/* ============================================================
   基础重置 + 通用容器 + 滚动条
   ============================================================ */
* { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: clamp(15px, 1vw + 8px, 17px);
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  font-feature-settings: var(--font-feature-cn);
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

img { max-width: 100%; display: block; }

::selection {
  background: var(--accent);
  color: var(--accent-fg);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 通用容器 */
main { padding-top: 88px; }

section {
  padding: clamp(80px, 12vh, 140px) var(--gutter);
  position: relative;
}

.container {
  max-width: var(--maxw);
  margin: 0 auto;
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.section-eyebrow::before {
  content: '';
  width: 24px; height: 1px;
  background: var(--muted);
  opacity: 0.5;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.2;
  color: var(--fg);
  margin-bottom: 18px;
}

.section-subtitle {
  font-size: clamp(16px, 1.6vw, 18px);
  color: var(--muted);
  max-width: 60ch;
  line-height: 1.6;
  margin-top: 12px;
}

/* 滚动条 */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--surface-2); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent); }