/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: var(--font-size-base); }
body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; }
::selection { background: var(--color-primary); color: #fff; }

/* ===== LAYOUT ===== */
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 var(--container-padding); }
.section { padding: var(--section-padding); position: relative; }
.section--alt { background-color: var(--color-bg-alt); }
.section--soft { background: var(--grad-soft); }
.section--dark { background-color: var(--color-bg-dark); color: #c7c3de; }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 { color: #fff; }

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-extrabold);
  line-height: var(--line-height-tight);
  color: var(--color-heading);
  letter-spacing: -0.01em;
}
h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
h5 { font-size: var(--font-size-md); }
h6 { font-size: var(--font-size-base); }
p { line-height: var(--line-height-loose); color: var(--color-text); }

.text-gradient {
  background: var(--grad-primary);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* ===== SECTION HEADER ===== */
.section-header { text-align: center; max-width: 640px; margin: 0 auto var(--space-3xl); }
.pill {
  display: inline-flex; align-items: center; gap: var(--space-sm);
  font-size: var(--font-size-sm); font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 7px 16px; border-radius: var(--radius-full);
  margin-bottom: var(--space-lg);
}
.pill .icon { font-size: 1.05em; }
.section-header h2 { margin-bottom: var(--space-md); }
.section-header p { color: var(--color-text-light); font-size: var(--font-size-md); }

/* ===== GRID ===== */
.grid { display: grid; gap: var(--space-xl); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 992px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 576px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

/* ===== UTILITIES ===== */
.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.text-white { color: #fff; }
.text-muted { color: var(--color-text-light); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

/* ===== PAGE BANNER（柔和渐变）===== */
.page-banner {
  background: var(--grad-soft);
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-3xl);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-banner::before {
  content: ''; position: absolute; top: -120px; right: -80px;
  width: 360px; height: 360px; border-radius: 50%;
  background: radial-gradient(circle, rgba(168,85,247,0.25), transparent 70%);
}
.page-banner::after {
  content: ''; position: absolute; bottom: -140px; left: -60px;
  width: 320px; height: 320px; border-radius: 50%;
  background: radial-gradient(circle, rgba(236,72,153,0.18), transparent 70%);
}
.page-banner h1 { font-size: var(--font-size-4xl); margin-bottom: var(--space-md); position: relative; }
.page-banner > .container > p { color: var(--color-text); position: relative; max-width: 600px; margin: 0 auto; }
.breadcrumb { display: flex; align-items: center; justify-content: center; gap: var(--space-sm); font-size: var(--font-size-sm); color: var(--color-text-light); position: relative; margin-top: var(--space-lg); }
.breadcrumb a { transition: color var(--transition-fast); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb .sep { color: var(--color-primary); }
.breadcrumb .current { color: var(--color-heading); font-weight: var(--font-weight-medium); }