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

:root {
  --primary: #5f9ea7;
  --primary-dark: #3a7278;
  --primary-light: #8dbdc4;
  --primary-pale: #ddf0f2;
  --primary-bg: #eff8f9;
  --ink: #1c3a3e;
  --text: #243638;
  --text-muted: #5a7578;
  --bg: #ffffff;
  --border: #d4e8eb;
  --shadow: 0 8px 32px rgba(58, 114, 120, 0.1);
  --max-width: 1080px;
  --radius: 16px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary-dark);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ── Header ── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
}

.site-logo-mark {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 0.875rem;
  font-weight: 800;
}

.site-logo:hover {
  text-decoration: none;
}

.site-nav a {
  margin-left: 28px;
  font-size: 0.9375rem;
  color: var(--text-muted);
  font-weight: 500;
}

.site-nav a:hover {
  color: var(--primary-dark);
  text-decoration: none;
}

/* ── Hero ── */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(155deg, #eff8f9 0%, #ddf0f2 45%, #ffffff 100%);
  padding: 88px 24px 96px;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

.hero-glow-1 {
  width: 420px;
  height: 420px;
  background: rgba(95, 158, 167, 0.22);
  top: -120px;
  right: -80px;
}

.hero-glow-2 {
  width: 300px;
  height: 300px;
  background: rgba(141, 189, 196, 0.18);
  bottom: -60px;
  left: -40px;
}

.hero-inner {
  position: relative;
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

@media (max-width: 860px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-points {
    align-items: center;
  }
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(95, 158, 167, 0.12);
  border: 1px solid rgba(95, 158, 167, 0.25);
  color: var(--primary-dark);
  font-size: 0.8125rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero-badge-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--primary);
}

.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--ink);
}

.hero h1 span {
  color: var(--primary-dark);
}

.hero .subtitle {
  margin: 0 0 28px;
  font-size: 1.0625rem;
  color: var(--text-muted);
  max-width: 480px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  padding: 13px 26px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff !important;
  font-weight: 600;
  font-size: 0.9375rem;
  box-shadow: 0 4px 16px rgba(58, 114, 120, 0.28);
  text-decoration: none;
  transition:
    transform 0.15s,
    box-shadow 0.15s;
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(58, 114, 120, 0.34);
  text-decoration: none;
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  padding: 13px 22px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.8);
  color: var(--text) !important;
  font-weight: 500;
  font-size: 0.9375rem;
  text-decoration: none;
}

.btn-ghost:hover {
  border-color: var(--primary-light);
  text-decoration: none;
}

.hero-points {
  display: flex;
  flex-direction: column;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.hero-points li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.hero-points li::before {
  content: '✓';
  color: var(--primary);
  font-weight: 700;
}

/* Hero card mockup */
.hero-visual {
  display: flex;
  justify-content: center;
}

.phone-card {
  width: 100%;
  max-width: 340px;
  background: #fff;
  border-radius: 24px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.phone-card-header {
  padding: 16px 20px 12px;
  background: linear-gradient(135deg, #5f9ea0 0%, #4a8a91 60%, #3a7278 100%);
  color: #fff;
}

.phone-card-header p {
  margin: 0;
  font-size: 0.75rem;
  opacity: 0.85;
}

.phone-card-header h3 {
  margin: 4px 0 0;
  font-size: 1rem;
  font-weight: 700;
}

.phone-card-body {
  padding: 20px;
}

.review-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  border-radius: 12px;
  background: var(--primary-bg);
  margin-bottom: 10px;
  font-size: 0.875rem;
}

.review-item-label {
  font-weight: 600;
  color: var(--ink);
}

.review-item-days {
  font-size: 0.8125rem;
  color: var(--primary-dark);
  font-weight: 600;
}

.rating-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-top: 16px;
}

.rating-btn {
  text-align: center;
  padding: 10px 4px;
  border-radius: 10px;
  font-size: 0.75rem;
  font-weight: 600;
}

.rating-btn.forgot {
  background: #fdecea;
  color: #c62828;
}

.rating-btn.fuzzy {
  background: #fff8e6;
  color: #e65100;
}

.rating-btn.known {
  background: #e8f5e9;
  color: #2e7d32;
}

/* ── Sections ── */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px;
}

.section-alt {
  background: var(--primary-bg);
}

.section-label {
  display: block;
  text-align: center;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 10px;
}

.section-title {
  margin: 0 0 12px;
  font-size: clamp(1.625rem, 3vw, 2rem);
  font-weight: 800;
  text-align: center;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.section-desc {
  margin: 0 auto 48px;
  max-width: 560px;
  text-align: center;
  color: var(--text-muted);
  font-size: 1rem;
}

/* ── Features ── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.feature-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition:
    box-shadow 0.2s,
    transform 0.2s;
}

.feature-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.section-alt .feature-card {
  background: #fff;
}

.feature-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--primary-pale);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--primary-dark);
  font-size: 1.25rem;
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--ink);
}

.feature-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── FSRS section ── */
.fsrs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

@media (max-width: 768px) {
  .fsrs-grid {
    grid-template-columns: 1fr;
  }
}

.fsrs-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.fsrs-card h3 {
  margin: 0 0 12px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--ink);
}

.fsrs-card p {
  margin: 0 0 16px;
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.fsrs-card p:last-child {
  margin-bottom: 0;
}

.fsrs-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: step;
}

.fsrs-steps li {
  counter-increment: step;
  position: relative;
  padding-left: 44px;
  margin-bottom: 24px;
}

.fsrs-steps li:last-child {
  margin-bottom: 0;
}

.fsrs-steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary-pale);
  color: var(--primary-dark);
  font-size: 0.8125rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.fsrs-steps strong {
  display: block;
  font-size: 0.9375rem;
  color: var(--ink);
  margin-bottom: 4px;
}

.fsrs-steps span {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.compare-table th,
.compare-table td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.compare-table th {
  font-weight: 600;
  color: var(--ink);
  background: var(--primary-bg);
}

.compare-table td {
  color: var(--text-muted);
}

.compare-table tr:last-child td,
.compare-table tr:last-child th {
  border-bottom: none;
}

.tag-yes {
  color: #2e7d32;
  font-weight: 600;
}

.tag-no {
  color: #9e9e9e;
}

/* ── Footer ── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 48px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  background: var(--primary-bg);
}

.site-footer p {
  margin: 4px 0;
}

.site-footer a {
  margin: 0 10px;
}

.site-footer-icp {
  margin-top: 16px;
  font-size: 0.8125rem;
}

.site-footer-icp a {
  margin: 0;
}

.site-footer-copy::before {
  content: ' · ';
}

/* privacy page (unchanged structure) */
.privacy-hero {
  background: var(--primary-bg);
  padding: 48px 24px 32px;
  border-bottom: 1px solid var(--border);
}

.privacy-hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.privacy-hero h1 {
  margin: 0 0 8px;
  font-size: 2rem;
  font-weight: 800;
  color: var(--ink);
}

.privacy-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.privacy-summary {
  background: #fff;
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: 8px;
  padding: 20px 24px;
  font-size: 0.9375rem;
}

.privacy-summary ul {
  margin: 8px 0 0;
  padding-left: 1.2em;
}

.privacy-layout {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 64px;
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 48px;
  align-items: start;
}

@media (max-width: 768px) {
  .privacy-layout {
    grid-template-columns: 1fr;
  }

  .privacy-toc {
    position: static !important;
  }
}

.privacy-toc {
  position: sticky;
  top: 72px;
}

.privacy-toc h2 {
  margin: 0 0 12px;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.privacy-toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.privacy-toc a {
  font-size: 0.875rem;
  color: var(--text-muted);
  display: block;
  padding: 4px 0;
}

.privacy-section {
  margin-bottom: 40px;
  scroll-margin-top: 72px;
}

.privacy-section h2 {
  margin: 0 0 16px;
  font-size: 1.25rem;
  font-weight: 700;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.privacy-section h3 {
  margin: 24px 0 8px;
  font-size: 1rem;
  font-weight: 600;
}

.privacy-section p {
  margin: 0 0 12px;
}

.privacy-section ul {
  margin: 0 0 12px;
  padding-left: 1.4em;
}

.privacy-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  margin-top: 12px;
}

.privacy-table th,
.privacy-table td {
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: left;
}

.privacy-table th {
  background: var(--primary-bg);
}

.privacy-contact {
  background: var(--primary-bg);
  border-radius: 12px;
  padding: 24px;
  margin-top: 16px;
}