:root {
  --bg: #0b0f19;
  --bg-elevated: #111827;
  --bg-card: #161f33;
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --border: #26324d;
  --accent: #38bdf8;
  --accent-secondary: #818cf8;
  --badge-bg: rgba(56, 189, 248, 0.12);
  --badge-text: #7dd3fc;
  --shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
}

[data-theme="light"] {
  --bg: #f8fafc;
  --bg-elevated: #ffffff;
  --bg-card: #ffffff;
  --text-main: #0f172a;
  --text-muted: #475569;
  --border: #e2e8f0;
  --accent: #0284c7;
  --accent-secondary: #4f46e5;
  --badge-bg: rgba(2, 132, 199, 0.1);
  --badge-text: #0369a1;
  --shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.06);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg);
  color: var(--text-main);
  line-height: 1.6;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-main);
  text-decoration: none;
  letter-spacing: -0.02em;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

.theme-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  width: 38px;
  height: 38px;
  border-radius: 10px;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: border-color 0.2s, transform 0.15s;
}

.theme-btn:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* Hero */
.hero {
  padding: 5.5rem 1.5rem 4rem;
}

.hero-badge {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  background: var(--badge-bg);
  color: var(--badge-text);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: clamp(2.1rem, 4.5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}

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

.hero-desc {
  max-width: 640px;
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.72rem 1.35rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
  color: #ffffff;
}

.btn-primary:hover {
  opacity: 0.92;
  transform: translateY(-2px);
}

.btn-outline {
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-main);
}

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

/* Sections */
.section {
  padding: 3.5rem 1.5rem;
}

.section-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.section-title {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 0.25rem;
}

/* Filter Buttons */
.filter-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.45rem 0.95rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--badge-bg);
  color: var(--accent);
  border-color: var(--accent);
}

/* Project Cards */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 1.35rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow);
  transition: transform 0.22s ease, border-color 0.22s ease;
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.project-card.hidden {
  display: none;
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.85rem;
}

.card-category {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.76rem;
  color: var(--accent);
}

.card-status {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.18rem 0.55rem;
  border-radius: 999px;
}

.status-active {
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
}

.status-sample {
  background: rgba(148, 163, 184, 0.15);
  color: var(--text-muted);
}

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}

.card-desc {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.tech-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.25rem;
}

.tech-tags li {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  padding: 0.22rem 0.6rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
}

.card-links {
  display: flex;
  gap: 1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border);
}

.card-link {
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-main);
  text-decoration: none;
  transition: color 0.2s;
}

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

/* Tech Stack Grid */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.stack-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.4rem;
}

.stack-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.stack-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.stack-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.stack-pills span {
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.3rem 0.7rem;
  border-radius: 8px;
  background: var(--badge-bg);
  color: var(--badge-text);
}

/* Policy Box */
.policy-box {
  margin-top: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.5rem;
  display: grid;
  gap: 1.25rem;
}

.policy-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.policy-num {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--accent);
  background: var(--badge-bg);
  padding: 0.3rem 0.55rem;
  border-radius: 6px;
}

.policy-item h4 {
  font-size: 1rem;
  margin-bottom: 0.25rem;
}

.policy-item p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.footer-inner a {
  color: var(--text-muted);
  text-decoration: none;
}

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

@media (max-width: 640px) {
  .hero {
    padding: 3.5rem 1.25rem 2.5rem;
  }
  .nav-links a {
    display: none;
  }
}