:root {
  --bg: #f6faf6;
  --panel: #ffffff;
  --text: #1e2a22;
  --muted: #6a786f;
  --line: #dbe8dd;
  --soft: #edf6ef;
  --accent: #6c8d71;
  --accent-strong: #4d6a53;
  --shadow: 0 16px 40px rgba(47, 73, 55, 0.08);
  --radius: 22px;
  --radius-sm: 14px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: radial-gradient(circle at top left, #f8fff8 0, #f6faf6 36%, #f2f7f3 100%);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.7;
  font-size: 16px;
}

a { color: var(--accent-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, h4, p { margin: 0; }

/* ===== Layout ===== */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(246, 250, 246, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.site-header.scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 2px 20px rgba(47, 73, 55, 0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 20px;
  font-weight: 800;
  color: var(--accent-strong);
  letter-spacing: -0.02em;
}

.logo span { color: var(--text); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--accent-strong); text-decoration: none; }

.lang-switch {
  font-size: 13px;
  color: var(--muted);
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.lang-switch a { font-size: 13px; }
.lang-switch strong { color: var(--accent-strong); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
  border-radius: var(--radius-sm);
  transition: transform 0.16s ease, box-shadow 0.16s ease;
  text-decoration: none;
}

.btn:hover { transform: translateY(-1px); text-decoration: none; }

.btn-primary,
.nav-links a.btn-primary,
a.btn-primary {
  background: var(--accent-strong);
  color: #fff !important;
  padding: 10px 20px;
  font-size: 14px;
  box-shadow: 0 8px 24px rgba(77, 106, 83, 0.18);
}

.btn-secondary {
  background: #fff;
  color: var(--accent-strong);
  padding: 10px 20px;
  font-size: 14px;
  border: 1px solid var(--line);
}

.btn-large {
  padding: 16px 32px;
  font-size: 16px;
  border-radius: var(--radius);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ===== Hero ===== */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--accent-strong);
  border: 1px solid var(--line);
  background: var(--soft);
  border-radius: 999px;
  padding: 8px 16px;
  margin-bottom: 24px;
  font-weight: 600;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.12;
  letter-spacing: -0.03em;
  max-width: 800px;
  margin: 0 auto 20px;
}

.hero h1 em {
  font-style: normal;
  color: var(--accent-strong);
}

.hero-desc {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
  max-width: 680px;
  margin: 0 auto 32px;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 48px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--accent-strong);
  line-height: 1.2;
}

.stat-label {
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
}

/* ===== Section Common ===== */
.section {
  padding: 72px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: clamp(24px, 3.5vw, 36px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.section-header p {
  color: var(--muted);
  font-size: 16px;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ===== Card Grid (Feature, Personality, etc.) ===== */
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 20px 50px rgba(47, 73, 55, 0.12);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

/* ===== Feature Cards ===== */
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--soft);
  border: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 17px;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* ===== Personality Cards ===== */
.personality-card {
  padding: 18px;
  text-align: center;
  cursor: pointer;
}

.personality-card img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 16px;
  background: var(--soft);
  margin-bottom: 14px;
}

.personality-card .p-code {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent-strong);
  margin-bottom: 2px;
}

.personality-card .p-name {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 8px;
}

.personality-card .p-intro {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
  display: none;
}

.personality-card.expanded .p-intro {
  display: block;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  text-align: left;
}

/* ===== How It Works ===== */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}

.step-card {
  text-align: center;
  position: relative;
}

.step-num {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--accent-strong);
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.step-card h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.step-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ===== Models Section ===== */
.model-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.model-card {
  padding: 20px 16px;
  text-align: center;
}

.model-card .m-icon {
  font-size: 28px;
  margin-bottom: 12px;
}

.model-card h3 {
  font-size: 15px;
  margin-bottom: 10px;
}

.model-card p {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

/* ===== Test Embed ===== */
.test-section {
  padding: 72px 0;
}

.iframe-wrap {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.iframe-wrap iframe {
  width: 100%;
  height: 800px;
  border: 0;
  display: block;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: grid;
  gap: 12px;
}

.faq-item {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(47, 73, 55, 0.04);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: background 0.2s;
}

.faq-item summary:hover { background: var(--soft); }
.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: '+';
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-strong);
  flex-shrink: 0;
  transition: transform 0.3s;
}

.faq-item[open] summary::after {
  content: '-';
}

.faq-answer {
  padding: 0 24px 20px;
  color: #304034;
  font-size: 15px;
  line-height: 1.9;
}

/* ===== Resources ===== */
.resource-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.resource-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.resource-card .r-icon {
  font-size: 28px;
}

.resource-card h3 {
  font-size: 16px;
}

.resource-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
  flex: 1;
}

.resource-card .btn {
  align-self: flex-start;
}

/* ===== CTA Banner ===== */
.cta-banner {
  text-align: center;
  padding: 56px 32px;
  background: linear-gradient(135deg, var(--accent-strong), var(--accent));
  border-radius: var(--radius);
  color: #fff;
  box-shadow: 0 20px 50px rgba(77, 106, 83, 0.25);
}

.cta-banner h2 {
  font-size: clamp(24px, 3.5vw, 36px);
  margin-bottom: 14px;
}

.cta-banner p {
  font-size: 16px;
  opacity: 0.9;
  margin-bottom: 28px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.cta-banner .btn {
  background: #fff;
  color: var(--accent-strong);
  padding: 16px 36px;
  font-size: 16px;
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 40px 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.8;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-links {
  display: flex;
  gap: 20px;
  list-style: none;
}

.footer-links a {
  font-size: 13px;
  color: var(--muted);
}

.footer-links a:hover { color: var(--accent-strong); }

/* ===== Mobile Nav Overlay ===== */
.mobile-nav {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(246, 250, 246, 0.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 99;
  padding: 32px 20px;
}

.mobile-nav.open { display: block; }

.mobile-nav a {
  display: block;
  padding: 16px 0;
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  border-bottom: 1px solid var(--line);
}

.mobile-nav a:hover { text-decoration: none; color: var(--accent-strong); }

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }

  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(3, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .model-grid { grid-template-columns: repeat(3, 1fr); }
  .resource-grid { grid-template-columns: repeat(2, 1fr); }

  .hero { padding: 56px 0 40px; }
  .section { padding: 56px 0; }
  .hero-stats { gap: 28px; }
}

@media (max-width: 600px) {
  .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .model-grid { grid-template-columns: repeat(2, 1fr); }
  .resource-grid { grid-template-columns: 1fr; }

  .hero h1 { font-size: 28px; }
  .hero-desc { font-size: 15px; }
  .section-header h2 { font-size: 22px; }

  .hero-stats { gap: 20px; }
  .stat-num { font-size: 26px; }

  .iframe-wrap iframe { height: 600px; }

  .footer-inner { flex-direction: column; }
}