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

:root {
    --primary-color: #4CAF50;
    --secondary-color: #2196F3;
    --background-color: #f5f5f5;
    --text-color: #333;
    --card-background: #ffffff;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 20px;
    background: var(--card-background);
    border-radius: 16px;
    box-shadow: var(--shadow);
}

h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 20px;
}

.language-selector {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.lang-btn {
    padding: 8px 16px;
    border: 2px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 14px;
}

.lang-btn:hover,
.lang-btn.active {
    background: var(--primary-color);
    color: white;
}

main {
    background: var(--card-background);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.breathing-circle-container {
    position: relative;
    width: 300px;
    height: 300px;
    margin: 0 auto 40px;
}

.breathing-circle {
    position: absolute;
    width: 280px;
    height: 280px;
    background: linear-gradient(135deg, #E3F2FD 0%, #BBDEFB 100%);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: transform 4s ease-in-out;
    top: 10px;
    left: 10px;
    z-index: 2;
}

.breathing-circle.inhaling {
    transform: scale(1.1);
}

.breathing-circle.exhaling {
    transform: scale(0.9);
}

.nose-icon {
    font-size: 60px;
    margin-bottom: 10px;
}

.breath-text {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

.progress-ring {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
}

.controls {
    margin-bottom: 40px;
}

.timing-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.timing-group {
    display: flex;
    flex-direction: column;
}

.timing-group label {
    font-weight: 500;
    margin-bottom: 8px;
    color: #666;
}

.timing-group input {
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    text-align: center;
    transition: border-color 0.3s ease;
}

.timing-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.session-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 12px;
}

.session-group {
    display: flex;
    flex-direction: column;
}

.session-group label {
    font-weight: 500;
    margin-bottom: 8px;
    color: #666;
}

.session-group input {
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    text-align: center;
    width: 80px;
}

.session-timer {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

.start-btn {
    width: 100%;
    padding: 18px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
}

.start-btn:hover {
    background: #45a049;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

.start-btn:active {
    transform: translateY(0);
}

.start-btn.active {
    background: #f44336;
}

.info-section {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 12px;
}

.info-section h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
}

.benefits-list {
    list-style-position: inside;
    margin-bottom: 30px;
}

.benefits-list li {
    margin-bottom: 12px;
    padding-left: 10px;
    line-height: 1.8;
}

.tips {
    background: white;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.tips h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.tips p {
    margin-bottom: 10px;
    color: #666;
}

footer {
    text-align: center;
    padding: 20px;
    color: #666;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    main {
        padding: 20px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .breathing-circle-container {
        width: 250px;
        height: 250px;
    }
    
    .breathing-circle {
        width: 230px;
        height: 230px;
    }
    
    .progress-ring svg {
        width: 250px;
        height: 250px;
    }
    
    .progress-ring circle {
        cx: 125;
        cy: 125;
        r: 120;
    }
    
    .session-controls {
        flex-direction: column;
        gap: 20px;
    }
    
    .timing-controls {
        grid-template-columns: 1fr;
    }
}