* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    color: white;
}

header h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 300;
}

.start-workout-container {
    text-align: center;
    margin-top: 2rem;
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.7rem !important;
    min-width: 250px;
    min-height: 60px;
}

main {
    display: grid;
    gap: 2rem;
}

.timer-section {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    text-align: center;
}

.timer-display {
    margin-bottom: 2rem;
}

.time {
    font-size: 4rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 0.5rem;
    font-family: 'Hack', 'Courier New', monospace;
}

.timer-status {
    font-size: 1.2rem;
    color: #666;
    font-weight: 500;
}

.timer-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    min-width: 100px;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #f8f9fa;
    color: #333;
    border: 2px solid #e9ecef;
}

.btn-secondary:hover:not(:disabled) {
    background: #e9ecef;
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a52 100%);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(40, 167, 69, 0.4);
}

.btn-white {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-white:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.timer-settings {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid #f1f3f4;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.setting-group label {
    font-weight: 600;
    color: #555;
    font-size: 0.9rem;
}

.setting-group input {
    padding: 0.75rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.setting-group input:focus {
    outline: none;
    border-color: #667eea;
}

/* Exercise Builder Styles */
.exercise-builder {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.exercise-builder h2 {
    margin-bottom: 1.5rem;
    color: #333;
    font-size: 1.5rem;
}

.builder-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.exercise-list {
    margin-bottom: 2rem;
    max-height: 400px;
    overflow-y: auto;
}

.exercise-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    margin-bottom: 0.5rem;
    border-left: 4px solid #667eea;
}

.exercise-item.rest {
    border-left-color: #ff6b6b;
}

.exercise-item.group {
    border-left-color: #28a745;
    background: #e8f5e8;
}

.exercise-item.group-header {
    background: #d4edda;
    border-left-color: #28a745;
    font-weight: 600;
}

.exercise-item.group-item {
    margin-left: 2rem;
    background: #f8f9fa;
    border-left-color: #6c757d;
}

.exercise-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.exercise-name {
    font-weight: 600;
    color: #333;
}

.exercise-duration {
    font-size: 0.9rem;
    color: #666;
}

.exercise-group-indicator {
    font-size: 0.8rem;
    color: #28a745;
    font-weight: 500;
    margin-top: 0.25rem;
}

.exercise-controls {
    display: flex;
    gap: 0.5rem;
}

.exercise-controls button {
    padding: 0.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
}

.exercise-controls .edit-btn {
    background: #007bff;
    color: white;
}

.exercise-controls .delete-btn {
    background: #dc3545;
    color: white;
}

.exercise-controls .move-up-btn {
    background: #6c757d;
    color: white;
}

.exercise-controls .move-down-btn {
    background: #6c757d;
    color: white;
}

.exercise-controls button:hover {
    opacity: 0.8;
}

.saved-workouts {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid #f1f3f4;
}

.saved-workouts h3 {
    margin-bottom: 1rem;
    color: #333;
}

.workout-selector {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.workout-selector select {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    min-width: 200px;
}

.workout-selector select:focus {
    outline: none;
    border-color: #667eea;
}

/* Full Screen Timer Styles */
.fullscreen-timer {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: #28a745;
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    transition: background-color 0.5s ease;
}

.fullscreen-timer.active {
    display: flex;
}

.fullscreen-timer.workout {
    background: #28a745;
}

.fullscreen-timer.workout.warning {
    background: #007bff;
}

.fullscreen-timer.rest {
    background: #dc3545;
}

.fullscreen-timer.get-ready {
    background: #ffc107;
}

.fullscreen-timer.well-done {
    background: #28a745;
}

.fullscreen-content {
    text-align: center;
    color: white;
    max-width: 90vw;
}

.fullscreen-time {
    font-size: 8rem;
    font-weight: 700;
    font-family: 'Hack', 'Courier New', monospace;
    margin-bottom: 1rem;
    text-shadow: 0 4px 8px rgba(0,0,0,0.3);
}

.fullscreen-status {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.fullscreen-exercise {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.fullscreen-progress {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 2rem;
    opacity: 0.9;
    white-space: pre-line;
    line-height: 1.4;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.fullscreen-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.fullscreen-controls .btn {
    min-width: 120px;
    font-size: 1.1rem;
    padding: 1rem 2rem;
}

.workout-history {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.workout-history h2 {
    margin-bottom: 1.5rem;
    color: #333;
    font-size: 1.5rem;
}

.history-list {
    margin-bottom: 1.5rem;
    max-height: 300px;
    overflow-y: auto;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    margin-bottom: 0.5rem;
    border-left: 4px solid #667eea;
}

.history-item:last-child {
    margin-bottom: 0;
}

.history-info {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.history-date {
    font-weight: 600;
    color: #333;
}

.history-duration {
    font-size: 0.9rem;
    color: #666;
}

.history-delete {
    background: none;
    border: none;
    color: #ff6b6b;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.5rem;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.history-delete:hover {
    background: #ffe6e6;
}

.empty-history {
    text-align: center;
    color: #666;
    font-style: italic;
    padding: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .time {
        font-size: 3rem;
    }
    
    .fullscreen-time {
        font-size: 4rem;
    }
    
    .fullscreen-status {
        font-size: 1.5rem;
    }
    
    .timer-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
    }
    
    .timer-settings {
        grid-template-columns: 1fr;
    }
    
    .builder-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .exercise-item {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
    
    .exercise-controls {
        justify-content: center;
    }
    
    .workout-selector {
        flex-direction: column;
        align-items: stretch;
    }
    
    .history-item {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
    
    .fullscreen-controls {
        flex-direction: column;
        align-items: center;
    }
}

/* Animation for timer */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.timer-running .time {
    animation: pulse 1s infinite;
    color: #ff6b6b;
}

/* Scrollbar styling */
.history-list::-webkit-scrollbar,
.exercise-list::-webkit-scrollbar {
    width: 6px;
}

.history-list::-webkit-scrollbar-track,
.exercise-list::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb,
.exercise-list::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb:hover,
.exercise-list::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}