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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
    line-height: 1.6;
}

.container {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

main {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.timer-display {
    text-align: center;
    margin-bottom: 40px;
    padding: 40px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 15px;
    transition: all 0.3s ease;
}

.timer-display.complete {
    animation: pulse 0.5s ease-in-out;
    background: linear-gradient(135deg, #a8ff78 0%, #78ffd6 100%);
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.time-left {
    font-size: 4rem;
    font-weight: 700;
    color: #333;
    font-variant-numeric: tabular-nums;
}

.separator {
    animation: blink 1s infinite;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

.status-text {
    margin-top: 10px;
    font-size: 1.1rem;
    color: #666;
}

.controls {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 40px;
}

.btn {
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: #f39c12;
    color: white;
}

.btn-secondary:hover {
    background: #e67e22;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

.settings {
    margin-bottom: 40px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
}

.settings h2 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: #333;
}

.setting-group {
    margin-bottom: 15px;
}

.setting-group label {
    display: flex;
    align-items: center;
    font-size: 1rem;
    color: #555;
}

.setting-group input[type="number"] {
    margin-left: 10px;
    padding: 8px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    width: 80px;
    transition: border-color 0.3s ease;
}

.setting-group input[type="number"]:focus {
    outline: none;
    border-color: #667eea;
}

.setting-group input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 10px;
    cursor: pointer;
}

.exercise-guide {
    margin-top: 40px;
}

.exercise-guide h2 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: #333;
}

.exercise-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.exercise-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 10px;
    transition: transform 0.3s ease;
}

.exercise-item:hover {
    transform: translateX(5px);
}

.exercise-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.exercise-item h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: #333;
}

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

footer {
    text-align: center;
    margin-top: 30px;
    color: white;
}

.lang-switcher {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 15px;
}

.lang-btn {
    padding: 6px 15px;
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    color: white;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.lang-btn:hover {
    background: rgba(255,255,255,0.3);
}

.lang-btn.active {
    background: white;
    color: #667eea;
}

@media (max-width: 600px) {
    .container {
        padding: 15px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .time-left {
        font-size: 3rem;
    }
    
    .controls {
        flex-wrap: wrap;
    }
    
    .btn {
        padding: 10px 25px;
        font-size: 0.95rem;
    }
    
    main {
        padding: 20px;
    }
    
    .timer-display {
        padding: 30px;
    }
}