/* ============================================================
   STUDY GUIDE — Main Stylesheet
   Closely mirrors the TU Delft studiegids visual language:
   - Clean white backgrounds with light grey (#f5f7fa) accents
   - Orange/cyan hero banner
   - Card-based content sections with subtle rounded corners
   - Green active-period badges
   ============================================================ */

/* ── Reset & Base ──────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Brand palette — change these per-university */
  --color-primary: #00a6d6;      /* TU Delft cyan */
  --color-primary-dark: #0083b3;
  --color-accent: #e65100;       /* Orange accent */
  --color-accent-light: #ff8a50;
  --color-green: #4caf50;        /* Active period */
  --color-green-dark: #388e3c;

  /* Neutrals */
  --color-bg: #ffffff;
  --color-bg-light: #f5f7fa;
  --color-bg-card: #ffffff;
  --color-border: #e0e4e8;
  --color-text: #1a1a2e;
  --color-text-secondary: #555;
  --color-text-muted: #888;
  --color-link: #00a6d6;
  --color-link-hover: #0083b3;

  /* Layout */
  --max-width: 1360px;
  --sidebar-width: 280px;
  --header-height: 60px;
  --radius: 8px;
  --radius-sm: 4px;

  /* Typography */
  --font-body: 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-base: 15px;
  --line-height: 1.6;
}

html { font-size: var(--font-size-base); scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg-light);
  line-height: var(--line-height);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-link); text-decoration: none; transition: color 0.15s; }
a:hover { color: var(--color-link-hover); }

img { max-width: 100%; height: auto; }

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

/* ── Header ────────────────────────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}
.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 100%;
  gap: 32px;
}
.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  flex: 0 0 auto;
}
.logo-image {
  display: block;
  height: 58px;
  width: auto;
}

.main-nav { flex: 1; display: flex; justify-content: center; }
.nav-list {
  list-style: none; display: flex; gap: 8px;
}
.nav-item a {
  display: block; padding: 8px 24px;
  font-size: 15px; font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
}
.nav-item a:hover { background: var(--color-bg-light); color: var(--color-primary); }
.nav-item--active a {
  color: var(--color-primary);
  border-bottom: 3px solid var(--color-primary);
  border-radius: 0;
}

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.hamburger {
  display: block; width: 24px; height: 2px; background: var(--color-text);
  position: relative;
}
.hamburger::before, .hamburger::after {
  content: ''; position: absolute; left: 0; width: 24px; height: 2px;
  background: var(--color-text);
}
.hamburger::before { top: -7px; }
.hamburger::after { top: 7px; }

.lang-switch {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 2px;
}
.lang-current {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-primary);
  padding: 3px 6px;
  border-radius: var(--radius-sm);
  background: rgba(0, 166, 214, 0.08);
}
.lang-option {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 3px 6px;
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}
.lang-option:hover {
  color: var(--color-primary);
  background: rgba(0, 166, 214, 0.08);
}

/* ── Hero Banner ───────────────────────────────────────────── */
.hero-banner {
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-light) 40%, var(--color-primary) 100%);
  padding: 48px 24px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero-banner::before {
  content: '';
  position: absolute; top: -40%; left: -10%; width: 60%; height: 200%;
  background: var(--color-primary);
  border-radius: 50%;
  opacity: 0.3;
  pointer-events: none;
}
.hero-banner::after {
  content: '';
  position: absolute; top: -20%; right: -15%; width: 50%; height: 180%;
  background: var(--color-accent-light);
  border-radius: 50%;
  opacity: 0.2;
  pointer-events: none;
}
.hero-title {
  font-size: 2.4rem; font-weight: 300; color: #fff;
  position: relative; z-index: 1;
  font-style: italic;
}
.hero-subtitle {
  font-size: 1.1rem; color: rgba(255,255,255,0.9);
  margin-top: 8px; position: relative; z-index: 1;
}
.hero-banner--home { padding: 64px 24px; }

/* ── Home Page ─────────────────────────────────────────────── */
.home-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px;
}
.home-intro {
  max-width: 720px;
  margin: 0 auto 40px;
  text-align: center;
  font-size: 1.05rem;
  color: var(--color-text-secondary);
}
.home-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.home-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: box-shadow 0.2s, transform 0.2s;
  color: var(--color-text);
}
.home-card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transform: translateY(-2px);
  color: var(--color-text);
}
.home-card-icon { margin-bottom: 16px; color: var(--color-primary); }
.home-card h2 { font-size: 1.25rem; font-weight: 600; margin-bottom: 8px; }
.home-card p { font-size: 0.9rem; color: var(--color-text-secondary); }

/* ── Breadcrumb ────────────────────────────────────────────── */
.breadcrumb {
  display: flex; align-items: center; gap: 8px;
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}
.breadcrumb-link { color: var(--color-text-muted); display: flex; align-items: center; }
.breadcrumb-link:hover { color: var(--color-primary); }
.breadcrumb-sep { color: var(--color-text-muted); }
.breadcrumb-current { color: var(--color-text-secondary); }

/* ── Course Detail Page ────────────────────────────────────── */
.course-detail {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 60px;
}
.course-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.course-badges {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
}
.code-badge {
  display: inline-block;
  background: var(--color-text);
  color: #fff;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}
.jump-pill {
  display: inline-block;
  background: var(--color-bg-light);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.78rem;
  transition: background 0.15s, color 0.15s;
}
.jump-pill:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.course-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 32px;
  align-items: start;
}

.course-main { min-width: 0; }

/* ── Accordion Cards (collapsible sections) ────────────────── */
.accordion-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.accordion-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 20px 24px;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
}
.accordion-trigger:hover { background: var(--color-bg-light); }
.accordion-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
}
.accordion-chevron {
  flex-shrink: 0;
  transition: transform 0.25s ease;
  color: var(--color-text-muted);
}
.accordion-card--open .accordion-chevron { transform: rotate(180deg); }
.accordion-panel { padding: 0 24px 20px; }
.accordion-content {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-text);
}
.accordion-content p { margin-bottom: 12px; }
.accordion-content ul, .accordion-content ol { margin-left: 20px; margin-bottom: 12px; }

.subject-units {
  display: grid;
  gap: 16px;
}
.subject-unit {
  padding: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: #fff;
}
.subject-unit h3 {
  font-size: 1rem;
  margin-bottom: 10px;
}
.subject-unit-content,
.subject-unit-outcomes {
  font-size: 0.94rem;
}
.subject-unit-content p:last-child,
.subject-unit-outcomes p:last-child {
  margin-bottom: 0;
}
.subject-unit-outcomes {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
}
.subject-unit-outcomes h4 {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}
.subject-syllabus-note {
  padding: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-light);
}

.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin: 16px 0;
}
.subject-stat {
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: #fff;
}
.subject-stat-label {
  display: block;
  font-size: 0.76rem;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}
.subject-stat-value {
  font-weight: 600;
}
.subject-block {
  margin-bottom: 16px;
}
.subject-block h3 {
  margin-bottom: 8px;
}
.subject-table-wrap {
  overflow-x: auto;
  margin: 10px 0 16px;
}
.subject-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border: 1px solid var(--color-border);
  font-size: 0.92rem;
  line-height: 1.5;
}
.subject-table th,
.subject-table td {
  padding: 8px 10px;
  border: 1px solid var(--color-border);
  vertical-align: top;
  text-align: left;
}
.subject-table th {
  background: var(--color-bg-light);
  font-weight: 600;
}

.contact-hours-heading {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 16px;
  margin-bottom: 4px;
}

/* ── Course Sidebar ────────────────────────────────────────── */
.course-sidebar { position: sticky; top: calc(var(--header-height) + 16px); }
.sidebar-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}
.sidebar-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-bg-light);
}
.sidebar-item:last-child { border-bottom: none; }
.sidebar-icon {
  flex-shrink: 0;
  color: var(--color-text-muted);
  padding-top: 2px;
}
.sidebar-content { display: flex; flex-direction: column; min-width: 0; }
.sidebar-label {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}
.sidebar-value {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text);
  word-break: break-word;
}
.sidebar-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.92rem;
  font-weight: 500;
}
.email-icon {
  font-size: 0.9rem;
  text-decoration: none;
  opacity: 0.6;
  transition: opacity 0.15s;
}
.email-icon:hover { opacity: 1; }

/* ── Semester Badge ────────────────────────────────────────── */
.semester-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  height: 24px;
  padding: 0 8px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--color-green);
  color: #fff;
  border: 1px solid var(--color-green-dark);
}

/* ── Courses List Page ─────────────────────────────────────── */
.courses-page {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  gap: 0;
  min-height: 80vh;
}

/* Filter sidebar */
.filter-sidebar {
  background: var(--color-bg);
  border-right: 1px solid var(--color-border);
  padding: 24px 20px;
  position: sticky;
  top: var(--header-height);
  max-height: calc(100vh - var(--header-height));
  overflow-y: auto;
}
.filter-header { margin-bottom: 16px; }
.filter-results-title { font-size: 1.1rem; font-weight: 700; }
.filter-results-count { font-size: 0.85rem; color: var(--color-text-muted); margin-top: 2px; }

.filter-search {
  position: relative; margin-bottom: 24px;
}
.filter-search input {
  width: 100%;
  padding: 10px 40px 10px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.15s;
}
.filter-search input:focus { border-color: var(--color-primary); }
.search-icon {
  position: absolute;
  right: 12px; top: 50%; transform: translateY(-50%);
  color: var(--color-primary);
  pointer-events: none;
}

.filter-group {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 12px;
  margin-bottom: 12px;
}
.filter-group-title {
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  padding: 8px 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.filter-group-title::after {
  content: '';
  width: 8px; height: 8px;
  border-right: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  transform: rotate(45deg);
  transition: transform 0.2s;
}
details[open] .filter-group-title::after {
  transform: rotate(-135deg);
}
.filter-group-title::-webkit-details-marker { display: none; }

.filter-options { padding: 4px 0 4px 4px; }
.filter-option {
  display: flex; align-items: center; gap: 8px;
  padding: 4px 0;
  font-size: 0.88rem;
  cursor: pointer;
  color: var(--color-text-secondary);
}
.filter-option input[type="checkbox"] {
  width: 16px; height: 16px;
  accent-color: var(--color-primary);
  cursor: pointer;
}

.filter-ec-range {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 0;
}
.ec-input {
  width: 60px;
  padding: 6px 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-family: inherit;
  text-align: center;
}
.ec-separator { font-size: 0.85rem; color: var(--color-text-muted); }

/* Course table */
.courses-content {
  background: var(--color-bg);
  padding: 16px 24px;
}
.courses-toolbar {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  margin-bottom: 12px;
}
.view-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--color-text-secondary);
}
.view-toggle select {
  padding: 6px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.85rem;
  background: var(--color-bg);
}

.courses-table {
  width: 100%;
  border-collapse: collapse;
}
.courses-table th {
  text-align: left;
  padding: 12px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  border-bottom: 2px solid var(--color-border);
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
}
.courses-table th:hover { color: var(--color-primary); }
.courses-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-bg-light);
  font-size: 0.9rem;
  vertical-align: middle;
}
.courses-table tbody tr { transition: background 0.1s; }
.courses-table tbody tr:hover { background: var(--color-bg-light); }

.col-name { width: 30%; }
.col-code { width: 16%; }
.col-programme { width: 26%; }
.col-ec { width: 10%; text-align: center; }
.col-semester { width: 18%; }

.courses-table td.col-code,
.courses-table th.col-code {
  white-space: nowrap;
}

.courses-table td.col-code {
  font-variant-numeric: tabular-nums;
}

.courses-table--compact td.col-code,
.courses-table--compact th.col-code,
.courses-table--compact td.col-ec,
.courses-table--compact th.col-ec {
  text-align: center;
}

.courses-table .col-name a {
  color: var(--color-primary);
  font-weight: 500;
}
.courses-table .col-name a:hover { text-decoration: underline; }
.courses-table .col-ec { text-align: center; }

.courses-table--compact { font-size: 0.88rem; }
.courses-table--compact th, .courses-table--compact td { padding: 8px 12px; }

.no-results {
  text-align: center;
  padding: 40px;
  color: var(--color-text-muted);
  font-size: 1rem;
}

/* ── Programme Pages ───────────────────────────────────────── */
.programme-detail {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 60px;
}
.programme-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 24px;
}
.programme-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 32px;
  align-items: start;
}
.programme-main { min-width: 0; }
.programme-sidebar { position: sticky; top: calc(var(--header-height) + 16px); }
.programme-sidebar .sidebar-item {
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
}
.programme-sidebar .sidebar-label,
.programme-sidebar .sidebar-value {
  text-align: left;
}

.card-block {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.curriculum { margin-top: 16px; }
.curriculum h2 { font-size: 1.4rem; font-weight: 700; margin-bottom: 16px; }
.curriculum-year { margin-bottom: 24px; }
.curriculum-year h3 {
  font-size: 1.1rem; font-weight: 600; margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}
.curriculum-semester { margin-bottom: 16px; }
.curriculum-semester h4 { font-size: 0.95rem; font-weight: 500; margin-bottom: 8px; color: var(--color-text-secondary); }

/* Programme list cards */
.list-page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px;
}
.programme-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}
.programme-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: box-shadow 0.2s, transform 0.15s;
  color: var(--color-text);
}
.programme-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
  transform: translateY(-1px);
  color: var(--color-text);
}
.programme-card-header { margin-bottom: 12px; }
.programme-level-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}
.programme-level-badge.bachelor { background: #e3f2fd; color: #1565c0; }
.programme-level-badge.master { background: #f3e5f5; color: #7b1fa2; }
.programme-card h2 { font-size: 1.15rem; font-weight: 600; margin-bottom: 8px; }
.programme-card-faculty { font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 12px; }
.programme-card-meta {
  display: flex; gap: 16px; font-size: 0.82rem; color: var(--color-text-secondary);
}

.empty-state { color: var(--color-text-muted); font-size: 1rem; grid-column: 1 / -1; text-align: center; padding: 40px; }

/* ── Footer ────────────────────────────────────────────────── */
.site-footer {
  background: var(--color-text);
  color: #ccc;
  padding: 40px 24px 0;
  margin-top: 40px;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-logo-image {
  display: block;
  width: 100%;
  max-width: 260px;
  height: auto;
}
.footer-university {
  margin-top: 14px;
  font-size: 0.95rem;
  font-weight: 600;
  color: #fff;
}
.footer-tagline { font-size: 0.85rem; margin-top: 8px; color: #999; }
.footer-contact { font-size: 0.85rem; line-height: 1.8; }
.footer-contact a { color: var(--color-primary); }
.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.85rem;
}
.footer-links a { color: #ccc; }
.footer-links a:hover { color: #fff; }
.footer-bottom {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 0;
  font-size: 0.78rem;
  color: #777;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.footer-bottom p { margin: 0; }
.footer-version {
  color: #8f8f8f;
  font-variant-numeric: tabular-nums;
}

/* ── Responsive ────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .course-layout { grid-template-columns: 1fr; }
  .course-sidebar { position: static; order: -1; }
  .programme-layout { grid-template-columns: 1fr; }
  .programme-sidebar { position: static; order: -1; }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    height: auto;
    min-height: var(--header-height);
    padding-top: 10px;
    padding-bottom: 10px;
    gap: 16px;
  }
  .logo-image { height: 48px; }
  .courses-page { grid-template-columns: 1fr; }
  .filter-sidebar {
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }
  .nav-list { display: none; }
  .nav-toggle { display: block; }
  .nav-list.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0; right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 24px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
  }
  .hero-title { font-size: 1.8rem; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-bottom { align-items: flex-start; }
  .courses-table .col-code { display: none; }
}