/* ============================================
   CGER - Center for Galaxy Evolution Research
   Shared Stylesheet — Light Theme
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;700;900&family=Noto+Sans+KR:wght@300;400;500;700&family=Space+Mono:wght@400;700&display=swap');

/* === CSS Variables (Light Theme) === */
:root {
  --color-bg:       #ffffff;
  --color-surface:  #f7f8fc;
  --color-surface2: #eef1f8;
  --color-accent:   #1a5bbf;
  --color-accent-lt:#e8effc;
  --color-gold:     #a07820;
  --color-text:     #111827;
  --color-sub:      #374151;
  --color-muted:    #6b7280;
  --color-border:   #d1d9e8;
  --color-border-hv:#93aad6;
  --color-white:    #ffffff;
  --font-display: 'Noto Sans KR', sans-serif;
  --font-body:    'Noto Sans KR', sans-serif;
  --font-mono:    'Space Mono', monospace;
  --nav-height: 70px;
  --max-width: 1200px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 1px 4px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 1px 4px rgba(0,0,0,0.04);
  --shadow-hv: 0 8px 24px rgba(26,91,191,0.12), 0 2px 6px rgba(0,0,0,0.06);
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  overflow-x: hidden;
}

/* 배경 장식: 매우 연한 점 패턴 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: radial-gradient(circle, #d1d9e8 1px, transparent 1px);
  background-size: 32px 32px;
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}

/* === Navigation === */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.nav-inner {
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nav-logo {
  display: flex;
  align-items: center;
}

.nav-logo img {
  height: 50px;
  width: auto;
  display: block;
}


.nav-logo-icon {
  width: 40px; height: 40px;
  background: linear-gradient(135deg, var(--color-accent), #2d6fd4);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.62rem; font-weight: 700;
  color: #ffffff;
  letter-spacing: 0.04em;
  box-shadow: 0 2px 8px rgba(26,91,191,0.3);
}

.nav-logo {
  background-image: url('img2/logo_cger.jpg');
  background-size: cover;
  background-repeat: no-repeat;
}

.nav-links {
  display: flex; list-style: none;
  gap: 0.2rem; flex-wrap: nowrap; overflow: hidden;
}

.nav-links a {
  display: block;
  padding: 0.45rem 0.75rem;
  font-size: 1rem; font-weight: 500;
  color: var(--color-sub);
  text-decoration: none;
  border-radius: 5px;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--color-accent);
  background: var(--color-accent-lt);
}

.nav-links a.active {
  color: var(--color-accent);
  background: var(--color-accent-lt);
  font-weight: 700;
}

.nav-lang {
  padding: 0.4rem 1rem;
  border: 1.5px solid var(--color-border);
  border-radius: 20px;
  font-size: 0.82rem; font-weight: 500;
  color: var(--color-muted);
  text-decoration: none;
  transition: all var(--transition);
  white-space: nowrap; flex-shrink: 0;
}

.nav-lang:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-lt);
}

/* Hamburger */
.nav-toggle {
  display: none; flex-direction: column; gap: 5px;
  cursor: pointer; padding: 4px;
  background: none; border: none; flex-shrink: 0;
}
.nav-toggle span {
  display: block; width: 24px; height: 2px;
  background: var(--color-text);
  transition: all var(--transition); border-radius: 2px;
}

.nav-check { display: none; }

/* navcheck가 체크되면 nav-mobile 내려오기
   (중요) nav-mobile이 navcheck “뒤에” 있어야 ~ 선택자가 먹습니다 */
#navcheck:checked ~ .nav-mobile { transform: translateY(0); }

/* Mobile Nav */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--nav-height); left: 0; right: 0;
  background: rgba(255,255,255,0.98);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  padding: 1rem 0;
  z-index: 999;
  transform: translateY(-100%);
  transition: transform var(--transition);
}
.nav-mobile.open { transform: translateY(0); }
.nav-mobile ul { list-style: none; padding: 0 1.5rem; }
.nav-mobile ul li a {
  display: block; padding: 0.85rem 0;
  color: var(--color-sub); text-decoration: none;
  font-size: 1rem; font-weight: 500;
  border-bottom: 1px solid var(--color-border);
  transition: color var(--transition);
}
.nav-mobile ul li a:hover,
.nav-mobile ul li a.active { color: var(--color-accent); }

/* === Page Layout === */
.page-wrap {
  position: relative; z-index: 1;
  padding-top: var(--nav-height);
  min-height: 100vh;
}

/* === Page Hero === */
.page-hero {
  padding: 5rem 2rem 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 3rem;

  /* 우주 배경 이미지 */
  background-image: url('img2/cger_bg.jpg');
  background-size: cover;
  background-position: center 40%;
  background-repeat: no-repeat;
}

/* 텍스트 가독성을 위한 오버레이 — 하단으로 갈수록 흰색 배경과 자연스럽게 연결 */
.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      to bottom,
      rgba(5, 10, 30, 0.55) 0%,
      rgba(5, 10, 30, 0.45) 50%,
      rgba(255, 255, 255, 0.92) 100%
    );
  z-index: 0;
}

.page-hero > * {
  position: relative;
  z-index: 1;
}

.page-hero-label {
  font-family: var(--font-mono);
  font-size: 0.68rem; letter-spacing: 0.22em;
  color: rgba(180, 210, 255, 0.95); text-transform: uppercase;
  margin-bottom: 0.75rem;
  text-shadow: 0 1px 6px rgba(0,0,0,0.5);
}
.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 3rem); font-weight: 700;
  color: #ffffff; line-height: 1.2;
  text-shadow: 0 2px 12px rgba(0,0,0,0.55);
}
.page-hero p {
  margin-top: 0.75rem;
  color: rgba(210, 225, 255, 0.88); font-size: 0.95rem;
  max-width: 600px; margin-left: auto; margin-right: auto;
  text-shadow: 0 1px 6px rgba(0,0,0,0.45);
}

/* === Container === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 2rem; }

/* === Section === */
.section { padding: 1rem 0; }

/* === Cards === */
.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px; padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}
.card:hover {
  background: var(--color-accent-lt);
  border-color: var(--color-border-hv);
  box-shadow: var(--shadow-hv);
  transform: translateY(-2px);
}

/* === Buttons === */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.6rem 1.4rem; border-radius: 6px;
  font-size: 0.85rem; font-weight: 600;
  text-decoration: none; transition: all var(--transition);
  cursor: pointer; border: none;
}
.btn-primary {
  background: var(--color-accent); color: #ffffff;
  box-shadow: 0 2px 8px rgba(26,91,191,0.25);
}
.btn-primary:hover {
  background: #154fa8; transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(26,91,191,0.3);
}
.btn-outline {
  border: 1.5px solid var(--color-border);
  color: var(--color-sub); background: transparent;
}
.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent); background: var(--color-accent-lt);
}

/* === Divider === */
.divider { height: 1px; background: var(--color-border); margin: 2rem 0; }

/* === Footer === */
.footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  padding: 2.5rem 2rem; margin-top: 4rem;
}
.footer-content {
  max-width: var(--max-width); margin: 0 auto;
  display: flex; flex-wrap: wrap;
  justify-content: space-between; align-items: center; gap: 1rem;
}
.footer-info { color: var(--color-muted); font-size: 0.8rem; line-height: 1.8; text-align: left; }
.footer-info strong { color: var(--color-sub); }
.footer-copy { color: var(--color-muted); font-size: 0.75rem; opacity: 0.7; }

/* === Utilities === */
.text-accent { color: var(--color-accent); }
.text-gold   { color: var(--color-gold); }
.text-muted  { color: var(--color-muted); }
.text-mono   { font-family: var(--font-mono); }
.text-center { text-align: center; }

/* === Responsive === */
@media (max-width: 1100px) {
  .nav-links { display: none; }
  .nav-lang  { display: none; }
  .nav-toggle { display: flex; }
  .nav-mobile { display: block; }
}
@media (max-width: 600px) {
  .container  { padding: 0 1rem; }
  .page-hero  { padding: 3.5rem 1rem 3rem; background-position: center center; }
  .section    { padding: 2.5rem 0; }
  .footer-content { flex-direction: column; text-align: center; }
  .footer-info    { text-align: center; }
}