/* ═══════════════════════════════════════════
   URSP3600 — Shared Design Tokens & Base Styles
   099 Supply Museum-Grid System
   ═══════════════════════════════════════════ */

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

/* --- Tokens: Colors --- */
:root {
  --color-canvas-white: #ffffff;
  --color-ink: #101010;
  --color-charcoal: #000000;
  --color-muted-hard: #222222;
  --color-muted: #555555;
  --color-muted-soft: #999999;
  --color-border-soft: #c8c8c8;
  --color-border-subtle: #e0e0e0;
  --color-accent: #101010;

  /* --- Tokens: Typography --- */
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', 'Space Mono', monospace;

  /* --- Tokens: Spacing --- */
  --sp-4: 4px;  --sp-5: 5px;  --sp-6: 6px;
  --sp-8: 8px;  --sp-10: 10px; --sp-11: 11px;
  --sp-12: 12px; --sp-16: 16px; --sp-24: 24px;
  --sp-32: 32px; --sp-40: 40px; --sp-60: 60px; --sp-80: 80px;

  /* --- Tokens: Radii --- */
  --radius-card: 8px;
  --radius-badge: 0px;
  --radius-input: 4px;
  --radius-button: 9999px;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-mono);
  font-weight: 400;
  color: var(--color-ink);
  background: var(--color-canvas-white);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* --- Utility --- */
.uppercase { text-transform: uppercase; }
.tracking-wide { letter-spacing: 0.18em; }
.tracking-mid { letter-spacing: 0.08em; }
.tracking-tight { letter-spacing: 0.02em; }
.text-muted { color: var(--color-muted); }
.text-muted-soft { color: var(--color-muted-soft); }
.text-ink { color: var(--color-ink); }

/* --- Layout --- */
.page { width: 100%; }
.section { padding: var(--sp-80) var(--sp-40); }
.section + .section { border-top: 1px solid var(--color-border-subtle); }
.section-inner { max-width: 1400px; margin: 0 auto; }

/* --- Navigation --- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--color-canvas-white);
  border-bottom: 1px solid var(--color-border-subtle);
  padding: var(--sp-12) var(--sp-40);
  display: flex; align-items: center; justify-content: space-between;
}
.nav-code {
  font-size: 12px; font-weight: 500;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--color-ink);
}
.nav-links { display: flex; gap: var(--sp-24); }
.nav-links a {
  font-size: 10px; font-weight: 400;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--color-muted-soft);
  transition: color 0.2s;
}
.nav-links a:hover, .nav-links a.active { color: var(--color-ink); }

/* --- Section Heading --- */
.section-heading {
  font-size: 26px; font-weight: 500;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--color-muted-soft);
  margin-bottom: var(--sp-40);
}
.section-subheading {
  font-size: 12px; font-weight: 400;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--color-muted);
  margin-bottom: var(--sp-24);
}

/* --- Cards --- */
.card {
  background: var(--color-canvas-white);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-card);
  padding: var(--sp-16);
  transition: border-color 0.2s;
}
.card:hover { border-color: var(--color-muted-soft); }

/* --- Buttons --- */
.btn-primary {
  background: var(--color-ink); color: var(--color-canvas-white);
  border: none; border-radius: var(--radius-button);
  padding: var(--sp-10) var(--sp-16);
  font-family: var(--font-mono); font-size: 12px; font-weight: 400;
  text-transform: uppercase; letter-spacing: 0.08em;
  cursor: pointer; transition: background 0.2s;
  display: inline-block;
}
.btn-primary:hover { background: var(--color-muted-soft); }
.btn-primary:disabled { background: var(--color-border-soft); cursor: not-allowed; }

.btn-ghost {
  background: transparent; color: var(--color-muted);
  border: 1px solid var(--color-muted-soft);
  border-radius: var(--radius-button);
  padding: var(--sp-10) var(--sp-16);
  font-family: var(--font-mono); font-size: 12px; font-weight: 400;
  text-transform: uppercase; letter-spacing: 0.08em;
  cursor: pointer; transition: border-color 0.2s, color 0.2s;
  display: inline-block;
}
.btn-ghost:hover { border-color: var(--color-ink); color: var(--color-ink); }

.btn-sm {
  padding: var(--sp-6) var(--sp-12);
  font-size: 10px;
}

/* --- Forms --- */
.input {
  width: 100%; border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-input);
  padding: var(--sp-10) var(--sp-12);
  font-family: var(--font-mono); font-size: 12px;
  color: var(--color-ink); background: var(--color-canvas-white);
  outline: none; transition: border-color 0.2s;
}
.input:focus { border-color: var(--color-muted-soft); }
.input::placeholder { color: var(--color-border-soft); }

.textarea {
  width: 100%; border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-input);
  padding: var(--sp-12);
  font-family: var(--font-mono); font-size: 12px;
  color: var(--color-ink); background: var(--color-canvas-white);
  outline: none; transition: border-color 0.2s;
  resize: vertical; min-height: 100px;
  line-height: 1.6;
}
.textarea:focus { border-color: var(--color-muted-soft); }

.select {
  width: 100%; border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-input);
  padding: var(--sp-10) var(--sp-12);
  font-family: var(--font-mono); font-size: 12px;
  color: var(--color-ink); background: var(--color-canvas-white);
  outline: none; appearance: none; cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23999' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
}
.select:focus { border-color: var(--color-muted-soft); }

/* --- Labels --- */
.form-label {
  display: block;
  font-size: 10px; font-weight: 400;
  text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--color-muted-soft);
  margin-bottom: var(--sp-8);
}

.form-group { margin-bottom: var(--sp-16); }

/* --- Progress Bar --- */
.progress-bar {
  width: 100%; height: 4px;
  background: var(--color-border-subtle);
  border-radius: 2px; overflow: hidden;
}
.progress-bar-fill {
  height: 100%;
  background: var(--color-ink);
  border-radius: 2px;
  transition: width 0.4s ease;
}

/* --- Badge --- */
.badge {
  display: inline-block;
  font-size: 10px; text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-muted-soft);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-badge);
  padding: var(--sp-4) var(--sp-8);
}
.badge.active {
  color: var(--color-ink);
  border-color: var(--color-ink);
}

/* --- Divider --- */
.divider {
  border: none;
  border-top: 1px solid var(--color-border-subtle);
  margin: var(--sp-24) 0;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--color-border-subtle);
  padding: var(--sp-40);
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: var(--sp-16);
}
.footer-left {
  font-size: 10px; text-transform: uppercase;
  letter-spacing: 0.18em; color: var(--color-muted-soft);
}
.footer-right {
  font-size: 10px; color: var(--color-muted);
  letter-spacing: 0.02em;
}
.footer-right a {
  color: var(--color-muted); transition: color 0.2s;
}
.footer-right a:hover { color: var(--color-ink); }

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--color-canvas-white); }
::-webkit-scrollbar-thumb { background: var(--color-border-soft); border-radius: 2px; }

/* --- Animations --- */
.fade-in { opacity: 0; transform: translateY(8px); transition: opacity 0.5s, transform 0.5s; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* --- Responsive --- */
@media (max-width: 1200px) {
  .grid-5 { grid-template-columns: repeat(4, 1fr) !important; }
}
@media (max-width: 900px) {
  .section { padding: var(--sp-40) var(--sp-16); }
  .nav { padding: var(--sp-12) var(--sp-16); }
  .grid-5 { grid-template-columns: repeat(3, 1fr) !important; }
  .grid-4 { grid-template-columns: repeat(2, 1fr) !important; }
  .grid-3 { grid-template-columns: repeat(2, 1fr) !important; }
  .nav-links { gap: var(--sp-16); }
}
@media (max-width: 600px) {
  .grid-5, .grid-4, .grid-3 { grid-template-columns: 1fr !important; }
  .nav-links { display: none; }
}