/* ============================================================
   GP Sourcing — Base Reset + Typography + Layout
   ============================================================ */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  -webkit-text-size-adjust: 100%;
  font-size: 17px;
  background: var(--bg);
  transition: background var(--t-slow) var(--ease-smooth);
}

@media (min-width: 1200px) {
  html {
    font-size: 18px;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 16px;
  }
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: transparent;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: color var(--t-slow) var(--ease-smooth);
}

img, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; background: none; border: none; }
ul, ol { list-style: none; }
input, textarea, select { font-family: inherit; }

/* ── Layout ── */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: var(--section-py) 0;
}

/* ── Typography scale ── */
.text-hero {
  font-family: var(--font-display);
  font-size: clamp(46px, 7.5vw, 92px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.035em;
  color: var(--text);
}

.text-h1 {
  font-family: var(--font-display);
  font-size: clamp(38px, 5.5vw, 68px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.025em;
  color: var(--text);
}

.text-h2 {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text);
}

.text-h3 {
  font-family: var(--font-display);
  font-size: clamp(20px, 2.5vw, 26px);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.015em;
  color: var(--text);
}

.text-body-lg {
  font-size: 1.2rem;
  line-height: 1.65;
  color: var(--text-2);
}

.text-body {
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--muted);
}

.text-sm {
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--muted);
}

/* ── Gradient text ── */
.text-gradient {
  background: linear-gradient(
    90deg,
    var(--text-gradient-start) 0%,
    var(--text-gradient-mid) 25%,
    var(--text-gradient-end) 50%,
    var(--text-gradient-mid) 75%,
    var(--text-gradient-start) 100%
  );
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: textShimmer 15s linear infinite;
  transition: filter 0.3s ease;
  display: inline-block;
}

@media (min-width: 769px) {
  .text-gradient {
    white-space: nowrap !important;
  }
}

.text-gradient:hover {
  filter: drop-shadow(0 0 10px rgba(59, 130, 246, 0.45));
}

@keyframes textShimmer {
  0% { background-position: 0% center; }
  100% { background-position: 200% center; }
}

/* ── Section label ── */
.label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
  /* Always center within any parent */
  margin-left: auto;
  margin-right: auto;
}

.label-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
}

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

/* ── Mobile ── */
@media (max-width: 768px) {
  :root { --section-py: 64px; }
  .container { padding: 0 16px; }
  .hide-mobile { display: none !important; }
}

@media (min-width: 769px) {
  .show-mobile { display: none !important; }
}

/* ── Language-specific visibility ── */
html[lang="zh-CN"] .lang-en-only { display: none !important; }
html[lang="en"] .lang-zh-only { display: none !important; }