:root {
  --ink: #16181d;
  --ink-2: #3d424d;
  --ink-3: #6b7280;
  --line: #e4e7ec;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --brand: #0a7d54;
  --brand-dark: #065c3e;
  --brand-soft: #e8f4ef;
  --warn: #b45309;
  --warn-soft: #fef3e2;
  --danger: #c62a2a;
  --danger-soft: #fdeceb;
  --radius: 14px;
  --maxw: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5 { margin: 0; font-weight: 600; line-height: 1.35; letter-spacing: -0.01em; }
p { margin: 0; }
ul, ol, dl, dd { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 40px; height: 40px; border-radius: 10px;
  background: var(--brand); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 13px; letter-spacing: 0.02em;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-text strong { font-size: 15px; }
.brand-text span { font-size: 11px; color: var(--ink-3); }

.nav { display: flex; align-items: center; gap: 26px; font-size: 14px; color: var(--ink-2); }
.nav a { transition: color .15s; }
.nav a:hover { color: var(--brand); }
.nav-cta {
  background: var(--brand); color: #fff !important;
  padding: 8px 16px; border-radius: 8px; font-weight: 500;
}
.nav-cta:hover { background: var(--brand-dark); }

.nav-toggle { display: none; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--ink); margin: 4px 0; border-radius: 2px; }

/* ---------- hero ---------- */
.hero { background: linear-gradient(180deg, #f4faf7 0%, #ffffff 100%); padding: 76px 0 84px; }
.hero-inner { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center; }

.badge {
  display: inline-block; background: var(--brand-soft); color: var(--brand-dark);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 500;
}
.hero h1 { font-size: 46px; margin: 20px 0 20px; letter-spacing: -0.02em; }
.hero h1 em { font-style: normal; color: var(--brand); position: relative; }
.hero h1 em::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 2px;
  height: 8px; background: var(--brand-soft); z-index: -1; border-radius: 2px;
}
.hero-copy > p { font-size: 16px; color: var(--ink-2); max-width: 540px; }

.hero-actions { display: flex; gap: 12px; margin: 30px 0 38px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 24px; border-radius: 10px; font-size: 15px; font-weight: 500;
  border: 1px solid transparent; cursor: pointer; transition: all .18s;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); transform: translateY(-1px); }
.btn-ghost { border-color: var(--line); color: var(--ink-2); background: #fff; }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-block { width: 100%; }

.hero-stats { display: flex; gap: 40px; flex-wrap: wrap; }
.hero-stats dt { font-size: 28px; font-weight: 600; color: var(--brand); line-height: 1.2; }
.hero-stats dd { font-size: 13px; color: var(--ink-3); margin-top: 2px; }

.hv-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; box-shadow: 0 12px 32px rgba(22, 24, 29, 0.07);
}
.hv-head {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 500; color: var(--ink-2);
  padding-bottom: 16px; border-bottom: 1px solid var(--line); margin-bottom: 16px;
}
.hv-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--brand); }
.hv-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 9px 0; font-size: 13px; color: var(--ink-3);
  border-bottom: 1px dashed #f0f1f4;
}
.hv-row b { font-weight: 500; font-size: 13px; }
.hv-row .ok { color: var(--brand); }
.hv-row .warn { color: var(--warn); }
.wave { margin: 18px 0 12px; height: 60px; background: #fbfbfc; border-radius: 8px; padding: 4px; }
.wave svg { width: 100%; height: 100%; display: block; }
.hv-note { font-size: 12px; color: var(--ink-3); line-height: 1.6; }

/* ---------- stats band ---------- */
.stats-band { background: var(--ink); color: #fff; padding: 34px 0; }
.stats-band-inner { text-align: center; font-size: 18px; }
.stats-band-inner span { color: #6ee7b7; font-weight: 600; }

/* ---------- sections ---------- */
.section { padding: 84px 0; }
.section-alt { background: var(--bg-soft); }

.section-head { max-width: 640px; margin-bottom: 48px; }
.eyebrow {
  display: inline-block; font-size: 12px; font-weight: 600;
  letter-spacing: 0.12em; color: var(--brand); text-transform: uppercase; margin-bottom: 12px;
}
.section-head h2 { font-size: 32px; margin-bottom: 14px; }
.section-head p { color: var(--ink-2); font-size: 16px; }

.lead { color: var(--ink-2); font-size: 16px; }

/* ---------- courses ---------- */
.course-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.course {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 22px; transition: border-color .18s, transform .18s;
  display: flex; flex-direction: column;
}
.course:hover { border-color: var(--brand); transform: translateY(-3px); }
.course-no {
  font-size: 13px; font-weight: 600; color: var(--brand);
  background: var(--brand-soft); width: 36px; height: 36px; border-radius: 9px;
  display: flex; align-items: center; justify-content: center; margin-bottom: 18px;
}
.course h3 { font-size: 18px; margin-bottom: 10px; }
.course > p { font-size: 14px; color: var(--ink-3); margin-bottom: 16px; }
.course ul { display: flex; flex-direction: column; gap: 8px; margin-bottom: 20px; flex: 1; }
.course ul li { font-size: 13px; color: var(--ink-2); padding-left: 16px; position: relative; }
.course ul li::before {
  content: ""; position: absolute; left: 0; top: 9px;
  width: 5px; height: 5px; border-radius: 50%; background: var(--brand);
}
.course-meta { display: flex; gap: 16px; padding-top: 16px; border-top: 1px solid var(--line); }
.course-meta span { font-size: 12px; color: var(--ink-3); }

/* ---------- high voltage ---------- */
.hv-layout { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 60px; }
.hv-text h2 { font-size: 32px; margin-bottom: 16px; }

.steps { margin-top: 36px; display: flex; flex-direction: column; gap: 4px; }
.steps li { display: flex; gap: 18px; padding: 18px 0; border-top: 1px solid var(--line); }
.step-no {
  flex-shrink: 0; width: 28px; height: 28px; border-radius: 50%;
  background: var(--brand); color: #fff; font-size: 13px; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
}
.steps h4 { font-size: 16px; margin-bottom: 4px; }
.steps p { font-size: 14px; color: var(--ink-3); }

.hv-side { display: flex; flex-direction: column; gap: 16px; }
.stat-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; text-align: center;
}
.stat-num { font-size: 40px; font-weight: 600; color: var(--brand); display: block; line-height: 1.2; }
.stat-card p { font-size: 14px; color: var(--ink-3); margin-top: 4px; }

.cert-list {
  background: var(--brand); color: #fff; border-radius: var(--radius); padding: 26px;
}
.cert-list h4 { font-size: 16px; margin-bottom: 14px; opacity: .9; }
.cert-list p {
  font-size: 14px; padding: 8px 0 8px 20px; position: relative; opacity: .95;
}
.cert-list p::before {
  content: ""; position: absolute; left: 0; top: 15px;
  width: 6px; height: 6px; border-radius: 50%; background: #6ee7b7;
}

/* ---------- equipment ---------- */
.equip-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.equip {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 22px;
}
.equip-icon {
  width: 44px; height: 44px; border-radius: 11px; background: var(--brand-soft);
  color: var(--brand); display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
}
.equip-icon svg { width: 24px; height: 24px; }
.equip h3 { font-size: 17px; margin-bottom: 8px; }
.equip p { font-size: 14px; color: var(--ink-3); }

/* ---------- rules ---------- */
.rules { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.rule {
  background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--danger);
  border-radius: var(--radius); padding: 26px 24px;
}
.rule-no { font-size: 12px; font-weight: 600; color: var(--danger); letter-spacing: .08em; }
.rule h3 { font-size: 18px; margin: 10px 0 10px; }
.rule p { font-size: 14px; color: var(--ink-3); }

/* ---------- faq ---------- */
.faq-layout { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: 60px; }
.faq-layout h2 { font-size: 32px; margin-bottom: 14px; }

.faq-list details {
  border-bottom: 1px solid var(--line); padding: 20px 0;
}
.faq-list summary {
  font-size: 16px; font-weight: 500; cursor: pointer; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+"; font-size: 22px; color: var(--brand); font-weight: 400; flex-shrink: 0;
}
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { font-size: 14px; color: var(--ink-3); margin-top: 12px; padding-right: 24px; }

/* ---------- enroll ---------- */
.enroll { background: var(--brand-dark); color: #fff; }
.enroll-layout { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 60px; align-items: start; }
.enroll h2 { font-size: 32px; margin-bottom: 14px; }
.enroll .eyebrow { color: #6ee7b7; }
.enroll .lead { color: rgba(255, 255, 255, .8); }

.enroll-points { margin-top: 28px; display: flex; flex-direction: column; gap: 10px; }
.enroll-points li { font-size: 14px; padding-left: 24px; position: relative; color: rgba(255,255,255,.9); }
.enroll-points li::before {
  content: ""; position: absolute; left: 0; top: 8px; width: 12px; height: 7px;
  border-left: 2px solid #6ee7b7; border-bottom: 2px solid #6ee7b7;
  transform: rotate(-45deg);
}

.enroll-form {
  background: #fff; color: var(--ink); border-radius: var(--radius);
  padding: 32px; box-shadow: 0 16px 40px rgba(0, 0, 0, .18);
}
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 13px; font-weight: 500; margin-bottom: 7px; }
.field input, .field select, .field textarea {
  width: 100%; padding: 11px 13px; border: 1px solid var(--line); border-radius: 9px;
  font-size: 14px; font-family: inherit; color: var(--ink); background: #fff;
  transition: border-color .15s; resize: vertical;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--brand);
}
.field.invalid input, .field.invalid select { border-color: var(--danger); }
.err { display: none; font-size: 12px; color: var(--danger); margin-top: 6px; }
.field.invalid .err { display: block; }

.form-status { font-size: 13px; margin-top: 14px; text-align: center; min-height: 20px; }
.form-status.ok { color: var(--brand); }
.form-status.fail { color: var(--danger); }

/* ---------- footer ---------- */
.site-footer { background: var(--ink); color: rgba(255, 255, 255, .7); padding: 56px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.2fr 1.8fr; gap: 60px; padding-bottom: 44px; }
.footer-brand { margin-bottom: 16px; }
.footer-brand .brand-text strong { color: #fff; }
.footer-note { font-size: 13px; max-width: 340px; line-height: 1.7; }

.footer-cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.footer-cols h5 { font-size: 14px; color: #fff; margin-bottom: 14px; }
.footer-cols a, .footer-cols span { display: block; font-size: 13px; padding: 4px 0; }
.footer-cols a:hover { color: #6ee7b7; }

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .1); padding: 20px 24px;
  font-size: 12px;
}

/* ---------- responsive ---------- */
@media (max-width: 1024px) {
  .course-grid, .equip-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-inner, .hv-layout, .faq-layout, .enroll-layout { grid-template-columns: 1fr; gap: 40px; }
  .hero h1 { font-size: 36px; }
  .rules { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 36px; }
}

@media (max-width: 720px) {
  .section { padding: 60px 0; }
  .section-head h2, .hv-text h2, .faq-layout h2, .enroll h2 { font-size: 25px; }
  .hero { padding: 48px 0 56px; }
  .hero h1 { font-size: 29px; }
  .hero-stats { gap: 26px; }
  .hero-stats dt { font-size: 23px; }

  .nav {
    display: none; position: absolute; top: 68px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; gap: 0; padding: 8px 24px 16px;
  }
  .nav.open { display: flex; }
  .nav a { padding: 11px 0; border-bottom: 1px solid #f2f3f5; }
  .nav-cta { margin-top: 12px; text-align: center; border-bottom: 0 !important; }
  .nav-toggle { display: block; }

  .course-grid, .equip-grid { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr 1fr; gap: 24px; }
  .enroll-form { padding: 24px 20px; }
}