:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #07090f;
  color: #f4f7fb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: #07090f;
}

a {
  color: inherit;
}

.site-header {
  display: flex;
  align-items: center;
  gap: 28px;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0;
}

.brand {
  margin-right: auto;
  color: #f4f7fb;
  font-size: 1.5rem;
  font-weight: 800;
  text-decoration: none;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 26px;
  color: #c6cfdd;
  font-size: 0.95rem;
  font-weight: 700;
}

.site-nav a,
.nav-button,
.button,
.icon-link {
  text-decoration: none;
}

.nav-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 6px;
  background: #2f6df6;
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 800;
}

.hero {
  position: relative;
  overflow: hidden;
  width: min(1180px, calc(100% - 32px));
  min-height: clamp(520px, 68vh, 720px);
  margin: 18px auto 0;
  border-radius: 8px;
  background: #111827;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.42);
}

.hero img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(5, 8, 15, 0.86), rgba(5, 8, 15, 0.48) 54%, rgba(5, 8, 15, 0.18));
}

.hero-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: min(680px, 100%);
  min-height: inherit;
  padding: clamp(32px, 7vw, 74px);
  color: #ffffff;
}

.eyebrow {
  margin: 0 0 12px;
  color: #82a8ff;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #9ebcff;
}

h1 {
  margin: 0 0 16px;
  max-width: 620px;
  font-size: clamp(2.45rem, 6vw, 4.9rem);
  line-height: 1.02;
}

p {
  margin: 0;
  font-size: 1.1rem;
  line-height: 1.65;
}

.hero p:not(.eyebrow) {
  max-width: 570px;
  color: rgba(255, 255, 255, 0.9);
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border: 1px solid #2f6df6;
  border-radius: 6px;
  background: #2f6df6;
  color: #ffffff;
  font-weight: 800;
}

.button.secondary {
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
}

.notice {
  display: grid;
  grid-template-columns: minmax(160px, 240px) 1fr auto;
  align-items: center;
  gap: 28px;
  width: min(900px, calc(100% - 48px));
  margin: -42px auto 0;
  padding: 22px 26px;
  border: 1px solid #273244;
  border-radius: 8px;
  background: #111827;
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.34);
  position: relative;
  z-index: 2;
}

h2 {
  margin: 0;
  color: #f4f7fb;
  font-size: clamp(1.45rem, 3vw, 2rem);
  line-height: 1.12;
}

.notice p {
  color: #aab5c6;
}

.icon-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 76px;
  min-height: 40px;
  border-radius: 6px;
  background: #203154;
  color: #b8ccff;
  font-weight: 800;
}

.about {
  width: min(900px, calc(100% - 32px));
  margin: 74px auto 88px;
}

.about p:not(.eyebrow) {
  max-width: 660px;
  margin-top: 14px;
  color: #aab5c6;
}

.lesson {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
  padding: 64px 0;
}

code {
  padding: 2px 5px;
  border-radius: 4px;
  background: #1d2635;
  color: #f4f7fb;
}

@media (max-width: 760px) {
  .site-header {
    flex-wrap: wrap;
    gap: 14px;
  }

  .site-nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    gap: 12px;
    padding-top: 4px;
  }

  .nav-button {
    min-height: 38px;
    padding: 0 14px;
    font-size: 0.88rem;
  }

  .hero {
    min-height: 560px;
    margin-top: 10px;
  }

  .hero-overlay {
    background: linear-gradient(180deg, rgba(8, 15, 31, 0.72), rgba(8, 15, 31, 0.38));
  }

  .hero-content {
    justify-content: flex-end;
    padding: 28px;
  }

  .notice {
    grid-template-columns: 1fr;
    gap: 12px;
    margin-top: 18px;
  }

  .icon-link {
    width: 100%;
  }
}