:root {
    --bg-color: #f0f2f5; /* Softer modern background */
    --text-color: #2c3e50;
    --canvas-bg: #ffffff;
    --primary: #4CAF50;
    --primary-hover: #45a049;
    --dfs-color: #9C27B0;
    --dfs-hover: #7B1FA2;
    --dijkstra-color: #009688;
    --dijkstra-hover: #00796b;
    --floyd-color: #FF9800;
    --floyd-hover: #F57C00;
    --prims-color: #3F51B5;
    --prims-hover: #303F9F;
    --kruskal-color: #E91E63;
    --kruskal-hover: #C2185B;
    --danger: #f44336;
    --danger-hover: #da190b;
    --panel-shadow: 0 8px 30px rgba(0,0,0,0.08);
}

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    margin: 0;
}

h1 { 
    margin-bottom: 25px; 
    text-align: center; 
    font-weight: 800;
    color: #1a252f;
    letter-spacing: -0.5px;
}

.main-container {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    max-width: 1200px;
    width: 100%;
    justify-content: center;
}

.viz-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    max-width: 600px;
}

/* --- MODERN SEGMENTED CONTROL (Run/Edit/Delete) --- */
.edit-bar {
    display: flex;
    gap: 15px;
    background: #fff;
    padding: 10px;
    border-radius: 12px;
    box-shadow: var(--panel-shadow);
    margin-bottom: 20px;
    width: 100%;
    justify-content: space-between;
    align-items: center;
    box-sizing: border-box;
}

.segmented-control {
    display: flex;
    background: #e4e6eb;
    border-radius: 8px;
    padding: 4px;
    flex-grow: 1;
}

.segmented-control input[type="radio"] {
    display: none; /* Hide the ugly circles */
}

.segmented-control label {
    flex: 1;
    text-align: center;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
    font-size: 14px;
    color: #555;
    transition: all 0.3s ease;
}

/* When a radio is checked, highlight its label */
.segmented-control input[type="radio"]:checked + label {
    background: #ffffff;
    color: #111;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.clear-btn { 
    background-color: #607D8B; 
    padding: 10px 15px;
}
.clear-btn:hover { background-color: #455A64; }

.edit-hint {
    text-align: center;
    color: #E91E63;
    margin-top: 10px;
    font-weight: bold;
    background: #fce4ec;
    padding: 8px 15px;
    border-radius: 20px;
    font-size: 13px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.02); }
    100% { transform: scale(1); }
}

/* --- SETTINGS BAR & CUSTOM SLIDER --- */
.settings-bar {
    display: flex;
    gap: 20px;
    background: #fff;
    padding: 15px 25px;
    border-radius: 12px;
    box-shadow: var(--panel-shadow);
    margin-bottom: 20px;
    width: 100%;
    justify-content: center;
    box-sizing: border-box;
}

.setting-item { display: flex; align-items: center; gap: 10px; font-size: 14px; }
.setting-item select { 
    padding: 8px 12px; 
    border-radius: 6px; 
    border: 1px solid #ccc; 
    font-weight: bold; 
    background: #f9f9f9;
    cursor: pointer;
    outline: none;
}

/* Custom Webkit Slider */
input[type=range] {
    -webkit-appearance: none;
    width: 120px;
    background: transparent;
}
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 18px; width: 18px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    margin-top: -6px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
input[type=range]::-webkit-slider-runnable-track {
    width: 100%; height: 6px;
    cursor: pointer;
    background: #ddd;
    border-radius: 3px;
}

/* --- INTERACTIVE BUTTON PHYSICS --- */
.controls {
    margin-bottom: 20px;
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    justify-content: center;
}

button {
    padding: 12px 18px;
    font-size: 14px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    color: white;
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.2s cubic-bezier(0.25, 0.8, 0.25, 1); /* Snappy transition */
}

/* Hover Effect: Lift up */
button:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 7px 14px rgba(0,0,0,0.15);
}

/* Active Effect: Press down */
button:active:not(:disabled) {
    transform: translateY(1px);
    box-shadow: 0 2px 3px rgba(0,0,0,0.1);
}

#startBfsBtn { background-color: var(--primary); }
#startDfsBtn { background-color: var(--dfs-color); }
#startDijkstraBtn { background-color: var(--dijkstra-color); }
#startFloydBtn { background-color: var(--floyd-color); }
#startPrimsBtn { background-color: var(--prims-color); }
#startKruskalBtn { background-color: var(--kruskal-color); }
#resetBtn { background-color: var(--danger); }

button:disabled { 
    background-color: #bdc3c7 !important; 
    color: #ecf0f1;
    cursor: not-allowed; 
    transform: none;
    box-shadow: none;
}

/* --- CANVAS DRAFTING BOARD --- */
canvas { 
    background-color: var(--canvas-bg); 
    border-radius: 12px; 
    box-shadow: var(--panel-shadow); 
    width: 100%; 
    /* NEW: Polka dot grid background */
    background-image: radial-gradient(#d5d5d5 2px, transparent 2px);
    background-size: 30px 30px;
    border: 2px solid #e0e5ec;
}

/* --- DATA STRUCTURE CARDS --- */
.ds-wrapper {
    width: 100%;
    background: #fff;
    border-radius: 12px;
    padding: 15px;
    margin-bottom: 20px;
    box-shadow: var(--panel-shadow);
    box-sizing: border-box;
}

.ds-wrapper h3 { margin: 0 0 12px 0; font-size: 16px; color: var(--text-color); text-align: center; }

.ds-container {
    display: flex;
    gap: 10px;
    min-height: 60px;
    align-items: center;
    justify-content: center;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px dashed #ccc;
    overflow-x: auto;
}

.ds-item {
    background-color: #87CEFA;
    color: #111;
    font-weight: 800;
    font-size: 15px;
    padding: 10px 18px;
    border-radius: 8px;
    border: 2px solid #2c3e50;
    animation: popIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); /* Bouncy pop in */
    box-shadow: 0 4px 0 #2c3e50; /* 3D effect */
    transform: translateY(-2px);
}

@keyframes popIn { 
    0% { transform: scale(0.5) translateY(0); opacity: 0; } 
    100% { transform: scale(1) translateY(-2px); opacity: 1; } 
}

/* --- LEGEND --- */
.legend { 
    display: flex; gap: 15px; margin-top: 15px; font-size: 14px; flex-wrap: wrap; justify-content: center;
    background: #fff; padding: 10px 20px; border-radius: 20px; box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.legend-item { display: flex; align-items: center; gap: 8px; font-weight: bold; color: #555;}
.color-box { width: 16px; height: 16px; border: 2px solid #333; border-radius: 4px; }

/* --- RIGHT INFO PANEL & TERMINAL LOG --- */
.info-panel { flex: 1; min-width: 300px; max-width: 450px; display: flex; flex-direction: column; gap: 20px; }

.card { 
    background: #fff; 
    padding: 25px; 
    border-radius: 12px; 
    box-shadow: var(--panel-shadow); 
}
.card h3 { margin-top: 0; color: var(--text-color); border-bottom: 2px solid #f0f0f0; padding-bottom: 10px; }
.concept-text { line-height: 1.6; font-size: 15px; color: #444; }
.complexity { 
    margin-top: 15px; 
    background: #f8f9fa; 
    padding: 12px; 
    border-radius: 6px;
    border-left: 5px solid #333; 
    font-family: 'Courier New', Courier, monospace; 
    font-size: 14px; 
}

/* Custom Terminal Scrollbar */
.log-container { 
    flex-grow: 1; 
    background: #1e1e1e; 
    color: #4CAF50; 
    padding: 20px; 
    border-radius: 12px; 
    font-family: 'Courier New', Courier, monospace; 
    font-size: 14px; 
    height: 350px; 
    overflow-y: auto; 
    box-shadow: inset 0 4px 10px rgba(0,0,0,0.5); 
}
.log-container::-webkit-scrollbar { width: 8px; }
.log-container::-webkit-scrollbar-track { background: #2c2c2c; border-radius: 8px; }
.log-container::-webkit-scrollbar-thumb { background: #555; border-radius: 8px; }

.log-entry { margin-bottom: 10px; border-bottom: 1px solid #333; padding-bottom: 6px; }
.log-entry:last-child { border-bottom: none; }

/* --- RESULTS BOX --- */
.results-wrapper { 
    width: 100%; max-width: 1200px; 
    background: #fff; border-radius: 12px; 
    padding: 25px; margin-top: 20px; 
    box-shadow: var(--panel-shadow); box-sizing: border-box; 
    display: none; animation: slideUp 0.5s ease-out; 
}
@keyframes slideUp {
    from { transform: translateY(30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.results-wrapper h3 { margin-top: 0; margin-bottom: 15px; border-bottom: 2px solid #eee; padding-bottom: 10px; }
.results-content { 
    font-size: 16px; font-family: 'Courier New', Courier, monospace; 
    color: #333; background: #f8f9fa; padding: 20px; border-radius: 8px; 
    border-left: 6px solid var(--text-color); display: flex; flex-wrap: wrap; gap: 15px; align-items: center; overflow-x: auto; 
}
.result-badge { 
    background: #fff; padding: 10px 15px; border-radius: 6px; 
    border: 1px solid #ddd; color: #111; font-weight: bold; box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.path-arrow { color: #888; font-size: 22px; font-weight: bold; }

/* Matrix specific tweaks */
.matrix-table { border-collapse: separate; border-spacing: 2px; margin: 0 auto; background: transparent; font-size: 14px; }
.matrix-table th, .matrix-table td { border: none; background: white; padding: 8px 14px; text-align: center; border-radius: 4px; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.matrix-table th { background: #e4e6eb; color: #333; }
.matrix-highlight { background-color: var(--floyd-color) !important; color: white !important; transform: scale(1.1); transition: all 0.2s; }
.matrix-update { background-color: #32CD32 !important; color: white !important; transform: scale(1.1); transition: all 0.2s; }