/* ============================================
   Atlas Theme System — 博客风格统一主题
   参考 blog.amarea.cn (VOID 主题风格)
   ============================================ */

/* ---------- 基础变量（浅色模式默认） ---------- */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --bg-hover: #f0f0f0;
  --text-primary: #1a1a1a;
  --text-secondary: #555555;
  --text-muted: #888888;
  --border: #e8e8e8;
  --border-light: #f0f0f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --nav-bg: rgba(255,255,255,0.85);
  --nav-border: rgba(0,0,0,0.06);
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
  --shadow-lg: 0 4px 20px rgba(0,0,0,0.08);
  --radius: 12px;
  --radius-sm: 8px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Consolas", monospace;
  --max-content: 720px;
  --nav-height: 60px;
}

/* ---------- 深色模式变量 ---------- */
[data-theme="dark"] {
  --bg-primary: #121212;
  --bg-secondary: #1a1a1a;
  --bg-card: #1e1e1e;
  --bg-hover: #2a2a2a;
  --text-primary: #e8e8e8;
  --text-secondary: #a0a0a0;
  --text-muted: #666666;
  --border: #333333;
  --border-light: #252525;
  --accent: #4dabf7;
  --accent-hover: #339af0;
  --nav-bg: rgba(18,18,18,0.85);
  --nav-border: rgba(255,255,255,0.06);
  --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.2);
  --shadow-lg: 0 4px 20px rgba(0,0,0,0.4);
}

/* ---------- 系统偏好自动适配 ---------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-primary: #121212;
    --bg-secondary: #1a1a1a;
    --bg-card: #1e1e1e;
    --bg-hover: #2a2a2a;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --border: #333333;
    --border-light: #252525;
    --accent: #4dabf7;
    --accent-hover: #339af0;
    --nav-bg: rgba(18,18,18,0.85);
    --nav-border: rgba(255,255,255,0.06);
    --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.2);
    --shadow-lg: 0 4px 20px rgba(0,0,0,0.4);
  }
}

/* ---------- 基础重置（低权重，允许页面覆盖） ---------- */
*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0; padding: 0;
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.3s ease, color 0.3s ease;
}

a { color: var(--accent); text-decoration: none; transition: color 0.2s ease; }
a:hover { color: var(--accent-hover); }

/* ---------- 统一导航栏 ---------- */
.atlas-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--nav-height);
  background: var(--nav-bg);
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  border-bottom: 1px solid var(--nav-border);
  transition: background 0.3s ease, border-color 0.3s ease;
}

.atlas-nav-inner {
  max-width: var(--max-content); margin: 0 auto; height: 100%;
  display: flex; align-items: center; justify-content: space-between; padding: 0 20px;
}

.atlas-nav-logo {
  font-size: 18px; font-weight: 700; letter-spacing: 0.15em;
  color: var(--text-primary); text-transform: uppercase; transition: color 0.3s ease;
}
.atlas-nav-logo:hover { color: var(--accent); }

.atlas-nav-links { display: flex; align-items: center; gap: 28px; }
.atlas-nav-links a { font-size: 14px; font-weight: 500; color: var(--text-secondary); transition: color 0.2s ease; }
.atlas-nav-links a:hover { color: var(--text-primary); }

.atlas-theme-toggle {
  width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--border);
  background: var(--bg-card); color: var(--text-secondary); font-size: 16px;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: all 0.2s ease;
}
.atlas-theme-toggle:hover { background: var(--bg-hover); color: var(--text-primary); }

@media (max-width: 640px) {
  .atlas-nav-links { gap: 16px; }
  .atlas-nav-links a { font-size: 13px; }
  .atlas-nav-logo { font-size: 16px; }
}

/* ---------- 内容区 ---------- */
.atlas-main { padding-top: var(--nav-height); min-height: 100vh; }

/* ---------- 统一页脚 ---------- */
.atlas-footer {
  border-top: 1px solid var(--border); padding: 40px 20px; text-align: center;
  background: var(--bg-secondary);
  transition: background 0.3s ease, border-color 0.3s ease;
}
.atlas-footer-inner { max-width: var(--max-content); margin: 0 auto; }
.atlas-footer p, .atlas-footer a { font-size: 13px; color: var(--text-muted); line-height: 1.8; }
.atlas-footer a:hover { color: var(--text-secondary); }
.atlas-footer-divider { margin: 0 8px; color: var(--border); }

/* ---------- 文章卡片 ---------- */
.atlas-post-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; margin-bottom: 20px;
  transition: box-shadow 0.3s ease, transform 0.2s ease, border-color 0.3s ease;
  cursor: pointer;
}
.atlas-post-card:hover {
  box-shadow: var(--shadow-lg); transform: translateY(-2px); border-color: var(--border-light);
}
.atlas-post-meta { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; flex-wrap: wrap; }
.atlas-post-tag {
  font-size: 11px; font-weight: 600; color: var(--accent);
  letter-spacing: 0.05em; text-transform: uppercase;
}
.atlas-post-date { font-size: 12px; color: var(--text-muted); }
.atlas-post-title {
  font-size: 20px; font-weight: 600; color: var(--text-primary);
  margin-bottom: 8px; line-height: 1.4; transition: color 0.2s ease;
}
.atlas-post-card:hover .atlas-post-title { color: var(--accent); }
.atlas-post-excerpt { font-size: 15px; color: var(--text-secondary); line-height: 1.7; }

/* ---------- 侧边栏 ---------- */
.atlas-sidebar-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; margin-bottom: 20px; transition: border-color 0.3s ease;
}
.atlas-sidebar-title {
  font-size: 14px; font-weight: 600; color: var(--text-primary);
  margin-bottom: 16px; letter-spacing: 0.05em; text-transform: uppercase;
}
.atlas-sidebar-list { list-style: none; padding: 0; margin: 0; }
.atlas-sidebar-list li { margin-bottom: 10px; }
.atlas-sidebar-list a {
  font-size: 14px; color: var(--text-secondary);
  display: flex; align-items: center; justify-content: space-between; transition: color 0.2s ease;
}
.atlas-sidebar-list a:hover { color: var(--accent); }
.atlas-sidebar-list .count {
  font-size: 12px; color: var(--text-muted); background: var(--bg-secondary);
  padding: 2px 8px; border-radius: 999px;
}

/* ---------- 标签云 ---------- */
.atlas-tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; }
.atlas-tag {
  font-size: 13px; color: var(--text-secondary); background: var(--bg-secondary);
  padding: 5px 12px; border-radius: 999px; transition: all 0.2s ease; border: 1px solid var(--border);
}
.atlas-tag:hover { background: var(--accent); color: #ffffff; border-color: var(--accent); }

/* ---------- 按钮 ---------- */
.atlas-btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 20px; border-radius: var(--radius-sm); border: 1px solid var(--border);
  background: var(--bg-card); color: var(--text-primary); font-size: 14px; font-weight: 500;
  cursor: pointer; transition: all 0.2s ease;
}
.atlas-btn:hover { background: var(--bg-hover); border-color: var(--text-muted); }
.atlas-btn-primary { background: var(--accent); color: #ffffff; border-color: var(--accent); }
.atlas-btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* ---------- Hero ---------- */
.atlas-hero { padding: 100px 20px 60px; text-align: center; }
.atlas-hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem); font-weight: 700; color: var(--text-primary);
  letter-spacing: -0.02em; line-height: 1.2; margin-bottom: 16px;
}
.atlas-hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem); color: var(--text-secondary);
  max-width: 520px; margin: 0 auto; line-height: 1.6;
}

/* ---------- 布局 ---------- */
.atlas-container { max-width: var(--max-content); margin: 0 auto; padding: 0 20px; }
.atlas-layout {
  max-width: 1100px; margin: 0 auto; padding: 0 20px;
  display: grid; grid-template-columns: 1fr 300px; gap: 40px;
}
@media (max-width: 900px) { .atlas-layout { grid-template-columns: 1fr; } }

/* ---------- 文章页 ---------- */
.atlas-article { max-width: var(--max-content); margin: 0 auto; padding: 40px 20px; }
.atlas-article h1 { font-size: clamp(1.8rem, 4vw, 2.5rem); font-weight: 700; color: var(--text-primary); margin-bottom: 16px; line-height: 1.3; }
.atlas-article h2 { font-size: 1.5rem; font-weight: 600; color: var(--text-primary); margin-top: 40px; margin-bottom: 16px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.atlas-article h3 { font-size: 1.2rem; font-weight: 600; color: var(--text-primary); margin-top: 28px; margin-bottom: 12px; }
.atlas-article p { font-size: 16px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 20px; }
.atlas-article code { font-family: var(--font-mono); font-size: 14px; background: var(--bg-secondary); padding: 2px 6px; border-radius: 4px; color: var(--accent); }
.atlas-article pre { background: var(--bg-secondary); padding: 16px; border-radius: var(--radius-sm); overflow-x: auto; border: 1px solid var(--border); }
.atlas-article pre code { background: none; padding: 0; color: var(--text-primary); }

/* ---------- 分隔线 ---------- */
.atlas-divider { height: 1px; background: var(--border); margin: 40px 0; border: none; }