@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700;800&display=swap');

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

:root {
  --bg:       #f7f5ff;
  --white:    #ffffff;
  --accent:   #7c3aed;
  --accent2:  #ec4899;
  --accent3:  #f59e0b;
  --text:     #1e1b2e;
  --muted:    #6b7280;
  --shadow:   rgba(124,58,237,0.12);
}

html { scroll-behavior: smooth; }
body {
  font-family: 'Nunito', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* ── Header ── */
.ph-header {
  background: linear-gradient(135deg, #7c3aed 0%, #ec4899 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
  padding: 2rem 2rem 0;
}
.ph-header::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -10%;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  pointer-events: none;
}

.breadcrumb {
  display: flex;
  gap: .4rem;
  font-size: .78rem;
  font-weight: 600;
  color: rgba(255,255,255,0.6);
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: rgba(255,255,255,0.6); text-decoration: none; transition: color .2s; }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { opacity: .4; }

.ph-header-inner { padding-bottom: 1.5rem; }
.ph-eyebrow {
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.7);
  margin-bottom: .6rem;
}
.ph-title {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1rem;
  text-shadow: 0 2px 20px rgba(0,0,0,0.2);
}

.ph-labels { display: flex; gap: .5rem; flex-wrap: wrap; }
.label-tag {
  font-size: .72rem;
  font-weight: 700;
  padding: .25rem .75rem;
  border-radius: 2rem;
  background: rgba(255,255,255,0.2);
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff;
  text-decoration: none;
  transition: background .2s;
}
.label-tag:hover { background: rgba(255,255,255,0.35); }

.ph-hero-banner {
  margin-top: 1.5rem;
  border-radius: 12px 12px 0 0;
  overflow: hidden;
  max-width: 400px;
  box-shadow: 0 -4px 20px rgba(0,0,0,0.15);
}
.banner-img {
  width: 100%;
  display: block;
}

/* ── Main ── */
.ph-main {
  max-width: 900px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* ── Card grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.2rem;
  margin-bottom: 2.5rem;
}

.ph-card {
  background: var(--white);
  border-radius: 1rem;
  padding: 1.5rem;
  box-shadow: 0 4px 20px var(--shadow);
  transition: transform .25s, box-shadow .25s;
  opacity: 0;
  transform: translateY(20px);
}
.ph-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(124,58,237,0.2);
}
.ph-card.visible { opacity: 1; transform: translateY(0); }

.card-icon { font-size: 2rem; margin-bottom: .7rem; }
.card-title {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: .5rem;
}
.card-desc { font-size: .88rem; color: var(--muted); line-height: 1.55; }
.card-badge {
  display: inline-block;
  margin-top: .8rem;
  font-size: .68rem;
  font-weight: 700;
  padding: .2rem .6rem;
  border-radius: 2rem;
  background: rgba(124,58,237,0.1);
  color: var(--accent);
}
.card-invite { border-top: 4px solid var(--accent2); }
.card-math   { border-top: 4px solid var(--accent); }
.card-content{ border-top: 4px solid var(--accent3); }

.math-content {
  font-size: .82rem;
  line-height: 1.7;
  color: var(--text);
  margin-top: .4rem;
}
.math-content p { margin-bottom: .5rem; }

/* ── Full content section ── */
.ph-content-section {
  background: var(--white);
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: 0 4px 20px var(--shadow);
  margin-bottom: 2rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .6s ease, transform .6s ease;
}
.ph-content-section.visible { opacity: 1; transform: translateY(0); }

.event-body {
  font-size: .95rem;
  line-height: 1.75;
  color: var(--text);
}
.event-body h1 {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--accent);
  margin: 1.5rem 0 .5rem;
}
.event-body h2 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin: .8rem 0 .3rem;
}
.event-body h3 { font-size: .9rem; color: var(--muted); margin-bottom: .8rem; }
.event-body p { margin-bottom: .8rem; }
.event-body hr { border: none; border-top: 1px solid #e5e7eb; margin: 1rem 0; }
.event-body img { max-width: 100%; height: auto; display: block; margin: .4rem 0; }
.event-body strong { color: var(--accent); }

/* ── Table ── */
.event-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: .85rem;
}
.event-body table td {
  padding: .6rem .8rem;
  border: 1px solid #e5e7eb;
  vertical-align: top;
}
.event-body table tr:nth-child(even) td { background: #f9f7ff; }
.event-body table tr:first-child td {
  background: var(--accent);
  color: #fff;
  font-weight: 700;
}

/* ── Footer ── */
.ph-footer {
  padding-top: 1.5rem;
  border-top: 1px solid #e5e7eb;
}
.back-link {
  font-size: .85rem;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
  transition: color .2s;
}
.back-link:hover { color: var(--accent); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .card-grid { grid-template-columns: 1fr 1fr; }
  .ph-main { padding: 1.5rem 1rem; }
}
@media (max-width: 480px) {
  .card-grid { grid-template-columns: 1fr; }
  .ph-header { padding: 1.5rem 1rem 0; }
  .ph-content-section { padding: 1.2rem; }
}

/* ── Lightbox ── */
#lightbox{display:none;position:fixed;inset:0;background:rgba(0,0,0,.9);
  z-index:9999;align-items:center;justify-content:center;
  flex-direction:column;gap:.5rem}
#lightbox img{max-width:90vw;max-height:80vh;object-fit:contain}
.lb-close{position:fixed;top:1rem;right:1.5rem;font-size:2.5rem;
  color:#fff;cursor:pointer;line-height:1;opacity:.8}
.lb-close:hover{opacity:1}
.lb-nav{position:fixed;top:50%;transform:translateY(-50%);font-size:3rem;
  color:#fff;cursor:pointer;padding:.5rem;user-select:none;opacity:.7}
.lb-nav:hover{opacity:1}
.lb-prev{left:1rem}.lb-next{right:1rem}
.lb-caption{color:#ccc;font-size:.9rem;text-align:center;max-width:80vw}