/* ==========================================================================
   Design tokens
   ========================================================================== */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;

  /* Dark theme (default) */
  --bg: #08090c;
  --bg-elevated: #0f1116;
  --bg-card: #12141a;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text-primary: #f2f3f5;
  --text-secondary: #a7acb8;
  --text-tertiary: #6b7080;
  --accent: #5eead4;
  --accent-strong: #2dd4bf;
  --accent-soft: rgba(94, 234, 212, 0.12);
  --gradient-1: #5eead4;
  --gradient-2: #818cf8;
  --gradient-3: #f472b6;
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="light"] {
  --bg: #fafafa;
  --bg-elevated: #ffffff;
  --bg-card: #ffffff;
  --border: rgba(15, 17, 22, 0.08);
  --border-strong: rgba(15, 17, 22, 0.14);
  --text-primary: #14161a;
  --text-secondary: #4a4f5c;
  --text-tertiary: #7a808f;
  --accent: #0d9488;
  --accent-strong: #0f766e;
  --accent-soft: rgba(13, 148, 136, 0.1);
  --shadow-lg: 0 20px 60px rgba(20, 22, 26, 0.08);
}

/* ==========================================================================
   Reset
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3, p { margin: 0; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #08090c;
  padding: 12px 20px;
  z-index: 1000;
  border-radius: 0 0 8px 0;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.mono-tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-tertiary);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.01em;
}
.mono-tag--accent {
  color: var(--accent);
  border-color: var(--accent-soft);
  background: var(--accent-soft);
}

/* ==========================================================================
   Header / Nav
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.navbar {
  max-width: 1120px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav-logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
}
.logo-bracket { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 8px;
  align-items: center;
}

.nav-link {
  position: relative;
  padding: 8px 14px;
  font-size: 0.92rem;
  color: var(--text-secondary);
  border-radius: 8px;
  transition: color 0.2s var(--ease), background 0.2s var(--ease);
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-elevated); }
.nav-link.active { color: var(--accent); }
.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

.nav-actions { display: flex; align-items: center; gap: 12px; }

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-primary);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}
.theme-toggle:hover { border-color: var(--border-strong); transform: translateY(-1px); }
.theme-toggle .icon-moon { display: none; }
[data-theme="light"] .theme-toggle .icon-sun { display: none; }
[data-theme="light"] .theme-toggle .icon-moon { display: block; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 38px;
  height: 38px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 10px;
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0 auto;
  background: var(--text-primary);
  transition: transform 0.25s var(--ease), opacity 0.25s var(--ease);
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 120px 0 80px;
}

.hero-bg { position: absolute; inset: 0; z-index: 0; pointer-events: none; }
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 20%, transparent 75%);
  opacity: 0.6;
}
.hero-glow {
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(circle, var(--gradient-1) 0%, var(--gradient-2) 40%, transparent 70%);
  opacity: 0.14;
  filter: blur(80px);
}

.hero-inner { position: relative; z-index: 1; text-align: center; max-width: 780px; margin: 0 auto; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 28px;
}
.pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-strong);
  box-shadow: 0 0 0 0 rgba(45, 212, 191, 0.6);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(45, 212, 191, 0.5); }
  70% { box-shadow: 0 0 0 8px rgba(45, 212, 191, 0); }
  100% { box-shadow: 0 0 0 0 rgba(45, 212, 191, 0); }
}

.hero-title {
  font-size: clamp(2.2rem, 5.5vw, 3.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 20px;
  background: linear-gradient(180deg, var(--text-primary) 40%, var(--text-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.4vw, 1.4rem);
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 24px;
  line-height: 1.5;
}
.hero-subtitle .highlight {
  color: var(--text-primary);
  font-weight: 600;
  border-bottom: 2px solid var(--accent-soft);
}

.hero-intro {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 36px;
}

.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: var(--accent);
  color: #06110f;
}
.btn-primary:hover { box-shadow: 0 8px 24px var(--accent-soft); background: var(--accent-strong); }
.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-color: var(--border-strong);
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }
.btn-full { width: 100%; justify-content: center; }

.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-tertiary);
  animation: bob 2.2s ease-in-out infinite;
}
@keyframes bob {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}

/* ==========================================================================
   Sections (shared)
   ========================================================================== */
.section { padding: 110px 0; position: relative; }
.section-alt { background: var(--bg-elevated); }

.section-kicker {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  letter-spacing: 0.04em;
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}
.section-lede {
  color: var(--text-secondary);
  max-width: 640px;
  font-size: 1.05rem;
  margin-bottom: 48px;
}

/* ==========================================================================
   About
   ========================================================================== */
.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 56px;
  align-items: start;
  margin-top: 40px;
}
.about-text p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  font-size: 1.02rem;
}
.about-text strong { color: var(--text-primary); font-weight: 600; }

.about-facts { display: flex; flex-direction: column; gap: 14px; }
.fact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}
.fact-card:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.fact-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
}
.fact-value { font-size: 0.95rem; color: var(--text-primary); line-height: 1.5; }
.fact-value .mono-tag { margin-top: 6px; display: inline-block; }

/* ==========================================================================
   Projects
   ========================================================================== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.project-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  overflow: hidden;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.project-card--featured:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-lg);
}
.project-card-glow {
  position: absolute;
  top: -60%;
  right: -30%;
  width: 320px;
  height: 320px;
  background: radial-gradient(circle, var(--gradient-2), transparent 70%);
  opacity: 0.12;
  pointer-events: none;
}
.project-card--placeholder {
  border-style: dashed;
  justify-content: center;
  min-height: 100%;
  opacity: 0.75;
}

.project-header { display: flex; flex-direction: column; gap: 10px; position: relative; z-index: 1; }
.project-tag-line { display: flex; align-items: center; gap: 10px; margin-bottom: 4px; }
.project-index { font-family: var(--font-mono); color: var(--text-tertiary); font-size: 0.85rem; }
.project-title { font-size: 1.5rem; font-weight: 700; letter-spacing: -0.01em; }
.project-title--muted { color: var(--text-secondary); }
.project-oneliner { color: var(--text-secondary); font-size: 0.98rem; }

.project-body { position: relative; z-index: 1; }
.project-body p { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 14px; }
.project-body strong { color: var(--text-primary); font-weight: 600; }

.project-tags { display: flex; flex-wrap: wrap; gap: 8px; position: relative; z-index: 1; }
.tag {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 5px 11px;
  border-radius: 999px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}
.tag--ghost { border-style: dashed; color: var(--text-tertiary); }

.project-links { display: flex; gap: 20px; margin-top: auto; position: relative; z-index: 1; }
.project-link {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: color 0.2s var(--ease);
}
.project-link:hover { color: var(--accent); }

/* ==========================================================================
   Skills
   ========================================================================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}
.skill-category {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}
.skill-category:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.skill-category-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 18px;
}
.skill-category-title svg { color: var(--accent); flex-shrink: 0; }

.tag-pills { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  font-size: 0.85rem;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.pill:hover { border-color: var(--accent); color: var(--text-primary); }
.pill--active {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  background: var(--accent-soft);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Contact
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 56px;
  align-items: start;
}

.contact-info { display: flex; flex-direction: column; gap: 8px; }
.contact-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-weight: 500;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}
.contact-link:hover { border-color: var(--accent); transform: translateX(4px); color: var(--accent); }
.contact-note {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
  color: var(--text-primary);
  font-size: 0.92rem;
}

.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.form-row { display: flex; flex-direction: column; gap: 8px; }
.form-row label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}
.form-row input,
.form-row textarea {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  resize: vertical;
  transition: border-color 0.2s var(--ease);
}
.form-row input:focus,
.form-row textarea:focus {
  outline: none;
  border-color: var(--accent);
}
.form-status { font-size: 0.88rem; color: var(--accent); min-height: 1.2em; }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-tertiary);
}

/* ==========================================================================
   Scroll reveal
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.in-view {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 860px) {
  .about-grid,
  .contact-grid { grid-template-columns: 1fr; }
  .project-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px 20px;
    gap: 4px;
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s var(--ease), transform 0.2s var(--ease);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-link { padding: 12px 14px; }

  .section { padding: 72px 0; }
  .hero { padding: 110px 0 60px; }
}

@media (max-width: 480px) {
  .hero-cta { flex-direction: column; align-items: stretch; }
  .container { padding: 0 18px; }
  .project-card, .contact-form { padding: 24px; }
}