/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #6b7280;
  --color-accent: #475569;
  --color-border: #e5e7eb;
  --color-lang-bg: #f1f5f9;
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 960px;
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 60px;
}

body {
  font-family: var(--font-main);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 52px;
  background: rgba(250, 250, 250, 0);
  z-index: 100;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.navbar.scrolled {
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: 0 1px 0 var(--color-border);
}

.navbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  opacity: 0;
  transition: opacity var(--transition);
}

.navbar.scrolled .navbar-brand {
  opacity: 1;
}

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

.navbar-links a:not(.navbar-icon) {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition);
}

.navbar-links a:not(.navbar-icon):hover {
  color: var(--color-text);
}

.navbar-icon {
  color: var(--color-text-secondary);
  transition: color var(--transition);
  display: inline-flex;
}

.navbar-icon:hover {
  color: var(--color-text);
}

@media (max-width: 640px) {
  .navbar-links {
    gap: 20px;
  }
}

/* Hero */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  padding: 24px;
  opacity: 0;
  animation: fadeIn 1s ease forwards;
}

.hero-content {
  max-width: var(--max-width);
}

.hero-name {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--color-text);
}

h1 .hero-name-sub {
  display: block;
  font-size: clamp(1rem, 3vw, 1.75rem);
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--color-text-secondary);
  margin-top: 8px;
}

.hero-tagline {
  margin-top: 16px;
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 400;
  color: var(--color-text-secondary);
  letter-spacing: -0.01em;
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  color: var(--color-text-secondary);
  opacity: 0.4;
  cursor: pointer;
  transition: opacity var(--transition);
  animation: bounce 2s ease infinite;
}

.scroll-indicator:hover {
  opacity: 0.8;
}

/* Projects */
.projects {
  padding: 80px 0 120px;
}

.section-title {
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  margin-bottom: 48px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* Project Card */
.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
  opacity: 0;
  transform: translateY(12px);
}

.project-card.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.5s ease, transform 0.5s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.project-card.visible:hover {
  transform: translateY(-2px);
}

.project-name {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.project-desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  flex: 1;
}

.project-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 4px;
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.lang-name {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

.project-stars {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.project-stars svg {
  fill: var(--color-text-secondary);
}

/* Loading */
.loading {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px 0;
}

/* Error */
.error {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px 0;
}

/* Apps */
.apps {
  padding: 80px 0;
}

.app-card {
  display: flex;
  align-items: center;
  gap: 28px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 28px 32px;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.app-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.app-icon img {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  flex-shrink: 0;
}

.app-info {
  flex: 1;
  min-width: 0;
}

.app-title-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 2px;
}

.app-title {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.app-badge {
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-accent);
  background: var(--color-lang-bg);
  padding: 2px 8px;
  border-radius: 4px;
}

.app-tagline {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-bottom: 8px;
}

.app-desc {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 8px;
}

.app-meta {
  display: flex;
  gap: 4px;
  font-size: 0.7rem;
  color: var(--color-text-secondary);
}

.app-store-arrow {
  color: var(--color-text-secondary);
  flex-shrink: 0;
  transition: color var(--transition), transform var(--transition);
}

.app-card:hover .app-store-arrow {
  color: var(--color-text);
  transform: translate(2px, -2px);
}

@media (max-width: 640px) {
  .app-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding: 24px;
  }

  .app-store-arrow {
    display: none;
  }
}

/* Books */
.books {
  padding: 80px 0;
}

.book-card {
  display: flex;
  align-items: center;
  gap: 40px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 36px;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
 }

.book-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.book-cover {
  position: relative;
  width: 120px;
  height: 160px;
  flex-shrink: 0;
}

.book-front {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  border-radius: 2px 6px 6px 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 4px 4px 12px rgba(0, 0, 0, 0.15);
}

.book-icon {
  color: #94a3b8;
  font-size: 2rem;
}

.book-spine {
  position: absolute;
  left: 0;
  top: 2px;
  bottom: 2px;
  width: 8px;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  border-radius: 2px 0 0 2px;
}

.book-info {
  flex: 1;
  min-width: 0;
}

.book-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
}

.book-subtitle {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}

.book-meta {
  display: flex;
  gap: 4px;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}

.meta-sep {
  color: var(--color-border);
}

.book-desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

@media (max-width: 640px) {
  .book-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
    padding: 24px;
  }
  
  .book-cover {
    width: 90px;
    height: 120px;
  }
}

/* Blog (homepage) */
.blog {
  padding: 80px 0;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.blog-card {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 28px;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.blog-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

.blog-card-meta {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}

.blog-card-title {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  line-height: 1.3;
}

.blog-card-excerpt {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.blog-all-link {
  display: block;
  text-align: right;
  margin-top: 24px;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition);
}

.blog-all-link:hover {
  color: var(--color-text);
}

/* Footer */
.footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.footer-link {
  color: var(--color-text-secondary);
  transition: color var(--transition);
  display: inline-flex;
}

.footer-link:hover {
  color: var(--color-text);
}

/* Language Colors */
.lang-js { background: #f1e05a; }
.lang-ts { background: #3178c6; }
.lang-python { background: #3572A5; }
.lang-html { background: #e34c26; }
.lang-css { background: #563d7c; }
.lang-ruby { background: #701516; }
.lang-go { background: #00ADD8; }
.lang-rust { background: #dea584; }
.lang-java { background: #b07219; }
.lang-php { background: #4F5D95; }
.lang-swift { background: #F05138; }
.lang-kotlin { background: #A97BFF; }
.lang-dart { background: #00B4AB; }
.lang-shell { background: #89e051; }
.lang-vue { background: #41b883; }
.lang-default { background: var(--color-accent); }

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
  40% { transform: translateY(6px); }
  60% { transform: translateY(3px); }
}

/* Responsive */
@media (max-width: 640px) {
  .hero {
    min-height: 90vh;
  }
  
  .projects {
    padding: 60px 0 100px;
  }
  
  .section-title {
    margin-bottom: 32px;
  }
  
  .projects-grid {
    grid-template-columns: 1fr;
  }
}