/* ============================================================
   ISL Website — sonomaisl.ai
   ============================================================ */

/* 1. Custom Properties */
:root {
  --color-primary:      #1B3A5C;
  --color-primary-dark: #142c47;
  --color-primary-light:#4A7FA5;
  --color-accent:       #C8960C;
  --color-accent-dark:  #a87a09;
  --color-accent-light: #4A7FA5;
  --color-bg:           #F7F7F5;
  --color-text:         #1A1A2E;
  --color-text-muted:   #6B7280;
  --color-surface:      #FFFFFF;
  --color-border:       #d5d9e0;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg:  16px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.07);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.09);
  --shadow-lg: 0 8px 28px rgba(0,0,0,0.12);

  --container: 1200px;
  --nav-h:     68px;
  --ease:      0.2s ease;
}

/* 2. Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body { font-family: var(--font-sans); background: var(--color-bg); color: var(--color-text); line-height: 1.6; overflow-x: hidden; }
img  { max-width: 100%; height: auto; display: block; }
a    { color: inherit; text-decoration: none; }
ul   { list-style: none; }
button { font-family: inherit; }

/* 3. Typography */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.2; }
h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.05rem, 2vw, 1.3rem); }
h4 { font-size: 1rem; font-weight: 600; }
p  { line-height: 1.7; }

/* 4. Layout */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.5rem;
}
.section { padding: 5rem 0; }
.section-header { text-align: center; margin-bottom: 3rem; }
.section-header h2 { color: var(--color-primary); }
.section-header p  { color: var(--color-text-muted); max-width: 600px; margin: 0.75rem auto 0; }

/* 5. Buttons */
.btn {
  display: inline-block;
  padding: 0.72rem 1.75rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--ease);
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-primary:hover {
  background: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.65);
}
.btn-outline:hover {
  background: rgba(255,255,255,0.12);
  border-color: #fff;
}
.btn-teal {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn-teal:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* 6. Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--color-surface);
  height: var(--nav-h);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--ease);
}
.nav.scrolled { box-shadow: var(--shadow-md); }
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.nav-logo { display: flex; align-items: center; }
.nav-logo img {
  height: 112px;
  width: auto;
  max-width: 480px;
  object-fit: contain;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  position: relative;
  transition: color var(--ease);
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: var(--color-accent);
  transition: width var(--ease);
}
.nav-links a:hover { color: var(--color-primary); }
.nav-links a:hover::after { width: 100%; }
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem;
  color: var(--color-text);
}
.nav-hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: currentColor;
  margin: 5px 0;
  transition: all var(--ease);
}
.nav-hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }
.nav-mobile {
  display: none;
  position: absolute;
  top: var(--nav-h); left: 0; right: 0;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  padding: 0.5rem 1.5rem 1rem;
}
.nav-mobile.open { display: block; }
.nav-mobile a {
  display: block;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
  font-weight: 500;
}
.nav-mobile a:last-child { border-bottom: none; }

/* 7. Hero */
.hero {
  position: relative;
  min-height: 0;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--color-primary-dark);
}
.hero-bg { position: absolute; inset: 0; z-index: 0; }
.hero-bg video,
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: 0.3; }
.hero-overlay {
  position: absolute; inset: 0; z-index: 1;
  background: linear-gradient(135deg, rgba(27,58,92,0.72) 0%, rgba(10,25,45,0.65) 100%);
}
.hero-content {
  position: relative; z-index: 2;
  color: #fff;
  padding: 4rem 0;
  max-width: 760px;
}
.hero-content h1 { font-size: clamp(2.1rem, 5vw, 3.5rem); margin-bottom: 1.25rem; }
.hero-content p  { font-size: clamp(1rem, 2vw, 1.2rem); color: rgba(255,255,255,0.87); max-width: 600px; margin-bottom: 2rem; }
.hero-ctas { display: flex; gap: 1rem; flex-wrap: wrap; }

/* 8. Research Areas */
.research-areas { background: var(--color-surface); }
.areas-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.area-card {
  padding: 2rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-bg);
  transition: all var(--ease);
  display: block;
}
.area-card:hover { border-color: var(--color-primary); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.area-icon {
  width: 48px; height: 48px;
  background: rgba(27,58,92,0.08);
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 1.25rem;
}
.area-icon svg { width: 24px; height: 24px; stroke: var(--color-primary); fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.area-card h3 { color: var(--color-primary); margin-bottom: 0.5rem; font-size: 1.05rem; }
.area-card p  { color: var(--color-text-muted); font-size: 0.875rem; }

/* 9. Project Cards */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(290px, 100%), 1fr));
  gap: 1.5rem;
}
.project-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--ease);
}
.project-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }
.project-card[data-hidden="true"] { display: none; }
.project-img {
  height: 175px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  overflow: hidden;
}
.project-img img { width: 100%; height: 100%; object-fit: cover; }
.project-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.project-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.6rem;
}
.badge {
  display: inline-block;
  padding: 0.18rem 0.65rem;
  border-radius: 99px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.badge-active    { background: rgba(10,107,107,0.1); color: var(--color-primary); }
.badge-completed { background: rgba(212,130,10,0.1); color: var(--color-accent-dark); }
.project-years { font-size: 0.78rem; color: var(--color-text-muted); font-family: var(--font-mono); }
.project-body h3 { font-size: 0.975rem; margin-bottom: 0.5rem; }
.project-body p  { font-size: 0.855rem; color: var(--color-text-muted); flex: 1; margin-bottom: 0.75rem; }
.project-students { font-size: 0.78rem; color: var(--color-text-muted); margin-bottom: 0.85rem; }
.project-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  margin-top: auto;
  transition: gap var(--ease);
}
.project-link:hover { gap: 0.55rem; }
.section-cta { text-align: center; margin-top: 2.5rem; }

/* 10. People */
.people-section { background: var(--color-surface); }
.director-card {
  display: flex;
  gap: 2rem;
  align-items: flex-start;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 3rem;
}
.director-avatar {
  width: 88px; height: 88px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary-dark));
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  font-weight: 700;
  color: rgba(255,255,255,0.65);
}
.director-info h3 { font-size: 1.3rem; color: var(--color-primary); margin-bottom: 0.2rem; }
.director-info .title { color: var(--color-text-muted); font-size: 0.875rem; margin-bottom: 0.75rem; }
.director-info p   { font-size: 0.875rem; color: var(--color-text-muted); margin-bottom: 0.85rem; max-width: 680px; }
.director-info a   { color: var(--color-accent); font-weight: 600; font-size: 0.875rem; }
.director-links { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; margin-top: 0.25rem; }
.director-sep { color: var(--color-border); font-size: 1.1rem; }
.director-contact { color: var(--color-accent); font-weight: 600; font-size: 0.875rem; }
.students-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: 1rem;
  margin-bottom: 1rem;
}
.student-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1rem;
  text-align: center;
}
.student-avatar {
  width: 50px; height: 50px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
  margin: 0 auto 0.65rem;
  display: flex; align-items: center; justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
}
.student-card h4     { font-size: 0.85rem; margin-bottom: 0.2rem; }
.student-card .deg   { font-size: 0.72rem; font-family: var(--font-mono); color: var(--color-accent-dark); }
.student-card .focus { font-size: 0.72rem; color: var(--color-text-muted); margin-top: 0.3rem; }
.sub-heading {
  font-size: 1.1rem;
  color: var(--color-primary);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.45rem;
  border-bottom: 2px solid var(--color-border);
}

/* Alumni table */
.alumni-table { width: 100%; border-collapse: collapse; }
.alumni-table th {
  text-align: left;
  padding: 0.65rem 1rem;
  background: var(--color-bg);
  border-bottom: 2px solid var(--color-border);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
}
.alumni-table td { padding: 0.65rem 1rem; border-bottom: 1px solid var(--color-border); font-size: 0.875rem; }
.alumni-table tr:last-child td { border-bottom: none; }

/* 11. Impact */
/* Teaching */
.teaching-card {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 3rem;
  align-items: start;
  margin-bottom: 2rem;
}
.teaching-image img {
  width: 100%;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  background: var(--color-bg);
}
.teaching-course-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}
.teaching-main h3 {
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
}
.teaching-main p {
  color: var(--color-text-muted);
  max-width: 780px;
  line-height: 1.75;
}
.teaching-modules {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.25rem;
}
.teaching-module {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
  color: var(--color-text);
}
.teaching-notice {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  background: linear-gradient(135deg, rgba(27,58,92,0.06), rgba(74,127,165,0.08));
  border: 1px solid rgba(27,58,92,0.15);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
}
.teaching-notice-icon {
  flex-shrink: 0;
  width: 28px;
  color: var(--color-primary);
  margin-top: 2px;
}
.teaching-notice strong {
  display: block;
  color: var(--color-primary);
  margin-bottom: 0.4rem;
}
.teaching-notice p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.impact-section { background: var(--color-primary); color: #fff; }
.impact-section .section-header h2 { color: #fff; }
.impact-section .section-header p  { color: rgba(255,255,255,0.7); }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(155px, 1fr));
  gap: 1.25rem;
}
.stat-tile {
  text-align: center;
  padding: 1.5rem 1rem;
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,0.07);
}
.stat-number {
  display: block;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 0.5rem;
}
.stat-label { font-size: 0.8rem; color: rgba(255,255,255,0.78); line-height: 1.45; }

/* 12. Updates */
.updates-list { max-width: 740px; margin: 0 auto; }
.update-item {
  display: flex;
  gap: 1.25rem;
  padding: 1.2rem 0;
  border-bottom: 1px solid var(--color-border);
}
.update-item:last-child { border-bottom: none; }
.update-date { font-size: 0.78rem; font-family: var(--font-mono); color: var(--color-text-muted); white-space: nowrap; min-width: 90px; padding-top: 0.15rem; }
.cat-tag {
  display: inline-block;
  padding: 0.12rem 0.55rem;
  border-radius: 99px;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.35rem;
}
.cat-patent      { background: rgba(212,130,10,0.12); color: var(--color-accent-dark); }
.cat-publication { background: rgba(10,107,107,0.12); color: var(--color-primary); }
.cat-award       { background: rgba(212,130,10,0.12); color: var(--color-accent-dark); }
.cat-grant       { background: rgba(0,120,60,0.12);  color: #006830; }
.cat-project     { background: rgba(90,107,101,0.1); color: var(--color-text-muted); }
.cat-news        { background: rgba(90,107,101,0.1); color: var(--color-text-muted); }
.update-title  { font-weight: 600; font-size: 0.93rem; margin-bottom: 0.2rem; }
.update-blurb  { font-size: 0.845rem; color: var(--color-text-muted); }

/* 13. Join (homepage) */
.join-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.join-card {
  padding: 2rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-bg);
}
.join-card h3 { color: var(--color-primary); margin-bottom: 0.65rem; font-size: 1.05rem; }
.join-card p  { font-size: 0.875rem; color: var(--color-text-muted); margin-bottom: 1.5rem; }

/* 14. Footer */
.footer { background: #0a2020; color: rgba(255,255,255,0.72); padding: 3rem 0 2rem; }
.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-logo { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.65rem; }
.footer-logo img { height: 120px; width: auto; max-width: 525px; object-fit: contain; }
.footer-name { font-weight: 600; color: #fff; font-size: 0.9rem; }
.footer-tagline { font-size: 0.82rem; color: rgba(255,255,255,0.55); margin-bottom: 0.85rem; }
.footer-addr { font-size: 0.78rem; line-height: 1.9; }
.footer-addr a { color: var(--color-accent); }
.footer-dept { font-size: 0.73rem; color: rgba(255,255,255,0.38); margin-top: 0.4rem; }
.footer-nav h4 { color: #fff; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 0.75rem; }
.footer-nav a { display: block; font-size: 0.855rem; color: rgba(255,255,255,0.6); padding: 0.22rem 0; transition: color var(--ease); }
.footer-nav a:hover { color: var(--color-accent); }
.footer-bottom { font-size: 0.78rem; color: rgba(255,255,255,0.35); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem; }

/* ============================================================
   Page-specific
   ============================================================ */

/* Shared page hero */
.page-hero { background: var(--color-primary); color: #fff; padding: 5rem 0 4rem; }
.page-hero h1 { margin-bottom: 0.65rem; }
.page-hero p  { color: rgba(255,255,255,0.78); max-width: 600px; }

/* Research page filters */
.filter-bar { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 2.5rem; }
.filter-btn {
  padding: 0.4rem 1.1rem;
  border-radius: 99px;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  cursor: pointer;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: all var(--ease);
}
.filter-btn:hover  { border-color: var(--color-primary); color: var(--color-primary); }
.filter-btn.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* Publications */
.pub-group { margin-bottom: 3.5rem; }
.pub-group-title {
  font-size: 1.2rem;
  color: var(--color-primary);
  border-bottom: 2px solid var(--color-border);
  padding-bottom: 0.45rem;
  margin-bottom: 1.5rem;
}
.pub-item { padding: 1.2rem 0; border-bottom: 1px solid var(--color-border); }
.pub-item:last-child { border-bottom: none; }
.pub-title   { font-weight: 600; font-size: 0.95rem; margin-bottom: 0.3rem; }
.pub-meta    { font-size: 0.84rem; color: var(--color-text-muted); margin-bottom: 0.3rem; }
.pub-authors { font-size: 0.78rem; color: var(--color-text-muted); font-style: italic; }
.pub-abstract { font-size: 0.84rem; color: var(--color-text-muted); margin-top: 0.65rem; display: none; line-height: 1.7; }
.pub-abstract.open { display: block; }
.pub-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-primary);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.35rem 0;
  margin-top: 0.35rem;
}

/* Join page */
.join-page-section { padding: 4.5rem 0; }
.join-page-section:nth-child(even) { background: var(--color-surface); }
.join-page-section h2 { color: var(--color-primary); margin-bottom: 1rem; }
.join-page-section > .container > p { max-width: 640px; color: var(--color-text-muted); margin-bottom: 1rem; }
.join-page-section ul {
  list-style: disc;
  padding-left: 1.5rem;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
  max-width: 600px;
}
.join-page-section li { margin-bottom: 0.45rem; }

/* 404 */
.not-found {
  min-height: calc(100vh - var(--nav-h));
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}
.not-found .code { font-size: 7rem; font-weight: 700; font-family: var(--font-mono); color: var(--color-primary); opacity: 0.18; line-height: 1; }
.not-found h2    { color: var(--color-primary); margin-bottom: 0.65rem; }
.not-found p     { color: var(--color-text-muted); margin-bottom: 2rem; max-width: 380px; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
  .join-grid  { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
}

@media (max-width: 768px) {
  .nav-links    { display: none; }
  .nav-hamburger { display: block; }
  .nav-logo img { height: 64px; max-width: 260px; }
  .areas-grid   { grid-template-columns: 1fr; }
  .director-card { flex-direction: column; }
  .alumni-table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .alumni-table th, .alumni-table td { padding: 0.5rem 0.6rem; font-size: 0.8rem; }
}

@media (max-width: 520px) {
  .hero { min-height: 0; }
  .hero-content { padding: 2.5rem 1.5rem; }
  .hero-ctas { flex-direction: column; }
  .hero-ctas .btn { text-align: center; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .teaching-card { grid-template-columns: 1fr; }
  .students-grid { grid-template-columns: repeat(2, 1fr); }
  .update-item { flex-direction: column; gap: 0.4rem; }
  .update-date { min-width: unset; }
}