@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&display=swap');

:root {
  --blue: #0071e3;
  --blue-hover: #0077ed;
  --dark: #1d1d1f;
  --mid: #6e6e73;
  --light: #f5f5f7;
  --border: #d2d2d7;
  --white: #ffffff;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', sans-serif;
  font-weight: 400;
  color: var(--dark);
  background: var(--white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* NAV */
nav {
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 0 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav .logo {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--dark);
  text-decoration: none;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 10px;
}

nav .logo img {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 28px;
}

nav ul li a {
  color: var(--mid);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 400;
  transition: color 0.15s;
}

nav ul li a:hover {
  color: var(--dark);
}

nav ul li a.active {
  color: var(--dark);
  font-weight: 500;
}

/* HERO */
.hero {
  background: var(--light);
  padding: 100px 40px;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  color: var(--dark);
  margin-bottom: 16px;
  line-height: 1.1;
}

.hero p {
  font-size: 1.1rem;
  color: var(--mid);
  font-weight: 400;
  max-width: 520px;
  margin: 0 auto 28px;
  line-height: 1.6;
}

.hero-industries {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--mid);
  letter-spacing: 0.05em;
  margin: -16px auto 24px !important;
}

/* PAGE HEADER */
.page-header {
  background: var(--light);
  padding: 64px 40px 48px;
  text-align: center;
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--dark);
  margin-bottom: 8px;
}

.page-header p {
  color: var(--mid);
  font-size: 0.95rem;
}

/* MAIN */
main {
  max-width: 860px;
  margin: 0 auto;
  padding: 60px 40px;
}

/* SECTION */
section {
  margin-bottom: 56px;
}

section h2 {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--mid);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

/* CARDS */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}

.card {
  background: var(--light);
  border-radius: 12px;
  padding: 24px;
  text-decoration: none;
  color: var(--dark);
  display: block;
  transition: transform 0.15s, box-shadow 0.15s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.card p {
  font-size: 0.82rem;
  color: var(--mid);
  line-height: 1.5;
}

.card .tag {
  display: inline-block;
  margin-top: 12px;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--blue);
}

/* BIO LINKS */
.bio-links {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.bio-links a {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--blue);
  text-decoration: none;
  transition: opacity 0.15s;
}

.bio-links a:hover {
  opacity: 0.75;
  text-decoration: underline;
}

/* TABS */
.course-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}

.course-tabs button {
  background: none;
  border: none;
  padding: 8px 20px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--mid);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color 0.15s;
  font-family: inherit;
}

.course-tabs button:hover {
  color: var(--dark);
}

.course-tabs button.active {
  color: var(--blue);
  border-bottom-color: var(--blue);
}

.tab-panel {
  display: none;
  font-size: 0.85rem;
  color: var(--mid);
  padding: 4px 0 16px;
}

.tab-panel.active {
  display: block;
}

.tab-panel a {
  color: var(--blue);
  text-decoration: none;
}

.tab-panel a:hover {
  text-decoration: underline;
}

/* DROPDOWN (details/summary) */
details {
  border-bottom: 1px solid var(--border);
}

details:first-of-type {
  border-top: 1px solid var(--border);
}

details summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  cursor: pointer;
  list-style: none;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--dark);
  user-select: none;
}

details summary::-webkit-details-marker { display: none; }

details summary::after {
  content: '+';
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--mid);
  transition: transform 0.2s;
}

details[open] summary::after {
  content: '−';
}

.details-body {
  padding: 0 0 28px;
}

.course-desc {
  margin-top: 4px;
  margin-bottom: 12px;
}

/* COURSE */
.course {
  margin-bottom: 28px;
}

.course:last-child {
  margin-bottom: 0;
}

.course h3 {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: 4px;
}

.course p {
  font-size: 0.82rem;
  color: var(--mid);
  margin-bottom: 12px;
}

.course table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
}

.course table td {
  padding: 7px 10px;
  border-bottom: 1px solid var(--border);
}

.course table td:first-child {
  color: var(--mid);
  width: 120px;
  font-weight: 500;
}

.course table a {
  color: var(--blue);
  text-decoration: none;
}

.course table a:hover {
  text-decoration: underline;
}

/* DIVIDER */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 40px 0;
}

/* FOOTER */
footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 24px 40px;
  font-size: 0.75rem;
  color: var(--mid);
}

/* HAMBURGER */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  color: var(--dark);
  padding: 4px 8px;
}

/* RESPONSIVE */
@media (max-width: 640px) {
  nav { padding: 0 20px; flex-wrap: wrap; height: auto; min-height: 52px; }
  .nav-toggle { display: block; }
  nav ul {
    display: none;
    flex-direction: column;
    width: 100%;
    gap: 0;
    padding: 8px 0 16px;
  }
  nav ul.open { display: flex; }
  nav ul li a { display: block; padding: 10px 0; font-size: 0.85rem; }
  .hero { padding: 64px 20px; }
  .hero h1 { font-size: 2rem; }
  .page-header { padding: 48px 20px 32px; }
  main { padding: 40px 20px; }
  .card-grid { grid-template-columns: 1fr; }
}