/* ============================================================
 * 辅导员工作台 · 产品落地页样式
 * 依据：01-视觉设计规范.md（品牌令牌 + 页面结构 + 响应式）
 * 规范：全部颜色/形状/字体走 CSS 变量，禁止写死
 * ============================================================ */

/* ---------- 品牌令牌（规范 §二，逐字照抄） ---------- */
:root {
  --c-primary:      #2563EB;
  --c-primary-hover:#1D4ED8;
  --c-primary-weak: #EFF6FF;
  --c-primary-deep: #1E40AF;

  --c-bg:      #FFFFFF;
  --c-bg-soft: #F5F7FA;
  --c-card:    #FFFFFF;
  --c-text-1:  #1F2937;
  --c-text-2:  #6B7280;
  --c-text-3:  #9CA3AF;
  --c-border:  #E5E7EB;
  --c-divider: #F3F4F6;

  --c-success: #10B981;
  --c-warning: #F59E0B;
  --c-danger:  #EF4444;

  --r-sm: 8px;  --r-md: 12px;  --r-lg: 16px;
  --sh-sm: 0 1px 3px rgba(17,24,39,.06);
  --sh-md: 0 4px 12px rgba(17,24,39,.08);
  --sh-lg: 0 12px 32px rgba(17,24,39,.12);

  --font-sans: "PingFang SC","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif;
  --fs-xs:12px; --fs-sm:14px; --fs-md:16px; --fs-lg:20px; --fs-xl:28px; --fs-2xl:40px;
}

/* ---------- 基础 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: var(--font-sans);
  color: var(--c-text-1);
  background: var(--c-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 28px;
  border-radius: var(--r-sm);
  font-size: var(--fs-md);
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background .15s, transform .1s, box-shadow .15s;
  font-family: var(--font-sans);
  white-space: nowrap;
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--c-primary); color: #fff; }
.btn-primary:hover { background: var(--c-primary-hover); box-shadow: var(--sh-md); }
.btn-primary:disabled { background: var(--c-text-3); cursor: not-allowed; box-shadow: none; }
.btn-outline {
  background: var(--c-bg);
  color: var(--c-primary);
  border: 1px solid var(--c-border);
}
.btn-outline:hover { border-color: var(--c-primary); }
.btn-sm { padding: 8px 16px; font-size: var(--fs-sm); }

/* Hero 按钮 */
.btn-hero {
  background: #fff; color: var(--c-primary-deep);
  font-size: var(--fs-md); font-weight: 700; padding: 14px 32px;
}
.btn-hero:hover { background: var(--c-primary-weak); box-shadow: var(--sh-lg); }
.btn-hero-ghost {
  background: transparent; color: #fff;
  border: 1.5px solid rgba(255,255,255,.5);
  padding: 14px 32px;
}
.btn-hero-ghost:hover { border-color: #fff; background: rgba(255,255,255,.08); }

/* ---------- 吸顶导航（规范 §三-0） ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .2s, border-color .2s;
}
.nav.scrolled { box-shadow: var(--sh-md); border-color: var(--c-divider); }
.nav-inner {
  max-width: 1120px; margin: 0 auto; padding: 0 24px;
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
}
.nav-logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: var(--fs-lg); }
.logo-mark {
  width: 34px; height: 34px; border-radius: var(--r-sm);
  background: var(--c-primary); color: #fff;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700;
}
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--c-text-2); font-size: var(--fs-sm); font-weight: 500; transition: color .15s; }
.nav-links a:hover { color: var(--c-primary); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--c-text-1); padding: 8px; }

/* 移动端抽屉 */
.nav-links.open {
  display: flex; flex-direction: column;
  position: fixed; top: 64px; left: 0; right: 0;
  background: var(--c-bg); padding: 16px 24px;
  box-shadow: var(--sh-lg);
  gap: 4px;
}
.nav-links.open a { padding: 12px 0; border-bottom: 1px solid var(--c-divider); font-size: var(--fs-md); }

/* ---------- Hero（规范 §三-1，渐变 §二） ---------- */
.hero {
  position: relative;
  background: linear-gradient(135deg, #2563EB 0%, #1E40AF 100%);
  color: #fff;
  padding: 140px 0 90px;
  overflow: hidden;
}
.hero-decor {
  position: absolute; inset: 0;
  background-image:
    radial-gradient(circle at 78% 20%, rgba(255,255,255,.10) 0 1px, transparent 1px),
    radial-gradient(circle at 22% 80%, rgba(255,255,255,.08) 0 1px, transparent 1px);
  background-size: 28px 28px;
  pointer-events: none;
}
.hero-inner {
  position: relative;
  max-width: 1120px; margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 1.1fr 1fr;
  gap: 48px; align-items: center;
}
.hero-text h1 { font-size: var(--fs-2xl); font-weight: 800; line-height: 1.25; margin-bottom: 16px; }
.hero-sub { font-size: 18px; opacity: .92; margin-bottom: 28px; max-width: 460px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 20px; }
.hero-note { font-size: var(--fs-sm); opacity: .75; }

/* CSS 产品窗口 mock */
.hero-window {
  background: var(--c-bg);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-lg);
  overflow: hidden;
  color: var(--c-text-1);
}
.hwin-titlebar {
  display: flex; align-items: center; gap: 6px;
  padding: 10px 14px;
  background: var(--c-bg-soft);
  border-bottom: 1px solid var(--c-divider);
}
.hwin-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--c-text-3); }
.hwin-dot:first-child { background: #F87171; }
.hwin-dot:nth-child(2) { background: #FBBF24; }
.hwin-dot:nth-child(3) { background: #34D399; }
.hwin-title { margin-left: 8px; font-size: var(--fs-xs); color: var(--c-text-2); }
.hwin-body { display: grid; grid-template-columns: 120px 1fr; min-height: 300px; }
.hwin-side { background: var(--c-bg-soft); padding: 12px 0; border-right: 1px solid var(--c-divider); }
.hwin-side-item {
  display: block; padding: 8px 16px; font-size: var(--fs-xs); color: var(--c-text-2);
  border-left: 3px solid transparent;
}
.hwin-side-item.active {
  background: var(--c-primary-weak); color: var(--c-primary);
  border-left-color: var(--c-primary); font-weight: 600;
}
.hwin-main { padding: 16px; display: flex; flex-direction: column; gap: 14px; }
.hwin-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.hwin-stat {
  background: var(--c-bg-soft); border-radius: var(--r-sm); padding: 10px;
  text-align: center;
}
.hwin-stat b { display: block; font-size: 20px; color: var(--c-primary); }
.hwin-stat span { font-size: var(--fs-xs); color: var(--c-text-3); }
.hwin-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; flex: 1; }
.hwin-card {
  background: linear-gradient(160deg, var(--c-primary-weak), var(--c-bg));
  border: 1px solid var(--c-divider);
  border-radius: var(--r-sm);
}

/* ---------- 信任条（§三-2） ---------- */
.trustbar { background: var(--c-bg); border-bottom: 1px solid var(--c-divider); }
.trust-inner {
  max-width: 1120px; margin: 0 auto; padding: 16px 24px;
  display: flex; justify-content: center; gap: 48px; flex-wrap: wrap;
}
.trust-item { font-size: var(--fs-sm); color: var(--c-text-2); font-weight: 500; }

/* ---------- 通用区块 ---------- */
.section { padding: 72px 0; }
.section-alt { background: var(--c-bg-soft); }
.sec-title { font-size: var(--fs-xl); font-weight: 800; text-align: center; margin-bottom: 10px; }
.sec-sub { text-align: center; color: var(--c-text-2); margin-bottom: 40px; }

/* ---------- 卖点 6 卡（§三-3） ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature-card {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: 24px;
  box-shadow: var(--sh-sm);
  transition: transform .15s, box-shadow .15s;
}
.feature-card:hover { transform: translateY(-2px); box-shadow: var(--sh-md); }
.feature-icon {
  width: 48px; height: 48px; border-radius: var(--r-md);
  background: var(--c-primary-weak);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
}
.feature-icon svg { width: 24px; height: 24px; stroke: var(--c-primary); stroke-width: 1.5; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.feature-card h3 { font-size: var(--fs-md); font-weight: 700; margin-bottom: 6px; }
.feature-card p { font-size: var(--fs-sm); color: var(--c-text-2); }

/* ---------- 功能模块（§三-4） ---------- */
.module-groups { display: flex; flex-direction: column; gap: 28px; }
.module-group h3 {
  font-size: var(--fs-md); font-weight: 700;
  padding-left: 12px; border-left: 4px solid var(--c-primary);
  margin-bottom: 12px;
}
.module-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.module-card {
  background: var(--c-card); border: 1px solid var(--c-border);
  border-radius: var(--r-sm); padding: 14px 16px;
  transition: border-color .15s, box-shadow .15s;
}
.module-card:hover { border-color: var(--c-primary); box-shadow: var(--sh-md); }
.module-card b { display: block; font-size: var(--fs-sm); margin-bottom: 2px; }
.module-card span { font-size: var(--fs-xs); color: var(--c-text-3); }

/* ---------- 价格（§三-5） ---------- */
.promo-banner {
  background: linear-gradient(135deg, #FEF3C7, #FDE68A);
  border: 1px solid #F59E0B;
  border-radius: var(--r-md);
  padding: 14px 20px;
  text-align: center;
  font-weight: 600;
  margin-bottom: 28px;
  color: #92400E;
}
.promo-loading { color: var(--c-text-2); font-weight: 400; }
.price-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-bottom: 20px; }
.price-card {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: 28px 24px;
  position: relative;
  transition: box-shadow .15s;
}
.price-card:hover { box-shadow: var(--sh-md); }
.price-card.pro { border-color: var(--c-primary); box-shadow: var(--sh-md); }
.price-badge {
  position: absolute; top: -12px; left: 24px;
  background: var(--c-primary); color: #fff;
  font-size: var(--fs-xs); font-weight: 700;
  padding: 3px 12px; border-radius: 999px;
}
.price-card h3 { font-size: var(--fs-lg); font-weight: 800; margin-bottom: 4px; }
.price-tagline { font-size: var(--fs-sm); color: var(--c-text-2); margin-bottom: 18px; }
.price-terms { display: flex; flex-direction: column; gap: 10px; margin-bottom: 20px; }
.price-term {
  display: flex; justify-content: space-between; align-items: baseline;
  padding: 10px 14px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  cursor: pointer; transition: border-color .15s, background .15s;
}
.price-term:hover { border-color: var(--c-primary); }
.price-term.selected { border-color: var(--c-primary); background: var(--c-primary-weak); }
.price-term .pt-name { font-weight: 600; font-size: var(--fs-sm); }
.price-term .pt-price { font-size: var(--fs-md); font-weight: 700; }
.price-term .pt-price .orig { font-size: var(--fs-xs); color: var(--c-text-3); text-decoration: line-through; margin-right: 6px; font-weight: 400; }
.price-term .pt-price .final { color: var(--c-primary); }
.price-card .btn { width: 100%; }
.price-note { text-align: center; font-size: var(--fs-xs); color: var(--c-text-3); }

/* ---------- 购买弹窗（§三-6） ---------- */
.modal-mask {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(17,24,39,.55);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
}
.modal-mask[hidden] { display: none; }
.modal {
  background: var(--c-bg);
  border-radius: var(--r-lg);
  max-width: 420px; width: 100%;
  padding: 28px 24px;
  position: relative;
  box-shadow: var(--sh-lg);
  max-height: 90vh; overflow-y: auto;
}
.modal-close {
  position: absolute; top: 14px; right: 14px;
  background: none; border: none;
  font-size: 20px; color: var(--c-text-3); cursor: pointer; padding: 6px;
}
.modal-close:hover { color: var(--c-text-1); }
.modal h3 { font-size: var(--fs-lg); font-weight: 800; margin-bottom: 16px; }
.modal-step-title { font-size: var(--fs-sm); color: var(--c-text-2); margin-bottom: 12px; }
.modal-version-row { display: flex; gap: 10px; margin-bottom: 16px; }
.modal-version {
  flex: 1; border: 1.5px solid var(--c-border); border-radius: var(--r-md);
  padding: 14px; text-align: center; cursor: pointer; transition: all .15s;
}
.modal-version:hover { border-color: var(--c-primary); }
.modal-version.selected { border-color: var(--c-primary); background: var(--c-primary-weak); }
.modal-version b { display: block; font-size: var(--fs-md); }
.modal-version span { font-size: var(--fs-xs); color: var(--c-text-2); }
.modal-term-row { display: flex; gap: 8px; margin-bottom: 18px; }
.modal-term {
  flex: 1; border: 1.5px solid var(--c-border); border-radius: var(--r-sm);
  padding: 10px 6px; text-align: center; cursor: pointer; transition: all .15s;
}
.modal-term:hover { border-color: var(--c-primary); }
.modal-term.selected { border-color: var(--c-primary); background: var(--c-primary-weak); }
.modal-term .mt-name { display: block; font-size: var(--fs-sm); font-weight: 600; }
.modal-term .mt-price { display: block; font-size: var(--fs-xs); color: var(--c-text-2); }
.modal-term .mt-price .orig { text-decoration: line-through; color: var(--c-text-3); margin-right: 4px; }
.modal-term .mt-price .final { color: var(--c-primary); font-weight: 700; }
.modal-amount { text-align: center; margin: 4px 0 16px; font-size: var(--fs-lg); font-weight: 800; }
.modal-amount .orig { font-size: var(--fs-sm); color: var(--c-text-3); text-decoration: line-through; font-weight: 400; margin-right: 8px; }
.modal-amount .final { color: var(--c-primary); }
.modal-btn { width: 100%; }
.modal-qrcode { text-align: center; padding: 8px 0; }
.modal-qrcode canvas { width: 220px; height: 220px; margin: 10px auto; display: block; border-radius: var(--r-sm); border: 1px solid var(--c-divider); }
.modal-qr-tip { font-size: var(--fs-xs); color: var(--c-text-2); margin-bottom: 8px; }
.modal-status { text-align: center; font-size: var(--fs-sm); color: var(--c-text-2); padding: 6px 0; }
.modal-success { text-align: center; padding: 12px 0; }
.modal-success .ok-icon { font-size: 56px; margin-bottom: 8px; }
.modal-success h4 { font-size: var(--fs-lg); margin-bottom: 8px; }
.modal-success p { font-size: var(--fs-sm); color: var(--c-text-2); margin-bottom: 6px; }
.modal-code {
  background: var(--c-bg-soft); border-radius: var(--r-sm);
  padding: 12px; margin: 12px 0;
  font-family: ui-monospace, monospace; font-size: var(--fs-md);
  letter-spacing: 1px; user-select: all;
  word-break: break-all;
}
.modal-error { text-align: center; color: var(--c-danger); font-size: var(--fs-sm); padding: 8px 0; }

/* ---------- 下载（§三-7） ---------- */
.download-box {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: 28px;
  box-shadow: var(--sh-sm);
  margin-bottom: 32px;
}
.download-main { display: flex; align-items: center; gap: 16px; margin-bottom: 14px; }
.dl-icon {
  width: 56px; height: 56px; border-radius: var(--r-md);
  background: var(--c-primary-weak);
  display: flex; align-items: center; justify-content: center; font-size: 28px;
  flex: none;
}
.dl-info { flex: 1; }
.dl-name { font-size: var(--fs-lg); font-weight: 700; }
.dl-version { font-size: var(--fs-xs); color: var(--c-text-3); }
.dl-desc { font-size: var(--fs-sm); color: var(--c-text-2); margin-bottom: 14px; }
.dl-subscribe { display: flex; gap: 10px; max-width: 440px; }
.dl-subscribe input {
  flex: 1; padding: 12px 14px;
  border: 1px solid var(--c-border); border-radius: var(--r-sm);
  font-size: var(--fs-sm); font-family: var(--font-sans);
}
.dl-subscribe input:focus { outline: none; border-color: var(--c-primary); }
.dl-feedback { font-size: var(--fs-sm); color: var(--c-success); margin-top: 10px; min-height: 20px; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.step {
  background: var(--c-card); border: 1px solid var(--c-border);
  border-radius: var(--r-md); padding: 20px;
  display: flex; gap: 14px; align-items: flex-start;
}
.step-num {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--c-primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; flex: none;
}
.step p { font-size: var(--fs-sm); color: var(--c-text-2); }
.step b { color: var(--c-text-1); font-size: var(--fs-md); display: block; margin-bottom: 2px; }

/* ---------- FAQ（§三-8） ---------- */
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 10px; }
.faq-item {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  overflow: hidden;
}
.faq-q {
  display: flex; justify-content: space-between; align-items: center;
  padding: 16px 20px; cursor: pointer;
  font-weight: 600; font-size: var(--fs-md);
  transition: background .15s;
}
.faq-q:hover { background: var(--c-bg-soft); }
.faq-q .faq-icon { color: var(--c-text-3); transition: transform .2s; font-size: 14px; }
.faq-item.open .faq-icon { transform: rotate(180deg); }
.faq-item.open { border-left: 3px solid var(--c-primary); }
.faq-a {
  max-height: 0; overflow: hidden;
  transition: max-height .2s ease;
  font-size: var(--fs-sm); color: var(--c-text-2);
  padding: 0 20px;
}
.faq-item.open .faq-a { max-height: 400px; padding: 0 20px 16px; }

/* ---------- Footer（§三-9） ---------- */
.footer { background: #111827; color: var(--c-text-3); padding: 48px 0 24px; }
.footer-grid {
  max-width: 1120px; margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px;
  margin-bottom: 32px;
}
.footer-logo { font-size: var(--fs-lg); font-weight: 800; color: #fff; margin-bottom: 8px; }
.footer-brand p { font-size: var(--fs-sm); }
.footer-col h4 { color: #fff; font-size: var(--fs-sm); margin-bottom: 10px; }
.footer-col p { font-size: var(--fs-sm); margin-bottom: 6px; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  max-width: 1120px; margin: 0 auto; padding: 16px 24px 0;
  border-top: 1px solid rgba(255,255,255,.08);
  display: flex; justify-content: center; gap: 24px; flex-wrap: wrap;
  font-size: var(--fs-xs);
}

/* ---------- 响应式（规范 §五） ---------- */
@media (max-width: 1023px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero { padding: 120px 0 60px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .module-cards { grid-template-columns: repeat(2, 1fr); }
  .price-grid { gap: 16px; }
}

@media (max-width: 767px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-buy { display: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .module-cards { grid-template-columns: 1fr; }
  .price-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 20px; }
  .trust-inner { gap: 16px; }
  .hero-text h1 { font-size: 32px; }
  .hwin-body { grid-template-columns: 84px 1fr; }
  .dl-subscribe { flex-direction: column; }
  .btn { min-height: 44px; }  /* 触控目标 ≥44px */
  .nav-actions { gap: 8px; }
}
/* ========== 购买引导（2026-08-26：网页不收款，仅展示） ========== */
.buy-guide-box {
  display: flex; gap: 16px; align-items: flex-start;
  background: var(--c-primary-weak);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: 20px 24px;
}
.buy-guide-icon { font-size: 28px; line-height: 1.2; }
.buy-guide-box b { font-size: var(--fs-lg); color: var(--c-text-1); }
.buy-guide-box p { color: var(--c-text-2); margin-top: 6px; }
.price-buy-tip {
  margin-top: 16px; padding-top: 14px;
  font-size: var(--fs-sm); color: var(--c-text-3); text-align: center;
  border-top: 1px dashed var(--c-border);
}