/* =============================================================
   CW Satellite Workshop 2026 – IUCAA
   Stylesheet
   ============================================================= */

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

:root {
  --clr-bg:        #0b0f1a;
  --clr-surface:   #131929;
  --clr-primary:   #4a9eff;
  --clr-accent:    #7ec8e3;
  --clr-text:      #e2e8f0;
  --clr-muted:     #8898aa;
  --clr-border:    #1e2d45;
  --clr-card:      #162035;
  --radius:        10px;
  --max-width:     960px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.7;
  font-size: 1rem;
}

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

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

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

section { padding: 5rem 0; }

/* ---- Navigation ------------------------------------------- */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 15, 26, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--clr-border);
}

nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--clr-primary);
  letter-spacing: 0.01em;
}

.nav-links {
  display: flex;
  gap: 1.8rem;
  list-style: none;
}

.nav-links a {
  color: var(--clr-muted);
  font-size: 0.9rem;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--clr-text); text-decoration: none; }

/* ---- Hero -------------------------------------------------- */
#hero {
  padding: 6rem 0 5rem;
  text-align: center;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, #0d2040 0%, transparent 70%);
  border-bottom: 1px solid var(--clr-border);
  position: relative;
  overflow: hidden;
}

#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='600' height='600' viewBox='0 0 600 600'%3E%3Ccircle cx='300' cy='300' r='200' fill='none' stroke='%234a9eff10' stroke-width='1'/%3E%3Ccircle cx='300' cy='300' r='150' fill='none' stroke='%234a9eff0a' stroke-width='1'/%3E%3Ccircle cx='300' cy='300' r='100' fill='none' stroke='%234a9eff08' stroke-width='1'/%3E%3C/svg%3E") center/600px repeat;
  opacity: 0.6;
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  background: rgba(74,158,255,0.12);
  color: var(--clr-primary);
  border: 1px solid rgba(74,158,255,0.3);
  padding: 0.3rem 1rem;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}

#hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

#hero h1 span { color: var(--clr-primary); }

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--clr-muted);
  margin-bottom: 2.5rem;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
  color: var(--clr-accent);
}

.hero-meta-item svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: opacity 0.2s, transform 0.15s;
  cursor: pointer;
  border: none;
}

.btn:hover { opacity: 0.88; transform: translateY(-1px); text-decoration: none; }

.btn-primary { background: var(--clr-primary); color: #0b0f1a; }
.btn-outline {
  background: transparent;
  color: var(--clr-primary);
  border: 1px solid var(--clr-primary);
}

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

/* ---- Section headings ------------------------------------- */
.section-label {
  display: block;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.75rem;
  color: var(--clr-primary);
  font-weight: 700;
  margin-bottom: 0.75rem;
}

h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

/* ---- About ------------------------------------------------ */


#about { background: var(--clr-surface); border-top: 1px solid var(--clr-border); border-bottom: 1px solid var(--clr-border); }

#about p + p { margin-top: 1rem; }

#about p { color: var(--clr-muted); }

.highlight-box {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.highlight-box ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.highlight-box li {
  display: flex;
  gap: 0.75rem;
  font-size: 0.95rem;
  color: var(--clr-muted);
}

.highlight-box li::before {
  content: '→';
  color: var(--clr-primary);
  flex-shrink: 0;
  font-weight: 700;
}

/* ---- Speakers / Topics ------------------------------------ */
#topics {border-top: 1px solid var(--clr-border); border-bottom: 1px solid var(--clr-border); }

/* ---- Programm and participants -------------------------------------------- */

#programme {background: var(--clr-surface); border-top: 1px solid var(--clr-border); border-bottom: 1px solid var(--clr-border); }

.programme-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 2rem;
  font-size: 0.9rem;
}

.programme-table th, .programme-table td {
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--clr-border);
}

.programme-table th {
  background: var(--clr-card);
  color: var(--clr-muted);
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
}

.programme-table tr:hover td { background: rgba(255,255,255,0.02); }

.programme-table td:first-child {
  color: var(--clr-primary);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.tba { color: var(--clr-muted); font-style: italic; }

/* ---- Venue ------------------------------------------------ */
#venue {border-top: 1px solid var(--clr-border); border-bottom: 1px solid var(--clr-border); }

#venue .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

#venue p { color: var(--clr-muted); margin-bottom: 0.75rem; }

.venue-map {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4/3;
}

.venue-map iframe { width: 100%; height: 100%; border: none; }

#travel {
  border-top: 1px solid var(--clr-border);
  border-bottom: 1px solid var(--clr-border);
}
#travel p {
  color: var(--clr-muted);
  margin-bottom: 0.75rem;
}



/* ---- Team ----------------------------------------- */
#organizers {border-top: 1px solid var(--clr-border); border-bottom: 1px solid var(--clr-border); }

/* ---- Registration ----------------------------------------- */
#register {}

.form-card {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 2.5rem;
  max-width: 680px;
  margin-top: 2rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--clr-muted);
  letter-spacing: 0.02em;
}

.form-group label .req { color: var(--clr-primary); margin-left: 2px; }

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--clr-bg);
  border: 1px solid var(--clr-border);
  border-radius: 6px;
  color: var(--clr-text);
  padding: 0.65rem 0.9rem;
  font-size: 0.9rem;
  font-family: inherit;
  transition: border-color 0.2s;
  width: 100%;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
  box-shadow: 0 0 0 3px rgba(74,158,255,0.12);
}

.form-group select option { background: var(--clr-card); }
.form-group textarea { resize: vertical; min-height: 90px; }

.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--clr-muted); opacity: 0.6; }

.form-check {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.form-check input[type="checkbox"] {
  width: 16px;
  height: 16px;
  min-width: 16px;
  margin-top: 3px;
  accent-color: var(--clr-primary);
  cursor: pointer;
}

.form-check label {
  font-size: 0.88rem;
  color: var(--clr-muted);
  cursor: pointer;
}

.form-note {
  font-size: 0.82rem;
  color: var(--clr-muted);
  margin-top: 1rem;
}

.form-success {
  display: none;
  background: rgba(74,158,255,0.08);
  border: 1px solid rgba(74,158,255,0.3);
  border-radius: 8px;
  padding: 1.5rem;
  text-align: center;
  color: var(--clr-accent);
  font-size: 0.95rem;
  margin-top: 1.5rem;
}

/* ---- Organizers ------------------------------------------- */
#organizers { background: var(--clr-surface); border-top: 1px solid var(--clr-border); }

.org-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 2rem;
}

.org-card {
  display: flex;
  gap: 1rem;
  align-items: center;
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  min-width: 240px;
}

.org-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(74,158,255,0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--clr-primary);
  flex-shrink: 0;
}

.org-info h3 { font-size: 0.9rem; margin-bottom: 0.15rem; }
.org-info p { font-size: 0.8rem; color: var(--clr-muted); }

/* ---- Footer ----------------------------------------------- */
footer {
  border-top: 1px solid var(--clr-border);
  padding: 2.5rem 0;
  text-align: center;
  color: var(--clr-muted);
  font-size: 0.85rem;
}

footer a { color: var(--clr-muted); }
footer a:hover { color: var(--clr-primary); }

/* ---- Responsive ------------------------------------------- */
@media (max-width: 700px) {
  #about .container,
  #venue .container { grid-template-columns: 1fr; }

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

  .nav-links { display: none; }

  .form-card { padding: 1.5rem; }

  section { padding: 3.5rem 0; }
}