/* ===================================
   CSS Reset & Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-color: #0066cc;
    --primary-hover: #0052a3;
    --primary-light: #e6f2ff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --success-bg: #d4edda;
    --success-border: #c3e6cb;
    --error-color: #dc3545;
    --error-bg: #f8d7da;
    --error-border: #f5c6cb;
    --warning-color: #ffc107;
    
    /* Neutral Colors */
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-muted: #868e96;
    --border-color: #dee2e6;
    --background-primary: #ffffff;
    --background-secondary: #f8f9fa;
    --background-tertiary: #e9ecef;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.5rem;
    --font-size-xxl: 2rem;
    
    /* Borders & Shadows */
    --border-radius: 0.375rem;
    --border-radius-lg: 0.5rem;
    --box-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --box-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
}

/* ===================================
   Global Styles
   =================================== */
body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: var(--spacing-lg);
}

/* ===================================
   Container & Layout
   =================================== */
.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--background-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow-lg);
    overflow: hidden;
}

/* ===================================
   Header
   =================================== */
.form-header {
    background: linear-gradient(135deg, #0066cc 0%, #004c99 100%);
    color: white;
    padding: var(--spacing-xxl) var(--spacing-xl);
    text-align: center;
}

.logo-container h1 {
    font-size: var(--font-size-xxl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    font-size: var(--font-size-lg);
    font-weight: 300;
    opacity: 0.9;
}

/* ===================================
   Form Container
   =================================== */
.form-container {
    padding: var(--spacing-xxl) var(--spacing-xl);
}

/* ===================================
   Form Sections
   =================================== */
.form-section {
    margin-bottom: var(--spacing-xxl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--background-secondary);
}

.form-section:last-of-type {
    border-bottom: none;
}

.section-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.section-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: var(--font-size-base);
    font-weight: 700;
}

/* ===================================
   Form Rows & Groups
   =================================== */
.form-row {
    display: grid;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.form-row.two-col {
    grid-template-columns: 1fr 1fr;
}

.form-row.three-col {
    grid-template-columns: 2fr 1fr 1fr;
}

.form-row.full-width {
    grid-template-columns: 1fr;
}

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

.form-group.full-width {
    grid-column: 1 / -1;
}

/* ===================================
   Labels
   =================================== */
label {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    display: block;
}

label.required::after {
    content: ' *';
    color: var(--error-color);
    font-weight: 700;
}

.optional {
    color: var(--text-muted);
    font-weight: 400;
    font-style: italic;
}

/* ===================================
   Form Inputs
   =================================== */
input[type="text"],
input[type="email"],
input[type="tel"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: 0.625rem 0.875rem;
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    color: var(--text-primary);
    background-color: var(--background-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all var(--transition-base);
    outline: none;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="tel"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

input[type="text"]:hover,
input[type="email"]:hover,
input[type="tel"]:hover,
input[type="number"]:hover,
select:hover,
textarea:hover {
    border-color: var(--text-secondary);
}

input[type="text"].error,
input[type="email"].error,
input[type="tel"].error,
input[type="number"].error,
select.error,
textarea.error {
    border-color: var(--error-color);
    background-color: var(--error-bg);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

/* Remove number input spinners */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    -moz-appearance: textfield;
}

/* ===================================
   Select Dropdown
   =================================== */
select {
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23333' d='M10.293 3.293L6 7.586 1.707 3.293A1 1 0 00.293 4.707l5 5a1 1 0 001.414 0l5-5a1 1 0 10-1.414-1.414z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 12px;
    padding-right: 2.5rem;
    appearance: none;
}

/* ===================================
   Radio Buttons
   =================================== */
.radio-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.radio-option {
    display: flex;
    align-items: center;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-base);
}

.radio-option:hover {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
}

.radio-option input[type="radio"] {
    width: 20px;
    height: 20px;
    margin: 0;
    margin-right: var(--spacing-md);
    cursor: pointer;
    accent-color: var(--primary-color);
}

.radio-option label {
    margin: 0;
    cursor: pointer;
    flex: 1;
    font-weight: 500;
}

.radio-option:has(input[type="radio"]:checked) {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
}

/* ===================================
   Error Messages & Help Text
   =================================== */
.error-message {
    color: var(--error-color);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    display: none;
    font-weight: 500;
}

.error-message.show {
    display: block;
}

.help-text {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    font-style: italic;
}

/* ===================================
   Conditional Section
   =================================== */
.conditional-section {
    display: none;
    animation: slideDown var(--transition-base);
}

.conditional-section.show {
    display: block;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===================================
   Buttons
   =================================== */
.form-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-xxl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--background-secondary);
}

.btn {
    padding: 0.75rem 1.5rem;
    font-size: var(--font-size-base);
    font-weight: 600;
    font-family: var(--font-family);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-width: 140px;
}

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

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--box-shadow-lg);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--background-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

/* Button Loading State */
.btn-loader {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

/* ===================================
   Alerts
   =================================== */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-top: var(--spacing-lg);
    font-size: var(--font-size-base);
    border: 1px solid transparent;
}

.alert-success {
    background-color: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success-color);
}

.alert-error {
    background-color: var(--error-bg);
    border-color: var(--error-border);
    color: var(--error-color);
}

.alert strong {
    font-weight: 600;
}

/* ===================================
   Footer
   =================================== */
.form-footer {
    background: var(--background-secondary);
    padding: var(--spacing-lg);
    text-align: center;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

/* ===================================
   Responsive Design
   =================================== */

/* Tablets */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-md);
    }

    .form-header {
        padding: var(--spacing-xl) var(--spacing-lg);
    }

    .logo-container h1 {
        font-size: var(--font-size-xl);
    }

    .subtitle {
        font-size: var(--font-size-base);
    }

    .form-container {
        padding: var(--spacing-xl) var(--spacing-lg);
    }

    .section-title {
        font-size: var(--font-size-lg);
    }

    .form-row.two-col,
    .form-row.three-col {
        grid-template-columns: 1fr;
    }

    .form-actions {
        flex-direction: column-reverse;
    }

    .btn {
        width: 100%;
    }
}

/* Mobile */
@media (max-width: 480px) {
    body {
        padding: var(--spacing-sm);
    }

    .form-header {
        padding: var(--spacing-lg) var(--spacing-md);
    }

    .logo-container h1 {
        font-size: var(--font-size-lg);
    }

    .subtitle {
        font-size: var(--font-size-sm);
    }

    .form-container {
        padding: var(--spacing-lg) var(--spacing-md);
    }

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

    .section-title {
        font-size: var(--font-size-base);
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .section-number {
        width: 30px;
        height: 30px;
        font-size: var(--font-size-sm);
    }

    .form-row {
        gap: var(--spacing-md);
        margin-bottom: var(--spacing-md);
    }

    input[type="text"],
    input[type="email"],
    input[type="tel"],
    input[type="number"],
    select,
    textarea {
        font-size: 16px; /* Prevents zoom on iOS */
    }

    .radio-group {
        gap: var(--spacing-sm);
    }

    .radio-option {
        padding: var(--spacing-sm);
    }

    .form-actions {
        gap: var(--spacing-sm);
        padding-top: var(--spacing-lg);
        margin-top: var(--spacing-lg);
    }

    .btn {
        padding: 0.625rem 1rem;
        font-size: var(--font-size-sm);
        min-width: unset;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
        padding: 0;
    }

    .container {
        box-shadow: none;
    }

    .form-header {
        background: white;
        color: black;
        border-bottom: 2px solid black;
    }

    .btn,
    .form-actions {
        display: none;
    }

    .alert {
        border: 2px solid;
    }
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-primary: #000000;
    }

    input[type="text"],
    input[type="email"],
    input[type="tel"],
    input[type="number"],
    select,
    textarea {
        border-width: 3px;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}