:root {
  --bg: #0a1322;
  --bg-deep: #050b16;
  --surface: rgba(255, 255, 255, 0.06);
  --surface-strong: rgba(255, 255, 255, 0.1);
  --border: rgba(255, 255, 255, 0.12);
  --border-strong: rgba(255, 255, 255, 0.2);
  --text: #eef3fa;
  --text-muted: rgba(238, 243, 250, 0.65);
  --text-dim: rgba(238, 243, 250, 0.45);
  --accent: #f89521;
  --accent-deep: #f57819;
  --blue: #2f7fd6;
  --radius: 14px;
  --radius-lg: 20px;
  --max-width: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 0%, rgba(245, 120, 25, 0.16), transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(0, 85, 184, 0.20), transparent 70%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-deep) 100%);
  z-index: -1;
}

a { color: var(--accent); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.8; }

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

/* Nav */
.nav {
  position: sticky;
  top: 0;
  background: rgba(10, 19, 34, 0.75);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  max-width: var(--max-width);
  margin: 0 auto;
  position: relative;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 16px;
  white-space: nowrap;
}
.nav-brand img { width: 28px; height: 28px; border-radius: 7px; }
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--text-muted); font-size: 14px; font-weight: 500; }
.nav-links a:hover { color: var(--text); opacity: 1; }
.nav-burger {
  display: none;
  background: transparent;
  border: 0;
  padding: 8px;
  cursor: pointer;
  color: var(--text);
  border-radius: 8px;
  transition: background 0.15s;
}
.nav-burger:hover, .nav-burger:focus-visible { background: var(--surface); outline: none; }
.nav-burger svg { display: block; transition: transform 0.2s; }
.nav.open .nav-burger svg { transform: rotate(90deg); }

@media (max-width: 720px) {
  .nav-burger { display: block; }
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 19, 34, 0.97);
    backdrop-filter: saturate(180%) blur(24px);
    -webkit-backdrop-filter: saturate(180%) blur(24px);
    border-bottom: 1px solid var(--border);
    padding: 18px 24px 24px;
    gap: 0;
    transform: translateY(-6px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.18s ease, transform 0.18s ease;
  }
  .nav-links a {
    font-size: 16px;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
  }
  .nav-links a:last-child { border-bottom: 0; }
  .nav.open .nav-links {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
}

/* Hero */
.hero {
  padding: 96px 0 72px;
  text-align: center;
}
@media (max-width: 640px) {
  .hero { padding: 56px 0 48px; }
  .hero-icon { width: 96px; height: 96px; border-radius: 22px; margin-bottom: 22px; }
  .hero-lang-strip {
    padding: 10px 18px;
    font-size: 12px;
    gap: 10px;
    margin-bottom: 40px;
    max-width: calc(100% - 16px);
    flex-wrap: wrap;
    justify-content: center;
  }
  .hero-lang-strip span:not(:last-child)::after { margin-left: 10px; }
}
.hero-icon {
  width: 120px;
  height: 120px;
  border-radius: 28px;
  margin: 0 auto 28px;
  display: block;
  box-shadow: 0 20px 60px rgba(245, 120, 25, 0.25), 0 8px 24px rgba(0, 0, 0, 0.5);
  animation: float 6s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}
.hero h1 {
  font-size: clamp(40px, 7vw, 68px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
  line-height: 1.05;
  background: linear-gradient(180deg, #fff 0%, #b9c6d8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-tagline {
  font-size: clamp(18px, 2.4vw, 22px);
  color: var(--text-muted);
  max-width: 660px;
  margin: 0 auto 12px;
}
.hero-sub {
  font-size: 14px;
  color: var(--text-dim);
  margin: 0 0 36px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}
.hero-lang-strip {
  display: inline-flex;
  gap: 14px;
  padding: 10px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  margin-bottom: 8px;
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 500;
}
.hero-lang-strip > *:not(:last-child)::after {
  content: '·';
  margin-left: 14px;
  color: var(--text-dim);
}
.hero-lang-strip a {
  color: var(--text-muted);
  transition: color 0.15s;
}
.hero-lang-strip a:hover {
  color: var(--accent);
  opacity: 1;
}
.hero-lang-strip .current {
  color: var(--text);
  font-weight: 600;
}
.lang-pill:hover { opacity: 1; }
.lang-pill.current {
  border-color: var(--accent);
  color: var(--text);
  background: rgba(245, 120, 25, 0.12);
}

/* Sections */
section {
  padding: 80px 0;
  position: relative;
}
@media (max-width: 640px) {
  section { padding: 56px 0; }
  .container { padding: 0 20px; }
  .section-intro { font-size: 16px; margin-bottom: 36px; }
  .card { padding: 20px; }
  .scenario-group { padding: 20px; }
  .callout { padding: 26px 22px; }
  .split { gap: 28px; }
  .lesson-group { margin-bottom: 32px; }
  .lesson-group-header h3 { font-size: 20px; }
  .feature-grid { gap: 22px; }
}
.section-label {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin: 0 0 12px;
}
.section-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 20px;
  line-height: 1.15;
}
.section-intro {
  font-size: 18px;
  color: var(--text-muted);
  max-width: 660px;
  margin: 0 0 48px;
}

/* Card grid */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}
.card {
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.3s ease, border-color 0.3s ease, background 0.3s ease;
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  background: var(--surface-strong);
}
.card-tier {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 12px;
}
.card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 600;
}
.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}

/* Lessons — grouped */
.lesson-group { margin-bottom: 44px; }
.lesson-group:last-child { margin-bottom: 0; }
.lesson-group-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 18px;
}
.lesson-group-header h3 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
}
.lesson-group-header .group-badge {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 4px 10px;
  background: rgba(245, 120, 25, 0.15);
  color: var(--accent);
  border-radius: 6px;
}

/* Scenario chips */
.scenarios-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}
.scenario-group {
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  border-left: 3px solid var(--group-color, var(--accent));
}
.scenario-group-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.scenario-group-title h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
}
.scenario-count {
  font-size: 12px;
  color: var(--text-dim);
  font-weight: 600;
}
.scenario-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.scenario-list li {
  font-size: 14px;
  color: var(--text-muted);
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.scenario-list li::before {
  content: '·';
  color: var(--group-color, var(--accent));
  font-weight: 700;
}

/* Split layout */
.split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}
.split-content h2 { margin-top: 0; }
.split-content ul {
  padding: 0;
  margin: 24px 0 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 10px 28px;
}
.split-content ul li {
  padding-left: 22px;
  position: relative;
  color: var(--text-muted);
  font-size: 15px;
}
.split-content ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px rgba(245, 120, 25, 0.6);
}

/* Feature dots grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 28px;
}
.feature { padding: 0; }
.feature h4 {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--text);
}
.feature p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}

/* Language row */
.lang-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
}
@media (max-width: 560px) {
  .lang-row {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    max-width: 320px;
    margin-left: auto;
    margin-right: auto;
  }
  .lang-pill { text-align: center; }
}
.lang-pill {
  padding: 10px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  transition: all 0.2s;
}
.lang-pill:hover {
  border-color: var(--accent);
  color: var(--text);
}
.lang-pill strong {
  color: var(--text);
  font-weight: 600;
  margin-right: 6px;
}

/* Disclaimer & privacy note */
.callout {
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
  max-width: 760px;
  margin: 0 auto;
}
.callout p { margin: 0 0 12px; color: var(--text-muted); font-size: 15px; }
.callout p:last-child { margin-bottom: 0; }

/* Footer */
footer {
  padding: 56px 0 48px;
  border-top: 1px solid var(--border);
  margin-top: 40px;
  text-align: center;
}
@media (max-width: 560px) {
  footer { padding: 40px 0 36px; }
}
.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}
@media (max-width: 560px) {
  .footer-links { gap: 16px; }
}
.footer-links a { color: var(--text-muted); font-size: 14px; }
.footer-copy {
  font-size: 13px;
  color: var(--text-dim);
  max-width: 660px;
  margin: 0 auto;
  line-height: 1.6;
}
.footer-sign-off {
  margin-top: 16px;
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.04em;
}

/* Support page */
.faq { margin-top: 32px; }
.faq details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 12px;
  transition: background 0.2s;
}
.faq details[open] { background: var(--surface-strong); }
.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: '+';
  float: right;
  color: var(--accent);
  font-size: 22px;
  line-height: 1;
  transition: transform 0.2s;
}
.faq details[open] summary::after { content: '−'; }
.faq details > *:not(summary) {
  margin-top: 14px;
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.7;
}
.contact-block {
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
}
.contact-block a {
  display: inline-block;
  font-size: 18px;
  font-weight: 600;
  margin-top: 8px;
  word-break: break-word;
}
@media (max-width: 560px) {
  .contact-block { padding: 24px 20px; }
  .contact-block a { font-size: 16px; }
  .faq details { padding: 16px 18px; }
  .faq summary { font-size: 15px; }
}

/* Privacy page */
.prose { max-width: 720px; margin: 0 auto; }
.prose h2 { margin-top: 40px; font-size: 22px; }
.prose p, .prose ul { color: var(--text-muted); font-size: 16px; line-height: 1.7; }
.prose ul { padding-left: 22px; }
.prose ul li { margin-bottom: 6px; }
.prose .meta { font-size: 13px; color: var(--text-dim); margin-bottom: 32px; }

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.in {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}