/* =========================================================
   PAIC Website — styles.css
   Precision Agriculture Innovation Center, Oregon State Univ.
   ========================================================= */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* ---------- Custom Properties ---------- */
:root {
  /* Brand greens */
  --primary:        #1A6840;   /* medium emerald — headings, accents */
  --primary-mid:    #22A05A;   /* vibrant emerald — interactive */
  --primary-light:  #DCFCE7;   /* pale mint — tinted surfaces */

  /* Accent */
  --accent:         #D97706;   /* warm amber */
  --accent-light:   #FFFBEB;   /* pale amber — note backgrounds */

  /* Neutrals */
  --white:          #FFFFFF;
  --surface:        #F9FAFB;   /* near-white — default bg */
  --surface-alt:    #F0FDF4;   /* mint-tinted — alternating sections */
  --border:         #E5E7EB;

  /* Text */
  --text-dark:      #111827;   /* slate-900 */
  --text-mid:       #374151;   /* slate-700 */
  --text-light:     #6B7280;   /* slate-500 */

  /* Legacy aliases (keep for compatibility) */
  --green-dark:     var(--primary);
  --green-medium:   var(--primary-mid);
  --gold:           var(--accent);
  --gray-dark:      var(--text-dark);
  --gray-mid:       var(--text-light);
  --gray-light:     var(--surface-alt);

  /* Layout */
  --nav-height:   68px;
  --radius:       12px;
  --radius-sm:    6px;
  --shadow-sm:    0 1px 3px rgba(0,0,0,.06), 0 2px 8px rgba(0,0,0,.06);
  --shadow:       0 2px 8px rgba(0,0,0,.06), 0 8px 24px rgba(0,0,0,.07);
  --shadow-lg:    0 4px 16px rgba(0,0,0,.08), 0 16px 48px rgba(0,0,0,.10);
  --transition:   0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  color: var(--text-mid);
  background: var(--white);
  padding-top: var(--nav-height);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary-mid); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

ul { list-style: none; }

/* ---------- Container ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ==========================================
   NAVBAR
   ========================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: var(--white);
  z-index: 1000;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.nav-brand img {
  height: 46px;
  width: auto;
  border-radius: var(--radius-sm);
}

.nav-brand-text {
  color: var(--text-dark);
  font-size: 0.925rem;
  font-weight: 600;
  line-height: 1.25;
  max-width: 240px;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.125rem;
}

.nav-links a {
  color: var(--text-mid);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: color var(--transition), background var(--transition);
  position: relative;
  letter-spacing: 0.01em;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 0.9rem;
  right: 0.9rem;
  height: 2px;
  background: var(--primary-mid);
  border-radius: 1px;
  transform: scaleX(0);
  transition: transform var(--transition);
}

.nav-links a:hover {
  color: var(--primary-mid);
  background: var(--surface-alt);
  text-decoration: none;
}

.nav-links a.active {
  color: var(--primary-mid);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-mid);
  border-radius: 2px;
  transition: all var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ==========================================
   HERO
   ========================================== */
.hero {
  position: relative;
  height: 70vh;
  min-height: 440px;
  background-image: url('../images/hero.png');
  background-size: cover;
  background-position: center;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(160deg,
    rgba(13,74,47,0.72) 0%,
    rgba(5,25,15,0.55) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  color: var(--white);
  padding: 1.5rem;
  max-width: 760px;
}

.hero-label {
  display: inline-block;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.25);
  backdrop-filter: blur(4px);
  color: rgba(255,255,255,0.9);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  margin-bottom: 1rem;
}

.hero-content h1 {
  font-size: clamp(1.85rem, 4.5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 0.85rem;
  letter-spacing: -0.02em;
}

.hero-content p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: rgba(255,255,255,0.82);
  font-weight: 400;
  max-width: 540px;
  margin: 0 auto;
}

.hero-arrow {
  position: absolute;
  bottom: 1.75rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  color: rgba(255,255,255,0.5);
  font-size: 1.5rem;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(7px); }
}

/* ==========================================
   SECTIONS — shared
   ========================================== */
.section { padding: 4.5rem 0; }
.section-alt { background: var(--surface-alt); }

.section-header {
  text-align: center;
  margin-bottom: 2.75rem;
}

.section-header h2 {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.section-header p {
  color: var(--text-light);
  max-width: 580px;
  margin: 0 auto;
  font-size: 0.975rem;
}

.section-header h2::after {
  content: '';
  display: block;
  width: 36px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-mid), var(--accent));
  border-radius: 2px;
  margin: 0.6rem auto 0;
}

/* ==========================================
   PAGE HEADER (inner pages)
   ========================================== */
.page-header {
  background: var(--surface-alt);
  border-bottom: 1px solid #C6E8D0;
  color: var(--text-dark);
  padding: 3.5rem 0 3rem;
  text-align: center;
}

.page-header h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.page-header p {
  color: var(--text-light);
  max-width: 580px;
  margin: 0 auto;
  font-size: 0.975rem;
}

/* ==========================================
   ABOUT SECTION (Home)
   ========================================== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 3.5rem;
  align-items: center;
}

.about-text {
  border-left: 3px solid var(--primary-mid);
  padding-left: 1.75rem;
}

.about-text h2 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.about-text p { color: var(--text-light); }

.about-logo {
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-logo img {
  width: 100%;
  max-width: 240px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* ==========================================
   CARDS (Research Highlights)
   ========================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-img-placeholder {
  width: 100%;
  height: 160px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-mid) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
}

.card-body {
  padding: 1.35rem;
}

.card-body h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.card-body p {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-bottom: 1.1rem;
  line-height: 1.6;
}

/* ==========================================
   BUTTONS
   ========================================== */
.btn {
  display: inline-block;
  padding: 0.5rem 1.2rem;
  background: var(--primary-mid);
  color: var(--white);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  text-decoration: none;
  transition: background var(--transition), box-shadow var(--transition);
}

.btn:hover {
  background: var(--primary);
  box-shadow: 0 4px 12px rgba(13,74,47,0.25);
  text-decoration: none;
  color: var(--white);
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--primary-mid);
  color: var(--primary-mid);
}

.btn-outline:hover {
  background: var(--primary-mid);
  color: var(--white);
  box-shadow: 0 4px 12px rgba(13,74,47,0.2);
}

/* ==========================================
   NEWS TIMELINE (Home)
   ========================================== */
.news-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 780px;
  margin: 0 auto;
}

.news-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  padding: 1.25rem 1.5rem;
  background: var(--white);
  border: 1px solid var(--border);
  border-left: 3px solid var(--primary-mid);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition);
}

.news-item:hover { box-shadow: var(--shadow); }

.news-date {
  background: var(--accent);
  color: var(--white);
  font-size: 0.73rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  padding: 0.25rem 0.65rem;
  border-radius: 20px;
  white-space: nowrap;
  flex-shrink: 0;
  margin-top: 0.15rem;
}

.news-text h4 {
  font-size: 0.925rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 0.2rem;
}

.news-text p {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ==========================================
   PEOPLE PAGE
   ========================================== */
.people-section { margin-bottom: 3rem; }

.people-section-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-dark);
  letter-spacing: -0.01em;
  border-bottom: 2px solid var(--primary-light);
  padding-bottom: 0.6rem;
  margin-bottom: 1.5rem;
}

.person-card {
  display: flex;
  gap: 1.75rem;
  align-items: flex-start;
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  padding: 1.75rem;
  margin-bottom: 1.25rem;
  transition: box-shadow var(--transition), transform var(--transition);
}

.person-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.person-photo {
  flex-shrink: 0;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.person-photo.pi {
  width: 200px;
  height: 200px;
}

.person-photo svg { opacity: 0.5; }
.person-photo img { width: 100%; height: 100%; object-fit: cover; }

.person-info { flex: 1; }

.person-info h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.2rem;
  letter-spacing: -0.01em;
}

.person-info .role {
  font-size: 0.825rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  margin-bottom: 0.7rem;
}

.person-info p {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.4rem;
}

.person-info a {
  font-size: 0.875rem;
  color: var(--primary-mid);
  font-weight: 500;
}

.alumni-card {
  opacity: 0.72;
  background: var(--surface);
}

/* ==========================================
   RESEARCH PAGE
   ========================================== */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.research-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}

.research-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.research-card-img {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-mid) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
}

.research-card-body {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.research-card-body h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 0.75rem;
  line-height: 1.4;
  letter-spacing: -0.01em;
}

.research-card-body p {
  font-size: 0.875rem;
  color: var(--text-light);
  flex: 1;
  margin-bottom: 1.25rem;
  line-height: 1.65;
}

/* ==========================================
   PROJECT DETAIL PAGES
   ========================================== */
.breadcrumb {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 0;
  font-size: 0.825rem;
  color: var(--text-light);
}

.breadcrumb a {
  color: var(--primary-mid);
  font-weight: 500;
}

.breadcrumb span { margin: 0 0.4rem; color: var(--border); }

.project-banner {
  width: 100%;
  height: 300px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-mid) 60%, #2D9E59 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
  margin-bottom: 2.5rem;
  border-radius: var(--radius);
}

.project-body {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.project-text h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.75rem;
  margin-top: 1.5rem;
  letter-spacing: -0.01em;
}

.project-text h2:first-child { margin-top: 0; }

.project-text p {
  color: var(--text-light);
  margin-bottom: 0.75rem;
  font-size: 0.925rem;
}

.project-sidebar {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.project-sidebar h4 {
  color: var(--text-dark);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-light);
}

.project-sidebar ul { list-style: disc; padding-left: 1.1rem; }
.project-sidebar li {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 0.45rem;
}

.gallery-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.gallery-placeholder {
  height: 180px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-mid) 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: rgba(255,255,255,0.45);
}

/* ==========================================
   PROJECT FIGURES
   ========================================== */
.project-figure {
  margin: 1.75rem 0;
  text-align: center;
}

.project-figure img {
  max-width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  display: block;
  margin: 0 auto;
}

.project-figure figcaption {
  margin-top: 0.6rem;
  font-size: 0.825rem;
  color: var(--text-light);
  font-style: italic;
}

.project-figure-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin: 1.75rem 0;
}

/* ==========================================
   PUBLICATIONS PAGE
   ========================================== */
.publications-list {
  max-width: 860px;
  margin: 0 auto;
}

.pub-note {
  background: var(--accent-light);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 2rem;
  font-size: 0.875rem;
  color: #78350F;
}

.pub-item {
  padding: 1.25rem 0.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 1rem;
}

.pub-num {
  font-weight: 700;
  color: var(--accent);
  font-size: 0.925rem;
  flex-shrink: 0;
  width: 26px;
  padding-top: 0.1rem;
}

.pub-content { flex: 1; }

.pub-title {
  font-weight: 600;
  color: var(--primary-mid);
  font-size: 0.95rem;
  display: block;
  margin-bottom: 0.3rem;
  line-height: 1.4;
}

.pub-title:hover { text-decoration: underline; }

.pub-authors {
  font-size: 0.85rem;
  color: var(--text-mid);
  margin-bottom: 0.2rem;
}

.pub-journal {
  font-size: 0.85rem;
  color: var(--text-light);
  font-style: italic;
}

/* ==========================================
   TEACHING PAGE
   ========================================== */
.course-header-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  padding: 2rem;
  margin-bottom: 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.course-header-card h2 {
  grid-column: 1 / -1;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 0.25rem;
  letter-spacing: -0.02em;
}

.course-detail dt {
  font-weight: 600;
  color: var(--text-mid);
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.course-detail dd {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 0.7rem;
}

.teaching-section {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  padding: 2rem;
  margin-bottom: 1.5rem;
}

.teaching-section h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-dark);
  border-left: 3px solid var(--primary-mid);
  padding-left: 0.85rem;
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
}

.teaching-section p,
.teaching-section li {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.teaching-section ol,
.teaching-section ul {
  padding-left: 1.5rem;
}

.teaching-section ol { list-style: decimal; }
.teaching-section ul { list-style: disc; }

/* Tables */
.styled-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  margin-top: 0.75rem;
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.styled-table thead tr {
  background: var(--primary);
  color: var(--white);
}

.styled-table th {
  padding: 0.75rem 1rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.03em;
}

.styled-table td {
  padding: 0.65rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
  color: var(--text-light);
}

.styled-table tbody tr:nth-child(even) {
  background: var(--surface);
}

.styled-table tbody tr:hover {
  background: var(--primary-light);
}

.styled-table tfoot tr {
  background: var(--surface-alt);
  font-weight: 700;
  color: var(--primary);
}

.grade-tables {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1rem;
}

/* ==========================================
   PUBLICATIONS — section headers
   ========================================== */
.pub-section-header {
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-light);
}

.pub-section-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-dark);
  letter-spacing: -0.01em;
}

.pub-section-header:first-child { margin-top: 0; }

/* ==========================================
   ACCORDION (Teaching page)
   ========================================== */
.course-accordion {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 1.5rem;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.course-accordion summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem 2rem;
  background: var(--white);
  cursor: pointer;
  list-style: none;
  user-select: none;
  transition: background var(--transition);
}

.course-accordion summary::-webkit-details-marker { display: none; }
.course-accordion summary::marker { display: none; }

.course-accordion summary:hover { background: var(--surface-alt); }

.course-accordion[open] > summary {
  background: var(--surface-alt);
  border-bottom: 1px solid var(--border);
}

.accordion-title { flex: 1; }

.accordion-title h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-dark);
  margin: 0 0 0.2rem;
  letter-spacing: -0.01em;
}

.accordion-meta {
  font-size: 0.825rem;
  color: var(--text-light);
}

.accordion-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary-mid);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  margin-right: 0.4rem;
}

.accordion-tag.placeholder {
  background: #FEF9C3;
  color: #92400E;
}

.accordion-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text-light);
  font-size: 0.75rem;
  transition: transform var(--transition), background var(--transition);
}

.course-accordion[open] .accordion-icon {
  transform: rotate(180deg);
  background: var(--primary-light);
  color: var(--primary-mid);
  border-color: var(--primary-light);
}

.accordion-body {
  padding: 2rem;
  background: var(--white);
}

/* ==========================================
   FOOTER
   ========================================== */
.footer {
  background: #1E293B;
  color: rgba(255,255,255,0.72);
  padding: 3rem 0 1.75rem;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer h4 {
  color: var(--white);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.footer p,
.footer address {
  font-size: 0.85rem;
  line-height: 1.85;
  font-style: normal;
}

.footer a {
  color: rgba(255,255,255,0.65);
  transition: color var(--transition);
}

.footer a:hover {
  color: var(--white);
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12);
  padding-top: 1.25rem;
  text-align: center;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.4);
}

/* ==========================================
   RESPONSIVE
   ========================================== */
@media (max-width: 768px) {
  .hamburger { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    align-items: stretch;
    padding: 0.5rem 0 1rem;
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    border-top: 1px solid var(--border);
  }

  .nav-links.open { display: flex; }

  .nav-links a {
    padding: 0.85rem 1.5rem;
    border-radius: 0;
    font-size: 0.975rem;
  }

  .nav-links a::after { display: none; }

  .about-grid,
  .project-body,
  .course-header-card,
  .grade-tables { grid-template-columns: 1fr; }

  .about-logo { display: none; }

  .gallery-row { grid-template-columns: 1fr 1fr; }

  .person-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .footer-grid { grid-template-columns: 1fr; }

  .hero { height: 55vh; }
}

@media (max-width: 480px) {
  .nav-brand-text { display: none; }

  .hero-content h1 { font-size: 1.5rem; }

  .cards-grid { grid-template-columns: 1fr; }

  .gallery-row { grid-template-columns: 1fr; }

  .person-photo { width: 120px; height: 120px; }
  .person-photo.pi { width: 150px; height: 150px; }
}