/* Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    transition: background-color 0.3s, color 0.3s;
}

.app-container {
    max-width: 100%;
    margin: 0 auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

h1 {
    font-size: 1.5rem;
}

/* Tab Navigation */
.tabs {
    display: flex;
    margin-bottom: 20px;
    border-bottom: 1px solid #ccc;
}

.tab-btn {
    padding: 10px 20px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    opacity: 0.7;
    transition: opacity 0.3s;
}

.tab-btn.active {
    opacity: 1;
    border-bottom: 3px solid #4a90e2;
}

.tab-content {
    display: none;
}

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

/* Timer Controls */
.controls-container {
    margin-bottom: 20px;
}

.slider-container {
    margin-bottom: 20px;
}

.slider-container label {
    display: block;
    margin-bottom: 5px;
    font-size: 1rem;
}

.slider {
    width: 100%;
    height: 20px;
    -webkit-appearance: none;
    appearance: none;
    background: #ddd;
    outline: none;
    border-radius: 10px;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 25px;
    height: 25px;
    border-radius: 50%;
    background: #4a90e2;
    cursor: pointer;
}

.slider::-moz-range-thumb {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    background: #4a90e2;
    cursor: pointer;
}

/* Button Styles */
button {
    border: none;
    border-radius: 4px;
    padding: 10px 15px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.primary-btn {
    background-color: #4a90e2;
    color: white;
    font-weight: bold;
    font-size: 1.2rem;
    padding: 15px 30px;
    width: 100%;
    margin-top: 10px;
}

.control-btn {
    background-color: #f2f2f2;
    color: #333;
    margin: 0 5px;
}

/* Timer Display */
#timer-display {
    text-align: center;
}

#timer-display.hidden {
    display: none;
}

.exercise-info {
    margin-bottom: 20px;
}

.timer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 20px;
}

#animation-container {
    width: 200px;
    height: 200px;
    margin-bottom: 20px;
}

#animation-container svg {
    width: 100%;
    height: 100%;
}

.timer {
    font-size: 4rem;
    font-weight: bold;
    padding: 20px;
    border-radius: 50%;
    background-color: #f2f2f2;
    width: 150px;
    height: 150px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.timer-controls {
    display: flex;
    justify-content: center;
    margin-top: 20px;
}

/* Exercise List */
.exercise-group {
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    overflow: hidden;
}

.exercise-group-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    background-color: #f5f5f5;
    cursor: pointer;
}

.exercise-list {
    padding: 10px;
}

.exercise-item {
    display: flex;
    align-items: center;
    padding: 8px 0;
    border-bottom: 1px solid #eee;
}

.exercise-item:last-child {
    border-bottom: none;
}

.exercise-checkbox {
    margin-right: 10px;
}

.exercise-thumbnail {
    width: 40px;
    height: 40px;
    margin-right: 10px;
}

.exercises-controls {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
}

.hidden {
    display: none !important;
}

/* Responsive Design */
@media (min-width: 768px) {
    /* Tablet and up */
    .app-container {
        max-width: 768px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .timer-container {
        flex-direction: row;
        justify-content: space-around;
    }
    
    #animation-container {
        margin-bottom: 0;
        margin-right: 20px;
    }
}

@media (orientation: landscape) {
    .timer-container {
        flex-direction: row;
        justify-content: space-around;
    }
    
    #animation-container {
        margin-bottom: 0;
        margin-right: 20px;
    }
}