:root {
  --bg-deep: #0a1628;
  --bg-surface: #0f1f3a;
  --bg-card: #152847;
  --fg: #e8edf5;
  --fg-muted: #8b9ec2;
  --accent: #ff6b4a;
  --accent-glow: rgba(255, 107, 74, 0.15);
  --coral: #ff8f73;
  --teal: #2dd4bf;
  --lagoon: #38bdf8;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;
}

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

body {
  background: var(--bg-deep);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.15;
  font-weight: 700;
}

/* ===== HERO ===== */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px 100px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.spiral {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(56, 189, 248, 0.08);
}

.spiral-1 {
  width: 700px;
  height: 700px;
  top: -200px;
  right: -200px;
  background: radial-gradient(circle at center, rgba(56, 189, 248, 0.04) 0%, transparent 70%);
}

.spiral-2 {
  width: 500px;
  height: 500px;
  bottom: -100px;
  left: -150px;
  background: radial-gradient(circle at center, rgba(255, 107, 74, 0.04) 0%, transparent 70%);
}

.spiral-3 {
  width: 300px;
  height: 300px;
  top: 30%;
  left: 60%;
  background: radial-gradient(circle at center, rgba(45, 212, 191, 0.03) 0%, transparent 70%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
  text-align: center;
}

.hero-tag {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  color: var(--lagoon);
  background: rgba(56, 189, 248, 0.08);
  padding: 8px 20px;
  border-radius: 100px;
  margin-bottom: 32px;
}

.hero h1 {
  font-size: clamp(2.8rem, 6vw, 4.5rem);
  margin-bottom: 28px;
  letter-spacing: -1.5px;
}

.hero h1 .accent {
  background: linear-gradient(135deg, var(--accent), var(--coral));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lede {
  font-size: 1.15rem;
  color: var(--fg-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ===== FEATURES ===== */
.features {
  padding: 100px 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-surface);
  border: 1px solid rgba(139, 158, 194, 0.08);
  border-radius: 16px;
  padding: 40px 32px;
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.feature-card:hover {
  border-color: rgba(255, 107, 74, 0.2);
  transform: translateY(-2px);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: var(--fg);
}

.feature-card p {
  color: var(--fg-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* ===== SUBJECTS ===== */
.subjects {
  padding: 80px 24px 100px;
  background: var(--bg-surface);
}

.subjects-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.subjects h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 48px;
  letter-spacing: -1px;
  text-align: center;
}

.subjects-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.subject-group h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--teal);
  margin-bottom: 16px;
}

.subject-group ul {
  list-style: none;
}

.subject-group li {
  padding: 8px 0;
  color: var(--fg-muted);
  font-size: 0.95rem;
  border-bottom: 1px solid rgba(139, 158, 194, 0.06);
}

.subject-group li:last-child {
  border-bottom: none;
}

/* ===== CLOSING ===== */
.closing {
  padding: 120px 24px;
  text-align: center;
}

.closing-inner {
  max-width: 680px;
  margin: 0 auto;
}

.closing h2 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 24px;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--fg), var(--lagoon));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.closing p {
  color: var(--fg-muted);
  font-size: 1.1rem;
  line-height: 1.75;
}

/* ===== FOOTER ===== */
.site-footer {
  padding: 48px 24px;
  border-top: 1px solid rgba(139, 158, 194, 0.06);
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  text-align: center;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--fg);
  margin-bottom: 4px;
}

.footer-sub {
  color: var(--fg-muted);
  font-size: 0.85rem;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
  }

  .subjects-columns {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero {
    min-height: 80vh;
    padding: 60px 20px 80px;
  }

  .hero h1 {
    font-size: 2.4rem;
  }

  .features {
    padding: 60px 20px;
  }

  .subjects {
    padding: 60px 20px;
  }

  .closing {
    padding: 80px 20px;
  }

  .feature-card {
    padding: 28px 24px;
  }
}