:root {
  color-scheme: light;
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-soft: rgba(255, 255, 255, 0.72);
  --text: #111318;
  --muted: #555b68;
  --accent: #0a84ff;
  --accent-soft: rgba(10, 132, 255, 0.12);
  --border: rgba(9, 17, 33, 0.08);
  --radius: 18px;
  --shadow: 0 18px 38px rgba(10, 35, 71, 0.08);
  --transition: 180ms ease;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #090c11;
  --surface: rgba(18, 22, 31, 0.82);
  --surface-soft: rgba(21, 26, 36, 0.68);
  --text: #f4f6fd;
  --muted: #aeb3c5;
  --accent: #4da2ff;
  --accent-soft: rgba(77, 162, 255, 0.18);
  --border: rgba(244, 246, 255, 0.12);
  --shadow: 0 18px 38px rgba(0, 0, 0, 0.45);
}

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

body {
  font-family: "Inter", "SF Pro Text", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  letter-spacing: -0.01em;
  min-height: 100vh;
}

body.nav-open {
  overflow: hidden;
}

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

a:hover,
a:focus-visible {
  text-decoration: underline;
  text-decoration-thickness: 2px;
}

img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius) - 6px);
}

header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--surface);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.navbar {
  max-width: 74rem;
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  position: relative;
}

.nav-links {
  list-style: none;
  position: absolute;
  top: calc(100% + 0.75rem);
  left: 1.5rem;
  right: 1.5rem;
  display: grid;
  gap: 0.65rem;
  padding: 0.9rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
  z-index: 10;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-6px);
  transition: opacity var(--transition), transform var(--transition);
  text-align: left;
  visibility: hidden;
  max-height: calc(100vh - 6rem);
  overflow-y: auto;
}

.nav-links.is-open {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
  visibility: visible;
}

.nav-controls {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  margin-left: auto;
}

.nav-links a {
  display: block;
  padding: 0.55rem 1.1rem;
  border-radius: 999px;
  transition: background var(--transition), color var(--transition);
}

.nav-links a.active,
.nav-links a:hover,
.nav-links a:focus-visible {
  background: var(--accent-soft);
  text-decoration: none;
  color: var(--accent);
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 12px;
}

.nav-toggle {
  position: relative;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.28rem;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface-soft);
  color: inherit;
  cursor: pointer;
  transition: transform var(--transition), border var(--transition);
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  transform: translateY(-1px);
  border-color: var(--accent);
}

.nav-toggle-bar {
  width: 1.35rem;
  height: 0.12rem;
  border-radius: 999px;
  background: currentColor;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.is-open .nav-toggle-bar:nth-of-type(2) {
  transform: translateY(0.38rem) rotate(45deg);
}

.nav-toggle.is-open .nav-toggle-bar:nth-of-type(3) {
  opacity: 0;
}

.nav-toggle.is-open .nav-toggle-bar:nth-of-type(4) {
  transform: translateY(-0.38rem) rotate(-45deg);
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 1.1rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface-soft);
  color: inherit;
  cursor: pointer;
  transition: border var(--transition), transform var(--transition);
}

.toggle:hover,
.toggle:focus-visible {
  transform: translateY(-1px);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

main {
  max-width: 74rem;
  margin: 0 auto;
  padding: clamp(3.5rem, 9vw, 5.5rem) 1.5rem clamp(4rem, 10vw, 6rem);
  display: grid;
  gap: clamp(4rem, 9vw, 6rem);
}

.section {
  display: grid;
  gap: 1.75rem;
  max-width: 62rem;
  margin: 0 auto;
  text-align: left;
}

.section--center {
  text-align: center;
  justify-items: center;
}

.section--narrow {
  max-width: 48rem;
}

.section-header {
  display: grid;
  gap: 0.75rem;
}

.section-header p {
  color: var(--muted);
}

.eyebrow {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.28em;
  color: var(--muted);
}

h1,
h2,
h3 {
  letter-spacing: -0.035em;
  line-height: 1.1;
}

h1 {
  font-size: clamp(2.35rem, 8vw, 3.6rem);
}

h2 {
  font-size: clamp(1.9rem, 6vw, 2.6rem);
}

h3 {
  font-size: clamp(1.35rem, 4vw, 1.7rem);
}

.hero {
  gap: 2.5rem;
}

.hero p {
  color: var(--muted);
}

.hero__content {
  display: grid;
  gap: 1.35rem;
  text-align: center;
  justify-items: center;
}

.hero__media {
  display: grid;
  gap: 0.75rem;
  justify-items: center;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.85rem;
  margin-top: 0.5rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.55rem;
  border-radius: 999px;
  font-weight: 600;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 20px 30px rgba(10, 132, 255, 0.18);
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  text-decoration: none;
}

.button.button--ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: none;
}

.button.button--ghost:hover,
.button.button--ghost:focus-visible {
  background: var(--accent-soft);
  color: var(--accent);
}

.media-frame {
  width: min(24rem, 100%);
  aspect-ratio: 4 / 3;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  padding: 1rem;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.media-illustration {
  width: 100%;
  height: 100%;
  border-radius: calc(var(--radius) - 10px);
  display: grid;
  place-items: center;
  text-align: center;
  padding: 1.25rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.92);
  background: linear-gradient(135deg, #0a84ff, #3a7bf3);
}

.media-illustration span {
  display: block;
  line-height: 1.35;
}

.media-illustration--hero {
  background: linear-gradient(135deg, #0a84ff, #6a5df6);
}

.media-illustration--about {
  background: linear-gradient(135deg, #6a5df6, #0a84ff);
}

.media-illustration--suite {
  background: linear-gradient(135deg, #111318, #3a7bf3);
}

.media-illustration--gcse {
  background: linear-gradient(135deg, #0a84ff, #1fb6ff);
}

.media-illustration--alevel {
  background: linear-gradient(135deg, #6a5df6, #a45deb);
}

.media-illustration--nmr {
  background: linear-gradient(135deg, #0a84ff, #00c7b7);
}

.media-caption {
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
  margin-top: 0.75rem;
  max-width: 24rem;
}

.lead-copy {
  color: var(--muted);
  font-size: 1.05rem;
}

.text-grid {
  display: grid;
  gap: 1.25rem;
}

.card-grid {
  display: grid;
  gap: 1.75rem;
}

.card {
  padding: 1.8rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  display: grid;
  gap: 1.25rem;
  transition: transform var(--transition), border var(--transition), box-shadow var(--transition);
}

.card:hover,
.card:focus-within {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow);
}

.card__media {
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: calc(var(--radius) - 8px);
  overflow: hidden;
  background: var(--surface-soft);
  display: grid;
  place-items: center;
}

.card__media img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

.card__media .media-illustration {
  border-radius: calc(var(--radius) - 12px);
  font-size: 0.85rem;
}

.card__body {
  display: grid;
  gap: 0.9rem;
}

.card__body p,
.card__body li {
  color: var(--muted);
}

.list {
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

.list li {
  position: relative;
  padding-left: 1.25rem;
}

.list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6rem;
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--accent);
}

.prose {
  display: grid;
  gap: 1.1rem;
  color: var(--muted);
}

.prose h2,
.prose h4 {
  color: var(--text);
}

.prose ul {
  padding-left: 1.1rem;
}

.contact-card {
  justify-items: center;
  text-align: center;
}

footer {
  padding: 3rem 1.5rem 4rem;
  text-align: center;
  color: var(--muted);
}

footer a {
  text-decoration: underline;
  text-decoration-thickness: 2px;
}

.scroll-reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 420ms ease, transform 420ms ease;
}

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

@media (min-width: 48rem) {
  .navbar {
    gap: 1.25rem;
    padding-inline: 2rem;
  }

  .nav-toggle {
    display: none;
  }

  .nav-links {
    position: static;
    width: auto;
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0;
    border: 0;
    background: transparent;
    box-shadow: none;
    opacity: 1;
    pointer-events: auto;
    transform: none;
    visibility: visible;
    max-height: none;
    overflow: visible;
  }

  .nav-controls {
    gap: 0.85rem;
  }

  .hero {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: end;
  }

  .hero__content {
    text-align: left;
    justify-items: start;
  }

  .hero__media {
    justify-self: end;
  }

  .hero-cta {
    justify-content: flex-start;
  }

  .section {
    gap: 2rem;
  }

  .card-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .media-frame {
    width: 100%;
    max-width: 26rem;
  }
}

@media (min-width: 64rem) {
  main {
    padding-inline: 2.5rem;
  }

  .section {
    gap: 2.45rem;
  }
}