/* Mobile-first responsive design */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0066cc;
    --primary-hover: #0052a3;
    --secondary-color: #6c757d;
    --secondary-hover: #5a6268;
    --success-color: #28a745;
    --error-color: #dc3545;
    --background: #f8f9fa;
    --surface: #ffffff;
    --text: #212529;
    --text-muted: #6c757d;
    --border: #dee2e6;
    --border-radius: 8px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --tap-target-min: 44px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.6;
    padding: var(--spacing-sm);
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background-color: var(--surface);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-md);
    text-align: center;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.view {
    padding: var(--spacing-md);
}

.view.hidden {
    display: none;
}

.form-section {
    margin-bottom: var(--spacing-lg);
}

.form-section h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text);
    border-bottom: 2px solid var(--border);
    padding-bottom: var(--spacing-xs);
}

.form-group {
    margin-bottom: var(--spacing-md);
    position: relative;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--text);
}

.required {
    color: var(--error-color);
}

input[type="text"],
input[type="date"],
input[type="number"],
select {
    width: 100%;
    padding: var(--spacing-sm);
    font-size: 1rem;
    border: 2px solid var(--border);
    border-radius: var(--border-radius);
    background-color: var(--surface);
    color: var(--text);
    min-height: var(--tap-target-min);
    transition: border-color 0.2s;
}

input:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
}

input.error,
select.error {
    border-color: var(--error-color);
}

.file-upload-area {
    margin-bottom: var(--spacing-md);
}

#file-input {
    position: absolute;
    width: 1px;
    height: 1px;
    opacity: 0;
    overflow: hidden;
}

.file-label {
    display: block;
    padding: var(--spacing-md);
    border: 2px dashed var(--border);
    border-radius: var(--border-radius);
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background-color 0.2s;
    min-height: var(--tap-target-min);
}

.file-label:hover {
    border-color: var(--primary-color);
    background-color: rgba(0, 102, 204, 0.05);
}

.file-label-text {
    display: block;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.file-label-hint {
    display: block;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.file-list {
    margin-top: var(--spacing-sm);
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--background);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-xs);
    font-size: 0.875rem;
}

.file-item-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-item-remove {
    background: none;
    border: none;
    color: var(--error-color);
    cursor: pointer;
    padding: var(--spacing-xs);
    font-size: 1rem;
    min-width: var(--tap-target-min);
    min-height: var(--tap-target-min);
}


.button-group {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.btn {
    flex: 1;
    min-width: 120px;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    min-height: var(--tap-target-min);
    text-align: center;
}

.btn:active {
    transform: scale(0.98);
}

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: var(--secondary-hover);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.confirmation-content {
    text-align: center;
    padding: var(--spacing-lg) 0;
}

.confirmation-content h2 {
    color: var(--success-color);
    margin-bottom: var(--spacing-md);
    font-size: 1.5rem;
}

.timestamp {
    color: var(--text-muted);
    margin-bottom: var(--spacing-lg);
    font-size: 0.875rem;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    color: white;
}

.loading-overlay.hidden {
    display: none;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-sm);
}

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

/* Print styles for PDF generation */
@media print {
    body {
        background: white;
        padding: 0;
    }

    .container {
        box-shadow: none;
        max-width: 100%;
    }

    header {
        background-color: var(--primary-color);
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }

    .button-group,
    .file-upload-area,
    #file-input,
    .file-label {
        display: none;
    }

    .form-section {
        page-break-inside: avoid;
        margin-bottom: var(--spacing-md);
    }
}

/* Tablet and desktop */
@media (min-width: 768px) {
    body {
        padding: var(--spacing-md);
    }

    header h1 {
        font-size: 1.75rem;
    }

    .form-section h2 {
        font-size: 1.5rem;
    }

    .btn {
        flex: 0 1 auto;
    }
}