:root {
  --bg: #0b0b0b;
  --surface: #111;
  --text: #f5f5f5;
  --muted: #bcbcbc;
  --accent: #5bc0ff;
  --outline: rgba(255, 255, 255, 0.08);
  --max: 1100px;
  --radius: 16px;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Manrope", system-ui, sans-serif;
  line-height: 1.6;
}
a {
  color: inherit;
  text-decoration: none;
}
/* NAVIGATION */
.nav {
  position: sticky;
  top: 0;
  background: rgba(15, 15, 15, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--outline);
  z-index: 10;
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0.4px;
}
.brand img {
  width: 28px;
  height: 28px;
  background: #222;
  border-radius: 6px;
  object-fit: cover;
}
.menu {
  display: flex;
  gap: 22px;
  align-items: center;
  flex-wrap: wrap;
}
.menu-group,
.menu-actions {
  display: flex;
  gap: 16px;
  align-items: center;
}
.cta {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--outline);
}
.cta--accent {
  border: none;
  background: var(--accent);
  color: #000;
  font-weight: 700;
}

/* HERO */
header.hero {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 80px 20px;
  min-height: 80vh;
}
header.hero h1 {
  font-size: clamp(32px, 8vw, 64px);
  font-weight: 800;
  line-height: 1.2;
  margin: 0;
  max-width: 800px;
}
header.hero .accent {
  color: var(--accent);
}
header.hero p {
  color: var(--muted);
  margin: 18px auto 28px;
  max-width: 70ch;
  font-size: clamp(14px, 2.8vw, 18px);
}

/* SECTIONS */
section {
  padding: 70px 20px;
}
.container {
  max-width: var(--max);
  margin: 0 auto;
}
h2 {
  font-size: clamp(24px, 5vw, 36px);
  margin-bottom: 12px;
}
.lead {
  color: var(--muted);
  margin-bottom: 20px;
  font-size: clamp(14px, 2.8vw, 17px);
}

/* GRID CARDS */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}
.card {
  border: 1px solid var(--outline);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 20px;
  transition: transform 0.2s ease;
}
.card:hover {
  transform: translateY(-4px);
}
.card h3 {
  margin-top: 0;
  font-size: 1.2rem;
}

/* SEMINAR */
.seminar {
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  background: #0f0f0f;
  padding: 20px;
  margin-top: 24px;
}
.seminar h3 {
  color: var(--accent);
  margin-top: 0;
  font-size: 1.1rem;
}
.seminar time {
  display: block;
  color: var(--muted);
  margin-top: 4px;
  font-size: 0.9rem;
}
/* Inavtive Seminar */
.seminar.inactive {
  border: 1px solid var(--outline);
  background: #0a0a0a;
  color: var(--muted);
  opacity: 0.55;
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
  pointer-events: none;
}

.seminar.inactive h3 {
  color: var(--muted);
  text-decoration: line-through;
  margin-top: 0;
  font-size: 1.1rem;
}

.seminar.inactive::after {
  content: "종료됨";
  position: absolute;
  top: 12px;
  right: 16px;
  background: var(--outline);
  color: var(--muted);
  font-size: 0.75rem;
  padding: 4px 8px;
  border-radius: 8px;
  letter-spacing: 0.5px;
}
/* FOOTER */
footer {
  text-align: center;
  padding: 40px 20px;
  border-top: 1px solid var(--outline);
  color: var(--muted);
}
footer img {
  width: 64px;
  height: 36px;
  border-radius: 8px;
  background: #222;
  margin-bottom: 8px;
}

/* RESPONSIVE */
@media (max-width: 600px) {
  .nav-inner {
    flex-direction: column;
    gap: 8px;
  }
  .menu {
    flex-wrap: wrap;
    justify-content: center;
  }
  header.hero {
    padding: 60px 16px;
  }
}

.timeline {
  position: relative;
  margin-left: 20px;
  border-left: 2px solid var(--accent);
  padding-left: 20px;
}
.event {
  margin-bottom: 30px;
  position: relative;
}

.event h3 {
  margin: 0;
  font-size: 1.1rem;
  color: var(--accent);
}
.event p {
  margin: 4px 0 0;
  color: var(--muted);
}