/* ============================================================
   base.css — Reset + 排版 + 通用容器/组件
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

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

body {
  font-family: var(--font-cn);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--t-primary);
  background: var(--c-paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

/* ---- 容器：1920 下内容区 200~1720(宽1520)；窄屏按比例收边距 ---- */
.container {
  width: 100%;
  max-width: calc(var(--container) + 2 * var(--gutter));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---- 通用强调按钮 (青色实心) ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  height: 56px;
  padding: 0 25px;
  border-radius: var(--radius-md);
  font-size: var(--fs-base);
  font-weight: 500;
  line-height: 1;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
}
.btn-primary {
  background: var(--c-teal);
  color: var(--c-navy);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(61, 200, 193, .35);
}
/* 青色按钮上的箭头需为深色 */
.btn-primary .arrow { filter: brightness(0); }
.btn-ghost {
  background: rgba(255, 255, 255, .06);
  color: var(--c-white);
  border: 1px solid var(--c-line);
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, .12);
  transform: translateY(-2px);
}
.btn .arrow { width: 31px; height: 20px; flex: none; }

/* ---- 段标题 (设计稿: Source Han Normal 48px / 副标 20px 白 op.8) ---- */
.section-title {
  font-size: 48px;
  font-weight: 400;
  line-height: 1.2;
}
.section-sub {
  margin-top: 10px;
  font-family: var(--font-cn); font-weight: 300;
  font-size: 20px; line-height: 1.6;
  color: var(--c-white); opacity: .8;
}

/* ---- 通用区块纵向节奏 ---- */
.section { position: relative; }

/* ---- 渐变文字工具类 (logo WINSUN) ---- */
.grad-text {
  background: linear-gradient(90deg, var(--c-blue), var(--c-teal-bright));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---- 滚动出现动画 ---- */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

@media (max-width: 480px){
 
  .btn{
    height: 42px;
  }
}