:root {
  color-scheme: light dark;
  --bg: #f7f8fb;
  --surface: rgba(255, 255, 255, 0.82);
  --surface-strong: #ffffff;
  --text: #111318;
  --muted: #687080;
  --line: rgba(17, 19, 24, 0.1);
  --accent: #0a84ff;
  --accent-strong: #0066d6;
  --green: #34c759;
  --pink: #ff5d9e;
  --yellow: #ffb22c;
  --shadow: 0 24px 80px rgba(33, 42, 66, 0.13);
  --radius: 28px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 10% 5%, rgba(10, 132, 255, 0.15), transparent 30rem),
    radial-gradient(circle at 88% 12%, rgba(255, 93, 158, 0.12), transparent 26rem),
    var(--bg);
  color: var(--text);
  letter-spacing: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: blur(20px);
}

.nav {
  width: min(1120px, calc(100% - 32px));
  height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  color: white;
  background: linear-gradient(145deg, var(--accent), #6c5ce7);
  box-shadow: 0 10px 28px rgba(10, 132, 255, 0.28);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-weight: 650;
}

.nav-links a {
  padding: 10px 12px;
  border-radius: 999px;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--surface);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
  color: var(--text);
  font-weight: 800;
  box-shadow: 0 10px 28px rgba(33, 42, 66, 0.08);
}

.button.primary {
  border-color: transparent;
  background: var(--accent);
  color: white;
}

.button.primary:hover {
  background: var(--accent-strong);
}

.page {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  min-height: calc(100svh - 72px);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.84fr);
  align-items: center;
  gap: 56px;
  padding: 56px 0 72px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 9px 12px;
  border-radius: 999px;
  background: rgba(10, 132, 255, 0.12);
  color: var(--accent);
  font-weight: 800;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  max-width: 760px;
  font-size: clamp(48px, 8vw, 92px);
  line-height: 0.94;
  letter-spacing: 0;
}

.lead {
  max-width: 620px;
  margin-top: 24px;
  color: var(--muted);
  font-size: clamp(20px, 2.4vw, 27px);
  line-height: 1.28;
}

.hero-actions {
  margin-top: 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.phone-stage {
  min-height: 620px;
  display: grid;
  place-items: center;
}

.phone {
  width: min(360px, 100%);
  min-height: 690px;
  padding: 18px;
  border: 1px solid rgba(17, 19, 24, 0.1);
  border-radius: 46px;
  background: #0b0d11;
  box-shadow: var(--shadow);
}

.phone-screen {
  min-height: 654px;
  padding: 28px 22px;
  border-radius: 34px;
  overflow: hidden;
  background:
    radial-gradient(circle at 20% 0%, rgba(10, 132, 255, 0.35), transparent 13rem),
    radial-gradient(circle at 80% 8%, rgba(255, 93, 158, 0.24), transparent 12rem),
    #111318;
  color: white;
}

.phone-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 28px;
  font-weight: 800;
}

.mini-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 7px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  color: rgba(255, 255, 255, 0.86);
  font-size: 13px;
  font-weight: 800;
}

.level-card,
.quiz-card,
.word-card {
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.1);
  border-radius: 26px;
  backdrop-filter: blur(18px);
}

.level-card {
  padding: 22px;
}

.level-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 30px;
}

.level-card span,
.word-card span,
.quiz-card span {
  color: rgba(255, 255, 255, 0.68);
}

.quiz-card {
  margin-top: 18px;
  padding: 18px;
}

.quiz-row {
  display: flex;
  align-items: center;
  gap: 14px;
}

.icon-tile {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 17px;
  color: white;
  font-weight: 900;
}

.icon-tile.blue { background: var(--accent); }
.icon-tile.green { background: var(--green); }
.icon-tile.pink { background: var(--pink); }
.icon-tile.yellow { background: var(--yellow); }

.word-card {
  margin-top: 18px;
  padding: 20px;
}

.word-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 28px;
}

.section {
  padding: 74px 0;
}

.section-title {
  max-width: 720px;
  margin-bottom: 28px;
}

.section-title h2,
.content-page h1 {
  font-size: clamp(36px, 5vw, 58px);
  line-height: 1.02;
}

.section-title p,
.content-page .intro {
  margin-top: 14px;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.45;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 16px 44px rgba(33, 42, 66, 0.08);
}

.card h3 {
  margin-top: 16px;
  font-size: 23px;
}

.card p {
  margin-top: 10px;
  color: var(--muted);
  line-height: 1.55;
}

.split {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 22px;
  align-items: stretch;
}

.feature-list {
  display: grid;
  gap: 12px;
}

.feature-item {
  display: flex;
  gap: 14px;
  padding: 18px;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.feature-item strong {
  display: block;
  margin-bottom: 4px;
}

.feature-item p {
  color: var(--muted);
  line-height: 1.48;
}

.cta {
  margin: 74px 0;
  padding: 42px;
  border-radius: 34px;
  background:
    linear-gradient(135deg, rgba(10, 132, 255, 0.95), rgba(108, 92, 231, 0.95)),
    var(--accent);
  color: white;
  box-shadow: var(--shadow);
}

.cta h2 {
  max-width: 720px;
  font-size: clamp(34px, 4.6vw, 58px);
  line-height: 1.04;
}

.cta p {
  max-width: 660px;
  margin-top: 14px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 20px;
  line-height: 1.45;
}

.cta .button {
  margin-top: 24px;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 34px 0;
  color: var(--muted);
}

.footer-inner {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}

.footer-links {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.content-page {
  max-width: 850px;
  padding: 64px 0 96px;
}

.content-block {
  margin-top: 28px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.content-block h2 {
  margin-bottom: 12px;
  font-size: 28px;
}

.content-block p,
.content-block li {
  color: var(--muted);
  line-height: 1.65;
}

.content-block ul {
  margin: 10px 0 0;
  padding-left: 22px;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.contact-link {
  display: block;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface-strong);
}

.contact-link span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-weight: 700;
}

.contact-link strong {
  font-size: 20px;
}

.form {
  display: grid;
  gap: 16px;
}

.form-row {
  display: grid;
  gap: 8px;
}

.form-row label {
  font-weight: 800;
}

.form-row input,
.form-row textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 15px 16px;
  background: var(--surface-strong);
  color: var(--text);
  font: inherit;
  outline: none;
}

.form-row textarea {
  min-height: 150px;
  resize: vertical;
}

.form-row input:focus,
.form-row textarea:focus {
  border-color: color-mix(in srgb, var(--accent) 68%, var(--line));
  box-shadow: 0 0 0 4px rgba(10, 132, 255, 0.14);
}

.form-help {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
}

.form-status {
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  line-height: 1.45;
  font-weight: 750;
}

.form-status.success {
  color: #147a35;
  background: rgba(52, 199, 89, 0.13);
  border-color: rgba(52, 199, 89, 0.3);
}

.form-status.error {
  color: #b42318;
  background: rgba(255, 59, 48, 0.12);
  border-color: rgba(255, 59, 48, 0.28);
}

.hidden-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

@media (max-width: 860px) {
  .nav {
    height: auto;
    padding: 14px 0;
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero,
  .split,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 42px;
  }

  .phone-stage {
    min-height: auto;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .cta {
    padding: 28px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #05070a;
    --surface: rgba(29, 31, 36, 0.78);
    --surface-strong: #1b1d22;
    --text: #f5f7fb;
    --muted: #a1a8b5;
    --line: rgba(255, 255, 255, 0.12);
    --shadow: 0 28px 90px rgba(0, 0, 0, 0.32);
  }
}