*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 { margin: 0; font-weight: 600; line-height: 1.3; color: var(--c-text); }
h1 { font-size: clamp(28px, 4vw, 40px); }
h2 { font-size: clamp(22px, 2.6vw, 30px); }
h3 { font-size: clamp(18px, 2vw, 22px); }
h4 { font-size: 18px; }
p  { margin: 0 0 1em; }
a  { color: var(--c-primary); text-decoration: none; transition: color .15s var(--ease); }
a:hover { color: var(--c-primary-2); }
img, svg { max-width: 100%; display: block; }
ul, ol { margin: 0; padding: 0 0 0 1.4em; }
li { margin: .25em 0; }
hr { border: 0; border-top: 1px solid var(--c-line); margin: 32px 0; }

input, button, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 2px; border-radius: 2px; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: 64px 0; }
.section--tight { padding: 40px 0; }
.section--dark { background: var(--c-bg-dark); color: #fff; }
.section--soft { background: var(--c-bg-soft); }

.section-head { text-align: center; margin-bottom: 40px; }
.section-head .kicker { color: var(--c-accent); font-size: 14px; letter-spacing: .2em; text-transform: uppercase; margin-bottom: 8px; }
.section-head .title { color: var(--c-text); }
.section-head .lead { color: var(--c-text-soft); margin-top: 12px; max-width: 720px; margin-inline: auto; }
.section--dark .section-head .title { color: #fff; }
.section--dark .section-head .lead { color: rgba(255,255,255,.7); }

.text-soft { color: var(--c-text-soft); }
.text-muted { color: var(--c-text-muted); }
.text-accent { color: var(--c-accent); }
.text-center { text-align: center; }
.mt-0 { margin-top: 0; } .mb-0 { margin-bottom: 0; }
.mt-2 { margin-top: 16px; } .mt-4 { margin-top: 32px; }
.mb-2 { margin-bottom: 16px; } .mb-4 { margin-bottom: 32px; }
.hidden { display: none !important; }