/* ============================================================
   RiekeFest 2027 — Stylesheet
   Plain CSS, no build step. Colors are defined as CSS variables
   below so the palette can be changed in one place.
   ============================================================ */

:root {
  /* Core palette — edit these to retheme the whole site */
  --color-bg: #f7f5f1;              /* off-white main background */
  --color-surface: #ffffff;         /* card / panel background */
  --color-surface-alt: #efeae2;     /* alternating section background */
  --color-text: #1c1e24;
  --color-text-muted: #4a4e58;

  --color-hero-bg: #0a0e1a;         /* near-black/navy hero */
  --color-hero-bg-2: #10182b;
  --color-hero-text: #f2efe9;
  --color-hero-text-muted: #b9c0d4;

  --color-accent: #c9772f;          /* muted warm infrared/orange accent */
  --color-accent-strong: #a4431f;   /* restrained red-orange accent */

  --color-border: #ddd6c9;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", Times, serif;

  --max-width: 1100px;
}

/* ---------- Reset / base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4.5rem; /* keep anchored headings clear of the sticky nav */
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  line-height: 1.25;
  color: var(--color-text);
}

a {
  color: var(--color-accent-strong);
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---------- Navigation ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-hero-bg);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.navbar {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
}

.nav-brand {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: bold;
  color: var(--color-hero-text);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.6rem;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-hero-text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

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

/* Mobile nav toggle (CSS-only, no JavaScript) */
.nav-toggle-checkbox {
  display: none;
}

.nav-toggle-label {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 26px;
  height: 20px;
  cursor: pointer;
}

.nav-toggle-label span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-hero-text);
  border-radius: 2px;
}

/* ---------- Hero ---------- */
.hero {
  background: radial-gradient(ellipse at top, var(--color-hero-bg-2), var(--color-hero-bg) 70%);
  color: var(--color-hero-text);
  text-align: center;
  padding: 5rem 1.5rem 4.5rem;
  position: relative;
  overflow: hidden;
}

.hero-montage {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  opacity: 0.65;
}

.hero-montage-image {
  background-position: center;
  background-size: cover;
  filter: saturate(0.75) brightness(0.6);
}

.hero-montage-cleanroom {
  background-image: url("../images/inst/instst1.jpg");
}

.hero-montage-instrument {
  background-image: url("../images/inst/instst9.jpg");
}

.hero-montage-installation {
  background-image: url("../images/inst/nicmos_prep_rev.png");
  background-position: center 18%;
  background-size: auto 150%;
}

.hero-montage-nicmos {
  background-image: url("../images/inst/nicmosbig.jpg");
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(5, 9, 18, 0.58);
  pointer-events: none;
}

.hero-content {
  position: relative;
  max-width: 780px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3.2rem;
  margin: 0 0 0.5rem;
  color: var(--color-hero-text);
}

.hero-subtitle {
  font-size: 1.25rem;
  margin: 0 0 1.5rem;
  color: var(--color-hero-text-muted);
  font-weight: normal;
}

.hero-meta {
  font-size: 1.15rem;
  color: var(--color-accent);
  margin: 0 0 2rem;
  letter-spacing: 0.02em;
}

.hero-intro {
  color: var(--color-hero-text-muted);
  max-width: 620px;
  margin: 0 auto 2.2rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.6rem;
  border-radius: 3px;
  text-decoration: none;
  font-size: 1rem;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--color-accent);
  color: #14100b;
  font-weight: 600;
}

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

.btn-secondary {
  border-color: var(--color-hero-text-muted);
  color: var(--color-hero-text);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---------- Sections ---------- */
.section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--color-border);
}

.section-alt {
  background: var(--color-surface-alt);
}

.section h2 {
  font-size: 2rem;
  margin-top: 0;
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.6rem;
}

.section h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 60px;
  height: 3px;
  background: var(--color-accent);
}

.section-intro {
  color: var(--color-text-muted);
  max-width: 720px;
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2.5rem;
  align-items: start;
}

.placeholder-box {
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: 4px;
  min-height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--color-text-muted);
  padding: 1.5rem;
}

.placeholder-box span {
  font-size: 0.85rem;
}

.image-figure {
  margin: 0;
}

.image-figure img {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: 4px;
}

.image-figure figcaption {
  margin-top: 0.5rem;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* ---------- Program ---------- */
.program-theme {
  margin-bottom: 3rem;
}

.program-theme-header {
  margin-bottom: 0.75rem;
}

.program-dates {
  display: inline-block;
  color: var(--color-accent-strong);
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.03em;
  margin-bottom: 0.25rem;
}

.program-theme-header h3 {
  margin: 0.2rem 0 0;
  font-size: 1.5rem;
}

.topic-cards {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.topic-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: 4px;
  padding: 1rem 1.2rem;
}

.topic-card h4 {
  margin: 0;
  font-size: 1rem;
  font-family: var(--font-sans);
  font-weight: 600;
}

.placeholder-note {
  margin-top: 2rem;
  padding: 0.9rem 1.2rem;
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: 4px;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ---------- Dates table ---------- */
.dates-table {
  width: 100%;
  border-collapse: collapse;
  max-width: 700px;
}

.dates-table th,
.dates-table td {
  text-align: left;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--color-border);
}

.dates-table th {
  width: 45%;
  font-weight: 600;
  color: var(--color-text);
}

.dates-table td {
  color: var(--color-text-muted);
}

/* ---------- Venue ---------- */
.info-subsections {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin: 2rem 0;
}

.info-subsection {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 1.2rem 1.4rem;
}

.info-subsection h4 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
}

.info-subsection p {
  margin: 0;
  color: var(--color-text-muted);
}

.venue-image {
  margin-top: 1rem;
}

.venue-image img {
  max-width: 800px;
}

/* ---------- Local information ---------- */
.page-heading {
  background: var(--color-hero-bg-2);
  color: var(--color-hero-text);
  padding: 3.5rem 0;
}

.page-heading h1 {
  color: var(--color-hero-text);
  font-size: 2.8rem;
  margin: 0 0 0.6rem;
}

.page-heading p:not(.eyebrow) {
  color: var(--color-hero-text-muted);
  margin: 0;
  max-width: 720px;
}

.page-jump-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-jump-links a {
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  color: var(--color-hero-text);
  display: inline-block;
  font-size: 0.9rem;
  padding: 0.35rem 0.9rem;
  text-decoration: none;
}

.page-jump-links a:hover,
.page-jump-links a:focus {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---------- Code of conduct ---------- */
.policy-text {
  max-width: 760px;
}

.policy-text h2 {
  margin-top: 2rem;
}

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

.eyebrow {
  color: var(--color-accent);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin: 0 0 0.35rem;
  text-transform: uppercase;
}

.map-heading {
  display: flex;
  align-items: end;
  gap: 1.5rem;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.map-heading h2 {
  margin-bottom: 0.75rem;
}

.btn-map {
  background: var(--color-accent);
  color: #14100b;
  flex: 0 0 auto;
}

.btn-map:hover {
  background: var(--color-accent-strong);
  color: #fff;
}

.local-map {
  border: 1px solid var(--color-border);
  border-radius: 4px;
  overflow: hidden;
}

.local-map iframe {
  border: 0;
  display: block;
  height: 480px;
  width: 100%;
}

.local-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(3, 1fr);
}

.places-grid {
  grid-template-columns: repeat(2, 1fr);
}

.local-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: 4px;
  padding: 1.2rem 1.4rem;
}

.local-card h3 {
  font-size: 1.15rem;
  margin: 0 0 0.5rem;
}

.local-card p {
  color: var(--color-text-muted);
  margin: 0 0 0.8rem;
}

.local-card p:last-child {
  margin-bottom: 0;
}

/* ---------- Registration ---------- */
.notice-banner {
  display: inline-block;
  background: var(--color-accent);
  color: #14100b;
  font-weight: 600;
  padding: 0.6rem 1.1rem;
  border-radius: 4px;
  margin-bottom: 1.2rem;
}

.registration-list {
  max-width: 600px;
  padding-left: 1.2rem;
}

.registration-list li {
  margin-bottom: 0.5rem;
  color: var(--color-text-muted);
}

/* ---------- Organizers ---------- */
.organizers-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2rem;
}

.organizer-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 1.5rem;
}

.organizer-block h3 {
  margin-top: 0;
  font-size: 1.2rem;
}

.organizer-list {
  padding-left: 1.2rem;
  margin: 0;
}

.organizers-note {
  color: var(--color-text-muted);
  font-style: italic;
}

/* ---------- Contact ---------- */
#contact a {
  font-weight: 600;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-hero-bg);
  color: var(--color-hero-text-muted);
  padding: 2.5rem 0;
  text-align: center;
  font-size: 0.95rem;
}

.footer-title {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  color: var(--color-hero-text);
  margin: 0 0 0.4rem;
}

.site-footer a {
  color: var(--color-hero-text-muted);
}

.site-footer a:hover {
  color: var(--color-accent);
}

.footer-note {
  margin-top: 1rem;
  font-size: 0.8rem;
  color: #7c8399;
}

/* ---------- Responsive ---------- */
/* Tighter nav spacing just above the mobile-menu breakpoint */
@media (min-width: 901px) and (max-width: 1100px) {
  .nav-links {
    gap: 0.9rem;
  }

  .nav-links a {
    font-size: 0.9rem;
  }
}

@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
  }

  .topic-cards {
    grid-template-columns: repeat(2, 1fr);
  }

  .info-subsections {
    grid-template-columns: repeat(2, 1fr);
  }

  .local-grid,
  .places-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 640px) {
  .hero {
    padding: 3.5rem 1.2rem 3rem;
  }

  .hero-montage {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-title {
    font-size: 2.3rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

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

  .info-subsections {
    grid-template-columns: 1fr;
  }

  .page-heading {
    padding: 2.75rem 0;
  }

  .page-heading h1 {
    font-size: 2.2rem;
  }

  .map-heading {
    align-items: start;
    flex-direction: column;
  }

  .local-map iframe {
    height: 340px;
  }

  .local-grid,
  .places-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 2.75rem 0;
  }

  /* Collapsible mobile nav */
  .nav-toggle-label {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-hero-bg-2);
    padding: 1rem 1.5rem;
    gap: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
  }

  .nav-links li {
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .nav-links a {
    display: block;
    padding: 0.75rem 0;
  }

  .nav-toggle-checkbox:checked ~ .nav-links {
    display: flex;
  }
}