/* ========== Base ========== */

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

:root {
  --bg: #020617;
  --bg-elevated: #020617;
  --bg-muted: #020617;
  --text: #e5e7eb;
  --text-muted: #9ca3af;
  --accent: #3b82f6;
  --accent-soft: rgba(59, 130, 246, 0.18);
  --border-subtle: rgba(148, 163, 184, 0.25);
  --shadow-soft: 0 32px 80px rgba(15, 23, 42, 0.9);
  --radius-lg: 18px;
  --radius-full: 999px;
  --transition-fast: 0.18s ease-out;
  --max-width: 1040px;
}

/* Keep body always in dark theme */
body.theme-dark {
  background: radial-gradient(circle at top, #020617 0, #020617 45%, #020617 100%);
}


html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* ========== Layout ========== */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 4.5rem 0;
}

.section-inner {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.section-header h2 {
  font-size: 1.75rem;
  margin: 0 0 0.5rem;
}

.section-header p {
  margin: 0;
  color: var(--text-muted);
  max-width: 32rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: linear-gradient(
    to bottom,
    rgba(15, 23, 42, 0.96),
    rgba(15, 23, 42, 0.88),
    rgba(15, 23, 42, 0.72)
  );
  border-bottom: 1px solid rgba(148, 163, 184, 0.22);
  transition: background 0.2s ease, border-color 0.2s ease,
    box-shadow 0.2s ease, transform 0.2s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0;
  transition: padding 0.18s ease;
}

/* When scrolled */
.site-header.header-scrolled {
  background: rgba(15, 23, 42, 0.98);
  box-shadow: 0 10px 40px rgba(15, 23, 42, 0.9);
  transform: translateY(-1px);
}

.site-header.header-scrolled .header-inner {
  padding: 0.55rem 0;
}


/* ========== Header / Nav ========== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: linear-gradient(
    to bottom,
    rgba(2, 6, 23, 0.9),
    rgba(2, 6, 23, 0.6),
    transparent
  );
  border-bottom: 1px solid rgba(148, 163, 184, 0.15);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-mark {
  width: 20px;
  height: 20px;
  border-radius: 40%;
  background: radial-gradient(circle at 30% 20%, #a5b4fc, #3b82f6 55%, #0ea5e9);
  box-shadow: 0 0 18px rgba(59, 130, 246, 0.9);
}

.brand-text {
  font-weight: 600;
  letter-spacing: 0.02em;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-link {
  text-decoration: none;
  font-size: 0.95rem;
  color: var(--text-muted);
  position: relative;
  padding-bottom: 0.1rem;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.2rem;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width var(--transition-fast);
}

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

.nav-link:hover::after {
  width: 100%;
}

/* ========== Hero ========== */

.hero {
  padding: 4rem 0 4.5rem;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 2.75rem;
  align-items: center;
}

.hero-kicker {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.hero-title {
  font-size: clamp(2.5rem, 4vw, 3.2rem);
  margin: 0.2rem 0;
}

.hero-subtitle {
  font-size: 1.1rem;
  margin: 0 0 0.8rem;
  color: var(--text-muted);
}

.hero-body {
  margin: 0 0 1.4rem;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.35rem;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast), transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

.btn.primary {
  background: linear-gradient(135deg, #2563eb, #0ea5e9);
  color: #f9fafb;
  box-shadow: 0 14px 35px rgba(37, 99, 235, 0.5);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px rgba(37, 99, 235, 0.65);
}

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

body.theme-dark .btn.secondary {
  color: var(--text-muted);
}

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

/* Hero Card */

.hero-card {
  border-radius: var(--radius-lg);
  background: radial-gradient(circle at top left, #1d283a, #020617);
  box-shadow: var(--shadow-soft);
  padding: 1px;
}

.hero-card-inner {
  border-radius: inherit;
  background: radial-gradient(circle at top, rgba(15, 23, 42, 0.98), #020617);
  padding: 1.4rem 1.5rem;
}

.hero-card-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--text-muted);
  margin: 0 0 0.6rem;
}

.hero-card-title {
  font-size: 1.1rem;
  margin: 0 0 0.9rem;
}

.hero-card-list {
  list-style: none;
  padding: 0;
  margin: 0;
  color: var(--text-muted);
}

.hero-card-list li + li {
  margin-top: 0.4rem;
}

/* ========== Cards / Grid ========== */

.card {
  border-radius: var(--radius-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  padding: 1.4rem 1.5rem;
  box-shadow: 0 8px 25px rgba(15, 23, 42, 0.12);
}

.card h3 {
  margin-top: 0;
  margin-bottom: 0.6rem;
}

.grid {
  display: grid;
  gap: 1.5rem;
}

.grid.two-column {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid.three-column {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pill,
.pill-link {
  border-radius: var(--radius-full);
  padding: 0.35rem 0.85rem;
  font-size: 0.8rem;
  border: 1px solid var(--border-subtle);
  background: rgba(15, 23, 42, 0.02);
  color: var(--text-muted);
  text-decoration: none;
}

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

/* ========== Projects ========== */

.project-card {
  position: relative;
  overflow: hidden;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast),
    border-color var(--transition-fast);
}

.project-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    circle at top right,
    var(--accent-soft),
    transparent 55%
  );
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-soft);
  border-color: rgba(59, 130, 246, 0.5);
}

.project-card:hover::before {
  opacity: 1;
}

.project-title {
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.project-description {
  margin: 0 0 0.6rem;
  color: var(--text-muted);
}

.project-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.project-link {
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--accent);
  position: relative;
}

.project-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.12rem;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width var(--transition-fast);
}

.project-link:hover::after {
  width: 100%;
}

/* Scroll reveal base state */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.5s ease-out,
    transform 0.5s ease-out;
  will-change: opacity, transform;
}

/* When visible */
.reveal-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Slight stagger for project cards */
.project-card.reveal {
  transition-delay: 0.05s;
}

.project-card.reveal:nth-child(2) {
  transition-delay: 0.12s;
}

.project-card.reveal:nth-child(3) {
  transition-delay: 0.18s;
}

/* ========== Contact ========== */

.section-contact {
  padding-bottom: 4rem;
}

.contact-inner {
  align-items: flex-start;
}

.contact-card {
  max-width: 420px;
}

.contact-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--text-muted);
  margin: 0 0 0.3rem;
}

.contact-link {
  font-size: 0.95rem;
  color: var(--text);
  text-decoration: none;
  display: inline-block;
  margin-bottom: 1rem;
}

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

/* ========== Footer ========== */

.site-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.2);
  padding: 1.25rem 0 1.5rem;
  margin-top: 1rem;
}

.footer-inner {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ========== Responsive ========== */

@media (max-width: 768px) {
  .header-inner {
    gap: 0.9rem;
  }

  .nav {
    display: none; /* simplified: could add a mobile menu later */
  }

  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-card {
    order: -1;
  }

  .hero {
    padding-top: 3rem;
  }
}