/* base.css */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
input, select, textarea { font: inherit; color: inherit; }

:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

/* typography */
h1, h2, h3, h4 { margin: 0; font-weight: 700; line-height: var(--lh-tight); letter-spacing: -0.02em; }
h1 { font-size: var(--fs-3xl); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-xl); }
h4 { font-size: var(--fs-lg); }
p { margin: 0; }
.muted { color: var(--text-muted); }
.faint { color: var(--text-faint); }
.mono { font-family: var(--font-mono); }

/* utilities */
.stack { display: flex; flex-direction: column; gap: var(--space-4); }
.row { display: flex; align-items: center; gap: var(--space-3); }
.row-between { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.grid { display: grid; gap: var(--space-4); }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* empty state */
.empty-state {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; padding: var(--space-12) var(--space-6);
  color: var(--text-muted);
}
.empty-state svg { width: 48px; height: 48px; margin-bottom: var(--space-4); color: var(--text-faint); }
.empty-state h3 { color: var(--text); margin-bottom: var(--space-2); }
.empty-state p { max-width: 36ch; margin-bottom: var(--space-6); }

/* skeleton */
.skeleton {
  background: linear-gradient(90deg, var(--bg-subtle) 0%, var(--bg-muted) 50%, var(--bg-subtle) 100%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--r-sm);
}
@keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* page transition */
.view { display: none; }
.view.active { display: block; animation: fadeUp var(--dur-base) var(--ease-out); }
@keyframes fadeUp { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* scrollbar */
* { scrollbar-width: thin; scrollbar-color: var(--border-strong) transparent; }