/* ==========================================
   Les Houches Summer School Les Houches Summer School, August 2027
   Design: Alpine-academic, refined minimal
   ========================================== */

:root {
  --ink:        #1a1a2e;
  --ink-soft:   #3d3d5c;
  --sage:       #6b8f71;
  --sage-light: #a8c5ad;
  --sage-pale:  #e8f0ea;
  --stone:      #8c8c9a;
  --stone-light:#d4d4de;
  --cream:      #f8f7f4;
  --white:      #ffffff;
  --alpine:     #4a6fa5;
  --alpine-dark:#2e4a7a;
  --accent:     #c17c3a;

  --font-display: 'Cormorant Garamond', Georgia, serif;
  --font-body:    'DM Sans', system-ui, sans-serif;

  --max-w: 1100px;
  --radius: 8px;
  --shadow: 0 4px 24px rgba(26,26,46,0.08);
  --shadow-lg: 0 12px 48px rgba(26,26,46,0.14);
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--cream);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--sage); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--alpine); }

/* ==========================================
   NAVBAR
   ========================================== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(248,247,244,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--stone-light);
  transition: box-shadow 0.3s;
}

.navbar.scrolled {
  box-shadow: 0 2px 16px rgba(26,26,46,0.10);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.02em;
}
.nav-logo span { color: var(--sage); }
.nav-logo:hover { color: var(--ink); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  padding: 0.5rem 0.85rem;
  border-radius: 4px;
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--ink); background: var(--sage-pale); }

.nav-links a.nav-cta {
  background: var(--sage);
  color: var(--white);
  padding: 0.5rem 1.1rem;
}
.nav-links a.nav-cta:hover { background: var(--alpine); }
.nav-links a.nav-cta.active { background: var(--alpine); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  width: 32px; height: 32px;
}
.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

/* ==========================================
   HERO
   ========================================== */
.hero {
  position: relative;
  min-height: 75vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  padding-top: 64px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(160deg, #1a2a3a 0%, #2e4a5a 40%, #3d5a4a 80%, #2a3a2a 100%);
  z-index: 0;
}

/* Subtle mountain silhouette via SVG mask decoration */
.hero::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 120px;
  background: var(--cream);
  clip-path: polygon(
    0% 100%, 0% 60%, 5% 45%, 10% 55%, 15% 35%, 20% 50%,
    27% 20%, 32% 40%, 38% 15%, 43% 35%, 50% 10%, 57% 30%,
    63% 18%, 68% 38%, 74% 22%, 80% 42%, 86% 28%, 92% 48%,
    97% 38%, 100% 55%, 100% 100%
  );
  z-index: 2;
  opacity: 0.9;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center top, rgba(107,143,113,0.18) 0%, transparent 70%);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2.5rem;
  padding: 3rem 2rem 8rem;
  text-align: center;
  animation: fadeUp 0.9s ease both;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-header-img {
  max-width: 700px;
  width: 100%;
  filter: drop-shadow(0 8px 32px rgba(0,0,0,0.5));
}

.hero-header-img img {
  width: 100%;
  border-radius: 4px;
}

.hero-meta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  animation: fadeUp 0.9s 0.2s ease both;
}

.hero-badge {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sage-light);
  background: rgba(107,143,113,0.18);
  border: 1px solid rgba(168,197,173,0.35);
  padding: 0.4rem 1.1rem;
  border-radius: 99px;
}

.hero-dates {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 300;
  color: rgba(255,255,255,0.85);
  letter-spacing: 0.02em;
}

.hero-scroll {
  position: absolute;
  bottom: 140px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 4;
  color: rgba(255,255,255,0.45);
  font-size: 1.3rem;
  animation: bounce 2s infinite;
}

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

/* ==========================================
   PAGE HERO (inner pages)
   ========================================== */
.page-hero {
  position: relative;
  min-height: 280px;
  display: flex;
  align-items: flex-end;
  padding-top: 64px;
  overflow: hidden;
}

.page-hero-short { min-height: 220px; }

.page-hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #1a2a3a 0%, #2e4a5a 60%, #3d5a4a 100%);
}

.page-hero-bgimg {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center 40%;
  filter: brightness(0.45);
}

.page-hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(26,26,46,0.75) 0%, rgba(26,26,46,0.2) 100%);
}

.page-hero-content {
  position: relative;
  z-index: 2;
  padding: 2.5rem 2rem 3rem;
  color: var(--white);
}

.page-hero-content h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.1;
  color: var(--white);
  margin-bottom: 0.6rem;
}

.page-hero-sub {
  font-size: 1rem;
  color: rgba(255,255,255,0.75);
  max-width: 560px;
}

/* ==========================================
   CONTAINER
   ========================================== */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 2rem;
}

/* ==========================================
   SECTION TITLES
   ========================================== */
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}
.section-title.centered { text-align: center; }
.section-title::after {
  content: '';
  display: block;
  width: 3rem;
  height: 3px;
  background: var(--sage);
  border-radius: 2px;
  margin-top: 0.6rem;
}
.section-title.centered::after { margin: 0.6rem auto 0; }

/* ==========================================
   ABOUT SECTION
   ========================================== */
.section-about {
  padding: 5rem 0 4rem;
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 3.5rem;
  align-items: start;
}

.about-text p {
  font-size: 1.02rem;
  color: var(--ink-soft);
  margin-bottom: 1.1rem;
}
.about-text em { color: var(--alpine); font-style: italic; }

.info-card {
  background: var(--white);
  border: 1px solid var(--stone-light);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  position: sticky;
  top: 80px;
}

.info-item {
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--sage-pale);
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.info-item:last-of-type { border-bottom: none; }

.info-label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--stone);
}

.info-value {
  font-size: 0.95rem;
  color: var(--ink);
  font-weight: 400;
}

.btn-primary {
  display: block;
  margin-top: 1.5rem;
  text-align: center;
  background: var(--sage);
  color: var(--white);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.85rem 1.5rem;
  border-radius: 5px;
  transition: background 0.2s, transform 0.15s;
}
.btn-primary:hover { background: var(--alpine); color: var(--white); transform: translateY(-1px); }

/* ==========================================
   TOPICS
   ========================================== */
.section-topics {
  padding: 4rem 0;
  background: var(--ink);
  position: relative;
  overflow: hidden;
}

.section-topics::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 70% 50%, rgba(107,143,113,0.12) 0%, transparent 70%);
}

.section-topics .section-title {
  color: var(--white);
  position: relative;
}
.section-topics .section-title::after { background: var(--sage-light); }

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  position: relative;
}

.topic-card {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: background 0.2s, transform 0.2s;
}
.topic-card:hover {
  background: rgba(255,255,255,0.09);
  transform: translateY(-3px);
}

.topic-icon {
  font-size: 1.6rem;
  margin-bottom: 1rem;
}

.topic-card h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--sage-light);
  margin-bottom: 0.65rem;
}

.topic-card p {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.62);
  line-height: 1.55;
}

/* ==========================================
   ORGANIZERS
   ========================================== */
.section-organizers {
  padding: 4.5rem 0;
}

.organizers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
}

.organizer-card {
  background: var(--white);
  border: 1px solid var(--stone-light);
  border-radius: var(--radius);
  padding: 1.5rem;
  border-left: 3px solid var(--sage);
  box-shadow: var(--shadow);
}

.organizer-name {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.3rem;
}

.organizer-affil {
  font-size: 0.83rem;
  color: var(--stone);
  line-height: 1.4;
}

/* ==========================================
   LOGOS
   ========================================== */
.section-logos {
  padding: 3.5rem 0 4rem;
  background: var(--white);
  border-top: 1px solid var(--stone-light);
}

.logos-label {
  text-align: center;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--stone);
  margin-bottom: 2rem;
}

.logos-row {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 1.5rem;
}

.logo-houches {
  max-height: none;
  width: 100%;
  max-width: 800px;   /* adjust to taste */
  opacity: 0.9;
}

.logos-row-secondary {
  gap: 2.5rem;
}

.logo-item {
  max-height: 100px;
  width: auto;
  opacity: 0.82;
  transition: opacity 0.2s;
  filter: grayscale(5%);
}
.logo-item:hover { opacity: 1; }

.logo-peprq { max-height: 110px; }
.logo-round { border-radius: 50%; overflow: hidden; }

/* ==========================================
   SPEAKERS PAGE
   ========================================== */
.section-speakers {
  padding: 4rem 0 5rem;
}

.speakers-note {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--stone);
  background: var(--sage-pale);
  border: 1px solid var(--sage-light);
  border-radius: 4px;
  padding: 0.4rem 0.9rem;
  margin-bottom: 2.5rem;
}

.note-star { color: var(--accent); font-size: 0.9rem; }

.speakers-intro {
  font-size: 0.95rem;
  color: var(--stone);
  margin-bottom: 1.75rem;
  margin-top: -0.75rem;
}

.track-title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--alpine-dark);
  margin: 2rem 0 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--sage-pale);
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.track-slots {
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--stone);
  background: var(--sage-pale);
  padding: 0.2rem 0.6rem;
  border-radius: 99px;
}

.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}

.speaker-card {
  background: var(--white);
  border: 1px solid var(--stone-light);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem 1.25rem 1rem;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  transition: box-shadow 0.2s, transform 0.2s, border-color 0.2s;
  position: relative;
}

.speaker-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
  border-color: var(--sage-light);
}

.speaker-card.confirmed {
  border-left: 3px solid var(--sage);
}

.speaker-star {
  font-size: 0.75rem;
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 3px;
}

.speaker-name {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.2;
  margin-bottom: 0.25rem;
}

.speaker-affil {
  font-size: 0.8rem;
  color: var(--stone);
  margin-bottom: 0.45rem;
  line-height: 1.35;
}

.speaker-topic {
  font-size: 0.85rem;
  color: var(--ink-soft);
  line-height: 1.4;
  font-style: italic;
}

.slot-count {
  font-style: normal;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--alpine);
  background: rgba(74,111,165,0.1);
  padding: 0.1rem 0.45rem;
  border-radius: 99px;
  margin-left: 0.3rem;
}

/* ==========================================
   PRACTICAL PAGE
   ========================================== */
.section-practical {
  padding: 4rem 0 5rem;
}

.practical-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(440px, 1fr));
  gap: 2.5rem 3rem;
}

.practical-block h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--alpine-dark);
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--sage-pale);
}

.practical-block p {
  font-size: 0.97rem;
  color: var(--ink-soft);
  margin-bottom: 0.85rem;
  line-height: 1.65;
}

.practical-list {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0.85rem;
}
.practical-list li {
  font-size: 0.93rem;
  color: var(--ink-soft);
  padding: 0.3rem 0 0.3rem 1.2rem;
  position: relative;
}
.practical-list li::before {
  content: '–';
  position: absolute;
  left: 0;
  color: var(--sage);
}

/* ==========================================
   REGISTRATION PAGE
   ========================================== */
.section-registration {
  padding: 4rem 0 5rem;
}

.reg-status-banner {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(74,111,165,0.08);
  border: 1px solid rgba(74,111,165,0.25);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin-bottom: 3rem;
}

.reg-status-icon { font-size: 1.5rem; flex-shrink: 0; }

.reg-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(440px, 1fr));
  gap: 2.5rem 3rem;
}

.reg-block h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--alpine-dark);
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--sage-pale);
}

.reg-block p {
  font-size: 0.97rem;
  color: var(--ink-soft);
  margin-bottom: 0.85rem;
  line-height: 1.65;
}

.contact-link {
  font-weight: 600;
  font-size: 1rem;
  color: var(--alpine);
}
.contact-link:hover { color: var(--sage); }

/* ==========================================
   FOOTER
   ========================================== */
.site-footer {
  background: var(--ink);
  padding: 2rem 0;
  border-top: 1px solid rgba(255,255,255,0.07);
}

.site-footer p {
  text-align: center;
  font-size: 0.83rem;
  color: rgba(255,255,255,0.4);
}

.site-footer a {
  color: var(--sage-light);
  transition: color 0.2s;
}
.site-footer a:hover { color: var(--white); }

/* ==========================================
   RESPONSIVE
   ========================================== */
@media (max-width: 860px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
  .info-card { position: static; }

  .practical-grid,
  .reg-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 64px;
    left: 0; right: 0;
    background: rgba(248,247,244,0.97);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--stone-light);
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 1rem 1rem;
    transform: translateY(-10px);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s, opacity 0.25s;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 0.65rem 0.75rem; border-radius: 4px; }
  .nav-links a.nav-cta { text-align: center; margin-top: 0.25rem; }

  .hero-header-img { max-width: 95vw; }
  .hero-dates { font-size: 1.05rem; }

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

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

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

  .logos-row { gap: 1.5rem; }
  .logo-houches { max-height: 50px; }
  .logo-item { max-height: 64px; }
  .logo-peprq { max-height: 72px; }

  .section-about,
  .section-topics,
  .section-organizers,
  .section-speakers,
  .section-practical,
  .section-registration {
    padding: 3rem 0;
  }

  .container { padding: 0 1.25rem; }
}

@media (max-width: 400px) {
  .practical-grid,
  .reg-grid {
    grid-template-columns: 1fr;
  }
}