:root {
  --indigo: #4F46E5;
  --indigo-dark: #3730A3;
  --cyan: #A5F3FC;
  --green: #059669;
  --ink: #0F172A;
  --slate: #475569;
  --slate-light: #64748B;
  --bg: #FAFAFA;
  --card: #FFFFFF;
  --border: #E2E8F0;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Inter", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

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

.nav-links a {
  color: var(--slate);
  font-size: 15px;
  font-weight: 500;
}

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

/* Hero */
.hero {
  padding: 96px 0 80px;
  background: linear-gradient(135deg, #EEF2FF 0%, #FAFAFA 60%);
  text-align: center;
}

.hero h1 {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--indigo) 0%, var(--indigo-dark) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero .tagline {
  font-size: 22px;
  color: var(--slate);
  max-width: 720px;
  margin: 0 auto 36px;
}

.hero .cta-row {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 16px;
  transition: transform 0.15s, box-shadow 0.15s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--indigo), var(--indigo-dark));
  color: #fff;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.25);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  color: var(--indigo);
  border: 1.5px solid var(--indigo);
}

.btn-ghost:hover {
  background: var(--indigo);
  color: #fff;
  text-decoration: none;
}

/* Sections */
section {
  padding: 80px 0;
}

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

.section-title {
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-align: center;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 18px;
  color: var(--slate);
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

/* Features grid */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.feature {
  background: var(--card);
  padding: 32px;
  border-radius: 16px;
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.06);
}

.feature .icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--indigo), var(--indigo-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: #fff;
  font-size: 22px;
  font-weight: 700;
}

.feature h3 {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature p {
  color: var(--slate);
  font-size: 15px;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.about-grid p {
  font-size: 17px;
  color: var(--slate);
  margin-bottom: 16px;
}

.about-visual {
  background: linear-gradient(135deg, var(--indigo), var(--indigo-dark));
  border-radius: 20px;
  padding: 48px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.about-visual img {
  width: 200px;
  height: 200px;
}

/* Article (privacy / terms) */
.article {
  max-width: 780px;
  margin: 0 auto;
  padding: 64px 24px;
}

.article h1 {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.article .meta {
  color: var(--slate-light);
  font-size: 14px;
  margin-bottom: 40px;
}

.article h2 {
  font-size: 24px;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.article h3 {
  font-size: 18px;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
}

.article p, .article li {
  font-size: 16px;
  color: var(--slate);
  margin-bottom: 12px;
}

.article ul, .article ol {
  padding-left: 24px;
  margin-bottom: 16px;
}

.article strong {
  color: var(--ink);
}

.notice {
  background: #FEF3C7;
  border-left: 4px solid #F59E0B;
  padding: 16px 20px;
  border-radius: 8px;
  margin: 24px 0;
  font-size: 15px;
  color: #78350F;
}

/* Contact */
.contact-card {
  max-width: 560px;
  margin: 0 auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px;
  text-align: center;
}

.contact-card h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.contact-card p {
  color: var(--slate);
  margin-bottom: 24px;
}

.contact-email {
  display: inline-block;
  font-size: 18px;
  font-weight: 600;
  color: var(--indigo);
  padding: 12px 24px;
  background: #EEF2FF;
  border-radius: 10px;
}

/* Footer */
footer {
  background: var(--ink);
  color: #94A3B8;
  padding: 48px 0 32px;
  margin-top: 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 32px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: 7px;
}

footer h4 {
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
}

footer ul {
  list-style: none;
}

footer li {
  margin-bottom: 8px;
}

footer a {
  color: #94A3B8;
  font-size: 14px;
}

footer a:hover {
  color: #fff;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid #1E293B;
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
}

/* Responsive */
@media (max-width: 720px) {
  .hero {
    padding: 64px 0 56px;
  }
  .hero h1 {
    font-size: 38px;
  }
  .hero .tagline {
    font-size: 18px;
  }
  .section-title {
    font-size: 28px;
  }
  .nav-links {
    display: none;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}