:root {
  --bg: #f3f8ff;
  --surface: #ffffff;
  --text: #10233f;
  --muted: #4d617f;
  --primary: #0f8bff;
  --primary-dark: #0c6cd9;
  --line: #d9e6ff;
  --hero-from: #ffffff;
  --hero-to: #edf5ff;
  --cta-panel-bg: #0f203c;
  --cta-panel-text: #eaf2ff;
  --body-overlay: radial-gradient(circle at 5% 0%, #dceeff 0%, transparent 45%);
}

:root[data-theme="dark"] {
  --bg: #081422;
  --surface: #0f1f33;
  --text: #e7f0ff;
  --muted: #9ab0cf;
  --primary: #3a9bff;
  --primary-dark: #267fdf;
  --line: #243a55;
  --hero-from: #0f1f33;
  --hero-to: #0b182a;
  --cta-panel-bg: #101b2d;
  --cta-panel-text: #e7f0ff;
  --body-overlay: radial-gradient(circle at 5% 0%, #1a3a5f 0%, transparent 45%);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
}

body {
  background: var(--body-overlay), var(--bg);
  color: var(--text);
  font-family: "Plus Jakarta Sans", sans-serif;
  min-height: 100vh;
  line-height: 1.5;
  transition: background 220ms ease, color 220ms ease;
}

main {
  margin: 0 auto;
  max-width: 1120px;
  padding: 56px 20px 72px;
}

.topbar {
  align-items: center;
  display: flex;
  justify-content: space-between;
  margin-bottom: 16px;
}

.controls {
  align-items: center;
  display: flex;
  gap: 10px;
}

.brand {
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 0.03em;
}

.language-toggle {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  display: inline-flex;
  overflow: hidden;
}

.lang-button {
  background: transparent;
  border: 0;
  color: var(--muted);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.86rem;
  font-weight: 700;
  padding: 9px 12px;
  transition: background 160ms ease, color 160ms ease;
}

.lang-button:hover {
  color: var(--text);
}

.lang-button.is-active {
  background: var(--primary);
  color: #fff;
}

.theme-toggle {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  font-weight: 700;
  padding: 10px 14px;
  transition: background 160ms ease, border-color 160ms ease, transform 160ms ease;
}

.theme-toggle:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}

.hero {
  background: linear-gradient(130deg, var(--hero-from) 0%, var(--hero-to) 100%);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: 0 20px 50px rgba(16, 35, 63, 0.08);
  padding: 56px 32px;
  text-align: center;
}

.tag {
  color: var(--primary-dark);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  margin: 0 0 12px;
  text-transform: uppercase;
}

h1 {
  font-size: clamp(2rem, 4.5vw, 3.6rem);
  line-height: 1.15;
  margin: 0;
}

.subtext {
  color: var(--muted);
  font-size: 1.1rem;
  margin: 18px auto 30px;
  max-width: 650px;
}

.cta {
  background: var(--primary);
  border-radius: 999px;
  color: #fff;
  display: inline-block;
  font-weight: 700;
  padding: 14px 24px;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.cta:hover {
  background: var(--primary-dark);
  box-shadow: 0 12px 24px rgba(12, 108, 217, 0.28);
  transform: translateY(-2px);
}

.features {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 26px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 10px 28px rgba(14, 34, 62, 0.06);
  padding: 24px;
}

.feature-card h2 {
  font-size: 1.15rem;
  margin: 0 0 10px;
}

.feature-card p {
  color: var(--muted);
  margin: 0;
}

.cta-panel {
  align-items: center;
  background: var(--cta-panel-bg);
  border-radius: 22px;
  color: var(--cta-panel-text);
  display: flex;
  gap: 18px;
  justify-content: space-between;
  margin-top: 28px;
  padding: 30px 26px;
}

.cta-panel h2 {
  font-size: clamp(1.2rem, 2.7vw, 1.8rem);
  line-height: 1.25;
  margin: 0;
  max-width: 620px;
}

.cta-secondary {
  background: #1e7fff;
  flex-shrink: 0;
}

.cta-secondary:hover {
  background: #56a1ff;
}

@media (max-width: 860px) {
  main {
    padding-top: 32px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .controls {
    width: 100%;
  }

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

  .cta-panel {
    align-items: flex-start;
    flex-direction: column;
  }
}

.reveal-up {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 480ms ease, transform 480ms ease;
}

.reveal-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}