0.02em; }
.blog-post-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 16px; font-size: 0.85rem; color: var(--text-tertiary); }

.blog-post-body { font-size: 1.02rem; line-height: 1.85; color: var(--text); }
.blog-post-body h2 { font-size: 1.45rem; margin: 40px 0 16px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.blog-post-body h3 { font-size: 1.18rem; margin: 30px 0 12px; }
.blog-post-body h4 { font-size: 1.02rem; margin: 24px 0 10px; }
.blog-post-body p { margin-bottom: 18px; }
.blog-post-body ul, .blog-post-body ol { margin: 0 0 18px 22px; }
.blog-post-body li { margin-bottom: 8px; }
.blog-post-body a { text-decoration: underline; text-underline-offset: 2px; }
.blog-post-body strong { font-weight: 600; color: var(--text); }
.blog-post-body blockquote {
  margin: 20px 0; padding: 14px 18px;
  border-left: 3px solid var(--accent); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--surface-2); color: var(--text-secondary);
}
.blog-post-body code {
  padding: 2px 6px; border-radius: 5px;
  background: var(--surface-2); font-family: var(--font-mono); font-size: 0.88em;
}
.blog-post-body pre {
  margin: 20px 0; padding: 18px 20px; border-radius: var(--radius-sm);
  background: var(--surface-2); overflow-x: auto;
}
.blog-post-body pre code { background: transparent; padding: 0; font-size: 0.86em; }
.blog-post-body img { border-radius: var(--radius-sm); margin: 20px 0; }
.blog-post-body hr { margin: 32px 0; border: none; border-top: 1px solid var(--border); }
.blog-post-body table { width: 100%; margin: 20px 0; border-collapse: collapse; font-size: 0.94rem; }
.blog-post-body th, .blog-post-body td { padding: 10px 14px; border: 1px solid var(--border); text-align: left; }
.blog-post-body th { background: var(--surface-2); font-weight: 600; }

.blog-post-footer { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--border); }
.blog-post-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.blog-post-back {
  display: inline-flex; align-items: center;
  color: var(--text-secondary); font-size: 0.92rem; font-weight: 500; text-decoration: none;
}
.blog-post-back:hover { color: var(--accent); }

/* =========================================================
   详情页侧栏（分类列表 + 推荐文章，防孤岛）
   ========================================================= */
.blog-layout { display: grid; gap: 32px; align-items: start; }
@media (min-width: 1000px) { .blog-layout { grid-template-columns: minmax(0, 1fr) 260px; } }
.blog-sidebar { display: grid; gap: 20px; }
.blog-sidebar .card { padding: 18px 20px; }
.blog-sidebar h3 { font-size: 0.95rem; margin-bottom: 12px; }
.blog-sidebar ul { list-style: none; display: grid; gap: 8px; }
.blog-sidebar li a { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.5; text-decoration: none; }
.blog-sidebar li a:hover { color: var(--accent); }
.blog-sidebar .sidebar-count { color: var(--text-tertiary); font-size: 0.8rem; }
@media (max-width: 999px) { .blog-sidebar { order: 2; } }

/* 面包屑 */
.breadcrumb { padding: 20px 0 0; font-size: 0.85rem; color: var(--text-tertiary); }
.breadcrumb ol { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; list-style: none; }
.breadcrumb li { display: inline-flex; align-items: center; gap: 6px; }
.breadcrumb li + li::before { content: "/"; color: var(--border-strong); }
.breadcrumb a { color: var(--text-secondary); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb [aria-current="page"] { color: var(--text-tertiary); }

/* =========================================================
   关于页
   ========================================================= */
.about-page { padding: 40px 24px 0; }
.about-content { font-size: 1.02rem; line-height: 1.85; }
.about-content h2 { font-size: 1.4rem; margin: 36px 0 14px; }
.about-content h3 { font-size: 1.12rem; margin: 26px 0 10px; }
.about-content p { margin-bottom: 16px; }
.about-content ul { margin: 0 0 18px 22px; }
.about-content li { margin-bottom: 8px; }

.author-card {
  display: flex; gap: 20px; align-items: flex-start;
  padding: 24px; margin: 28px 0;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
}
.author-avatar {
  width: 68px; height: 68px; border-radius: 50%; flex-shrink: 0;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
  font-size: 1.7rem; font-weight: 700;
}
.author-info { flex: 1; min-width: 0; }
.author-info h2, .author-info h3 { font-size: 1.08rem; margin-bottom: 6px; }
.author-info p { font-size: 0.93rem; color: var(--text-secondary); margin: 0; line-height: 1.7; }

/* =========================================================
   杂项补充
   ========================================================= */
.btn--primary { background: var(--primary); color: var(--primary-foreground); }
.btn--primary:hover { filter: brightness(1.12); color: var(--primary-foreground); }
.cta-row { display: flex; align-items: center; gap: 12px; }
.muted { color: var(--text-secondary); }
.container-wide { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.i-sun, .i-moon { display: block; }
.blog-post-category { margin-right: 2px; }

/* 跳转到主内容：默认移出视口，键盘聚焦时显示 */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 300;
  padding: 10px 18px; border-radius: 0 0 var(--radius-sm) 0;
  background: var(--primary); color: var(--primary-foreground);
  font-size: 0.9rem; font-weight: 600; text-decoration: none;
}
.skip-link:focus { left: 0; outline: 2px solid var(--ring); }

@media (max-width: 768px) {
  .sidebar {
    position: fixed; left: 0; top: 0; z-index: 200;
    transform: translateX(-100%); transition: transform 0.22s ease, width 0.22s ease;
  }
  .shell--open .sidebar { transform: translateX(0); box-shadow: var(--shadow-lg); }
  .shell--collapsed .sidebar { width: var(--sidebar-w); }
  .shell--collapsed .nav-item-label,
  .shell--collapsed .nav-group-title,
  .shell--collapsed .collapse-btn .label { display: revert; }
  .menu-toggle { display: grid; }
  .scrim {
    display: none; position: fixed; inset: 0; background: hsl(0 0% 0% / 0.4); z-index: 150;
  }
  .shell--open .scrim { display: block; }
  .topbar { padding: 0 16px; }
  .container, .container-narrow { padding: 0 16px; }
  .page-hero h1 { font-size: 1.7rem; }
}