/* Topological Sort Step-Through - vis-network MicroSim
 * =====================================================
 * Full-height network canvas with absolute-positioned overlays.
 * Overlays are SIBLINGS of #network (vis-network erases #network innerHTML).
 */

/* ===========================================
   RESET & BASE
   =========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: aliceblue;
}

/* ===========================================
   CONTAINER & NETWORK CANVAS
   =========================================== */
.container {
    position: relative;
    width: 100%;
    height: 100vh;
}

#network {
    width: 100%;
    height: 100%;
    background-color: aliceblue;
}

/* ===========================================
   TITLE (Top Center)
   =========================================== */
.title {
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 18px;
    font-weight: bold;
    color: black;
    background-color: rgba(240, 248, 255, 0.85);
    padding: 4px 12px;
    border-radius: 6px;
    white-space: nowrap;
    z-index: 10;
}

/* ===========================================
   LEGEND (Upper Left)
   =========================================== */
.legend {
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 6px 8px;
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    z-index: 10;
}

.legend-item {
    display: flex;
    align-items: center;
    margin: 3px 0;
    font-size: 11px;
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    margin-right: 6px;
    border: 2px solid #333;
}

.color-gray { background-color: #d9d9d9; }
.color-gold { background-color: #ffca28; }
.color-green { background-color: #66bb6a; }

/* ===========================================
   RIGHT PANEL (Controls, Lists, Status)
   =========================================== */
.right-panel {
    position: absolute;
    top: 46px;
    right: 10px;
    width: 250px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 10;
    max-height: calc(100vh - 56px);
    overflow-y: auto;
}

.controls {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
    background-color: rgba(255, 255, 255, 0.97);
    padding: 10px 12px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.step-counter {
    font-size: 13px;
    font-weight: bold;
    color: #555;
    width: 100%;
    margin-bottom: 2px;
}

.btn {
    padding: 8px 16px;
    font-size: 13px;
    font-weight: bold;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background-color: #2196f3;
    color: white;
}

.btn-primary:hover {
    background-color: #1976d2;
}

.btn-primary:disabled {
    background-color: #bbdefb;
    color: #eee;
    cursor: not-allowed;
}

.btn-secondary {
    background-color: #757575;
    color: white;
}

.btn-secondary:hover {
    background-color: #616161;
}

/* ===========================================
   LIST PANELS (Output Order + Eligible Now)
   =========================================== */
.list-panel {
    background-color: rgba(255, 255, 255, 0.97);
    border-radius: 8px;
    padding: 10px 12px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.list-title {
    font-weight: bold;
    font-size: 13px;
    color: #333;
    margin-bottom: 6px;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 4px;
}

.output-list {
    list-style-position: inside;
    font-size: 12px;
    line-height: 1.7;
    color: #2e7d32;
}

.output-list li {
    font-weight: bold;
}

.output-list li.empty-note {
    color: #999;
    font-weight: normal;
    font-style: italic;
    list-style: none;
}

.eligible-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    min-height: 22px;
}

.eligible-list li {
    background-color: #ffca28;
    color: #5d4037;
    font-size: 11px;
    font-weight: bold;
    padding: 3px 8px;
    border-radius: 10px;
    border: 1px solid #f5a623;
}

.eligible-list li.none-note {
    background: none;
    border: none;
    color: #999;
    font-weight: normal;
    font-style: italic;
    padding: 3px 0;
}

/* ===========================================
   STATUS / EXPLANATION
   =========================================== */
.status-info {
    background-color: rgba(255, 255, 255, 0.97);
    border-radius: 8px;
    padding: 10px 12px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    border-left: 4px solid #2196f3;
}

.status-title {
    font-weight: bold;
    font-size: 12px;
    color: #1976d2;
    margin-bottom: 5px;
}

.status-text {
    font-size: 12px;
    line-height: 1.5;
    color: #333;
}

.status-text .caption {
    display: block;
    margin-top: 6px;
    font-style: italic;
    color: #666;
}

/* ===========================================
   RESPONSIVE (stack below 700px)
   =========================================== */
@media (max-width: 700px) {
    .container {
        height: auto;
        min-height: 100vh;
    }

    #network {
        height: 320px;
    }

    .right-panel {
        position: static;
        width: auto;
        max-height: none;
        margin: 8px;
        overflow-y: visible;
    }

    .title {
        font-size: 15px;
    }

    .legend {
        font-size: 10px;
    }
}