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

:root {
  --color-bg: #0a0a0a;
  --color-surface: #141414;
  --color-surface-hover: #1a1a1a;
  --color-border: #232323;
  --color-text: #e5e5e5;
  --color-text-muted: #888888;
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-subtle: rgba(59, 130, 246, 0.12);
  --header-bg: rgba(10, 10, 10, 0.85);
  --radius: 10px;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --max-width: 960px;
}

.light-theme {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-surface-hover: #f5f5f5;
  --color-border: #e5e5e5;
  --color-text: #171717;
  --color-text-muted: #6b7280;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-subtle: rgba(37, 99, 235, 0.1);
  --header-bg: rgba(250, 250, 250, 0.85);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

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

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

img {
  max-width: 100%;
  display: block;
}

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

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

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

.nav a {
  font-size: 14px;
  color: var(--color-text-muted);
  font-weight: 500;
  transition: color 0.2s;
}

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

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 7px;
  cursor: pointer;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s, border-color 0.2s, background-color 0.2s;
  margin-left: 4px;
}

.theme-toggle:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
  background-color: var(--color-surface);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  width: 18px;
  height: 18px;
}

.theme-toggle .icon-sun {
  display: none;
}

.light-theme .theme-toggle .icon-sun {
  display: block;
}

.light-theme .theme-toggle .icon-moon {
  display: none;
}

/* ===== Hero ===== */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px 64px;
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 64px;
}

.hero-text {
  flex: 1;
}

.hero-label {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.hero h1 {
  font-size: 42px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: 20px;
}

.highlight {
  color: var(--color-accent);
}

.hero-description {
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-muted);
  max-width: 480px;
  margin-bottom: 32px;
}

.hero-description a {
  color: var(--color-text);
  font-weight: 500;
  border-bottom: 1px solid var(--color-border);
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

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

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

.btn-secondary {
  background-color: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
}

.hero-image img {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
  transition: border-color 0.3s ease;
}

/* ===== Featured Projects ===== */
.featured {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
}

.section-header {
  margin-bottom: 32px;
}

.section-header h2 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  color: var(--color-text);
}

.section-subtitle {
  color: var(--color-text-muted);
  font-size: 15px;
}

.featured-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}

.featured-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
}

.featured-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(59, 130, 246, 0.08);
  color: inherit;
}

.featured-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 4px;
}

.featured-card-icon {
  width: 22px;
  height: 22px;
  color: var(--color-accent);
  flex-shrink: 0;
}

.featured-card-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.featured-card-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background-color: var(--color-accent-subtle);
  color: var(--color-accent);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.featured-card-description {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.65;
  margin: 14px 0 20px;
  flex: 1;
}

.featured-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}

.featured-card-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 13px;
  color: var(--color-text-muted);
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 5px;
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.tag {
  font-size: 11px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 999px;
  background-color: var(--color-accent-subtle);
  color: var(--color-accent);
}

.tag.small-tag {
  letter-spacing: 0.2px;
}

.featured-cta {
  text-align: center;
}

.featured-cta .btn {
  font-size: 15px;
  padding: 12px 28px;
}

/* ===== Projects (shared) ===== */
.projects {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.projects-header {
  margin-bottom: 32px;
}

.projects h2 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  color: var(--color-text);
}

.projects-subtitle {
  color: var(--color-text-muted);
  font-size: 15px;
}

/* ===== Filter Bar (Projects page) ===== */
.filter-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 28px;
  flex-wrap: wrap;
  align-items: center;
}

.filter-btn {
  padding: 6px 16px;
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font-sans);
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-btn:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

.filter-btn.active {
  background-color: var(--color-accent);
  color: #ffffff;
  border-color: var(--color-accent);
}

/* Search & Controls (Projects page) */
.projects-controls {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
  align-items: center;
}

.search-input {
  flex: 1;
  min-width: 200px;
  padding: 9px 14px 9px 36px;
  font-size: 14px;
  font-family: var(--font-sans);
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color 0.2s, background-color 0.3s;
  outline: none;
}

.search-input::placeholder {
  color: var(--color-text-muted);
}

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

.search-wrapper {
  position: relative;
  flex: 1;
  min-width: 200px;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--color-text-muted);
  pointer-events: none;
}

.sort-select {
  padding: 9px 14px;
  font-size: 13px;
  font-family: var(--font-sans);
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color 0.2s, background-color 0.3s;
  outline: none;
  appearance: auto;
}

.sort-select:focus {
  border-color: var(--color-accent);
}

.results-count {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

/* Projects grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.project-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.2s, transform 0.2s, background-color 0.3s;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  opacity: 0;
  transform: translateY(12px);
  animation: fadeUp 0.4s ease forwards;
}

.project-card:hover {
  border-color: var(--color-text-muted);
  transform: translateY(-2px);
  color: inherit;
}

.project-card:nth-child(1) { animation-delay: 0.05s; }
.project-card:nth-child(2) { animation-delay: 0.1s; }
.project-card:nth-child(3) { animation-delay: 0.15s; }
.project-card:nth-child(4) { animation-delay: 0.2s; }
.project-card:nth-child(5) { animation-delay: 0.25s; }
.project-card:nth-child(6) { animation-delay: 0.3s; }
.project-card:nth-child(7) { animation-delay: 0.35s; }
.project-card:nth-child(8) { animation-delay: 0.4s; }
.project-card:nth-child(9) { animation-delay: 0.45s; }
.project-card:nth-child(10) { animation-delay: 0.5s; }

.project-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.project-card-icon {
  width: 20px;
  height: 20px;
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.project-card-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.project-card-description {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.project-card-tags {
  margin: 6px 0 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.project-card-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 12px;
  color: var(--color-text-muted);
}

/* Loading & Error */
.loading {
  text-align: center;
  padding: 48px 0;
  color: var(--color-text-muted);
  font-size: 14px;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.error {
  text-align: center;
  padding: 48px 0;
  color: var(--color-text-muted);
  font-size: 14px;
}

.empty-state {
  text-align: center;
  padding: 48px 0;
  color: var(--color-text-muted);
  font-size: 14px;
  grid-column: 1 / -1;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
  transition: border-color 0.3s ease;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--color-text-muted);
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  color: var(--color-text-muted);
  font-size: 13px;
}

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

/* ===== Scroll Animations ===== */
.hero,
.featured,
.projects {
  overflow: hidden;
}

.scroll-hidden {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* Stagger delays for children */
.scroll-delay-1 { transition-delay: 0.1s; }
.scroll-delay-2 { transition-delay: 0.2s; }
.scroll-delay-3 { transition-delay: 0.3s; }

/* ===== Animations ===== */
@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero {
    padding: 48px 24px 40px;
  }

  .hero-content {
    flex-direction: column-reverse;
    gap: 32px;
    text-align: center;
  }

  .hero h1 {
    font-size: 32px;
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-links {
    justify-content: center;
  }

  .hero-image img {
    width: 180px;
    height: 180px;
  }

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

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

  .projects-controls {
    flex-direction: column;
  }

  .search-wrapper {
    width: 100%;
  }

  .sort-select {
    width: 100%;
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }

  .nav {
    gap: 16px;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: 0 16px;
  }

  .hero {
    padding: 32px 16px;
  }

  .featured {
    padding: 0 16px 60px;
  }

  .projects {
    padding: 32px 16px 60px;
  }

  .nav {
    gap: 12px;
  }

  .nav a {
    font-size: 13px;
  }
}