body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f4f4f4;
    color: #333;
}

h1 {
    color: #2c3e50;
    border-bottom: 2px solid #3498db;
    padding-bottom: 10px;
    text-align: center;
}

h1 a {
    color: #2c3e50;
    text-decoration: none;
    transition: color 0.3s ease;
}

h1 a:hover {
    color: #3498db;
}

h2 {
    color: #3498db;
    border-bottom: 1px solid #bdc3c7;
    padding-bottom: 5px;
}

h3 {
    color: #2980b9;
    margin-bottom: 10px;
}

section {
    background-color: white;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

ul {
    list-style-type: none;
    padding: 0;
}

li {
    margin-bottom: 8px;
    display: block;  /* Ensures vertical stacking */
}

a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #2980b9;
    text-decoration: underline;
}

#problemSolving ul ul {
    margin-left: 20px;
    margin-top: 5px;
}

/* Styles for Time display */
.time-display {
    font-size: 1.8rem;
    font-weight: bold;
    color: #2c3e50;
    text-align: center;
    padding: 10px;
    margin: 10px 0;
    background-color: #ecf0f1;
    border-radius: 5px;
    box-shadow: inset 0 0 5px rgba(0,0,0,0.1);
}

/* Tab container styles */
.tab-container {
    border-radius: 5px;
    overflow: hidden;
    margin-top: 15px;
}

.tab-buttons {
    display: flex;
    background-color: #ecf0f1;
    border-radius: 5px 5px 0 0;
}

.tab-button {
    flex: 1;
    padding: 10px;
    background-color: #ecf0f1;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: background-color 0.3s;
}

.tab-button.active {
    background-color: #3498db;
    color: white;
}

.tab-button:hover:not(.active) {
    background-color: #d5dbdb;
}

.tab-content {
    display: none;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 0 0 5px 5px;
}

.tab-content.active {
    display: block;
}

/* Timer and Stopwatch controls */
.timer-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.timer-input {
    width: 60px;
    padding: 8px;
    border: 1px solid #bdc3c7;
    border-radius: 4px;
    font-size: 1rem;
}

.timer-button {
    padding: 8px 15px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
}

.timer-button:hover:not(:disabled) {
    background-color: #2980b9;
}

.timer-button:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

/* Laps container for stopwatch */
.laps-container {
    max-height: 200px;
    overflow-y: auto;
    margin-top: 15px;
    background-color: white;
    border-radius: 5px;
    padding: 10px;
    box-shadow: inset 0 0 5px rgba(0,0,0,0.1);
}

.lap-item {
    padding: 8px;
    border-bottom: 1px solid #ecf0f1;
    font-family: monospace;
    font-size: 0.9rem;
}

.lap-item:first-child {
    font-weight: bold;
    color: #3498db;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .time-display {
        font-size: 1.5rem;
    }
    
    .timer-controls {
        justify-content: center;
    }
}