:root {
  --bg-main: #0a0e17;
  --bg-card: rgba(18, 24, 38, 0.75);
  --bg-card-hover: rgba(28, 38, 58, 0.9);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(56, 189, 248, 0.3);
  --primary: #38bdf8;
  --primary-glow: #0284c7;
  --accent-purple: #a855f7;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "Source Code Pro", "Fira Code", monospace;
}

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

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: var(--font-family);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(56, 189, 248, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 30%, rgba(168, 85, 247, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 50% 80%, rgba(16, 185, 129, 0.06) 0%, transparent 50%),
    linear-gradient(to bottom, rgba(10, 14, 23, 0.9), rgba(10, 14, 23, 1));
}

/* Subtle background cyber grid */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-size: 40px 40px;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  pointer-events: none;
  z-index: 0;
}

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
  z-index: 1;
}

/* Navigation Header */
header {
  position: sticky;
  top: 0;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(10, 14, 23, 0.8);
  border-bottom: 1px solid var(--border-color);
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #fff;
}

.logo-badge {
  background: linear-gradient(135deg, #0284c7 0%, #38bdf8 100%);
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 20px;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.4);
}

.logo-text {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

/* User / Login Pill */
.user-pill {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  transition: all 0.2s;
}

.user-pill:hover {
  border-color: var(--border-glow);
  background: rgba(255, 255, 255, 0.08);
}

.user-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
}

.btn-login {
  background: linear-gradient(135deg, #2563eb 0%, #38bdf8 100%);
  color: #fff;
  padding: 8px 18px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 13px;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
  transition: all 0.2s;
}

.btn-login:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.45);
}

/* Hero Section */
.hero {
  padding: 50px 0 35px 0;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 16px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.hero-title {
  font-size: 42px;
  font-weight: 900;
  margin-bottom: 14px;
  letter-spacing: -1px;
  background: linear-gradient(135deg, #ffffff 30%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 30px auto;
  line-height: 1.6;
}

/* Category Filter Bar */
.filter-bar {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 8px 18px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

.filter-btn.active {
  background: var(--primary);
  color: #0b0f19;
  border-color: var(--primary);
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.4);
}

/* Games Grid */
.games-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 24px;
  margin-bottom: 60px;
}

.game-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 18px;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(12px);
  position: relative;
}

.game-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-glow);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35), 0 0 20px rgba(56, 189, 248, 0.15);
  background: var(--bg-card-hover);
}

.game-thumb {
  height: 170px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 64px;
  position: relative;
  overflow: hidden;
}

.thumb-2048 {
  background: linear-gradient(135deg, #1e1b4b 0%, #4338ca 100%);
}
.thumb-racer {
  background: linear-gradient(135deg, #022c22 0%, #059669 100%);
}
.thumb-snake {
  background: linear-gradient(135deg, #1e293b 0%, #0284c7 100%);
}
.thumb-minesweeper {
  background: linear-gradient(135deg, #311025 0%, #be123c 100%);
}
.thumb-gomoku {
  background: linear-gradient(135deg, #2a1b02 0%, #b45309 100%);
}
.thumb-tetris {
  background: linear-gradient(135deg, #2e1065 0%, #7c3aed 100%);
}

.game-badge {
  position: absolute;
  top: 14px;
  right: 14px;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 11px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 20px;
  letter-spacing: 0.5px;
}

.game-body {
  padding: 22px;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.game-title {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 8px;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.game-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 18px;
}

.game-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 16px;
}

.game-stats {
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 12px;
}

.game-stats span strong {
  color: #fff;
}

.btn-play {
  background: #2563eb;
  color: #fff;
  text-decoration: none;
  padding: 8px 18px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-play:hover {
  background: #3b82f6;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
}

/* Modal for Games & Leaderboard */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-backdrop.active {
  display: flex;
}

.modal-window {
  background: #0f172a;
  border: 1px solid var(--border-color);
  border-radius: 18px;
  width: 100%;
  max-width: 900px;
  max-height: 92vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7), 0 0 30px rgba(56, 189, 248, 0.2);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border-color);
  background: rgba(15, 23, 42, 0.95);
}

.modal-title {
  font-size: 18px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.modal-close {
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: #fff;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.modal-close:hover {
  background: #ef4444;
}

.modal-body {
  padding: 0;
  flex: 1;
  overflow: auto;
  position: relative;
}

.modal-iframe {
  width: 100%;
  height: 650px;
  border: none;
  display: block;
}

/* Leaderboard Table */
.leaderboard-wrap {
  padding: 24px;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.leaderboard-table th {
  text-align: left;
  padding: 12px 16px;
  color: var(--text-muted);
  font-weight: 600;
  border-bottom: 1px solid var(--border-color);
}

.leaderboard-table td {
  padding: 14px 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  font-weight: 800;
  font-size: 12px;
}

.rank-1 { background: #eab308; color: #000; box-shadow: 0 0 10px rgba(234, 179, 8, 0.5); }
.rank-2 { background: #94a3b8; color: #000; }
.rank-3 { background: #b45309; color: #fff; }

/* Footer */
footer {
  border-top: 1px solid var(--border-color);
  padding: 30px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

footer a {
  color: var(--primary);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}