/* Three-Color DFS Cycle Detection - Stylesheet
 * =============================================
 *
 * GRAPH POSITIONING NOTES:
 * ------------------------
 * The graph network position is controlled by TWO areas in three-color-dfs.js:
 *
 * 1. NODE POSITIONS (lines 24-33 in JS file):
 *    Each node has x, y coordinates that determine its position relative to
 *    the canvas center (0,0). Negative x values move nodes left, negative y
 *    values move nodes up.
 *
 *    Example: { id: 1, label: 'Variables', x: -350, y: -150 }
 *
 * 2. CAMERA/VIEW POSITION (line 90 in JS file, positionView function):
 *    The moveTo() call sets where the camera looks at the graph:
 *
 *    position: { x: -90, y: 60 }
 *
 *    - Lower x value = moves the view RIGHT (shows more of left side of graph)
 *    - Higher y value = moves the view UP (shows more of bottom of graph)
 *    - scale: 1 = default zoom level
 *
 *    Adjust these values if the graph appears cut off or poorly centered.
 */

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

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

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

/* The vis-network canvas container
 * This fills the entire viewport - the graph is positioned within it
 * using the JS positionView() function */
#network {
    width: 100%;
    height: 100%;
    background-color: aliceblue;
}

/* ===========================================
   TITLE (Top Center)
   =========================================== */
.title {
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 20px;
    font-weight: bold;
    color: black;
    background-color: aliceblue;
    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: 12px;
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    margin-right: 4px;
    border: 2px solid #333;
}

/* Legend color swatches - these should match the colors object in JS:
 * colors.white.background = #e0e0e0
 * colors.gray.background  = #ffd700 (yellow for "in progress")
 * colors.black.background = #4caf50 (green for "completed") */
.color-white {
    background-color: #e0e0e0;
}

.color-gray {
    background-color: #ffd700;
}

.color-black {
    background-color: #4caf50;
}

/* ===========================================
   RIGHT PANEL (Controls, Stack, Status)
   =========================================== */
.right-panel {
    position: absolute;
    top: 50px;
    right: 10px;
    width: 280px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 10;
}

/* ===========================================
   DFS STACK VISUALIZATION
   =========================================== */
.stack-container {
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 8px;
    padding: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.stack-title {
    font-weight: bold;
    margin-bottom: 8px;
    font-size: 13px;
}

/* Stack display - column-reverse makes newest items appear at top */
.stack {
    display: flex;
    flex-direction: column-reverse;
    border: 2px solid #333;
    border-radius: 4px;
    min-height: 60px;
    max-height: 120px;
    overflow-y: auto;
    background-color: #fafafa;
}

.stack-empty {
    padding: 15px;
    text-align: center;
    color: #999;
    font-style: italic;
    font-size: 12px;
}

/* Stack items use the same yellow as "in progress" nodes */
.stack-item {
    padding: 8px;
    text-align: center;
    border-top: 1px solid #ccc;
    font-weight: bold;
    font-size: 12px;
    background-color: #ffd700;
}

.stack-item:first-child {
    border-top: none;
}

.stack-label {
    text-align: center;
    font-size: 11px;
    color: #666;
    margin-top: 4px;
}

/* ===========================================
   STATUS INFO PANEL
   =========================================== */
.status-info {
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 8px;
    padding: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.status-title {
    font-weight: bold;
    margin-bottom: 6px;
    font-size: 13px;
}

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

/* ===========================================
   CYCLE ALERT (Red Warning Box)
   =========================================== */
.cycle-alert {
    background-color: rgba(255, 235, 238, 0.95);
    border: 2px solid #f44336;
    border-radius: 8px;
    padding: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    display: none;
}

.cycle-alert.visible {
    display: block;
}

.cycle-alert-title {
    color: #c62828;
    font-weight: bold;
    margin-bottom: 6px;
    font-size: 13px;
}

.cycle-alert-text {
    color: #c62828;
    font-size: 12px;
    line-height: 1.4;
}

/* ===========================================
   CONTROL BUTTONS
   =========================================== */
.controls {
    display: flex;
    gap: 10px;
    align-items: center;
    background-color: rgba(255, 255, 255, 0.95);
    padding: 10px 12px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.step-counter {
    font-size: 14px;
    color: #666;
    margin-right: 10px;
}

.btn {
    padding: 10px 20px;
    font-size: 14px;
    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: #90caf9;
    cursor: not-allowed;
}

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

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

/* ===========================================
   RESPONSIVE STYLES
   =========================================== */
@media (max-width: 600px) {
    .title {
        font-size: 16px;
        padding: 6px 12px;
    }

    .legend {
        padding: 8px 10px;
    }

    .legend-title {
        font-size: 11px;
    }

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

    .legend-color {
        width: 16px;
        height: 16px;
    }

    .info-panel {
        width: 200px;
    }

    .controls {
        padding: 8px 12px;
    }

    .btn {
        padding: 8px 14px;
        font-size: 12px;
    }

    .step-counter {
        font-size: 12px;
    }
}