/* ==========================================================================
   swingjam.cn 官网 —— 编辑感黑白
   Token 源自 docs/DESIGN_SYSTEM.md（墨色打底 + 暖中性留白 + 描边代阴影 + 主题绿点睛）
   ========================================================================== */

:root {
  /* 品牌 / 主题 */
  --primary: #01B169;
  --primary-strong: #018a52;
  --primary-tint: #e6f7f0;
  --on-primary: #ffffff;

  /* 墨色 / 中性（界面 90% 的颜色） */
  --ink: #1a1a1a;
  --ink-2: rgba(26, 26, 26, .82);
  --ink-mute: #908d86;
  --ink-faint: rgba(26, 26, 26, .40);
  --ink-05: rgba(26, 26, 26, .05);
  --ink-08: rgba(26, 26, 26, .08);

  /* 表面 / 描边 */
  --canvas: #ffffff;
  --surface: #f6f6f3;
  --hairline: #e7e5df;
  --hairline-soft: #eeece6;

  /* 语义 */
  --status-success: #5a8a1e;

  /* 尺度 */
  --maxw: 1120px;
  --gutter: clamp(20px, 5vw, 48px);
  --radius: 14px;
  --radius-sm: 10px;
  --radius-pill: 999px;

  /* 字体 */
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--surface);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, p { margin: 0; }
a { color: inherit; text-decoration: none; }
ul { margin: 0; padding: 0; list-style: none; }
img, svg { display: block; max-width: 100%; }

/* ---------- 布局工具 ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(56px, 9vw, 104px); }
.section--tight { padding-block: clamp(40px, 6vw, 72px); }
.center { text-align: center; }

/* 眉标 */
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 18px;
}

/* 区块标题 */
.h-section {
  font-size: clamp(26px, 4.4vw, 40px);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.18;
}
.sub-section {
  margin-top: 16px;
  font-size: clamp(15px, 1.9vw, 18px);
  color: var(--ink-2);
  max-width: 640px;
}
.center .sub-section { margin-inline: auto; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 700;
  padding: 13px 24px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .12s ease, background .15s ease, border-color .15s ease;
}
.btn:active { transform: translateY(1px); }
.btn--primary {
  background: var(--primary);
  color: var(--on-primary);
}
.btn--primary:hover { background: var(--primary-strong); }
.btn--ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--ink-08);
}
.btn--ghost:hover { border-color: var(--ink); }
.btn--lg { padding: 16px 30px; font-size: 16px; }

/* ==========================================================================
   导航
   ========================================================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: saturate(1.1) blur(10px);
  transition: box-shadow .2s ease, background .2s ease;
}
.nav.is-stuck {
  border-bottom: 1px solid var(--hairline);
  box-shadow: 0 1px 0 rgba(0,0,0,.02);
}
.nav__inner {
  display: flex;
  align-items: center;
  gap: 20px;
  height: 66px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 800;
  letter-spacing: -.01em;
  font-size: 18px;
}
.brand__mark {
  width: 26px; height: 26px;
  border-radius: 8px;
  background: var(--ink);
  color: var(--surface);
  display: grid; place-items: center;
  font-size: 15px; font-weight: 900;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: 26px;
  margin-left: 12px;
}
.nav__links a {
  font-size: 15px;
  color: var(--ink-2);
  font-weight: 500;
}
.nav__links a:hover { color: var(--ink); }
.nav__links .nav__price-link {
  padding: 6px 14px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius-pill);
  color: var(--ink);
  font-weight: 700;
  background: rgba(255, 255, 255, .52);
}
.nav__links .nav__price-link:hover,
.nav__links .nav__price-link[aria-current="page"] {
  border-color: var(--primary);
  color: var(--primary-strong);
  background: var(--primary-tint);
}
.nav__spacer { flex: 1; }
.nav__dancer {
  font-size: 14px;
  color: var(--ink-mute);
  font-weight: 500;
}
.nav__dancer:hover { color: var(--primary-strong); }
.nav__cta { padding: 10px 20px; font-size: 14px; }
.nav__burger {
  display: none;
  background: none; border: 0; cursor: pointer;
  width: 40px; height: 40px;
  align-items: center; justify-content: center;
}

/* ==========================================================================
   Hero
   ========================================================================== */
/* Hero：整屏一句 slogan */
.hero-slogan {
  min-height: 66vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding-block: clamp(64px, 12vh, 140px);
}
.hero-slogan h1 {
  margin-top: 6px;
  font-size: clamp(38px, 8vw, 84px);
  font-weight: 850;
  line-height: 1.06;
  letter-spacing: -.04em;
}

/* 介绍段：原 hero 内容下移 */
.intro { border-bottom: 1px solid var(--hairline); }

.hero__grid {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}
.hero h1 {
  font-size: clamp(34px, 6vw, 60px);
  font-weight: 850;
  line-height: 1.08;
  letter-spacing: -.035em;
}
.hero__sub {
  margin-top: 22px;
  font-size: clamp(16px, 2.1vw, 19px);
  color: var(--ink-2);
  max-width: 500px;
}
.hero__sub b { color: var(--ink); font-weight: 700; }
.hero__cta {
  margin-top: 32px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.hero__trust {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  font-size: 13.5px;
  color: var(--ink-mute);
}
.hero__trust span { display: inline-flex; align-items: center; gap: 6px; }
.dot { width: 5px; height: 5px; border-radius: 50%; background: var(--primary); }

/* Hero 产品卡（伪截图，纯 CSS 描边示意） */
.mock {
  background: var(--canvas);
  border: 1px solid var(--hairline);
  border-radius: 18px;
  overflow: hidden;
}
.mock__bar {
  display: flex; align-items: center; gap: 6px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--hairline-soft);
}
.mock__bar i { width: 9px; height: 9px; border-radius: 50%; background: var(--ink-08); }
.mock__bar b {
  margin-left: 8px; font-size: 12px; color: var(--ink-mute); font-weight: 600;
}
.mock__body { padding: 18px; display: grid; gap: 12px; }
.mock__row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.mock__stat {
  border: 1px solid var(--hairline); border-radius: 10px; padding: 12px;
}
.mock__stat small { font-size: 11px; color: var(--ink-mute); }
.mock__stat b { display: block; font-size: 22px; font-weight: 800; margin-top: 3px; }
.mock__stat b.accent { color: var(--primary); }
.mock__line {
  border: 1px solid var(--hairline); border-radius: 10px; padding: 12px 14px;
  display: flex; align-items: center; gap: 12px;
}
.mock__line .tag {
  font-size: 11px; font-weight: 700; padding: 3px 9px; border-radius: 999px;
  background: var(--primary-tint); color: var(--primary-strong);
}
.mock__line .tag.mute { background: var(--ink-05); color: var(--ink-mute); }
.mock__line .grow { flex: 1; }
.mock__line .t { font-size: 13.5px; font-weight: 600; }
.mock__line .s { font-size: 11.5px; color: var(--ink-mute); }
.mock__line .price { font-weight: 800; }

/* ==========================================================================
   痛点
   ========================================================================== */
.pain { background: var(--canvas); border-block: 1px solid var(--hairline); }
.pain__grid {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.pain__card {
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  padding: 24px;
  background: var(--surface);
}
.pain__card h3 { font-size: 19px; font-weight: 750; letter-spacing: -.01em; }
.pain__card .now { margin-top: 6px; color: var(--ink-mute); font-size: 14.5px; }
.pain__card .fix {
  margin-top: 14px; padding-top: 14px;
  border-top: 1px solid var(--hairline);
  color: var(--primary-strong); font-weight: 650; font-size: 14.5px;
  display: flex; gap: 8px; align-items: baseline;
}
.pain__card .fix::before { content: "→"; color: var(--primary); font-weight: 800; }

/* ==========================================================================
   能力宫格
   ========================================================================== */
.feat__grid {
  margin-top: 44px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.feat__card {
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  padding: 26px 24px;
  background: var(--canvas);
  transition: border-color .15s ease;
}
.feat__card:hover { border-color: var(--ink); }
.feat__ico {
  width: 42px; height: 42px;
  border: 1px solid var(--hairline);
  border-radius: 11px;
  display: grid; place-items: center;
  color: var(--ink);
}
.feat__card h3 { margin-top: 18px; font-size: 18px; font-weight: 750; }
.feat__card p { margin-top: 8px; color: var(--ink-2); font-size: 14.5px; }
.feat__more {
  margin-top: 16px; font-size: 13.5px; font-weight: 650; color: var(--ink-mute);
  display: inline-flex; gap: 5px;
}
.feat__card:hover .feat__more { color: var(--primary-strong); }

/* ==========================================================================
   杀手锏（深色反白）
   ========================================================================== */
.killer { background: var(--ink); color: var(--surface); }
.killer .eyebrow { color: rgba(246,246,243,.5); }
.killer h2 { font-size: clamp(26px, 4.6vw, 42px); font-weight: 800; letter-spacing: -.025em; line-height: 1.15; }
.killer h2 b { color: var(--primary); font-weight: 800; }
.killer__lead {
  margin-top: 20px; max-width: 620px;
  color: rgba(246,246,243,.78); font-size: clamp(15px, 2vw, 18px);
}
.killer__cards {
  margin-top: 40px;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
.killer__card {
  border: 1px solid rgba(246,246,243,.16);
  border-radius: var(--radius);
  padding: 24px;
}
.killer__card h3 { font-size: 17px; font-weight: 750; color: var(--surface); }
.killer__card p { margin-top: 10px; font-size: 14px; color: rgba(246,246,243,.7); }
.killer__note { margin-top: 26px; font-size: 13px; color: rgba(246,246,243,.45); }

/* ==========================================================================
   全链路条
   ========================================================================== */
.chain__flow {
  margin-top: 40px;
  display: flex;
  align-items: stretch;
  gap: 0;
  flex-wrap: wrap;
}
.chain__step {
  flex: 1 1 160px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background: var(--canvas);
  padding: 20px 18px;
  position: relative;
}
.chain__step .n {
  font-size: 12px; font-weight: 800; color: var(--ink-faint); letter-spacing: .04em;
}
.chain__step .t { margin-top: 10px; font-size: 15px; font-weight: 700; line-height: 1.35; }
.chain__step:last-child { border-color: var(--primary); }
.chain__step:last-child .t { color: var(--primary-strong); }
.chain__arrow { align-self: center; color: var(--ink-faint); padding: 0 6px; font-weight: 800; }
.chain__punch {
  margin-top: 34px; text-align: center;
  font-size: clamp(20px, 3.2vw, 30px); font-weight: 800; letter-spacing: -.02em;
}

/* ==========================================================================
   入驻流程
   ========================================================================== */
.steps__grid {
  margin-top: 44px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.step {
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  padding: 26px 22px;
  background: var(--canvas);
}
.step .num {
  font-size: 34px; font-weight: 850; letter-spacing: -.03em;
  color: var(--ink); line-height: 1;
}
.step h3 { margin-top: 16px; font-size: 17px; font-weight: 750; }
.step p { margin-top: 8px; color: var(--ink-2); font-size: 14px; }
.steps__cta { margin-top: 40px; text-align: center; }

/* ==========================================================================
   适合谁
   ========================================================================== */
.who { background: var(--surface); }
.who__grid {
  margin-top: 40px;
  display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 56px);
  align-items: start;
}
.who__list li {
  display: flex; gap: 12px; padding: 16px 0;
  border-bottom: 1px solid var(--hairline);
  font-size: 15.5px; color: var(--ink-2);
}
.who__list li:last-child { border-bottom: 0; }
.who__list .check {
  flex: none; margin-top: 3px; color: var(--primary);
}
.who__styles {
  border: 1px solid var(--hairline); border-radius: var(--radius);
  padding: 26px; background: var(--canvas);
}
.who__styles h3 { font-size: 18px; font-weight: 750; }
.who__styles p { margin-top: 10px; color: var(--ink-2); font-size: 14.5px; }
.chips { margin-top: 18px; display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  font-size: 13.5px; font-weight: 600; padding: 7px 15px;
  border-radius: var(--radius-pill); border: 1px solid var(--hairline);
  color: var(--ink-2);
}
.chip.on { border-color: var(--primary); color: var(--primary-strong); background: var(--primary-tint); }
.chip.soon { color: var(--ink-mute); }
.chip.soon::after { content: " · 陆续接入"; color: var(--ink-faint); font-weight: 500; }

/* ==========================================================================
   FAQ
   ========================================================================== */
.faq__list { margin-top: 40px; border-top: 1px solid var(--hairline); }
.faq__item { border-bottom: 1px solid var(--hairline); }
.faq__q {
  width: 100%; text-align: left; background: none; border: 0; cursor: pointer;
  padding: 22px 0; font-size: 17px; font-weight: 700; color: var(--ink);
  display: flex; align-items: center; gap: 16px; font-family: inherit;
}
.faq__q .plus {
  flex: none; margin-left: auto; width: 22px; height: 22px; position: relative;
  transition: transform .2s ease;
}
.faq__q .plus::before, .faq__q .plus::after {
  content: ""; position: absolute; inset: 0; margin: auto;
  background: var(--ink);
}
.faq__q .plus::before { width: 14px; height: 2px; }
.faq__q .plus::after { width: 2px; height: 14px; transition: opacity .2s ease; }
.faq__item.open .plus { transform: rotate(90deg); }
.faq__item.open .plus::after { opacity: 0; }
.faq__a {
  overflow: hidden; max-height: 0;
  transition: max-height .25s ease, padding .25s ease;
}
.faq__a p { color: var(--ink-2); font-size: 15px; padding-bottom: 0; }
.faq__item.open .faq__a { padding-bottom: 22px; }

/* ==========================================================================
   舞者入口占位
   ========================================================================== */
.dancer {
  background: var(--canvas); border-top: 1px solid var(--hairline);
}
.dancer__inner {
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  padding-block: 26px;
}
.dancer__inner p { color: var(--ink-2); font-size: 15px; }
.dancer__inner b { color: var(--ink); }
.dancer__link {
  margin-left: auto; font-weight: 700; color: var(--primary-strong);
  display: inline-flex; align-items: center; gap: 6px; font-size: 15px;
}

/* ==========================================================================
   底部 CTA
   ========================================================================== */
.cta {
  background: var(--ink); color: var(--surface);
  text-align: center;
}
.cta h2 {
  font-size: clamp(28px, 5vw, 48px); font-weight: 850; letter-spacing: -.03em;
  line-height: 1.12; max-width: 720px; margin-inline: auto;
}
.cta__lead {
  margin-top: 16px; color: rgba(246, 246, 243, .72);
  font-size: clamp(15px, 2vw, 18px);
}
.cta__row {
  margin-top: 32px; display: flex; gap: 14px; justify-content: center;
  flex-wrap: wrap; align-items: center;
}
.cta .btn--ghost { color: var(--surface); border-color: rgba(246,246,243,.28); }
.cta .btn--ghost:hover { border-color: var(--surface); }
.cta__wechat {
  margin-top: 28px;
  color: rgba(246,246,243,.6); font-size: 15px;
}
.cta__wechat b {
  color: var(--surface); font-weight: 700; letter-spacing: .04em;
  user-select: all;
}
.copy-btn {
  margin-left: 12px; vertical-align: middle;
  display: inline-flex; align-items: center; gap: 6px;
  font: inherit; font-size: 13px; font-weight: 600;
  color: var(--surface); background: transparent;
  border: 1px solid rgba(246, 246, 243, .28); border-radius: 999px;
  padding: 5px 12px; cursor: pointer;
  transition: border-color .15s ease, color .15s ease;
}
.copy-btn:hover { border-color: var(--surface); }
.copy-btn.copied { border-color: var(--primary); color: var(--primary); }

/* ==========================================================================
   Footer
   ========================================================================== */
.footer { background: #131313; color: rgba(246,246,243,.7); }
.footer__top {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 32px;
  padding-block: 52px;
}
.footer .brand { color: var(--surface); }
.footer__slogan { margin-top: 14px; font-size: 14px; max-width: 280px; }
.footer h4 {
  font-size: 12px; letter-spacing: .1em; text-transform: uppercase;
  color: rgba(246,246,243,.4); font-weight: 700; margin-bottom: 14px;
}
.footer__col a { display: block; padding: 6px 0; font-size: 14px; }
.footer__col a:hover { color: var(--surface); }
.footer__bottom {
  border-top: 1px solid rgba(246,246,243,.12);
  padding-block: 22px;
  display: flex; flex-wrap: wrap; gap: 8px 20px;
  font-size: 12.5px; color: rgba(246,246,243,.42);
}
.footer__bottom a:hover { color: var(--surface); }

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 900px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__mock { order: -1; max-width: 460px; }
  .feat__grid, .killer__cards { grid-template-columns: repeat(2, 1fr); }
  .steps__grid { grid-template-columns: repeat(2, 1fr); }
  .who__grid { grid-template-columns: 1fr; }
  .footer__top { grid-template-columns: 1fr 1fr; }
  .nav__links, .nav__dancer { display: none; }
  .nav__burger { display: flex; }
  .nav.open .nav__links {
    display: flex; position: absolute; top: 66px; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--canvas); border-bottom: 1px solid var(--hairline);
    padding: 8px var(--gutter) 16px;
  }
  .nav.open .nav__links a { padding: 12px 0; width: 100%; border-bottom: 1px solid var(--hairline-soft); }
  .nav.open .nav__links .nav__price-link {
    border: 0;
    border-bottom: 1px solid var(--hairline-soft);
    border-radius: 0;
    background: transparent;
    color: var(--ink-2);
  }
}
@media (max-width: 560px) {
  .pain__grid, .feat__grid, .killer__cards,
  .steps__grid, .footer__top { grid-template-columns: 1fr; }
  .chain__arrow { transform: rotate(90deg); }
  .hero__cta .btn, .cta__row .btn { flex: 1 1 auto; justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}