:root {
  --bg: #fafafa;
  --bg-elevated: #ffffff;
  --text: #18181b;
  --text-muted: #71717a;
  --border: #e4e4e7;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-soft: #eef2ff;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 4px 16px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 4px 8px rgba(0, 0, 0, 0.08), 0 12px 32px rgba(0, 0, 0, 0.08);
}

[data-theme="dark"] {
  --bg: #101014;
  --bg-elevated: #1a1a20;
  --text: #f4f4f5;
  --text-muted: #a1a1aa;
  --border: #2a2a32;
  --accent: #818cf8;
  --accent-hover: #a5b4fc;
  --accent-soft: #23233a;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 4px 8px rgba(0, 0, 0, 0.5), 0 12px 32px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  transition: background 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

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

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav-logo .accent {
  color: var(--accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--text);
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg-elevated);
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: rotate(15deg);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

[data-theme="light"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: none; }

/* ---------- Hero ---------- */

.hero {
  padding: 96px 24px 80px;
  max-width: 1080px;
}

.hero-kicker {
  font-size: 1rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 8px;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.hero-subtitle {
  margin-top: 12px;
  font-size: 1.25rem;
  color: var(--text-muted);
  font-weight: 500;
}

.hero-desc {
  margin-top: 24px;
  max-width: 560px;
  font-size: 1.05rem;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-top: 32px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease,
    transform 0.2s ease;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-ghost {
  border-color: var(--border);
  color: var(--text);
  background: var(--bg-elevated);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.social-links {
  display: flex;
  gap: 20px;
  margin-top: 40px;
}

.social-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.social-links a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ---------- Sections ---------- */

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 32px;
}

.section-head h2 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-more {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.section-more:hover {
  color: var(--accent);
}

/* ---------- Posts ---------- */

.posts {
  padding-bottom: 96px;
}

.post-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.post-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.post-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.post-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 10px;
  border-radius: 999px;
}

.post-meta time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.post-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
}

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

.post-excerpt {
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-muted);
  flex: 1;
}

.post-link {
  margin-top: 18px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
}

.post-link::after {
  content: " →";
  transition: margin-left 0.2s ease;
}

.post-card:hover .post-link::after {
  margin-left: 4px;
}

/* ---------- About ---------- */

.about {
  padding-bottom: 96px;
}

.about-body {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.tag {
  font-size: 0.8rem;
  font-weight: 500;
  padding: 5px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.tag:hover {
  color: var(--accent);
  border-color: var(--accent);
}

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

.stat {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 24px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.stat-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- Subscribe ---------- */

.subscribe {
  padding-bottom: 96px;
  text-align: center;
}

.subscribe h2 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subscribe p {
  margin-top: 12px;
  color: var(--text-muted);
}

.subscribe-form {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 28px;
  flex-wrap: wrap;
}

.subscribe-form input {
  width: 300px;
  max-width: 100%;
  padding: 12px 18px;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-elevated);
  color: var(--text);
  outline: none;
  transition: border-color 0.2s ease;
}

.subscribe-form input:focus {
  border-color: var(--accent);
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- Article page ---------- */

.article-page main {
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 24px 96px;
}

.article-back {
  display: inline-block;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  transition: color 0.2s ease;
}

.article-back:hover {
  color: var(--accent);
}

.article-header h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.article-content {
  margin-top: 32px;
}

.article-content p {
  margin-bottom: 20px;
  color: color-mix(in srgb, var(--text) 85%, var(--text-muted));
}

.article-content h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 40px 0 16px;
  letter-spacing: -0.01em;
}

.article-content blockquote {
  margin: 24px 0;
  padding: 16px 24px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 10px 10px 0;
  color: var(--text-muted);
}

.article-content ul {
  margin: 0 0 20px 24px;
  color: color-mix(in srgb, var(--text) 85%, var(--text-muted));
}

.article-content li {
  margin-bottom: 8px;
}

.article-content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.875em;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: 5px;
}

.article-content pre {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  overflow-x: auto;
  margin-bottom: 20px;
}

.article-content pre code {
  background: none;
  color: var(--text);
  padding: 0;
}

/* ---------- Reveal animation ---------- */

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ---------- Responsive ---------- */

@media (max-width: 900px) {
  .post-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .hero {
    padding: 64px 24px 56px;
  }

  .nav-links a {
    display: none;
  }

  .post-grid {
    grid-template-columns: 1fr;
  }

  .about-body {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about-stats {
    flex-direction: row;
  }

  .stat {
    flex: 1;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 16px;
  }
}