/* ==========================================================================
   DESIGN TOKENS — locked contract, doc 02_DESIGN_SYSTEM.md
   ========================================================================== */
:root {
  --color-bg:        #0a0b0d;
  --color-surface:   #14161a;
  --color-surface-2: #1c1f24;

  --color-text:      #f2f3f5;
  --color-muted:     #8b9099;

  --color-primary:   #d7dadd;
  --color-accent:    #4fd1c5;

  --color-success:   #4ade80;
  --color-warning:   #fbbf24;
  --color-error:     #f87171;

  --color-glass-bg:     rgba(255,255,255,0.04);
  --color-glass-border: rgba(255,255,255,0.08);

  --font-display: 'Space Grotesk', -apple-system, 'Segoe UI', sans-serif;
  --font-body:    'Inter', -apple-system, 'Segoe UI', sans-serif;
  --font-mono:    'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;

  --text-hero:  clamp(2.5rem, 6vw, 6rem);
  --text-h1:    clamp(2rem, 4vw, 3.5rem);
  --text-h2:    clamp(1.5rem, 3vw, 2.25rem);
  --text-body:  1rem;
  --text-small: 0.875rem;
  --text-mono:  0.9rem;

  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-6: 3rem;
  --space-8: 4rem;
  --space-12: 6rem;

  --ease-reveal: cubic-bezier(0.16, 1, 0.3, 1);
  --max-width: 1440px;
}

/* ==========================================================================
   RESET / BASE
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@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; scroll-behavior: auto !important; }
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { font-family: var(--font-display); font-weight: 600; line-height: 1.1; margin: 0 0 var(--space-2); color: var(--color-text); }
p { margin: 0 0 var(--space-2); color: var(--color-muted); }
a { color: var(--color-accent); text-decoration: none; }
img { max-width: 100%; display: block; }
.mono { font-family: var(--font-mono); }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 200;
  background: var(--color-accent); color: var(--color-bg); padding: var(--space-1) var(--space-2);
}
.skip-link:focus { left: var(--space-2); top: var(--space-2); }

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-12) var(--space-4);
  position: relative;
  border-bottom: 1px solid rgba(255,255,255,0.04); /* doc 02 §5 — thin structural lines, opacity ≤0.15 */
}
section:last-of-type { border-bottom: none; }
@media (max-width: 639px) {
  section { padding: var(--space-8) var(--space-2); }
}

/* ==========================================================================
   SCROLL PROGRESS BAR (doc 02 §6 "Orient" motion job)
   ========================================================================== */
#scroll-progress {
  position: fixed; top: 0; left: 0; right: 0; height: 2px; z-index: 150;
  background: transparent;
}
#scroll-progress-bar {
  display: block; height: 100%; width: 0%;
  background: var(--color-accent);
  transition: width 80ms linear;
}

/* ==========================================================================
   3D BACKDROP (Phase 2 — simplified single-scene stand-in for the full
   multi-scene Three.js engine specced in doc 05; see modules/scene.js)
   ========================================================================== */
#three-bg {
  position: fixed; inset: 0; width: 100%; height: 100%;
  z-index: 0; pointer-events: none;
}

/* ==========================================================================
   LOADING SEQUENCE (doc 06 §7)
   ========================================================================== */
#loader-overlay {
  position: fixed; inset: 0; z-index: 500; background: var(--color-bg);
  display: flex; align-items: center; justify-content: center;
  transition: opacity 600ms var(--ease-reveal);
}
#loader-overlay.loader-done { opacity: 0; pointer-events: none; }
.loader-title { color: var(--color-accent); letter-spacing: 0.2em; font-size: var(--text-small); margin-bottom: var(--space-3); text-align: center; }
.loader-checklist { list-style: none; margin: 0; padding: 0; font-family: var(--font-mono); font-size: var(--text-small); color: var(--color-muted); }
.loader-checklist li { display: flex; align-items: center; gap: var(--space-1); padding: 4px 0; }
.loader-checklist .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--color-glass-border); transition: background 200ms; }
.loader-checklist li.done .dot { background: var(--color-accent); }
.loader-checklist li.done { color: var(--color-text); }
@media (prefers-reduced-motion: reduce) {
  #loader-overlay { display: none; }
}

/* ==========================================================================
   NAV
   ========================================================================== */
#site-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--space-2) var(--space-4);
  backdrop-filter: blur(12px);
  background: rgba(10,11,13,0.6);
  border-bottom: 1px solid var(--color-glass-border);
}
.nav-mark { font-family: var(--font-mono); color: var(--color-accent); font-size: 1.1rem; letter-spacing: 0.05em; }
#nav-list { list-style: none; display: flex; gap: var(--space-4); margin: 0; padding: 0; }
#nav-list a {
  color: var(--color-muted); font-size: var(--text-small); letter-spacing: 0.02em;
  transition: color 200ms var(--ease-reveal);
}
#nav-list a:hover, #nav-list a.active { color: var(--color-accent); }
#nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: var(--space-1); }
#nav-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); margin: 4px 0; }

@media (max-width: 1023px) {
  #nav-toggle { display: block; }
  #nav-list {
    position: fixed; inset: 0; top: 60px; flex-direction: column; padding: var(--space-4);
    background: var(--color-bg); transform: translateX(100%); transition: transform 300ms var(--ease-reveal);
  }
  #nav-list.open { transform: translateX(0); }
  #nav-list a { font-size: 1.25rem; display: block; padding: var(--space-2) 0; min-height: 44px; }
}

/* ==========================================================================
   HERO
   ========================================================================== */
#hero {
  min-height: 100vh; display: flex; align-items: center; z-index: 1;
  padding-top: var(--space-12);
}
.hero-inner {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: var(--space-8); align-items: center; width: 100%;
}
.eyebrow { color: var(--color-accent); letter-spacing: 0.15em; font-size: var(--text-small); margin-bottom: var(--space-2); }
#hero h1 { font-size: var(--text-hero); margin-bottom: var(--space-2); }
.hero-tagline { font-size: 1.25rem; color: var(--color-muted); max-width: 32ch; }
.hero-cta { display: flex; gap: var(--space-2); margin-top: var(--space-4); flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 0.85rem 1.75rem; border-radius: 4px; font-size: var(--text-small);
  letter-spacing: 0.02em; transition: transform 200ms var(--ease-reveal), background 200ms var(--ease-reveal);
  min-height: 44px; display: inline-flex; align-items: center;
}
.btn-primary { background: var(--color-accent); color: var(--color-bg); }
.btn-primary:hover { transform: translateY(-2px); }
.btn-secondary { background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); color: var(--color-text); }
.btn-secondary:hover { border-color: var(--color-accent); color: var(--color-accent); }

.hero-portrait { position: relative; display: flex; justify-content: center; }
.hero-portrait img {
  width: 100%; max-width: 380px; border-radius: 50%; object-fit: cover; aspect-ratio: 1/1;
  border: 1px solid var(--color-glass-border); position: relative; z-index: 1;
  transition: transform 300ms var(--ease-reveal);
}
.portrait-glow {
  position: absolute; inset: 0; margin: auto; width: 90%; max-width: 340px; aspect-ratio: 1/1;
  background: radial-gradient(circle, rgba(79,209,197,0.18), transparent 70%);
  border-radius: 50%; filter: blur(30px);
}

@media (max-width: 1023px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-cta { justify-content: center; }
  .hero-portrait { order: -1; }
  .hero-portrait img { max-width: 240px; }
}

.scroll-indicator { position: absolute; bottom: var(--space-12); left: 50%; transform: translateX(-50%); }
.scroll-indicator span {
  display: block; width: 1px; height: 40px; background: linear-gradient(var(--color-accent), transparent);
}

/* ==========================================================================
   STATS BAR (real, data-derived counts — no invented numbers)
   ========================================================================== */
.stats-bar {
  position: absolute; bottom: var(--space-4); left: var(--space-4); right: var(--space-4);
  display: flex; gap: var(--space-6); flex-wrap: wrap;
  border-top: 1px solid var(--color-glass-border); padding-top: var(--space-3);
}
.stat-item { display: flex; flex-direction: column; }
.stat-num { font-family: var(--font-display); font-size: 1.75rem; font-weight: 700; color: var(--color-accent); }
.stat-label { font-family: var(--font-mono); font-size: 0.7rem; color: var(--color-muted); letter-spacing: 0.05em; text-transform: uppercase; }
@media (max-width: 639px) { .stats-bar { position: static; margin-top: var(--space-6); gap: var(--space-4); } }

/* ==========================================================================
   SECTION HEADERS
   ========================================================================== */
.section-header { display: flex; align-items: baseline; gap: var(--space-2); margin-bottom: var(--space-6); }
.section-num { color: var(--color-accent); font-size: var(--text-mono); }
.section-header h2 { font-size: var(--text-h2); }
.section-note { color: var(--color-muted); font-size: var(--text-small); margin-bottom: var(--space-4); max-width: 60ch; }
.about-body p { max-width: 70ch; font-size: 1.05rem; }

/* ==========================================================================
   FILTER BAR
   ========================================================================== */
.filter-bar { display: flex; gap: var(--space-1); flex-wrap: wrap; margin-bottom: var(--space-4); }
.filter-btn {
  background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); color: var(--color-muted);
  font-family: var(--font-mono); font-size: var(--text-small); padding: 0.5rem 1rem; border-radius: 4px;
  cursor: pointer; min-height: 44px; transition: all 200ms var(--ease-reveal);
}
.filter-btn.active, .filter-btn:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* ==========================================================================
   PROJECT GRID / CARDS
   ========================================================================== */
.project-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-3); }
.project-grid.featured { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 1023px) { .project-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 639px) { .project-grid { grid-template-columns: 1fr; } }

.project-card {
  background: var(--color-surface); border: 1px solid var(--color-glass-border); border-radius: 6px;
  overflow: hidden; cursor: pointer; transition: transform 150ms var(--ease-reveal), border-color 200ms var(--ease-reveal);
  display: flex; flex-direction: column; transform-style: preserve-3d; will-change: transform;
}
.project-card:hover, .project-card:focus-visible { border-color: rgba(79,209,197,0.3); }
@media (hover: none) {
  .project-card:active { transform: translateY(-2px); }
}
.card-thumb {
  aspect-ratio: 16/10; background: var(--color-surface-2); overflow: hidden; position: relative;
  display: flex; align-items: center; justify-content: center;
}
.card-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 400ms var(--ease-reveal); }
.project-card:hover .card-thumb img { transform: scale(1.06); }
.card-thumb::after {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: var(--color-accent); transform: scaleX(0); transform-origin: left;
  transition: transform 300ms var(--ease-reveal);
}
.project-card:hover .card-thumb::after { transform: scaleX(1); }
.card-thumb .placeholder-label {
  position: absolute; bottom: var(--space-1); left: var(--space-1); background: rgba(10,11,13,0.75);
  color: var(--color-warning); font-family: var(--font-mono); font-size: 0.65rem; padding: 2px 6px; border-radius: 3px;
  letter-spacing: 0.05em;
}
.card-thumb .no-image { color: var(--color-muted); font-family: var(--font-mono); font-size: var(--text-small); }
.card-body { padding: var(--space-3); flex: 1; display: flex; flex-direction: column; }
.card-category { color: var(--color-accent); font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.05em; margin-bottom: var(--space-1); text-transform: uppercase; }
.card-title { font-family: var(--font-display); font-size: 1.05rem; color: var(--color-text); margin-bottom: var(--space-1); font-weight: 600; }
.card-desc { font-size: var(--text-small); color: var(--color-muted); flex: 1; }
.card-status {
  font-family: var(--font-mono); font-size: 0.65rem; color: var(--color-muted); margin-top: var(--space-2);
  text-transform: uppercase; letter-spacing: 0.05em;
}

.empty-state { color: var(--color-muted); font-family: var(--font-mono); font-size: var(--text-small); padding: var(--space-4) 0; }

/* ==========================================================================
   SKILLS
   ========================================================================== */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: var(--space-2); }
.skill-card { background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); border-radius: 6px; padding: var(--space-3); }
.skill-name { font-family: var(--font-display); font-weight: 600; margin-bottom: var(--space-1); }
.skill-level { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.15em; margin-bottom: var(--space-1); }
.skill-dots { display: flex; gap: 4px; margin-bottom: var(--space-1); }
.skill-dots span { width: 8px; height: 8px; border-radius: 50%; background: var(--color-glass-border); }
.skill-dots span.filled { background: var(--color-accent); }
.skill-desc { font-size: var(--text-small); color: var(--color-muted); margin: 0; }

/* ==========================================================================
   SKILLS — graph + detail panel + fallback grid
   ========================================================================== */
.skills-layout { display: grid; grid-template-columns: 1.4fr 1fr; gap: var(--space-4); margin-bottom: var(--space-6); }
.skill-graph-wrap {
  background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); border-radius: 8px;
  aspect-ratio: 1/1; max-height: 520px;
}
#skill-graph { width: 100%; height: 100%; }
.sg-edge { stroke: var(--color-glass-border); stroke-width: 1; transition: stroke 200ms, stroke-width 200ms; }
.sg-edge.active { stroke: var(--color-accent); stroke-width: 1.5; }
.sg-node-circle { fill: var(--color-surface-2); stroke: var(--color-glass-border); stroke-width: 1.5; cursor: pointer; transition: all 200ms var(--ease-reveal); }
.sg-node:hover .sg-node-circle, .sg-node.active .sg-node-circle { stroke: var(--color-accent); fill: var(--color-surface); }
.sg-node.dimmed { opacity: 0.2; }
.sg-label { fill: var(--color-muted); font-family: var(--font-mono); font-size: 10px; pointer-events: none; }
.sg-node.active .sg-label, .sg-node:hover .sg-label { fill: var(--color-text); }

.skill-detail {
  background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); border-radius: 8px;
  padding: var(--space-3); display: flex; flex-direction: column;
}
.skill-detail .skill-detail-title { font-family: var(--font-display); font-size: 1.2rem; margin-bottom: var(--space-1); }
.skill-detail .skill-level { font-family: var(--font-mono); font-size: 0.7rem; color: var(--color-accent); letter-spacing: 0.1em; margin-bottom: var(--space-2); }
.skill-detail-projects { list-style: none; padding: 0; margin: var(--space-2) 0 0; }
.skill-detail-projects li { padding: var(--space-1) 0; border-top: 1px solid var(--color-glass-border); font-size: var(--text-small); }
.skill-detail-projects button { background: none; border: none; color: var(--color-text); text-align: left; cursor: pointer; padding: 0; font-size: inherit; }
.skill-detail-projects button:hover { color: var(--color-accent); }
@media (max-width: 1023px) { .skills-layout { grid-template-columns: 1fr; } }

/* ==========================================================================
   ALL PROJECTS / BROWSE
   ========================================================================== */
.browse-controls { display: flex; gap: var(--space-2); margin-bottom: var(--space-4); flex-wrap: wrap; }
.browse-controls input, .browse-controls select {
  background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); color: var(--color-text);
  padding: 0.75rem 1rem; border-radius: 4px; font-family: var(--font-body); font-size: var(--text-small);
  min-height: 44px;
}
.browse-controls input { flex: 1; min-width: 200px; }
.browse-controls input:focus, .browse-controls select:focus { border-color: var(--color-accent); }

/* ==========================================================================
   CASE STUDY — prev/next + related strip
   ========================================================================== */
.cs-nav-arrow {
  position: fixed; top: 50%; transform: translateY(-50%); z-index: 310;
  background: var(--color-glass-bg); border: 1px solid var(--color-glass-border); color: var(--color-text);
  width: 44px; height: 44px; border-radius: 50%; font-size: 1.25rem; cursor: pointer;
}
.cs-nav-arrow:hover { border-color: var(--color-accent); color: var(--color-accent); }
.cs-prev { left: var(--space-4); }
.cs-next { right: var(--space-4); }
@media (max-width: 639px) { .cs-nav-arrow { display: none; } }

.cs-related { margin-top: var(--space-4); padding-top: var(--space-3); border-top: 1px solid var(--color-glass-border); }
.cs-related h3 { font-family: var(--font-mono); font-size: var(--text-small); text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-muted); margin-bottom: var(--space-2); }
.cs-related-strip { display: flex; gap: var(--space-2); overflow-x: auto; padding-bottom: var(--space-2); scroll-snap-type: x proximity; }
.cs-related-strip .mini-card {
  scroll-snap-align: start; flex: 0 0 200px; background: var(--color-surface); border: 1px solid var(--color-glass-border);
  border-radius: 6px; padding: var(--space-2); cursor: pointer; transition: border-color 200ms;
}
.cs-related-strip .mini-card:hover { border-color: var(--color-accent); }
.cs-related-strip .mini-card .mc-cat { font-family: var(--font-mono); font-size: 0.65rem; color: var(--color-accent); text-transform: uppercase; }
.cs-related-strip .mini-card .mc-title { font-size: var(--text-small); font-weight: 600; margin-top: 2px; }

/* ==========================================================================
   CONTACT / FOOTER
   ========================================================================== */
.contact-body { text-align: center; }
.contact-email { font-size: 1.5rem; font-family: var(--font-mono); }
footer { text-align: center; padding: var(--space-4); color: var(--color-muted); font-size: var(--text-small); position: relative; z-index: 1; }

/* ==========================================================================
   CASE STUDY PANEL
   ========================================================================== */
.case-study-panel {
  position: fixed; inset: 0; z-index: 300; background: rgba(10,11,13,0.9); backdrop-filter: blur(6px);
  display: flex; align-items: flex-start; justify-content: center; overflow-y: auto; padding: var(--space-4);
}
.case-study-panel[hidden] { display: none; }
.case-study-inner {
  background: var(--color-surface); border: 1px solid var(--color-glass-border); border-radius: 8px;
  max-width: 800px; width: 100%; padding: var(--space-6); margin: var(--space-8) 0; position: relative;
}
.cs-close {
  position: absolute; top: var(--space-2); right: var(--space-2); background: var(--color-glass-bg);
  border: 1px solid var(--color-glass-border); color: var(--color-text); width: 44px; height: 44px; border-radius: 50%;
  font-size: 1.5rem; cursor: pointer; line-height: 1;
}
.cs-content h3 { color: var(--color-accent); font-size: var(--text-small); text-transform: uppercase; letter-spacing: 0.1em; margin-top: var(--space-4); font-family: var(--font-mono); }
.cs-content h2 { font-size: var(--text-h2); margin-bottom: var(--space-1); }
.cs-content img { border-radius: 6px; margin-bottom: var(--space-2); }
.cs-gallery { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: var(--space-1); margin-bottom: var(--space-2); }
.cs-gallery img { aspect-ratio: 4/3; object-fit: cover; margin-bottom: 0; }
.cs-note { background: rgba(251,191,36,0.08); border: 1px solid rgba(251,191,36,0.25); color: var(--color-warning); padding: var(--space-2); border-radius: 4px; font-size: var(--text-small); margin-top: var(--space-3); }

/* ==========================================================================
   SCROLL REVEAL
   ========================================================================== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 600ms var(--ease-reveal), transform 600ms var(--ease-reveal); }
.reveal.in-view { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { transform: none; }
}