:root {
  --indigo-900: #001a5c;
  --indigo-700: #003bbe;
  --indigo-500: #2f5fe6;
  --indigo-300: #8aa6ff;
  --ink: #0e1330;
  --muted: #5b6178;
  --bg: #f6f7fc;
  --surface: #ffffff;
  --border: #e6e8f2;
  --radius: 16px;
  --shadow: 0 12px 40px rgba(0, 59, 190, 0.10);
  --font: "Inter", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial,
    "Noto Sans Thai", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(246, 247, 252, 0.8);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: var(--indigo-700);
  color: #fff;
  font-weight: 800;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-weight: 500;
}

.nav__links a:hover {
  color: var(--ink);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}

.btn--primary {
  background: var(--indigo-700);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0, 59, 190, 0.28);
}

.btn--primary:hover {
  transform: translateY(-1px);
  background: var(--indigo-500);
}

.btn--ghost {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--ink);
}

.btn--ghost:hover {
  border-color: var(--indigo-300);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(1200px 400px at 80% -10%, rgba(47, 95, 230, 0.18), transparent),
    linear-gradient(180deg, #fff, var(--bg));
}

.hero__inner {
  max-width: 820px;
  margin: 0 auto;
  padding: 96px 24px 80px;
  text-align: center;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 16px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(0, 59, 190, 0.08);
  color: var(--indigo-700);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.hero__title {
  margin: 0;
  font-size: clamp(2.1rem, 5vw, 3.6rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.hero__accent {
  color: var(--indigo-700);
}

.hero__sub {
  max-width: 600px;
  margin: 22px auto 0;
  font-size: 1.12rem;
  color: var(--muted);
}

.hero__cta {
  margin-top: 34px;
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---------- Sections ---------- */
.section__inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 80px 24px;
}

.section__title {
  margin: 0 0 40px;
  text-align: center;
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  letter-spacing: -0.02em;
  font-weight: 800;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.card,
.course {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.18s ease, box-shadow 0.25s ease, border-color 0.2s ease;
}

.card:hover,
.course:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: var(--indigo-300);
}

.card__icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(0, 59, 190, 0.08);
  color: var(--indigo-700);
  font-size: 1.3rem;
  margin-bottom: 16px;
}

.card h3,
.course h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

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

.courses {
  background: linear-gradient(180deg, var(--bg), #fff);
}

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--indigo-900);
  color: #fff;
}

.cta-band__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  padding-top: 56px;
  padding-bottom: 56px;
}

.cta-band h2 {
  margin: 0;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
}

/* ---------- Footer ---------- */
.footer {
  background: #fff;
  border-top: 1px solid var(--border);
}

.footer__inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 28px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer__links {
  display: flex;
  gap: 20px;
}

.footer__links a:hover {
  color: var(--ink);
}

/* ---------- Responsive ---------- */
@media (max-width: 760px) {
  .grid {
    grid-template-columns: 1fr;
  }
  .nav__links a:not(.btn) {
    display: none;
  }
}