/* =================================================================
   시나버스 - 2026 Modern Design System (css/style.css)
   ================================================================= */
:root {
  --bg-primary: #0f172a;
  --bg-surface: rgba(15, 23, 42, 0.82);
  --bg-card: rgba(255, 255, 255, 0.05);
  --text-main: #f8fafc;
  --text-sub: #94a3b8;
  --border-color: rgba(255, 255, 255, 0.12);
  --accent-color: #06b6d4;
  --accent-blue: #2563eb;
  --accent-purple: #8b5cf6;
  --accent-cyan: #06b6d4;
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #8b5cf6 50%, #06b6d4 100%);
  --glass-blur: blur(16px);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.3);
  --radius-xl: 24px;
  --radius-lg: 16px;
  --radius-md: 10px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-surface: rgba(255, 255, 255, 0.82);
  --bg-card: #ffffff;
  --text-main: #0f172a;
  --text-sub: #64748b;
  --border-color: rgba(0, 0, 0, 0.08);
  --accent-color: #2563eb;
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.06);
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Noto Sans KR', 'Inter', sans-serif; transition: background-color 0.25s, color 0.25s, border-color 0.25s; }

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
}

header {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-surface);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
  display: flex; justify-content: space-between; align-items: center;
}

.logo-container { display: flex; align-items: center; gap: 0.5rem; text-decoration: none; }
.logo-img { height: 32px; width: auto; }
.logo-text {
  font-size: 1.3rem; font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}

.nav-links { display: flex; align-items: center; gap: 1.5rem; }
.nav-links a {
  color: var(--text-sub); text-decoration: none; font-weight: 600; font-size: 0.9rem;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent-color); }
@media (max-width: 700px) { .nav-links { display: none; } }

.nav-actions { display: flex; align-items: center; gap: 0.75rem; }

.theme-toggle-btn {
  background: var(--bg-card); border: 1px solid var(--border-color);
  color: var(--text-main); padding: 0.4rem 0.8rem; border-radius: var(--radius-md);
  cursor: pointer; font-size: 0.85rem; font-weight: 600; display: flex; align-items: center; gap: 0.4rem;
}

.container { max-width: 1200px; margin: 0 auto; padding: 2.5rem 1.5rem; }

.hero {
  text-align: center; padding: 3.5rem 1rem;
  background: radial-gradient(circle at center, rgba(56, 189, 248, 0.1) 0%, transparent 70%);
}

.grid-cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem;
}

.card {
  background: var(--bg-card); backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color); border-radius: var(--radius-lg);
  padding: 1.25rem; box-shadow: var(--shadow-lg); transition: transform 0.25s, border-color 0.25s;
  display: flex; flex-direction: column; justify-content: space-between;
}

.card:hover { transform: translateY(-4px); border-color: var(--accent-color); }
.card img { width: 100%; height: 200px; object-fit: cover; border-radius: var(--radius-md); margin-bottom: 0.8rem; }

.badge {
  display: inline-block; padding: 0.25rem 0.6rem; border-radius: 20px;
  background: rgba(56, 189, 248, 0.15); color: var(--accent-color);
  font-size: 0.75rem; font-weight: 600; margin-bottom: 0.5rem; align-self: flex-start;
}

.btn {
  display: inline-block; padding: 0.65rem 1.25rem;
  background: var(--accent-gradient); color: #fff;
  border: none; border-radius: var(--radius-md); font-weight: 600;
  cursor: pointer; text-decoration: none; text-align: center;
}
.btn:hover { opacity: 0.9; }
.btn-danger { background: linear-gradient(135deg, #f43f5e 0%, #e11d48 100%); }

.table-wrapper {
  overflow-x: auto; background: var(--bg-surface);
  border-radius: var(--radius-lg); border: 1px solid var(--border-color); margin-top: 1rem;
}

table { width: 100%; border-collapse: collapse; text-align: left; }
th, td { padding: 0.85rem 1rem; border-bottom: 1px solid var(--border-color); font-size: 0.88rem; }
th { color: var(--accent-color); background: rgba(0, 0, 0, 0.05); white-space: nowrap; }

input, textarea, select {
  width: 100%; padding: 0.75rem; margin-bottom: 1rem;
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); color: var(--text-main); outline: none;
}
input:focus, textarea:focus, select:focus { border-color: var(--accent-color); }

.instructor-profile-card {
  background: var(--bg-surface); border: 1px solid var(--border-color);
  border-radius: var(--radius-lg); padding: 2rem; margin-top: 1rem;
  display: grid; grid-template-columns: 220px 1fr; gap: 2rem;
}
@media (max-width: 768px) {
  .instructor-profile-card { grid-template-columns: 1fr; }
}

/* --- 글래스모피즘 & 브랜드 비주얼 유틸리티 --- */
.glass-panel {
  background: var(--bg-surface); backdrop-filter: var(--glass-blur); -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color);
}

.text-gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

.btn-outline {
  background: var(--bg-card); backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color); color: var(--text-main);
}
.btn-outline:hover { border-color: var(--accent-color); opacity: 1; }

.hero-badge {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.5rem 1rem; border-radius: 999px;
  background: rgba(37, 99, 235, 0.12); border: 1px solid rgba(37, 99, 235, 0.3);
  color: var(--accent-color); font-size: 0.75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.05em;
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent-color); position: relative; }
.hero-badge .dot::after {
  content: ''; position: absolute; inset: 0; border-radius: 50%; background: var(--accent-color);
  animation: pulseDot 1.6s infinite;
}
@keyframes pulseDot {
  0% { opacity: 0.8; transform: scale(1); }
  70% { opacity: 0; transform: scale(2.2); }
  100% { opacity: 0; transform: scale(2.2); }
}

.hero-grid {
  display: grid; grid-template-columns: 1.3fr 1fr; gap: 3rem; align-items: center;
  text-align: left; padding: 3rem 0;
}
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
}

.hero-grid h1 { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; line-height: 1.25; margin: 1.2rem 0; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 1.5rem; }
@media (max-width: 900px) { .hero-actions { justify-content: center; } }

.hero-visual { position: relative; }
.hero-card {
  background: var(--bg-surface); backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color); border-radius: var(--radius-xl);
  padding: 1.5rem; box-shadow: var(--shadow-lg);
  animation: floatCard 6s ease-in-out infinite;
}
@keyframes floatCard {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
.hero-card-media {
  position: relative; height: 260px; border-radius: var(--radius-lg); overflow: hidden;
  background: #0f172a; display: flex; align-items: center; justify-content: center;
}
.hero-blob {
  position: absolute; top: -100px; left: 50%; transform: translateX(-50%);
  width: 560px; height: 560px; max-width: 140vw;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.18) 0%, transparent 70%);
  z-index: -1; pointer-events: none;
}

.icon-circle {
  width: 52px; height: 52px; border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; margin-bottom: 0.75rem;
}
.icon-circle.blue { background: rgba(37, 99, 235, 0.12); color: var(--accent-blue); }
.icon-circle.cyan { background: rgba(6, 182, 212, 0.12); color: var(--accent-cyan); }
.icon-circle.purple { background: rgba(139, 92, 246, 0.12); color: var(--accent-purple); }

.section-title { display: flex; align-items: center; gap: 0.6rem; margin: 3.5rem 0 1rem; color: var(--accent-color); }
.section-title i { font-size: 1.05em; }

footer.site-footer {
  background: #0f172a; color: #94a3b8; padding: 3rem 1.5rem 2rem; margin-top: 4rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08); font-size: 0.85rem;
}
footer.site-footer .footer-inner { max-width: 1200px; margin: 0 auto; }
footer.site-footer .footer-top {
  display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center;
  gap: 1.5rem; padding-bottom: 1.5rem;
}
footer.site-footer .footer-brand { font-size: 1.2rem; font-weight: 800; color: #fff; }
footer.site-footer .footer-tagline { font-size: 0.75rem; color: #64748b; margin-top: 0.2rem; }
footer.site-footer .footer-social { display: flex; gap: 1rem; font-size: 1.1rem; }
footer.site-footer .footer-social a { color: #94a3b8; text-decoration: none; }
footer.site-footer .footer-social a:hover { color: #fff; }
footer.site-footer .footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08); padding-top: 1.2rem;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.8rem;
  font-size: 0.75rem; color: #64748b;
}

.bgm-toggle-btn {
  position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 60;
  display: flex; align-items: center; gap: 0.5rem; padding: 0.7rem 1rem;
  border-radius: 999px; background: var(--bg-surface); backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color); color: var(--accent-color);
  font-size: 0.75rem; font-weight: 700; cursor: pointer; box-shadow: var(--shadow-lg);
}
.bgm-toggle-btn i.spin { animation: spin 4s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (max-width: 500px) { .bgm-toggle-btn .bgm-label { display: none; } }

.eyebrow-label {
  display: block; text-align: center; font-size: 0.75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.15em; color: var(--accent-color); margin-bottom: 0.5rem;
}

.contact-card { border-radius: var(--radius-xl); padding: 2.5rem; }
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 1.5rem;
  text-align: center; padding-bottom: 2rem; margin-bottom: 2rem; border-bottom: 1px solid var(--border-color);
}
.contact-grid .contact-item i { font-size: 1.4rem; margin-bottom: 0.4rem; }
.contact-grid .contact-label { font-size: 0.75rem; color: var(--text-sub); margin: 0.3rem 0; }
.contact-grid .contact-value { font-weight: 700; }