/* ML ATLAS — Core Design Tokens & Base Styles */
:root {
  --bg-primary: #101923;
  --bg-secondary: #142332;
  --bg-card: #182a3a;
  --bg-card-elevated: #20374a;
  --bg-soft: rgba(20, 184, 166, 0.08);
  --visual-ink: #12212c;
  --visual-grid: rgba(217, 231, 224, 0.13);

  --accent-primary: #f0a34a;
  --accent-secondary: #2dd4bf;
  --accent-tertiary: #f28b82;
  --accent-gradient: linear-gradient(135deg, #f0a34a 0%, #2dd4bf 100%);

  --status-success: #22C55E;
  --status-warning: #F59E0B;
  --status-error: #EF4444;

  --text-primary: #F8FAFC;
  --text-secondary: #C7D2E0;
  --text-muted: #8B9AB4;

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(45, 212, 191, 0.35);

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'Space Grotesk', 'JetBrains Mono', 'Fira Code', monospace;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;

  --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 25px rgba(108, 99, 255, 0.18);
  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);

  --nav-h: 64px;
  --touch-target: 44px;
  --space-sm: .5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --reading-max: 72ch;
}

[data-theme="light"] {
  --bg-primary: #f4f1e9;
  --bg-secondary: #fbfaf6;
  --bg-card: #fffdf8;
  --bg-card-elevated: #ffffff;
  --bg-soft: rgba(20, 145, 132, 0.08);
  --visual-ink: #fdfaf0;
  --visual-grid: rgba(20, 58, 68, 0.11);

  --text-primary: #0F172A;
  --text-secondary: #334155;
  --text-muted: #64748B;

  --border-subtle: rgba(15, 23, 42, 0.1);
  --border-accent: rgba(13, 133, 122, 0.35);

  --shadow-card: 0 6px 24px rgba(15, 23, 42, 0.07);
  --shadow-glow: 0 6px 22px rgba(108, 99, 255, 0.15);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  background-image:
    linear-gradient(rgba(108, 99, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(108, 99, 255, 0.035) 1px, transparent 1px);
  background-size: 44px 44px;
  background-position: center top;
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
img { max-width: 100%; height: auto; }
[hidden] { display: none !important; }
main, section, article, aside, .card, .model-card, .model-hero > *, .dna-grid > * { min-width: 0; }
button, input, select { font: inherit; }
button, .btn, .icon-btn, select, summary { min-height: var(--touch-target); }
summary { cursor: pointer; padding: .75rem; }
pre { max-width: 100%; overflow: auto; }
h1, h2, h3, p, dd, a { overflow-wrap: anywhere; }
section[id], [id].card { scroll-margin-top: calc(var(--nav-h) + 1rem); }
::selection { background: rgba(108, 99, 255, 0.35); }

/* Accessibility */
.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--accent-primary); color: #fff;
  padding: 0.6rem 1.2rem; border-radius: var(--radius-sm); z-index: 3000;
}
.skip-link:focus { left: 1rem; top: 1rem; }
:focus-visible {
  outline: 2px solid var(--accent-secondary);
  outline-offset: 3px; border-radius: var(--radius-sm);
}

/* Layout */
.container { max-width: 1280px; margin: 0 auto; padding: 2rem 1.5rem 4rem; }
.container-wide { max-width: 1440px; }


/* Navigation */
.navbar {
  position: sticky; top: 0; z-index: 1000; height: var(--nav-h);
  background: color-mix(in srgb, var(--bg-primary) 82%, transparent);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-subtle);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 1.75rem; gap: 1rem;
}
.nav-brand {
  display: flex; align-items: center; gap: 0.6rem;
  font-weight: 800; font-size: 1.2rem; letter-spacing: 0.05em;
  background: var(--accent-gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  white-space: nowrap;
}
.nav-links { display: flex; align-items: center; gap: 0.1rem; list-style: none; }
.mobile-nav-header { display: none; }
.nav-secondary { display: none; }
.nav-link {
  display: inline-flex; align-items: center; min-height: var(--touch-target); padding: 0.45rem 0.6rem; border-radius: var(--radius-sm);
  color: var(--text-secondary); font-weight: 500; font-size: 0.92rem;
  transition: color var(--transition-fast), background var(--transition-fast);
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-soft); }
.nav-link.active {
  color: var(--text-primary); background: var(--bg-soft);
  box-shadow: inset 0 -2px 0 var(--accent-primary); font-weight: 700;
}
.nav-actions { display: flex; align-items: center; gap: 0.6rem; margin-left: auto; }

.hamburger {
  display: none; background: none; border: 1px solid var(--border-subtle);
  color: var(--text-primary); border-radius: var(--radius-sm);
  padding: 0.45rem 0.65rem; cursor: pointer; font-size: 1.3rem; line-height: 1;
}
.hamburger:hover { border-color: var(--border-accent); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--bg-card); border: 1px solid var(--border-subtle);
  color: var(--text-primary); border-radius: var(--radius-sm);
  padding: 0.6rem 1.1rem; font-weight: 600; font-size: 0.92rem;
  cursor: pointer; transition: all var(--transition-fast);
}
.btn:hover { background: var(--bg-card-elevated); border-color: var(--border-accent); }
.btn-primary { background: var(--accent-gradient); color: #fff; border: none; box-shadow: var(--shadow-glow); }
.btn-primary:hover { filter: brightness(1.08); transform: translateY(-1px); }
.btn-ghost { background: transparent; }
.btn-sm { padding: 0.35rem 0.75rem; font-size: 0.82rem; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.icon-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .4rem; min-width: var(--touch-target); flex-shrink: 0;
  background: var(--bg-card); border: 1px solid var(--border-subtle);
  color: var(--text-primary); padding: 0.5rem 0.8rem; border-radius: var(--radius-sm);
  cursor: pointer; transition: background var(--transition-fast), border var(--transition-fast);
  font-family: var(--font-mono); font-size: 0.85rem;
}
.icon-btn:hover { background: var(--bg-card-elevated); border-color: var(--border-accent); }
.creator-link { display: inline-flex; align-items: center; gap: .45rem; padding: .32rem .55rem .32rem .35rem; text-transform: none; text-decoration: none; }
.creator-avatar { display: grid; place-items: center; width: 1.65rem; height: 1.65rem; border-radius: 50%; background: var(--accent-gradient); color: #fff; font: 800 .62rem var(--font-mono); letter-spacing: -.03em; }
.creator-link-label { font-size: .76rem; font-weight: 700; }
.creator-link:hover .creator-avatar { filter: brightness(1.08); }
.btn-text {
  background: none; border: none; color: var(--accent-primary); cursor: pointer;
  font-family: var(--font-mono); font-weight: 600; font-size: 0.82rem; padding: 0.25rem;
}


/* Search Modal */
.search-modal {
  position: fixed; inset: 0; z-index: 2000;
  background: rgba(11, 16, 32, 0.8); -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
  display: flex; justify-content: center; align-items: flex-start; padding: min(5dvh, 3rem) 1rem;
  opacity: 0; pointer-events: none; transition: opacity var(--transition-fast);
}
.search-modal.active { opacity: 1; pointer-events: auto; }
.search-box {
  background: var(--bg-card-elevated); border: 1px solid var(--border-accent);
  border-radius: var(--radius-md); width: 92%; max-width: 640px;
  padding: 1.4rem; box-shadow: var(--shadow-glow); max-height: 90dvh; overflow-y: auto; overscroll-behavior: contain;
}
.search-input {
  width: 100%; background: var(--bg-primary); border: 1px solid var(--border-subtle);
  color: var(--text-primary); padding: 0.8rem 1rem; border-radius: var(--radius-sm);
  font-size: 1rem; outline: none; margin-bottom: 0.5rem;
}
.search-input:focus { border-color: var(--accent-secondary); }
.search-hint { font-size: 0.75rem; color: var(--text-muted); font-family: var(--font-mono); margin-bottom: 0.75rem; }
.search-results { list-style: none; max-height: min(340px, 45dvh); overflow-y: auto; }
.search-toolbar { display: flex; justify-content: space-between; align-items: center; gap: .5rem; margin-bottom: 1rem; }
.search-result-item > div { min-width: 0; }
.search-open, .menu-open { overflow-y: hidden; }
.search-result-item {
  padding: 0.7rem 1rem; border-bottom: 1px solid var(--border-subtle);
  cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  border-radius: var(--radius-sm);
}
.search-result-item:hover, .search-result-item.selected { background: var(--bg-primary); }
.search-result-item .tag {
  font-family: var(--font-mono); font-size: 0.7rem; color: var(--accent-secondary);
  background: var(--bg-soft); padding: 0.15rem 0.45rem; border-radius: 999px;
}
.search-empty { padding: 1rem; color: var(--text-muted); text-align: center; font-size: 0.9rem; }

/* Lab form controls */
input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: var(--touch-target);
  background: linear-gradient(var(--border-accent), var(--border-accent)) center / 100% 4px no-repeat; border-radius: 999px;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 16px; height: 16px;
  border-radius: 50%; background: var(--accent-primary);
  border: 2px solid var(--bg-card); cursor: pointer; box-shadow: var(--shadow-glow);
}
input[type="range"]::-moz-range-thumb {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent-primary); border: 2px solid var(--bg-card); cursor: pointer;
}
input[type="checkbox"] { accent-color: var(--accent-primary); width: 15px; height: 15px; cursor: pointer; }
select {
  background: var(--bg-card); color: var(--text-primary);
  border: 1px solid var(--border-subtle); border-radius: var(--radius-sm);
  padding: 0.4rem 0.6rem; font-family: inherit;
}

/* MathJax / equations */
mjx-container { display: block; max-width: 100%; overflow-x: auto; overflow-y: hidden; padding: .15rem 0; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-subtle); margin-top: 4rem;
  padding: 2rem 1.5rem; text-align: center; color: var(--text-muted);
  font-size: 0.85rem; font-family: var(--font-mono);
}