/* ===== GLOBAL ===== */
body {
    margin: 0;
    font-family: 'Segoe UI', Arial, sans-serif;
    background: linear-gradient(135deg, #eef2ff, #f8fafc);
    color: #1e2937;
}

/* ===== LAYOUT ===== */
.container {
    display: flex;
    gap: 20px;
    padding: 20px;
}

/* ===== PANEL ===== */
.panel {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    border-radius: 16px;
    padding: 20px;
    flex: 1;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    transition: 0.3s;
}

.panel:hover {
    transform: translateY(-4px);
}

/* SIZE */
.left {
    flex: 1;
}

.center {
    flex: 2;
}

.right {
    flex: 1;
}

/* ===== TEXT ===== */
h2 {
    margin-top: 0;
}

h3 {
    margin-bottom: 10px;
}

/* ===== TEXTAREA ===== */
textarea {
    width: 95%;
    height: 200px;
    border-radius: 12px;
    border: 2px solid #cbd5e1;
    padding: 10px;
    font-family: monospace;
    font-size: 14px;
    resize: none;
    margin-bottom: 15px;
}

textarea:focus {
    border-color: #3b82f6;
    outline: none;
}

/* ===== CONTROLS ===== */
.controls {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

/* ===== BUTTON ===== */
button {
    padding: 10px 14px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: bold;
    background: #3b82f6;
    color: white;
    transition: 0.2s;
}

button:hover {
    background: #2563eb;
}

/* ===== SELECT ===== */
select {
    padding: 10px;
    border-radius: 10px;
    border: 2px solid #cbd5e1;
}

/* ===== GRAPH ===== */
#network {
    height: 600px;
    border-radius: 12px;
    border: 2px solid #e2e8f0;
    background: #ffffff;
}

/* ===== INFO ===== */
#info {
    background: #ecfdf5;
    padding: 12px;
    border-radius: 10px;
    margin-bottom: 15px;
}

/* ===== COLOR GROUP ===== */
.color-group {
    padding: 10px;
    border-left: 5px solid #10b981;
    background: #f8fafc;
    margin-bottom: 8px;
    border-radius: 8px;
}

/* ===== EXPLANATION BOX (QUAN TRỌNG) ===== */
.explanation-box {
    background: #f1f5f9;
    border-left: 5px solid #3b82f6;
    padding: 12px;
    border-radius: 10px;
    margin-top: 10px;
    line-height: 1.6;
    font-size: 14px;
    max-height: 200px;
    overflow-y: auto;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1000px) {
    .container {
        flex-direction: column;
    }
}