body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 1rem;
}

.container {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    max-width: 800px;
    width: 100%;
    margin-top: 1rem;
    box-sizing: border-box;
}

@media (min-width: 768px) {
    body {
        padding: 2rem;
    }

    .container {
        padding: 2rem;
        margin-top: 2rem;
    }
}

h1 {
    color: #667eea;
    margin: 0 0 1.5rem 0;
    text-align: center;
}

.navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.nav-btn {
    padding: 0.5rem 0.75rem;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s;
    text-decoration: none;
    display: inline-block;
    white-space: nowrap;
    flex-shrink: 0;
}

@media (min-width: 768px) {
    .nav-btn {
        padding: 0.5rem 1rem;
        font-size: 1rem;
    }
}

.nav-btn:hover {
    background: #5568d3;
}

.nav-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.current-date {
    font-size: 1rem;
    font-weight: bold;
    color: #333;
    text-align: center;
    flex: 1;
    min-width: 0;
}

@media (min-width: 768px) {
    .current-date {
        font-size: 1.2rem;
        min-width: 200px;
    }
}

.workout-list {
    margin-bottom: 1.5rem;
    text-align: center;
}

.workout-list label {
    display: block;
    margin-bottom: 0.5rem;
    color: #555;
    font-weight: 500;
}

.date-picker {
    padding: 0.5rem 1rem;
    font-size: 1rem;
    border: 2px solid #667eea;
    border-radius: 5px;
    background: white;
    cursor: pointer;
    min-width: 200px;
}

.workout-content {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    min-height: 300px;
    white-space: pre-wrap;
    font-family: 'Courier New', monospace;
    line-height: 1.6;
    color: #333;
}

.loading {
    text-align: center;
    color: #999;
    font-style: italic;
}

.error {
    color: #e74c3c;
    text-align: center;
}