/* ==========================================================================
   CES — Climate, Energy & Sustainability Group, Chicago Booth
   Design tokens
   ========================================================================== */

:root {
  --ink: #16211f;
  --ink-soft: #45514e;
  --teal: #0b4f5c;
  --teal-dark: #083a44;
  --teal-overlay: rgba(8, 32, 38, 0.62);
  --green: #3b8c49;
  --green-dark: #2c6b38;
  --stone: #ece6d8;
  --stone-dark: #ddd4bf;
  --line: #d9d2c2;
  --line-on-dark: rgba(255, 255, 255, 0.22);
  --paper: #ffffff;

  --font-display: "Source Serif 4", Georgia, serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;

  --max: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; }

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 32px;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  margin: 0;
  color: var(--ink);
}

p { margin: 0 0 1em; max-width: 62ch; }

.eyebrow {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0 0 8px;
}

/* ==========================================================================
   Header / nav
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 84px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}

.brand img { height: 60px; width: 60px; }

.brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.2px;
}

.brand-name span {
  display: block;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 12px;
  color: var(--ink-soft);
  margin-top: 1px;
}

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  text-decoration: none;
  font-size: 15px;
  color: var(--ink-soft);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--ink);
  border-color: var(--green);
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: 6px;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  position: relative;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  padding: 13px 26px;
  border-radius: 6px;
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn-primary { background: var(--teal); color: #fff; }
.btn-primary:hover { background: var(--teal-dark); }

.btn-ghost { border-color: var(--ink); color: var(--ink); }
.btn-ghost:hover { border-color: var(--teal); color: var(--teal); }

.btn-ghost-light { border-color: rgba(255,255,255,0.55); color: #fff; }
.btn-ghost-light:hover { border-color: #fff; background: rgba(255,255,255,0.12); }

.btn-row { display: flex; gap: 14px; flex-wrap: wrap; }

/* ==========================================================================
   Hero — split (About / homepage)
   ========================================================================== */

.hero-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
  min-height: 560px;
}

.hero-split-text {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 64px 64px 64px 32px;
  max-width: 620px;
  margin: 0 auto 0 0;
}

.hero-split-text h1 {
  font-size: 40px;
  margin-bottom: 24px;
}

.hero-split-text p {
  font-size: 17px;
  color: var(--ink-soft);
}

.hero-split-image { position: relative; overflow: hidden; }

.hero-split-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  min-height: 320px;
}

/* ==========================================================================
   Hero — full bleed, centered (homepage)
   ========================================================================== */

.hero-full {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
}

.hero-full > img.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.hero-full::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8,32,38,0.55) 0%, rgba(8,32,38,0.35) 40%, rgba(8,32,38,0.75) 100%);
  z-index: 1;
}

.hero-full-content {
  position: relative;
  z-index: 2;
  max-width: 760px;
  padding: 0 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-full-content img.hero-mark {
  height: 56px;
  width: 56px;
  margin-bottom: 28px;
  background: #fff;
  border-radius: 14px;
  padding: 8px;
}

.hero-full-content h1 {
  color: #fff;
  font-size: 48px;
  line-height: 1.12;
  margin-bottom: 20px;
}

.hero-full-content p {
  color: rgba(255,255,255,0.92);
  font-size: 18px;
  max-width: 56ch;
  margin: 0 auto 32px;
}

.scroll-cue {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  color: rgba(255,255,255,0.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  letter-spacing: 0.5px;
}

.scroll-cue svg { animation: bob 1.8s ease-in-out infinite; }

@keyframes bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* ==========================================================================
   Mission statement block
   ========================================================================== */

.mission-block {
  text-align: center;
  max-width: 780px;
  margin: 0 auto;
}

.mission-block h2 {
  font-size: 30px;
  margin: 0 0 20px;
}

.mission-block p.lede {
  font-size: 20px;
  line-height: 1.6;
  color: var(--teal);
  font-weight: 500;
  max-width: 720px;
  margin: 0 auto;
}

.mission-support {
  max-width: none;
  text-align: center;
  font-size: 16px;
  color: var(--ink-soft);
  margin: 28px auto 0;
}

/* ==========================================================================
   Pillar grid (Core goals) with icons
   ========================================================================== */

.pillar-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.pillar-card {
  background: var(--paper);
  padding: 40px;
}

.pillar-icon {
  width: 40px;
  height: 40px;
  color: var(--green);
  margin-bottom: 20px;
}

.pillar-card h3 { font-size: 20px; margin-bottom: 14px; }

.pillar-card ul {
  margin: 0;
  padding-left: 18px;
  color: var(--ink-soft);
  font-size: 15px;
}

.pillar-card li { margin-bottom: 8px; }

/* ==========================================================================
   Photo CTA break (full bleed section with overlay text + button)
   ========================================================================== */

.photo-cta {
  position: relative;
  min-height: 340px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
}

.photo-cta img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.photo-cta::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--teal-overlay);
  z-index: 1;
}

.photo-cta-content { position: relative; z-index: 2; max-width: 640px; padding: 0 24px; }

.photo-cta-content h2 { color: #fff; font-size: 28px; margin-bottom: 18px; }

/* ==========================================================================
   Hero — banner (page headers with photo)
   ========================================================================== */

.hero-banner {
  position: relative;
  min-height: 420px;
  display: flex;
  align-items: flex-end;
  color: #fff;
  overflow: hidden;
}

.hero-banner > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.hero-banner::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--teal-overlay);
  z-index: 1;
}

.hero-banner .container {
  position: relative;
  z-index: 2;
  width: 100%;
  padding-top: 72px;
  padding-bottom: 48px;
}

.hero-banner h1 {
  color: #fff;
  font-size: 40px;
  margin-bottom: 12px;
}

.hero-banner p {
  color: rgba(255,255,255,0.88);
  font-size: 17px;
  max-width: none;
  margin: 0;
}

/* ==========================================================================
   Sections
   ========================================================================== */

.section { padding: 88px 0; }
.section-tight { padding: 64px 0; }
.section-stone { background: var(--stone); }

.section-head { max-width: 640px; margin: 0 0 40px; }
.section-head h2 { font-size: 30px; margin-bottom: 14px; }
.section-head p { color: var(--ink-soft); font-size: 16px; margin: 0; }

hr.rule {
  border: none;
  border-top: 1px solid var(--line);
  margin: 0;
}

/* ==========================================================================
   Chip / tag list
   ========================================================================== */

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.chip {
  font-size: 14px;
  padding: 9px 18px;
  border: none;
  border-radius: 20px;
  color: var(--teal-dark);
  background: #dfeae7;
  font-weight: 500;
}

.section-stone .chip { background: var(--paper); color: var(--teal-dark); }

/* ==========================================================================
   Editorial / hairline list (Core goals, Event types, Contact sections)
   ========================================================================== */

.hairline-list { border-top: 1px solid var(--line); }

.hairline-item {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 40px;
  padding: 32px 0;
  border-bottom: 1px solid var(--line);
}

.hairline-item h3 {
  font-size: 20px;
  font-weight: 600;
}

.item-title {
  display: flex;
  align-items: center;
  gap: 12px;
}

.hairline-icon {
  width: 22px;
  height: 22px;
  color: var(--green);
  flex-shrink: 0;
}

.hairline-item .item-body p {
  color: var(--ink-soft);
  font-size: 15.5px;
  margin: 0 0 8px;
  max-width: 60ch;
}

.hairline-item .item-body ul {
  margin: 0;
  padding-left: 18px;
  color: var(--ink-soft);
  font-size: 15.5px;
}

.hairline-item .item-body li { margin-bottom: 6px; }

/* ==========================================================================
   Editorial photo break
   ========================================================================== */

.photo-break { margin: 8px 0 48px; }
.photo-break img { width: 100%; height: auto; border-radius: 12px; }
.photo-break figcaption {
  font-size: 13.5px;
  color: var(--ink-soft);
  margin-top: 10px;
}

/* ==========================================================================
   Team grid (Members page)
   ========================================================================== */

.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.team-card {
  padding: 20px 20px 28px;
  border: 1px solid var(--line);
  border-radius: 14px;
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.team-card:hover {
  box-shadow: 0 12px 28px rgba(11,79,92,0.12);
  transform: translateY(-3px);
  border-color: var(--stone-dark);
}

.team-card img {
  width: 100%;
  aspect-ratio: 1 / 1;
  height: auto;
  border-radius: 10px;
  object-fit: cover;
  margin-bottom: 18px;
}

.team-card h3 { font-size: 19px; margin-bottom: 4px; }

.team-links {
  font-size: 13.5px;
  color: var(--teal);
  margin-bottom: 16px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.team-links a { text-decoration: none; }
.team-links a:hover { text-decoration: underline; }

.team-fields dt {
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--ink-soft);
  margin: 12px 0 2px;
}

.team-fields dd {
  font-size: 14.5px;
  margin: 0;
  color: var(--ink);
}

.placeholder-text { color: #9a9284; font-style: italic; }

/* ==========================================================================
   Placeholder / draft notice strip
   ========================================================================== */

.draft-notice {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  border: 1px dashed #b98a4e;
  background: #fbf3e7;
  color: #6b4a1e;
  padding: 18px 22px;
  border-radius: 4px;
  font-size: 14.5px;
  margin-bottom: 48px;
}

.draft-notice strong { display: block; margin-bottom: 4px; font-family: var(--font-body); }

/* ==========================================================================
   Sponsor tiers (placeholder)
   ========================================================================== */

.tier-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.tier-card {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px 28px;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.tier-card:hover {
  box-shadow: 0 12px 28px rgba(11,79,92,0.1);
  transform: translateY(-3px);
}

.tier-card h3 { font-size: 20px; margin-bottom: 12px; }
.tier-card ul { padding-left: 18px; color: var(--ink-soft); font-size: 14.5px; margin: 0; }
.tier-card li { margin-bottom: 8px; }

/* ==========================================================================
   Logo grid (Alumni companies, sponsor logos)
   ========================================================================== */

.logo-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.logo-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  height: 104px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.logo-card:hover {
  box-shadow: 0 12px 28px rgba(11,79,92,0.1);
  transform: translateY(-3px);
}

.logo-card img {
  max-height: 56px;
  max-width: 100%;
  object-fit: contain;
}

/* ==========================================================================
   Sponsor tiers
   ========================================================================== */

.tier-label {
  font-size: 17px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--green);
  font-weight: 600;
  margin: 0 0 6px;
}

.sponsor-tier { margin-bottom: 56px; }

.sponsor-list { border-top: 1px solid var(--line); }

.sponsor-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  padding: 36px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.sponsor-row .logo-frame {
  display: flex;
  align-items: center;
  height: 64px;
}

.sponsor-row img {
  max-height: 60px;
  max-width: 100%;
  object-fit: contain;
}

.sponsor-row h3 {
  font-size: 17px;
  margin-bottom: 10px;
}

.sponsor-row p {
  color: var(--ink-soft);
  font-size: 15px;
  margin: 0;
  max-width: none;
}

/* ==========================================================================
   Contact page blocks
   ========================================================================== */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
}

.contact-block h3 {
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--ink-soft);
  font-family: var(--font-body);
  font-weight: 600;
  margin-bottom: 14px;
}

.contact-block p { color: var(--ink-soft); font-size: 15.5px; }
.contact-block address { font-style: normal; }

.mail-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--teal);
  text-decoration: none;
  font-weight: 500;
  font-size: 15.5px;
}
.mail-link:hover { text-decoration: underline; }

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background: var(--teal-dark);
  color: rgba(255,255,255,0.85);
  padding: 56px 0 32px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--line-on-dark);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.footer-brand img {
  height: 36px;
  width: 36px;
  background: #fff;
  border-radius: 8px;
  padding: 4px;
}

.footer-brand-name {
  font-family: var(--font-display);
  color: #fff;
  font-size: 17px;
  font-weight: 600;
}

.site-footer p { color: rgba(255,255,255,0.7); font-size: 14.5px; }

.footer-heading {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: rgba(255,255,255,0.55);
  margin-bottom: 14px;
}

.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: rgba(255,255,255,0.85); text-decoration: none; font-size: 14.5px; }
.footer-links a:hover { text-decoration: underline; }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  padding-top: 24px;
  font-size: 13px;
  color: rgba(255,255,255,0.5);
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 860px) {
  .nav-links { display: none; }
  .nav-toggle { display: flex; }

  body.nav-open .nav-links {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 84px;
    left: 0;
    right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    padding: 16px 32px 24px;
    gap: 18px;
  }

  .hero-split { grid-template-columns: 1fr; }
  .hero-split-text { padding: 48px 24px; max-width: none; }
  .hero-split-image img { min-height: 260px; }

  .hairline-item { grid-template-columns: 1fr; gap: 10px; }
  .team-grid { grid-template-columns: repeat(2, 1fr); }
  .logo-grid { grid-template-columns: repeat(2, 1fr); }
  .sponsor-row { grid-template-columns: 1fr; gap: 16px; }
  .tier-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-top { grid-template-columns: 1fr; gap: 28px; }
  .section { padding: 56px 0; }
}

@media (max-width: 560px) {
  .container { padding: 0 20px; }
  .team-grid { grid-template-columns: 1fr; }
  .logo-grid { grid-template-columns: 1fr 1fr; }
  .hero-split-text h1, .hero-banner h1 { font-size: 30px; }
}