:root {
    --bg-color: #0f172a;
    --panel-bg: rgba(30, 41, 59, 0.8);
    --primary: #38bdf8;
    --primary-hover: #0284c7;
    --secondary: #c084fc;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --danger: #ef4444;
    --success: #10b981;
    --border: rgba(56, 189, 248, 0.2);
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
body { background-color: var(--bg-color); color: var(--text-main); line-height: 1.6; overflow-x: hidden; }
.hidden { display: none !important; }
.page { min-height: 100vh; }
.active { display: block; }
.mt-2 { margin-top: 1rem; }
.text-center { text-align: center; }

/* Typography & Effects */
.glow-text {
    color: var(--primary);
    text-shadow: 0 0 10px rgba(56, 189, 248, 0.5);
    margin-bottom: 1rem;
}

/* Authentication */
.auth-container { display: flex; justify-content: center; align-items: center; background: radial-gradient(circle at center, #1e293b 0%, #0f172a 100%); }
.auth-box { background: var(--panel-bg); padding: 2.5rem; border-radius: 15px; border: 1px solid var(--border); box-shadow: 0 8px 32px rgba(0,0,0,0.3); width: 100%; max-width: 400px; text-align: center; backdrop-filter: blur(10px); }
.tab-container { display: flex; margin: 1.5rem 0; background: rgba(0,0,0,0.2); border-radius: 8px; overflow: hidden; }
.tab-btn { flex: 1; padding: 0.8rem; border: none; background: transparent; color: var(--text-muted); cursor: pointer; transition: 0.3s; }
.tab-btn.active { background: var(--primary); color: #fff; font-weight: bold; }
.auth-form { display: none; flex-direction: column; gap: 1rem; }
.auth-form.active { display: flex; }
.password-wrapper { position: relative; width: 100%; }
.password-wrapper input { width: 100%; }
.btn-icon { position: absolute; right: 10px; top: 50%; transform: translateY(-50%); background: none; border: none; cursor: pointer; font-size: 1.2rem; }

/* Inputs & Buttons */
input, textarea, select { width: 100%; padding: 0.8rem 1rem; background: rgba(15, 23, 42, 0.6); border: 1px solid var(--border); color: var(--text-main); border-radius: 8px; outline: none; transition: 0.3s; }
input:focus, textarea:focus { border-color: var(--primary); box-shadow: 0 0 8px rgba(56, 189, 248, 0.3); }
button { font-weight: 600; border-radius: 8px; cursor: pointer; transition: 0.3s; border: none; }
.btn-primary { background: var(--primary); color: #000; padding: 0.8rem 1.5rem; width: 100%; }
.btn-primary:hover { background: var(--primary-hover); color: #fff; box-shadow: 0 0 15px var(--primary-hover); }
.btn-secondary { background: var(--secondary); color: #fff; padding: 0.6rem 1rem; }
.btn-danger { background: var(--danger); color: #fff; padding: 0.6rem 1rem; }
.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.9rem; }

/* Layout App Siswa */
.navbar { display: flex; justify-content: space-between; align-items: center; padding: 1rem 2rem; background: var(--panel-bg); border-bottom: 1px solid var(--border); backdrop-filter: blur(10px); }
.nav-brand { font-size: 1.5rem; font-weight: bold; color: var(--primary); letter-spacing: 2px; }
.main-layout { display: flex; min-height: calc(100vh - 70px); }
.sidebar { width: 250px; background: rgba(30, 41, 59, 0.5); padding: 1.5rem; border-right: 1px solid var(--border); display: flex; flex-direction: column; justify-content: space-between; }
.nav-menu { list-style: none; }
.nav-menu li { padding: 0.8rem 1rem; margin-bottom: 0.5rem; border-radius: 8px; cursor: pointer; transition: 0.3s; color: var(--text-muted); }
.nav-menu li:hover, .nav-menu li.active { background: rgba(56, 189, 248, 0.1); color: var(--primary); border-left: 4px solid var(--primary); }
.content-area { flex: 1; padding: 2rem; overflow-y: auto; }
.card { background: var(--panel-bg); padding: 1.5rem; border-radius: 12px; border: 1px solid var(--border); box-shadow: 0 4px 15px rgba(0,0,0,0.2); margin-bottom: 1.5rem; }

/* Progress Bar */
.progress-container { margin-top: auto; padding-top: 1rem; border-top: 1px solid var(--border); }
.progress-bar { width: 100%; height: 8px; background: #334155; border-radius: 4px; margin-top: 0.5rem; overflow: hidden; }
.progress-fill { height: 100%; background: var(--primary); width: 0%; transition: 0.5s ease; }

/* Materi */
.materi-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.materi-nav-top { display: flex; align-items: center; gap: 1rem; }
.materi-nav-top button { padding: 0.5rem 1rem; background: transparent; border: 1px solid var(--primary); color: var(--primary); }
.materi-nav-top button:disabled { opacity: 0.3; cursor: not-allowed; }

/* Simulasi & Interaktif */
.simulasi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }
.sim-card { text-align: center; }
.sim-card h3 { margin-bottom: 0.5rem; color: var(--secondary); }
.draggable-item { padding: 0.8rem; background: var(--primary); color: #000; margin: 0.5rem 0; border-radius: 5px; cursor: grab; font-weight: bold; }
.drop-zone { min-height: 150px; border: 2px dashed var(--border); border-radius: 8px; padding: 1rem; margin-top: 1rem; background: rgba(0,0,0,0.2); }

/* Table Guru */
.container { padding: 2rem; max-width: 1200px; margin: 0 auto; }
.futuristic-table { width: 100%; border-collapse: collapse; text-align: left; }
.futuristic-table th, .futuristic-table td { padding: 1rem; border-bottom: 1px solid var(--border); }
.futuristic-table th { background: rgba(56, 189, 248, 0.1); color: var(--primary); }
.futuristic-table tr:hover { background: rgba(255,255,255,0.02); }

/* Toast */
.toast { position: fixed; bottom: 20px; right: 20px; background: var(--success); color: white; padding: 1rem 2rem; border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.3); z-index: 1000; transition: 0.3s; }
.toast.error { background: var(--danger); }

@media (max-width: 768px) {
    .main-layout { flex-direction: column; }
    .sidebar { width: 100%; border-right: none; border-bottom: 1px solid var(--border); }
}