/* ==========================================================================
   基础样式 · reset + 通用
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  padding-top: 72px;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

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

::selection { background: var(--accent); color: #0a0b0d; }

/* —— Ambient 背景层 —— */
.ambient {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(60% 40% at 18% 22%, rgba(255, 106, 44, 0.16), transparent 65%),
    radial-gradient(55% 50% at 82% 65%, rgba(123, 92, 255, 0.10), transparent 70%);
  filter: blur(60px);
}

/* —— 容器 —— */
.container {
  position: relative;
  z-index: 1;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* —— 字号 / 标题 —— */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.025em;
  line-height: 1.05;
  margin: 0;
}
h1 { font-size: clamp(48px, 7vw, 88px); }
h2 { font-size: clamp(36px, 5vw, 56px); }
h3 { font-size: clamp(22px, 2.4vw, 28px); letter-spacing: -0.01em; font-family: var(--font-sans); font-weight: 600; }
h4 { font-size: 18px; font-family: var(--font-sans); font-weight: 600; letter-spacing: -0.01em; }

p { margin: 0; }

/* —— 段距 —— */
.lead {
  max-width: 620px;
  font-size: 18px;
  color: var(--text-mute);
  margin: 16px 0 0;
}

/* —— Eyebrow 标签 —— */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-soft);
  border: 1px solid rgba(255, 106, 44, 0.35);
  border-radius: var(--radius-pill);
  background: rgba(255, 106, 44, 0.06);
  font-family: var(--font-sans);
  font-weight: 500;
}
.eyebrow .pulse {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.7); }
}

/* —— 段落（通用） —— */
.section {
  padding: var(--section-py) 0;
}
.section__head {
  max-width: 720px;
  margin-bottom: 56px;
}
.section__head h2 { margin-top: 16px; }
.section__head p.lead { margin-top: 16px; }

/* —— 滚动揭示 —— */
.reveal {
  opacity: 0;
  transform: translateY(var(--reveal-y));
  filter: blur(var(--reveal-blur));
  transition: opacity var(--reveal-dur) var(--ease),
              transform var(--reveal-dur) var(--ease),
              filter var(--reveal-dur) var(--ease);
  will-change: auto;
}
.reveal.is-in {
  opacity: 1;
  transform: translateY(0);
  filter: blur(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; filter: none; transition: none; }
}

/* —— 移动端断点 —— */
@media (max-width: 768px) {
  h1 { font-size: clamp(40px, 11vw, 64px); }
  h2 { font-size: clamp(30px, 8vw, 44px); }
  .lead { font-size: 16px; }
  .section { padding: 64px 0; }
  .section__head { margin-bottom: 40px; }
}


/* 高质量图片渲染 */
img { image-rendering: auto; }