:root {
    --bg-color: #121212;
    --panel-bg: #1e1e1e;
    --accent: #2ecc71;
    --text-primary: #e0e0e0;
    --text-sec: #999;
    --border-color: #333;
    --danger: #e74c3c;
    --blue: #3498db;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg-color); color: var(--text-primary); font-family: 'Segoe UI', sans-serif; height: 100vh; display: flex; flex-direction: column; overflow: hidden; }

.nav-home {
    position: fixed;
    bottom: 1.5rem;
    left: 1.5rem;
    width: 3.5rem;
    height: 3.5rem;
    background: #2ecc71;
    border: 2px solid white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #121212;
    z-index: 999999;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    text-decoration: none;
    box-shadow: 0 0 20px rgba(46, 204, 113, 0.6);
}

.nav-home svg { width: 1.2rem; height: 1.2rem; stroke: currentColor; }

.nav-home:hover {
    transform: scale(1.1) rotate(-10deg);
    background: var(--accent);
    color: #000;
}

.navbar { background: var(--panel-bg); border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; padding: 12px 20px; }
.logo { font-size: 1.3rem; font-weight: 700; color: #fff; display: flex; align-items: center; gap: 10px;}
.badge { font-size: 0.75rem; background: var(--accent); color: #000; padding: 3px 8px; border-radius: 4px; font-weight: bold; }
.tools button { background: transparent; color: var(--text-primary); border: 1px solid #555; padding: 8px 15px; border-radius: 4px; cursor: pointer; transition: 0.2s; font-size: 0.9rem;}
.tools button:hover { background: #555; }

.app-container { display: flex; flex: 1; overflow: hidden; }
.sidebar { width: 400px; background: var(--bg-color); padding: 20px; border-right: 1px solid var(--border-color); display: flex; flex-direction: column; gap: 14px; overflow-y: auto; }
.main-content { flex: 1; display: flex; flex-direction: column; padding: 25px; gap: 15px; background: #161616; overflow: hidden; }

.section-title { font-size: 0.85rem; font-weight: 700; color: #fff; letter-spacing: 1px; }

input, select, textarea {
    background: #252525; border: 2px solid var(--border-color); border-radius: 6px; padding: 10px;
    color: var(--accent); font-family: 'Segoe UI', sans-serif; font-size: 0.95rem; width: 100%; outline: none; transition: 0.2s;
}
input:focus, select:focus, textarea:focus { border-color: var(--accent); }
textarea { resize: vertical; }

.input-group { display: flex; gap: 10px; }

.video-container { width: 100%; aspect-ratio: 4/3; background: #000; border: 2px solid var(--accent); border-radius: 6px; overflow: hidden; position: relative; }
video { width: 100%; height: 100%; object-fit: cover; }

button { border: none; border-radius: 6px; padding: 12px; font-size: 0.95rem; font-weight: bold; cursor: pointer; transition: 0.2s; outline: none; width: 100%; }
.primary-btn { background: #252525; border: 2px solid var(--accent); color: var(--accent); }
.primary-btn:hover:not(:disabled) { background: var(--accent); color: #000; }
.primary-btn:disabled { opacity: 0.5; cursor: not-allowed; border-color: #555; color: #555; }

.success-btn { background: var(--accent); color: #000; border: 2px solid var(--accent); }
.success-btn:hover { background: #27ae60; border-color: #27ae60;}
.danger-btn { background: transparent; border: 2px solid var(--danger); color: var(--danger); }
.danger-btn:hover { background: var(--danger); color: #fff; }

.btn-row { display: flex; gap: 12px; }
.qty-group { display: flex; align-items: center; gap: 12px; font-weight: bold; }
.qty-group input { width: 100px; text-align: center;}

.console { flex: 1; min-height: 120px; background: #1a1a1a; border: 1px solid var(--border-color); border-radius: 6px; padding: 10px; font-family: monospace; font-size: 0.85rem; overflow-y: auto; color: #ccc; line-height: 1.4;}
.log-sys { color: var(--accent); font-weight: bold; }
.log-ai { color: var(--blue); font-weight: bold; }
.log-err { color: var(--danger); font-weight: bold; }

.table-container { flex: 1; overflow: auto; border: 1px solid var(--border-color); border-radius: 8px; background: #1e1e1e;}
.inventory-table { width: 100%; border-collapse: collapse; text-align: left; }
.inventory-table th { background: #252525; color: var(--accent); padding: 14px 16px; position: sticky; top: 0; box-shadow: 0 1px 0 var(--border-color); z-index: 10; font-size: 0.9rem;}
.inventory-table td { padding: 12px 16px; border-bottom: 1px solid rgba(255,255,255,0.05); font-size: 0.95rem;}
.inventory-table tr:hover td { background: rgba(255,255,255,0.03); }

.act-btn { background: transparent; color: var(--text-sec); padding: 6px; font-size: 1.25rem; width: auto; margin-right: 6px; border-radius: 4px;}
.act-btn:hover { color: var(--accent); background: rgba(255,255,255,0.05); transform: scale(1.1); }
.act-btn.del:hover { color: var(--danger); }

/* Modal Styles */
.modal { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.85); z-index: 2000; align-items: center; justify-content: center; backdrop-filter: blur(5px);}
.modal.active { display: flex; }
.modal-content { background: var(--bg-color); padding: 30px; border-radius: 8px; width: 550px; border: 1px solid var(--border-color); display: flex; flex-direction: column; gap: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.5);}
.modal-content h3 { margin-bottom: 15px; color: var(--accent); font-size: 1.4rem;}
.modal-content label { font-size: 0.85rem; color: var(--text-sec); font-weight: 600; text-transform: uppercase; margin-bottom: -6px;}

/* Mobile Optimization: Seamless restructuring on smartphones */
@media (max-width: 900px) {
    .app-container { flex-direction: column; overflow-y: auto; }
    body { height: auto; overflow: auto; }
    .sidebar { width: 100%; border-right: none; border-bottom: 2px solid var(--accent); }
    .main-content { overflow: visible; min-height: 800px;}
}

/* Category Concertina (Collapsible) Logic */
.category-concertina { display: flex; flex-direction: column; gap: 10px; }
details {
    background: #1e1e1e;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: 0.3s;
}
details[open] { border-color: var(--accent); box-shadow: 0 4px 15px rgba(0,0,0,0.3); }

summary {
    list-style: none;
    padding: 15px 20px;
    background: #252525;
    color: var(--accent);
    font-weight: 700;
    cursor: pointer;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 1px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
}
summary::-webkit-details-marker { display: none; }
summary:after { content: '▼'; font-size: 0.7rem; transition: 0.3s; color: var(--text-sec); }
details[open] summary:after { transform: rotate(180deg); color: var(--accent); }
summary:hover { background: #2a2a2a; }

.category-table-wrapper { padding: 0; overflow-x: auto; }
.category-table { width: 100%; border-collapse: collapse; text-align: left; }
.category-table th { 
    background: rgba(255,255,255,0.03); 
    color: var(--text-sec); 
    padding: 12px 16px; 
    font-size: 0.75rem; 
    text-transform: uppercase;
    border-bottom: 1px solid var(--border-color);
}
.category-table td { padding: 12px 16px; border-bottom: 1px solid rgba(255,255,255,0.05); font-size: 0.95rem; }
.category-table tr:hover td { background: rgba(255,255,255,0.02); }