/* ============================================================
   树懒老K · 个人网站 — 雾霁蓝极浅主题 v2
   基调：轻、透、干净，致敬 Claude Cowork 的界面质感
   重点：雾霁蓝系仅作为点缀色，不喧宾夺主
   ============================================================ */

:root {
  --bg: #f4f7fc;
  --bg-nav: #ffffff;
  --bg-card: #ffffff;
  --bg-card-alt: #f8faff;
  --border: #e6ecf4;
  --border-light: #eef2f8;
  --shadow-sm: 0 1px 2px rgba(58,78,102,0.04);
  --shadow-md: 0 2px 12px rgba(58,78,102,0.06);
  --shadow-lg: 0 4px 24px rgba(58,78,102,0.08);
  --text-primary: #1e293b;
  --text-body: #3d4f63;
  --text-dim: #6b7f95;
  --text-dimmer: #94a7bd;
  --deep: #3A4E66;
  --mid: #48607C;
  --accent: #5B9BC8;
  --accent-light: #7ec8e3;
  --gold: #C8B99B;
  --light-blue: #B4CDE1;
  --tag-bg: rgba(91,155,200,0.07);
  --radius: 12px;
  --max-width: 960px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

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

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

/* 磨砂颗粒感 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.08;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.2' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 200px 200px;
}

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

/* ========== Navigation ========== */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  height: 56px;
  background: var(--bg-nav);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--deep);
  letter-spacing: 2px;
  font-weight: 600;
}

.nav-avatar {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  flex-shrink: 0;
}

.nav-brand span { letter-spacing: 2px; }

.nav-links { display: flex; gap: 28px; list-style: none; }

.nav-links a {
  font-size: 13px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
  padding: 4px 0;
  position: relative;
  transition: color 0.2s;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0; right: 0;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.2s;
}

.nav-links a:hover { color: var(--deep); }
.nav-links a.active { color: var(--deep); }
.nav-links a.active::after { transform: scaleX(1); }

/* ========== Hero ========== */

.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 100px 24px 80px;
  background: linear-gradient(180deg, #fafcff 0%, var(--bg) 40%);
}

.hero-avatar {
  width: 80px; height: 80px;
  border-radius: 50%;
  border: 2px solid var(--light-blue);
  margin-bottom: 20px;
  box-shadow: var(--shadow-md);
}

.hero h1 {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.hero .tagline {
  font-size: 14px;
  color: var(--accent);
  letter-spacing: 4px;
  margin-bottom: 8px;
  font-weight: 500;
}

.hero .sub {
  font-size: 13px;
  color: var(--text-dimmer);
  letter-spacing: 1px;
  margin-bottom: 28px;
}

.hero .qrcode-wrap {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  padding: 12px 16px 10px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.hero .qrcode { width: 90px; height: 90px; border-radius: 6px; }
.hero .qrcode-label { font-size: 11px; color: var(--text-dimmer); margin-top: 6px; letter-spacing: 1px; }

.entries {
  display: flex;
  gap: 10px;
  margin-top: 32px;
  flex-wrap: wrap;
  justify-content: center;
}

.entry-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: 50px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-body);
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: all 0.25s;
}

.entry-btn:hover {
  border-color: var(--accent);
  color: var(--deep);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.entry-btn .icon { font-size: 16px; }

/* ========== Page Header ========== */

.page-header {
  padding: 80px 24px 32px;
  text-align: center;
  background: linear-gradient(180deg, #fafcff 0%, var(--bg) 40%);
}

.page-header h1 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.page-header p {
  font-size: 13px;
  color: var(--text-dim);
  max-width: 520px;
  margin: 0 auto;
}

/* ========== Container ========== */

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px 48px; }

/* ========== Value Ring ========== */

.ring-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}

.ring-section h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.ring-section .ring-desc {
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 20px;
  line-height: 1.7;
}

.ring-section .ring-desc strong { color: var(--accent); font-weight: 600; }

.ring-svg-wrap {
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
}

.ring-svg-wrap svg { display: block; width: 100%; height: auto; }

/* ========== Stage Section ========== */

.stage-section { margin-bottom: 10px; }

.stage-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 0 12px;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 16px;
}

.stage-header .emoji { font-size: 18px; }

.stage-header h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}

.stage-header .badge {
  font-size: 10px;
  color: var(--accent);
  background: var(--tag-bg);
  padding: 1px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.stage-header .line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--border), transparent);
}

/* ========== Skills: 2-column grid ========== */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

@media (max-width: 700px) { .skills-grid { grid-template-columns: 1fr; } }

.skill-card {
  padding: 20px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: all 0.25s;
  position: relative;
}

.skill-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--light-blue);
  transform: translateY(-1px);
}

.skill-card.featured {
  border-color: var(--accent);
  background: linear-gradient(135deg, #fafcff, #f4f9ff);
}

.skill-card .card-top {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.skill-card .emoji { font-size: 20px; }

.skill-card .name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.skill-card .code {
  font-size: 10px;
  color: var(--text-dimmer);
  font-weight: 400;
}

.skill-card .tags {
  display: flex;
  gap: 4px;
  margin-left: auto;
  flex-shrink: 0;
}

.skill-card .tag {
  font-size: 9px;
  padding: 1px 6px;
  border-radius: 3px;
  background: var(--tag-bg);
  color: var(--accent);
  font-weight: 500;
}

.skill-card .tag-new { background: rgba(90,158,143,0.1); color: #3a8a7a; }
.skill-card .tag-hot { background: var(--deep); color: #fff; }

.skill-card .audience {
  font-size: 11px;
  color: var(--accent);
  margin-bottom: 8px;
}

.skill-card .desc {
  font-size: 12px;
  color: var(--text-dim);
  line-height: 1.7;
  margin-bottom: 4px;
}

.skill-card .links {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.skill-card .links a {
  font-size: 11px;
  color: var(--accent);
  padding: 3px 10px;
  border: 1px solid var(--light-blue);
  border-radius: 20px;
  transition: all 0.2s;
}

.skill-card .links a:hover {
  background: var(--tag-bg);
  border-color: var(--accent);
}

/* ========== Full-width cards (featured / hero skills) ========== */

.skill-card.full {
  grid-column: 1 / -1;
}

.skill-card.full .desc { font-size: 12.5px; }
.skill-card.full .audience { font-size: 11.5px; }

/* ========== Article Cards ========== */

.article-card {
  padding: 24px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  margin-bottom: 12px;
  transition: all 0.25s;
}

.article-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--light-blue);
}

.article-card h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.article-card .summary {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.8;
  margin-bottom: 12px;
}

.article-card .meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.article-card .tag {
  font-size: 10px;
  color: var(--accent);
  background: var(--tag-bg);
  padding: 2px 8px;
  border-radius: 20px;
}

.article-card .count { font-size: 11px; color: var(--text-dimmer); }

.article-card .read-link {
  font-size: 12px;
  color: var(--gold);
  letter-spacing: 0.5px;
  margin-left: auto;
  white-space: nowrap;
  transition: color 0.2s;
}

.article-card:hover .read-link { color: var(--accent); }

/* ========== About ========== */

.about-section { display: flex; flex-direction: column; gap: 16px; }

.about-block {
  padding: 24px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.about-block h2 {
  font-size: 16px;
  font-weight: 600;
  color: var(--deep);
  margin-bottom: 10px;
}

.about-block p { font-size: 13.5px; color: var(--text-dim); line-height: 1.8; }
.about-block .highlight { color: var(--accent); font-weight: 600; }

/* ========== Footer ========== */

.footer {
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-dimmer);
}

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

/* ========== Responsive ========== */

@media (max-width: 640px) {
  .nav { padding: 0 20px; }
  .nav-links { gap: 14px; }
  .nav-links a { font-size: 12px; }
  .hero h1 { font-size: 22px; }
  .entries { flex-direction: column; align-items: center; }
  .entry-btn { width: 100%; max-width: 260px; justify-content: center; }
  .skills-grid { grid-template-columns: 1fr; }
  .article-card { padding: 18px; }
}