/* ═══════════════════════════════════════════════════════════════
   SABRINA TIAN PORTFOLIO — BASE STYLES
   Shared across all pages. Import tokens.css first.
   ═══════════════════════════════════════════════════════════════ */

/* ── RESET ────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-variant-emoji: text; }

a { color: var(--color-link); }
a:hover { color: var(--color-accent-soft); }

body {
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── GRAIN TEXTURE ───────────────────────────────────────────── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 512 512' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 1000;
  opacity: 0.4;
}

/* ── NAVIGATION ──────────────────────────────────────────────── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.25rem 2.5rem;
  height: var(--nav-height);
  background: rgba(250, 248, 244, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-line);
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 300;
  letter-spacing: 0.02em;
  color: var(--color-ink);
  text-decoration: none;
  transition: color var(--transition);
}

.nav-logo {
  margin-right: auto;
}

.nav-logo:hover { color: var(--color-accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  line-height: 1;
  color: var(--color-ink-muted);
  text-decoration: none;
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a.active { color: var(--color-ink); }
.nav-links a.active { color: var(--color-accent); }

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-ink);
  transition: all 0.3s;
}

/* ── MOBILE MENU ─────────────────────────────────────────────── */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--color-bg);
  z-index: 99;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
}

.mobile-menu.open { display: flex; }

.mobile-menu a {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 300;
  color: var(--color-ink);
  text-decoration: none;
  transition: color var(--transition);
}

.mobile-menu a:hover { color: var(--color-accent); }

/* ── FOOTER ──────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--color-line);
  padding: 2rem 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-bg);
}

.footer-sig {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-style: italic;
  color: var(--color-ink-muted);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-links a:hover { color: var(--color-accent); }

/* ── TAG CHIPS ───────────────────────────────────────────────── */
.ptag {
  font-family: var(--font-mono);
  font-size: 0.55rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.7rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-line);
  color: var(--color-ink-muted);
  background: transparent;
  white-space: nowrap;
  cursor: default;
}

.ptag.physical { border-color: var(--color-tag-physical); color: var(--color-tag-physical); }
.ptag.software { border-color: var(--color-tag-software); color: var(--color-tag-software); }
.ptag.research { border-color: var(--color-tag-research); color: var(--color-tag-research); }
.ptag.craft   { border-color: var(--color-tag-craft);    color: var(--color-tag-craft); }

/* ── EMOJI → TEXT GLYPH ──────────────────────────────────────── */
/* Prevents ↗ ☽ ☀ ❤ ☻ from rendering as color emoji on mobile */
.theme-icon-moon,
.theme-icon-sun,
.project-arrow,
.nav-links a,
.mobile-menu a,
.footer-links a,
.footer-sig {
  font-variant-emoji: text;
}

/* ── THEME TOGGLE ────────────────────────────────────────────── */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--color-ink-muted);
  padding: 0.2rem 0.4rem;
  margin-left: 1.5rem;
  line-height: 1;
  display: flex;
  align-items: center;
  transition: color var(--transition);
}

.theme-toggle:hover { color: var(--color-ink); }

.theme-icon-sun  { display: none; }

[data-theme="dark"] .theme-icon-moon { display: none; }
[data-theme="dark"] .theme-icon-sun  { display: inline; }

[data-theme="dark"] nav {
  background: rgba(26, 24, 20, 0.92);
}

[data-theme="dark"] .mobile-menu {
  background: var(--color-bg);
}

/* ── UTILITIES ───────────────────────────────────────────────── */
.hidden { display: none !important; }

.fade-up {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s var(--ease-out), transform 0.55s var(--ease-out);
}

.fade-up.visible { opacity: 1; transform: none; }

/* ── RESPONSIVE BASE ─────────────────────────────────────────── */
@media (max-width: 768px) {
  nav { padding: 1rem 1.25rem; }
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  footer { flex-direction: column; gap: 1rem; text-align: center; }
  .footer-links { flex-wrap: wrap; justify-content: center; }
}