/* ============================================
   Personal Website — Style
   Design: Modern Minimalist · Chinese Aesthetic
   ============================================ */

:root {
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --text: #1a1a2e;
  --text-secondary: #64748b;
  --accent: #6366f1;
  --accent-light: #eef2ff;
  --border: #e2e8f0;
  --card-bg: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08);
  --nav-blur: rgba(255,255,255,0.85);
  --gradient-1: #6366f1;
  --gradient-2: #ec4899;
  --max-width: 960px;
  --radius: 12px;
  --radius-sm: 8px;
}

[data-theme="dark"] {
  --bg: #0f0f1a;
  --bg-alt: #1a1a2e;
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --accent: #818cf8;
  --accent-light: #1e1b4b;
  --border: #2d2d4a;
  --card-bg: #151528;
  --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.4);
  --nav-blur: rgba(15,15,26,0.88);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background 0.3s, color 0.3s;
  -webkit-font-smoothing: antialiased;
}

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

/* ---- Navbar ---- */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: var(--nav-blur);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s;
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.925rem;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0; right: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

/* ---- Theme Toggle ---- */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  transition: all 0.2s;
}

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

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

/* ---- Mobile Menu ---- */
.mobile-menu {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  border-radius: 2px;
  transition: 0.3s;
}

/* ---- Hero ---- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 60px;
}

.hero-bg {
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-light) 0%, transparent 70%);
  border-radius: 50%;
  opacity: 0.5;
  pointer-events: none;
}

.hero-content {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 60px;
  align-items: center;
  padding: 80px 24px;
}

.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 20px;
  font-size: 0.825rem;
  font-weight: 600;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 32px;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-bottom: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 0.925rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 2px 8px rgba(99,102,241,0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(99,102,241,0.4);
}

.btn-outline {
  border: 1.5px solid var(--border);
  color: var(--text);
}

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

.btn-text {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.925rem;
}

.btn-text:hover { text-decoration: underline; }

.hero-social {
  display: flex;
  gap: 12px;
}

.hero-social a {
  color: var(--text-secondary);
  transition: color 0.2s;
}

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

.hero-visual { text-align: center; }

.avatar-ring {
  width: 200px;
  height: 200px;
  margin: 0 auto 24px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  padding: 4px;
  animation: pulse-ring 3s ease-in-out infinite;
}

@keyframes pulse-ring {
  0%, 100% { box-shadow: 0 0 0 0 rgba(99,102,241,0.3); }
  50% { box-shadow: 0 0 0 16px rgba(99,102,241,0); }
}

.avatar {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: var(--bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.tech-stack span {
  padding: 4px 12px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 500;
}

/* ---- Sections ---- */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 48px;
  letter-spacing: -0.01em;
}

.section-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 48px;
}

.section-header-row .section-title {
  margin-bottom: 0;
}

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

.about-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: all 0.2s;
}

.about-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.about-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.about-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.about-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ---- Skills ---- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.skill-category {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.skill-category h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 4px 12px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  transition: all 0.2s;
}

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

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

.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all 0.2s;
}

.project-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.project-icon { font-size: 1.5rem; }

.project-badge {
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
}

.project-badge.active {
  background: #dcfce7;
  color: #16a34a;
}

[data-theme="dark"] .project-badge.active {
  background: #052e16;
  color: #4ade80;
}

.project-badge.done {
  background: #e0e7ff;
  color: #4f46e5;
}

[data-theme="dark"] .project-badge.done {
  background: #1e1b4b;
  color: #818cf8;
}

.project-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.project-card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.project-tags span {
  padding: 2px 10px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ---- Blog Preview ---- */
.blog-grid {
  display: grid;
  gap: 20px;
}

.blog-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all 0.2s;
  text-decoration: none;
  color: inherit;
  display: block;
}

.blog-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.blog-card-meta {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 8px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.blog-card-category {
  padding: 2px 8px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 4px;
  font-weight: 600;
  font-size: 0.75rem;
}

.blog-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.4;
}

.blog-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

.blog-card-tags {
  display: flex;
  gap: 6px;
  margin-top: 12px;
}

.blog-card-tags span {
  font-size: 0.75rem;
  color: var(--text-secondary);
  padding: 2px 8px;
  background: var(--bg-alt);
  border-radius: 4px;
}

/* ---- Contact ---- */
.contact-text {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  text-decoration: none;
  padding: 12px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

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

/* ---- Footer ---- */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
}

.footer p {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.footer-credit {
  margin-top: 8px;
  font-size: 0.8rem;
}

.footer-credit a {
  color: var(--accent);
  text-decoration: none;
}

.footer-credit a:hover { text-decoration: underline; }

/* ---- Blog Page ---- */
.blog-page-header {
  padding: 120px 0 60px;
  text-align: center;
}

.blog-page-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.blog-page-header p {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

/* ---- Blog Detail ---- */
.blog-detail {
  max-width: 720px;
  margin: 0 auto;
  padding: 120px 24px 60px;
}

.blog-detail h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.3;
}

.blog-detail-meta {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 32px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.blog-detail-content {
  font-size: 1rem;
  line-height: 1.9;
  color: var(--text);
}

.blog-detail-content h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 16px;
}

.blog-detail-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-top: 28px;
  margin-bottom: 12px;
}

.blog-detail-content p {
  margin-bottom: 16px;
}

.blog-detail-content ul,
.blog-detail-content ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.blog-detail-content li {
  margin-bottom: 6px;
}

.blog-detail-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 8px 16px;
  margin: 20px 0;
  background: var(--accent-light);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
}

.blog-detail-content code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85em;
  padding: 2px 6px;
  background: var(--bg-alt);
  border-radius: 4px;
}

.blog-detail-content pre {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  overflow-x: auto;
  margin-bottom: 20px;
}

.blog-detail-content pre code {
  background: none;
  padding: 0;
}

.blog-detail-content a {
  color: var(--accent);
  text-decoration: underline;
}

.blog-detail-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

/* ---- Animations ---- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease forwards;
}

.fade-in-delay {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease 0.2s forwards;
}

.fade-in-delay-1 {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease 0.1s forwards;
}

.fade-in-delay-2 {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease 0.2s forwards;
}

@keyframes fadeInUp {
  to { opacity: 1; transform: translateY(0); }
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
    padding: 60px 24px;
    text-align: center;
  }

  .hero-title { font-size: 2.2rem; }
  .hero-desc { margin: 0 auto 32px; }
  .hero-actions { justify-content: center; }
  .hero-social { justify-content: center; }
  .hero-bg { display: none; }

  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }

  .nav-links {
    display: none;
    position: absolute;
    top: 60px;
    left: 0; right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    flex-direction: column;
    gap: 16px;
  }

  .nav-links.open { display: flex; }

  .mobile-menu { display: block; }

  .section-header-row {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }

  .blog-detail { padding: 100px 16px 40px; }
  .blog-detail h1 { font-size: 1.6rem; }
}