:root {
  --bg: #ffffff;
  --bg-secondary: #f8fafc;
  --text: #1a1a2e;
  --text-muted: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --border: #e2e8f0;
  --card-bg: #ffffff;
  --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --bg-secondary: #1e293b;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --accent: #60a5fa;
    --accent-hover: #93c5fd;
    --border: #334155;
    --card-bg: #1e293b;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}

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

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

/* ── Layout ─────────────────────────────────────────── */

.container {
  width: 100%;
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ── Header / Nav ────────────────────────────────────── */

header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9375rem;
}

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

/* ── Hero ────────────────────────────────────────────── */

.hero {
  padding: 5rem 0 4rem;
  text-align: center;
}

.hero-eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--text-muted);
  max-width: 38rem;
  margin: 0 auto 2rem;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  border-radius: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.1s ease;
}

.btn:active {
  transform: scale(0.98);
}

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

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

.btn-secondary {
  background-color: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  margin-left: 0.75rem;
}

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

/* ── Sections ────────────────────────────────────────── */

section {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
}

.section-label {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 700;
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
}

/* ── About ───────────────────────────────────────────── */

.about p {
  color: var(--text-muted);
  max-width: 40rem;
  font-size: 1.0625rem;
  line-height: 1.75;
}

/* ── Projects ────────────────────────────────────────── */

.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

@media (min-width: 640px) {
  .cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .cards {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background-color: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.25rem 1.5rem;
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.1);
}

.card-title {
  font-size: 1rem;
  font-weight: 700;
}

.card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  flex: 1;
  line-height: 1.6;
}

.card-link {
  font-size: 0.875rem;
  font-weight: 600;
}

/* ── Contact ─────────────────────────────────────────── */

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 500;
  transition: border-color 0.2s ease, color 0.2s ease;
}

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

.contact-link svg {
  width: 1rem;
  height: 1rem;
  flex-shrink: 0;
}

/* ── Footer ──────────────────────────────────────────── */

footer {
  border-top: 1px solid var(--border);
  padding: 1.75rem 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}