body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: var(--font-base);
    line-height: 1.6;
    color: var(--gray-900);
    background: var(--gray-100);
    
    /* Disable zoom and gestures */
    touch-action: manipulation;
    -webkit-user-select: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

/* Prevent overscroll */
html, body {
    overflow-x: hidden;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

/* Screen management */
.screen {
    min-height: 100vh;
}

.screen.hidden , .hidden{
    display: none;
}

/* Typography */
h1 {
    font-size: var(--font-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--gray-900);
}

h2 {
    font-size: var(--font-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--gray-800);
}

h3 {
    font-size: var(--font-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--gray-800);
}

/* Button styles */
.button-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin: var(--spacing-lg) 0;
}

.btn {
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: var(--font-lg);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
    min-height: 56px;
    box-shadow: var(--shadow-sm);
}

.btn:active {
    transform: scale(0.98);
    box-shadow: none;
}

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

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: #1B5E20;
}

.btn-secondary {
    background: var(--secondary);
    color: white;
}

.btn-secondary:hover {
    background: #1565C0;
}

.btn-tertiary {
    background: var(--tertiary);
    color: white;
}

.btn-tertiary:hover {
    background: #6A1B9A;
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-success:hover {
    background: #2E7D32;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #C62828;
}

.btn-warning {
    background: var(--warning);
    color: white;
}

/* Input styles */
input[type="text"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-base);
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-md);
    background: white;
    margin-bottom: var(--spacing-md);
    transition: border-color 0.2s;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
}

/* Card styles */
.card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-md);
}

/* Loading spinner */
.spinner {
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: var(--spacing-xl) auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Alert messages */
.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.alert-success {
    background: #E8F5E9;
    color: #2E7D32;
    border: 1px solid #81C784;
}

.alert-error {
    background: #FFEBEE;
    color: #C62828;
    border: 1px solid #E57373;
}

.alert-warning {
    background: #FFF3E0;
    color: #E65100;
    border: 1px solid #FFB74D;
}

/* Form styles */
form {
    display: flex;
    flex-direction: column;
}

label {
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--gray-700);
}