/* ============================================================
   妙境AI · Base (reset, typography, utilities)
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; }

* { margin: 0; }

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  font-weight: var(--font-regular);
  text-rendering: optimizeLegibility;
}

img, svg, video, canvas { display: block; max-width: 100%; }
svg { width: 1.25em; height: 1.25em; flex-shrink: 0; }
svg:not([width]) { overflow: visible; }

input, button, textarea, select { font: inherit; color: inherit; }

button { cursor: pointer; background: none; border: none; }

a { color: inherit; text-decoration: none; }

ul, ol { list-style: none; padding: 0; }

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
}

h1 { font-size: var(--text-5xl); letter-spacing: var(--tracking-tighter); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }

p { color: var(--color-text-secondary); }

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

::selection { background: var(--color-primary-100); color: var(--color-primary-700); }

/* ---------- Layout utilities ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.container-narrow { max-width: var(--container-narrow); }

.section { padding-block: var(--space-24); }
.section-sm { padding-block: var(--space-16); }

.grid { display: grid; gap: var(--space-6); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }
.flex-1 { flex: 1; }

.text-center { text-align: center; }
.text-right { text-align: right; }

.w-full { width: 100%; }

/* ---------- Text helpers ---------- */
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.text-2xl { font-size: var(--text-2xl); }
.text-3xl { font-size: var(--text-3xl); }
.text-4xl { font-size: var(--text-4xl); }
.text-5xl { font-size: var(--text-5xl); }

.font-medium { font-weight: var(--font-medium); }
.font-semibold { font-weight: var(--font-semibold); }
.font-bold { font-weight: var(--font-bold); }

.text-secondary { color: var(--color-text-secondary); }
.text-tertiary { color: var(--color-text-tertiary); }
.text-primary { color: var(--color-primary); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-danger { color: var(--color-danger); }
.text-white { color: #fff; }

.tracking-tight { letter-spacing: var(--tracking-tight); }
.tracking-wide { letter-spacing: var(--tracking-wide); }

/* ---------- Spacing helpers ---------- */
.mt-1{margin-top:var(--space-1)}.mt-2{margin-top:var(--space-2)}.mt-3{margin-top:var(--space-3)}
.mt-4{margin-top:var(--space-4)}.mt-6{margin-top:var(--space-6)}.mt-8{margin-top:var(--space-8)}
.mt-10{margin-top:var(--space-10)}.mt-12{margin-top:var(--space-12)}
.mb-2{margin-bottom:var(--space-2)}.mb-3{margin-bottom:var(--space-3)}.mb-4{margin-bottom:var(--space-4)}
.mb-6{margin-bottom:var(--space-6)}.mb-8{margin-bottom:var(--space-8)}.mb-12{margin-bottom:var(--space-12)}

/* ---------- Display ---------- */
.hidden { display: none; }
.inline-flex { display: inline-flex; }
.relative { position: relative; }
.absolute { position: absolute; }

/* ---------- Eyebrow / section heading ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-primary);
  background: var(--color-primary-50);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  letter-spacing: var(--tracking-wide);
}

.section-title {
  font-size: var(--text-4xl);
  letter-spacing: var(--tracking-tighter);
  max-width: 36ch;
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 56ch;
  line-height: var(--leading-normal);
}

/* ---------- Gradient text ---------- */
.gradient-text {
  background: linear-gradient(135deg, var(--color-primary) 0%, #6366F1 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- Misc ---------- */
.divider { height: 1px; background: var(--color-border); border: 0; }
.muted { color: var(--color-text-tertiary); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ---------- Visually hidden (a11y) ---------- */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0);
  white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -100px;
  z-index: 9999;
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  transition: top var(--transition);
}
.skip-link:focus { top: var(--space-4); }

/* ---------- Responsive helpers ---------- */
@media (max-width: 960px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  h1 { font-size: var(--text-4xl); }
  h2, .section-title { font-size: var(--text-3xl); }
  .section { padding-block: var(--space-16); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Spinner / loader animation ---------- */
.spin-icon {
  animation: spin 1s linear infinite;
  transform-origin: center;
}
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}