@import url('https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Rajdhani:wght@400;600;700&family=Noto+Sans+KR:wght@300;400;700&display=swap');

:root {
  --bg-primary: #0A0E17;
  --bg-secondary: #0F1420;
  --bg-card: #131929;
  --bg-card-hover: #1A2235;
  --border: #1E2D45;
  --accent-green: #00FF88;
  --accent-blue: #3B9EFF;
  --accent-red: #FF4455;
  --accent-yellow: #FFD700;
  --text-primary: #E2EBF8;
  --text-secondary: #8899BB;
  --text-muted: #4A5A7A;
  --glow-green: 0 0 20px rgba(0,255,136,0.3);
  --glow-blue: 0 0 20px rgba(59,158,255,0.3);
}

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

html { scroll-behavior: smooth; }

body {
  background: radial-gradient(circle at 50% 50%, #161e2e 0%, #0A0E17 100%);
  color: var(--text-primary);
  font-family: 'Noto Sans KR', sans-serif;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── REMOVE CANVAS BG ── */
#matrix-canvas {
  display: none;
}

/* ── NAVBAR ── */
nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(10,14,23,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: 60px;
  display: flex; align-items: center;
}

.nav-inner {
  max-width: 1200px; margin: 0 auto;
  width: 100%; padding: 0 24px;
  display: flex; align-items: center; gap: 0;
}

.nav-logo {
  font-family: 'Share Tech Mono', monospace;
  font-size: 18px;
  color: var(--accent-green);
  text-decoration: none;
  letter-spacing: 2px;
  margin-right: 40px;
  text-shadow: var(--glow-green);
}

.nav-logo span { color: var(--text-secondary); }

.nav-links {
  display: flex; gap: 4px;
  list-style: none; flex: 1;
  align-items: center;
}

.nav-user-info {
  color: var(--accent-blue);
  font-size: 13px;
  font-family: 'Share Tech Mono', monospace;
  padding: 6px 14px; /* 다른 링크들과 동일한 패딩 적용 */
  display: flex;
  align-items: center;
  line-height: 1; /* 폰트 베이스라인 교정 */
  height: auto;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-family: 'Rajdhani', sans-serif;
  font-size: 14px; font-weight: 600;
  letter-spacing: 1px;
  padding: 6px 14px;
  border-radius: 4px;
  transition: all 0.2s;
  text-transform: uppercase;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-green);
  background: rgba(0,255,136,0.07);
}

.nav-actions { display: flex; gap: 10px; margin-left: auto; }

.btn-join, .btn-login {
  font-family: 'Rajdhani', sans-serif;
  font-size: 13px; font-weight: 700;
  padding: 7px 20px;
  border-radius: 4px;
  cursor: pointer;
  letter-spacing: 1px;
  text-transform: uppercase;
  border: none;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-join {
  background: transparent;
  border: 1px solid var(--accent-green);
  color: var(--accent-green);
}
.btn-join:hover { background: var(--accent-green); color: #000; box-shadow: var(--glow-green); }

.btn-login {
  background: var(--accent-blue);
  color: #fff;
}
.btn-login:hover { background: #2a8fff; box-shadow: var(--glow-blue); }

/* ── HERO ── */
.hero {
  position: relative; z-index: 1;
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  padding: 80px 24px 60px;
  text-align: center;
}

.hero::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 40%, rgba(59,158,255,0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content { max-width: 780px; }

.hero-badge {
  display: inline-block;
  font-family: 'Share Tech Mono', monospace;
  font-size: 11px;
  color: var(--accent-green);
  background: rgba(0,255,136,0.08);
  border: 1px solid rgba(0,255,136,0.25);
  padding: 5px 16px;
  border-radius: 2px;
  letter-spacing: 3px;
  margin-bottom: 32px;
}

.hero-title {
  font-family: 'Rajdhani', sans-serif;
  font-size: clamp(42px, 8vw, 80px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -1px;
  margin-bottom: 12px;
}

.hero-title .line1 { display: block; color: var(--text-primary); }
.hero-title .line2 {
  display: block;
  color: transparent;
  -webkit-text-stroke: 1px var(--accent-green);
  text-shadow: none;
}

.hero-subtitle {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 20px auto 40px;
  max-width: 520px;
}

.hero-cta {
  display: flex; gap: 14px; justify-content: center;
}

.btn-primary {
  font-family: 'Rajdhani', sans-serif;
  font-size: 15px; font-weight: 700;
  padding: 14px 36px;
  background: var(--accent-green);
  color: #000;
  border: none; border-radius: 4px;
  cursor: pointer;
  letter-spacing: 2px;
  text-transform: uppercase;
  text-decoration: none;
  transition: all 0.2s;
  box-shadow: 0 4px 24px rgba(0,255,136,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(0,255,136,0.4); }

/* ── SECTION ── */
section {
  position: relative; z-index: 1;
  padding: 80px 24px;
}

.section-inner { max-width: 1200px; margin: 0 auto; }

.section-label {
  font-family: 'Share Tech Mono', monospace;
  font-size: 11px;
  color: var(--accent-blue);
  letter-spacing: 3px;
  margin-bottom: 12px;
  text-transform: uppercase;
}

.section-title {
  font-family: 'Rajdhani', sans-serif;
  font-size: 36px; font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 48px;
  letter-spacing: -0.5px;
}

.section-title span { color: var(--accent-green); }

/* ── CHALLENGES ── */
.challenges-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.challenge-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 24px;
  transition: all 0.25s;
  position: relative;
  overflow: hidden;
}

.challenge-card.solved {
    border-color: var(--accent-green);
    box-shadow: inset 0 0 10px rgba(0,255,136,0.1);
}

.challenge-top {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 14px;
}

.challenge-id {
  font-family: 'Share Tech Mono', monospace;
  font-size: 11px;
  color: var(--text-muted);
}

.badge {
  font-family: 'Rajdhani', sans-serif;
  font-size: 11px; font-weight: 700;
  padding: 3px 10px;
  border-radius: 2px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.badge-easy { background: rgba(0,255,136,0.12); color: var(--accent-green); }
.badge-medium { background: rgba(255,215,0,0.12); color: var(--accent-yellow); }
.badge-hard { background: rgba(255,68,85,0.12); color: var(--accent-red); }

.challenge-name {
  font-family: 'Rajdhani', sans-serif;
  font-size: 18px; font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.challenge-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 18px;
}

.challenge-meta {
  display: flex; justify-content: space-between; align-items: center;
  font-family: 'Share Tech Mono', monospace;
  font-size: 12px;
}

.challenge-meta .pts { color: var(--accent-blue); }

/* ── RANKING TABLE ── */
.ranking-wrap {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.ranking-header {
  display: grid;
  grid-template-columns: 60px 1fr 100px;
  padding: 12px 24px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.ranking-header span {
  font-family: 'Rajdhani', sans-serif;
  font-size: 12px; font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.ranking-row {
  display: grid;
  grid-template-columns: 60px 1fr 100px;
  padding: 14px 24px;
  border-bottom: 1px solid rgba(30,45,69,0.6);
  align-items: center;
  transition: background 0.15s;
}
.ranking-row:last-child { border-bottom: none; }
.ranking-row:hover { background: var(--bg-card-hover); }

.rank-num {
  font-family: 'Share Tech Mono', monospace;
  font-size: 14px;
  color: var(--text-muted);
}

.username {
  font-family: 'Share Tech Mono', monospace;
  font-size: 14px;
  color: var(--text-primary);
}

.rank-score {
  font-family: 'Share Tech Mono', monospace;
  font-size: 14px;
  color: var(--accent-green);
}

/* ── FOOTER ── */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 32px 24px;
}

.footer-bottom {
  max-width: 1200px; margin: 0 auto;
  display: flex; justify-content: space-between; align-items: center;
}

.footer-bottom p {
  font-family: 'Share Tech Mono', monospace;
  font-size: 11px;
  color: var(--text-muted);
}

/* ── EMPHASIZED CODE STYLE ── */
code {
    background: rgba(0, 0, 0, 0.4);
    color: var(--accent-green);
    padding: 3px 8px;
    border-radius: 4px;
    font-family: 'Share Tech Mono', monospace;
    font-size: 13px;
    border: 1px solid rgba(0, 255, 136, 0.3);
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.1);
    margin: 0 4px;
    display: inline-block;
    vertical-align: middle;
}

/* ── GUIDE BOX COMMON STYLE ── */
.guide-box {
    margin-top: 40px;
    padding: 24px;
    background: rgba(13, 17, 23, 0.8);
    border: 1px dashed var(--border);
    border-radius: 6px;
}

.guide-box h4 {
    color: var(--accent-yellow);
    margin-bottom: 12px;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.guide-box p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.8;
}