:root {
    --bg-dark: #05070a;
    --bg-card: #0d1117;
    --bg-sidebar: #12161d;
    --bg-solved: #020406;
    --accent: #00f2ff;
    --accent-glow: rgba(0, 242, 255, 0.5);
    --text-main: #e6edf3;
    --text-dim: #8b949e;
    --border: #30363d;
    --very-easy: #00ffaa;
    --easy: #2ea043;
    --medium: #e3b341;
    --hard: #f85149;
}

html { scroll-behavior: smooth; }
* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    overflow-x: hidden;
}

/* NAVIGATION & LOGO */
nav {
    display: flex; justify-content: space-between; align-items: center;
    padding: 1rem 5%; background: rgba(5, 7, 10, 0.9);
    backdrop-filter: blur(10px); border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 100;
}
.logo-link { text-decoration: none; }
.logo-box {
    font-family: 'Orbitron', sans-serif; background: var(--accent);
    color: var(--bg-dark); padding: 5px 15px; font-weight: 900;
    clip-path: polygon(10% 0, 100% 0, 90% 100%, 0 100%); transition: 0.3s;
    display: inline-block;
}
.logo-box:hover { box-shadow: 0 0 15px var(--accent); transform: scale(1.05); }

.nav-links { display: flex; list-style: none; gap: 1.2rem; }
.nav-links a { color: var(--text-dim); text-decoration: none; font-size: 0.75rem; text-transform: uppercase; font-weight: 600; }
.nav-links a:hover { color: var(--accent); }

.score-container { color: var(--accent); font-family: 'Orbitron', sans-serif; border: 1px solid var(--accent); padding: 5px 15px; border-radius: 4px; }

/* DASHBOARD */
.hero { padding: 60px 5%; text-align: center; border-bottom: 1px solid var(--border); }
.glitch { font-family: 'Orbitron', sans-serif; font-size: 2.5rem; color: var(--accent); }
.container { max-width: 1200px; margin: 40px auto; padding: 0 20px; }
.category-block { margin-bottom: 60px; scroll-margin-top: 100px; }
.category-title { color: var(--text-dim); font-family: 'Orbitron', sans-serif; margin-bottom: 20px; font-size: 1rem; }

.grid-challenges { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }

.challenge-card { background: var(--bg-card); border: 1px solid var(--border); padding: 25px; border-radius: 8px; cursor: pointer; transition: 0.3s; }
.challenge-card:hover { border-color: var(--accent); transform: translateY(-5px); }

/* ÉTAT RÉUSSI (Sombre) */
.challenge-card.solved { background: var(--bg-solved) !important; opacity: 0.4; cursor: default; pointer-events: none; filter: grayscale(1); }
.challenge-card.solved h3::after { content: " \f058"; font-family: "Font Awesome 6 Free"; font-weight: 900; color: var(--very-easy); margin-left: 10px; }

.card-diff { font-size: 0.7rem; font-weight: 800; text-transform: uppercase; margin-bottom: 10px; display: inline-block; padding: 2px 8px; border: 1px solid; border-radius: 3px; }

/* SIDEBAR & BOUTONS TÉLÉCHARGEMENT */
.sidebar { position: fixed; top: 0; right: -450px; width: 400px; height: 100%; background: var(--bg-sidebar); z-index: 1001; transition: 0.5s; border-left: 1px solid var(--border); }
.sidebar.active { right: 0; }
.sidebar-content { padding: 40px; display: flex; flex-direction: column; height: 100%; }
.btn-close { background: none; border: none; color: var(--text-dim); font-size: 1.5rem; cursor: pointer; }
.description-box { background: rgba(0,0,0,0.3); padding: 20px; border-radius: 8px; flex-grow: 1; border: 1px solid var(--border); margin: 20px 0; }

.download-btn {
    display: inline-block; margin-top: 15px; padding: 10px 15px; 
    background: rgba(0, 242, 255, 0.1); color: var(--accent) !important; 
    border: 1px solid var(--accent); text-decoration: none; border-radius: 4px; font-weight: bold;
}
.download-btn:hover { background: var(--accent); color: var(--bg-dark) !important; }

.submission-zone input { width: 100%; padding: 12px; background: var(--bg-dark); border: 1px solid var(--border); color: white; margin-bottom: 10px; border-radius: 4px; }
.submission-zone button { width: 100%; padding: 12px; background: var(--accent); color: var(--bg-dark); border: none; font-weight: 800; cursor: pointer; border-radius: 4px; }

.overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.8); z-index: 1000; display: none; }
.overlay.active { display: block; }

/* Difficultés */
.v-easy { color: var(--very-easy); border-color: var(--very-easy); }
.easy { color: var(--easy); border-color: var(--easy); }
.medium { color: var(--medium); border-color: var(--medium); }
.hard { color: var(--hard); border-color: var(--hard); }

a {
    color: #00f2ff;
}