/* 清和乐章 AI 智能体服务 — landing */
:root {
  --green: #0e5c48;
  --green-dark: #0a4536;
  --green-light: #e8f2ef;
  --ink: #1a1a1a;
  --gray: #666;
  --gray-light: #999;
  --bg: #faf9f6;
  --card: #ffffff;
  --border: #e8e5df;
  --gold: #b8860b;
  --radius: 16px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 48px rgba(0, 0, 0, 0.12);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 249, 246, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.nav-logo { font-size: 18px; font-weight: 700; color: var(--green); text-decoration: none; letter-spacing: 0.5px; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { color: var(--gray); text-decoration: none; font-size: 14px; transition: color 0.2s; }
.nav-links a:hover { color: var(--green); }
.nav-user { font-size: 13px; color: var(--green); }

.btn {
  display: inline-block; border: none; cursor: pointer;
  font-size: 15px; font-weight: 600; text-decoration: none;
  border-radius: 10px; padding: 12px 28px;
  transition: all 0.2s; font-family: inherit;
}
.btn-primary { background: var(--green); color: #fff; }
.btn-primary:hover { background: var(--green-dark); transform: translateY(-1px); }
.btn-outline { background: transparent; color: var(--green); border: 1.5px solid var(--green); }
.btn-outline:hover { background: var(--green-light); }
.btn-sm { padding: 8px 20px; font-size: 13px; }
.btn-block { display: block; width: 100%; text-align: center; }
.btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }

/* ---------- Hero ---------- */
.hero { padding: 80px 0 64px; }
.hero-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 56px; align-items: center; }
.hero-tag {
  display: inline-block; background: var(--green-light); color: var(--green);
  font-size: 13px; font-weight: 600; padding: 6px 16px; border-radius: 100px;
  margin-bottom: 20px; letter-spacing: 0.5px;
}
.hero h1 { font-size: 44px; line-height: 1.25; font-weight: 800; margin-bottom: 20px; }
.hero h1 em { font-style: normal; color: var(--green); }
.hero-sub { font-size: 17px; color: var(--gray); margin-bottom: 36px; max-width: 480px; }
.hero-actions { display: flex; gap: 16px; }
.hero-img { border-radius: var(--radius); box-shadow: var(--shadow-lg); overflow: hidden; }
.hero-stats { display: flex; gap: 40px; margin-top: 44px; }
.hero-stat b { display: block; font-size: 28px; color: var(--green); font-weight: 800; }
.hero-stat span { font-size: 13px; color: var(--gray-light); }

/* ---------- Sections ---------- */
.section { padding: 72px 0; }
.section-alt { background: #fff; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 48px; }
.section-head h2 { font-size: 32px; font-weight: 800; margin-bottom: 12px; }
.section-head p { color: var(--gray); font-size: 16px; }

/* ---------- Capability cards ---------- */
.cap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.cap-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 32px 28px;
  transition: all 0.25s;
}
.cap-card:hover { box-shadow: var(--shadow); transform: translateY(-3px); }
.cap-icon { font-size: 32px; margin-bottom: 16px; }
.cap-card h3 { font-size: 18px; margin-bottom: 10px; }
.cap-card p { font-size: 14px; color: var(--gray); }

/* ---------- Feature rows ---------- */
.feat-row { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; margin-bottom: 72px; }
.feat-row:last-child { margin-bottom: 0; }
.feat-row.reverse .feat-text { order: 2; }
.feat-text h3 { font-size: 26px; font-weight: 800; margin-bottom: 16px; }
.feat-text p { color: var(--gray); font-size: 15px; margin-bottom: 20px; }
.feat-list { list-style: none; }
.feat-list li { padding-left: 28px; position: relative; margin-bottom: 12px; font-size: 15px; }
.feat-list li::before {
  content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 700;
}
.feat-img { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }

/* ---------- Pricing ---------- */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; align-items: stretch; }
.price-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 36px 30px;
  display: flex; flex-direction: column;
  position: relative; transition: all 0.25s;
}
.price-card:hover { box-shadow: var(--shadow-lg); }
.price-card.featured { border: 2px solid var(--green); box-shadow: var(--shadow); }
.price-badge {
  position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
  background: var(--green); color: #fff; font-size: 12px; font-weight: 700;
  padding: 5px 18px; border-radius: 100px; white-space: nowrap;
}
.price-name { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
.price-desc { font-size: 13px; color: var(--gray-light); margin-bottom: 20px; }
.price-amount { font-size: 40px; font-weight: 800; color: var(--ink); margin-bottom: 4px; }
.price-amount small { font-size: 15px; font-weight: 400; color: var(--gray-light); }
.price-note { font-size: 13px; color: var(--gold); margin-bottom: 24px; }
.price-feats { list-style: none; flex: 1; margin-bottom: 28px; }
.price-feats li { padding-left: 26px; position: relative; margin-bottom: 11px; font-size: 14px; color: #444; }
.price-feats li::before { content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 700; }

/* ---------- Cases ---------- */
.case-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.case-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px;
  transition: all 0.25s;
}
.case-card:hover { box-shadow: var(--shadow); }
.case-tag {
  display: inline-block; font-size: 12px; font-weight: 600;
  background: var(--green-light); color: var(--green);
  padding: 3px 12px; border-radius: 100px; margin-bottom: 12px;
}
.case-card h3 { font-size: 16px; margin-bottom: 8px; }
.case-card p { font-size: 14px; color: var(--gray); margin-bottom: 12px; }
.case-result { font-size: 13px; color: var(--green); font-weight: 600; }

/* ---------- FAQ ---------- */
.faq-list { max-width: 720px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--border); padding: 20px 0; }
.faq-item summary { font-size: 16px; font-weight: 600; cursor: pointer; list-style: none; position: relative; padding-right: 32px; }
.faq-item summary::after { content: "+"; position: absolute; right: 0; top: 0; color: var(--green); font-size: 20px; }
.faq-item[open] summary::after { content: "−"; }
.faq-item p { color: var(--gray); font-size: 14px; margin-top: 12px; }

/* ---------- CTA / footer ---------- */
.cta { text-align: center; padding: 80px 0; }
.cta h2 { font-size: 32px; font-weight: 800; margin-bottom: 14px; }
.cta p { color: var(--gray); margin-bottom: 32px; }
.footer { border-top: 1px solid var(--border); padding: 32px 0; text-align: center; color: var(--gray-light); font-size: 13px; }

/* ---------- Modals ---------- */
.modal-mask {
  display: none; position: fixed; inset: 0; z-index: 200;
  background: rgba(20, 20, 20, 0.5); backdrop-filter: blur(4px);
  align-items: center; justify-content: center; padding: 20px;
}
.modal-mask.open { display: flex; }
.modal {
  background: #fff; border-radius: 20px; padding: 40px 36px;
  width: 100%; max-width: 420px; position: relative;
  box-shadow: var(--shadow-lg);
  animation: pop 0.25s ease;
}
@keyframes pop { from { transform: scale(0.94); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.modal-close {
  position: absolute; top: 16px; right: 20px; border: none; background: none;
  font-size: 24px; color: var(--gray-light); cursor: pointer;
}
.modal h3 { font-size: 22px; font-weight: 800; margin-bottom: 6px; }
.modal-sub { font-size: 14px; color: var(--gray); margin-bottom: 24px; }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; color: #444; }
.form-group input {
  width: 100%; padding: 12px 14px; border: 1.5px solid var(--border);
  border-radius: 10px; font-size: 15px; font-family: inherit;
  transition: border 0.2s; background: var(--bg);
}
.form-group input:focus { outline: none; border-color: var(--green); background: #fff; }
.form-msg { font-size: 13px; margin: 10px 0; min-height: 18px; }
.form-msg.err { color: #c0392b; }
.form-msg.ok { color: var(--green); }
.modal-switch { text-align: center; font-size: 13px; color: var(--gray); margin-top: 18px; }
.modal-switch a { color: var(--green); cursor: pointer; font-weight: 600; text-decoration: none; }

/* payment modal */
.pay-modal { max-width: 400px; text-align: center; }
.pay-plan-name { font-size: 15px; color: var(--gray); margin-bottom: 4px; }
.pay-amount { font-size: 36px; font-weight: 800; color: var(--green); margin-bottom: 20px; }
.pay-qr {
  width: 240px; height: 240px; margin: 0 auto 20px;
  border: 1.5px solid var(--border); border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg); overflow: hidden;
}
.pay-qr img { width: 100%; height: 100%; object-fit: contain; }
.pay-qr-placeholder { color: var(--gray-light); font-size: 13px; padding: 20px; }
.pay-tip { font-size: 13px; color: var(--gray); margin-bottom: 8px; }
.pay-contact { font-size: 12px; color: var(--gray-light); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .hero-grid, .feat-row { grid-template-columns: 1fr; gap: 32px; }
  .feat-row.reverse .feat-text { order: 0; }
  .cap-grid, .price-grid { grid-template-columns: 1fr; }
  .case-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 32px; }
  .nav-links a.nav-anchor { display: none; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
}