/* US Tax Calculators - Main Stylesheet */

:root {
    /* Colors - Light Theme */
    --color-primary: #1a56db;
    --color-primary-dark: #1e429f;
    --color-primary-light: #3b82f6;
    --color-secondary: #0e9f6e;
    --color-accent: #7c3aed;
    
    --color-bg: #f9fafb;
    --color-bg-alt: #ffffff;
    --color-bg-card: #ffffff;
    --color-bg-hover: #f3f4f6;
    
    --color-text: #111827;
    --color-text-muted: #6b7280;
    --color-text-light: #9ca3af;
    
    --color-border: #e5e7eb;
    --color-border-dark: #d1d5db;
    
    --color-success: #059669;
    --color-warning: #d97706;
    --color-error: #dc2626;
    --color-info: #2563eb;
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'Fira Code', 'Consolas', monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Layout */
    --max-width: 1200px;
    --header-height: 64px;
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo:hover {
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    list-style: none;
}

.nav-link {
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text);
    font-weight: 500;
    font-size: 0.875rem;
    border-radius: var(--radius-md);
    transition: background-color 0.2s;
}

.nav-link:hover {
    background-color: var(--color-bg-hover);
    text-decoration: none;
}

.nav-dropdown {
    position: relative;
}

.nav-dropdown .nav-link::after {
    content: '▼';
    font-size: 0.625rem;
    margin-left: var(--spacing-xs);
    opacity: 0.6;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 220px;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s;
    list-style: none;
    padding: var(--spacing-sm) 0;
}

.nav-dropdown:hover .dropdown-menu,
.nav-dropdown.active .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text);
    font-size: 0.875rem;
}

.dropdown-menu a:hover {
    background-color: var(--color-bg-hover);
    text-decoration: none;
}

/* Search */
.search-container {
    position: relative;
}

.search-input {
    padding: var(--spacing-sm) var(--spacing-md);
    padding-left: 2.5rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    width: 200px;
    transition: all 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    width: 280px;
    box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1);
}

.search-icon {
    position: absolute;
    left: var(--spacing-sm);
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
}

.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    margin-top: var(--spacing-xs);
    display: none;
    max-height: 400px;
    overflow-y: auto;
}

.search-results.active {
    display: block;
}

.search-result-item {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item:hover {
    background-color: var(--color-bg-hover);
    text-decoration: none;
}

.result-category {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.search-no-results {
    padding: var(--spacing-md);
    color: var(--color-text-muted);
    text-align: center;
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    padding: var(--spacing-sm);
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    margin: 5px 0;
    transition: all 0.3s;
}

/* ============================================
   MAIN LAYOUT
   ============================================ */

.main-wrapper {
    display: flex;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-lg);
    gap: var(--spacing-xl);
    flex: 1;
}

.main-content {
    flex: 1;
    min-width: 0;
}

/* Sidebar TOC */
.toc {
    position: sticky;
    top: calc(var(--header-height) + var(--spacing-lg));
    width: 220px;
    max-height: calc(100vh - var(--header-height) - var(--spacing-2xl));
    overflow-y: auto;
    padding: var(--spacing-md);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    flex-shrink: 0;
}

.toc-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.toc-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.toc-list {
    list-style: none;
}

.toc-item {
    margin-bottom: var(--spacing-xs);
}

.toc-item a {
    display: block;
    padding: var(--spacing-xs) var(--spacing-sm);
    color: var(--color-text-muted);
    font-size: 0.875rem;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.toc-item a:hover {
    background-color: var(--color-bg-hover);
    color: var(--color-primary);
    text-decoration: none;
}

.toc-sub {
    padding-left: var(--spacing-md);
}

.toc-sub a {
    font-size: 0.8125rem;
}

/* ============================================
   BREADCRUMBS
   ============================================ */

.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--color-text-muted);
}

.breadcrumb a:hover {
    color: var(--color-primary);
}

.breadcrumb-sep {
    color: var(--color-text-light);
}

.breadcrumb-current {
    color: var(--color-text);
    font-weight: 500;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    color: var(--color-text);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: 1.5rem;
    margin-top: var(--spacing-2xl);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
}

h3 {
    font-size: 1.25rem;
    margin-top: var(--spacing-xl);
}

p {
    margin-bottom: var(--spacing-md);
}

.intro-text {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
}

/* ============================================
   CARDS
   ============================================ */

.card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.card-title-icon {
    color: var(--color-primary);
}

/* Calculator Card */
.calculator-card {
    border-left: 4px solid var(--color-primary);
}

.results-card {
    border-left: 4px solid var(--color-secondary);
    background: linear-gradient(to right, rgba(14, 159, 110, 0.05), transparent);
}

/* ============================================
   FORMS
   ============================================ */

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

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.form-hint {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
}

.form-input,
.form-select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1);
}

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

.form-error {
    color: var(--color-error);
    font-size: 0.75rem;
    margin-top: var(--spacing-xs);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.input-group {
    display: flex;
}

.input-prefix,
.input-suffix {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text-muted);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
}

.input-prefix {
    border-right: none;
    border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.input-suffix {
    border-left: none;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.input-group .form-input {
    border-radius: 0;
}

.input-group .form-input:only-child {
    border-radius: var(--radius-md);
}

/* Checkbox & Radio */
.form-check {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.form-check-input {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
}

.form-check-label {
    font-size: 0.875rem;
    cursor: pointer;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.875rem;
    font-weight: 500;
    font-family: inherit;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn:hover {
    text-decoration: none;
}

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

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

.btn-secondary {
    background: var(--color-bg);
    color: var(--color-text);
    border-color: var(--color-border);
}

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

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

.btn-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

/* ============================================
   RESULTS
   ============================================ */

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
}

.result-row:last-child {
    border-bottom: none;
}

.result-label {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.result-value {
    font-weight: 600;
    font-size: 1rem;
    font-family: var(--font-mono);
}

.result-total {
    background: var(--color-bg);
    margin: var(--spacing-md) calc(-1 * var(--spacing-lg));
    margin-bottom: calc(-1 * var(--spacing-lg));
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.result-total .result-label {
    font-weight: 600;
    color: var(--color-text);
}

.result-total .result-value {
    font-size: 1.5rem;
    color: var(--color-primary);
}

.result-highlight {
    color: var(--color-success);
}

.result-negative {
    color: var(--color-error);
}

/* ============================================
   ACCORDION (FAQ)
   ============================================ */

.accordion-group {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.accordion-item {
    border-bottom: 1px solid var(--color-border);
}

.accordion-item:last-child {
    border-bottom: none;
}

.accordion-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-alt);
    cursor: pointer;
    font-weight: 500;
    transition: background-color 0.2s;
}

.accordion-header:hover {
    background-color: var(--color-bg-hover);
}

.accordion-header::after {
    content: '+';
    font-size: 1.25rem;
    color: var(--color-text-muted);
    transition: transform 0.2s;
}

.accordion-item.active .accordion-header::after {
    content: '−';
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.accordion-item.active .accordion-content {
    max-height: 500px;
}

.accordion-body {
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    line-height: 1.7;
}

/* ============================================
   GRID LAYOUTS
   ============================================ */

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.category-card {
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    transition: all 0.2s;
}

.category-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.category-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.category-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.category-desc {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.category-links {
    list-style: none;
}

.category-links li {
    margin-bottom: var(--spacing-xs);
}

.category-links a {
    font-size: 0.875rem;
    color: var(--color-primary);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.category-links a::before {
    content: '→';
    opacity: 0;
    transform: translateX(-5px);
    transition: all 0.2s;
}

.category-links a:hover::before {
    opacity: 1;
    transform: translateX(0);
}

/* Related Calculators Grid */
.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.related-link {
    display: block;
    padding: var(--spacing-md);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--color-text);
    transition: all 0.2s;
}

.related-link:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    text-decoration: none;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background: var(--color-text);
    color: var(--color-bg);
    padding: var(--spacing-2xl) var(--spacing-md);
    margin-top: auto;
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
    color: white;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-light);
    font-size: 0.875rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: white;
    text-decoration: none;
}

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255,255,255,0.1);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 0.8125rem;
    color: var(--color-text-light);
}

.disclaimer {
    background: rgba(255,255,255,0.05);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */

.toast {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-text);
    color: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s;
    z-index: 9999;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

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

.toast-error {
    background: var(--color-error);
}

/* ============================================
   YEAR SELECTOR
   ============================================ */

.year-selector-wrapper {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-info);
    color: white;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
}

.year-selector {
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: var(--radius-sm);
    background: rgba(255,255,255,0.1);
    color: white;
    font-weight: 600;
    cursor: pointer;
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    text-align: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: white;
    margin: calc(-1 * var(--spacing-lg));
    margin-bottom: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: white;
}

.hero p {
    font-size: 1.125rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
}

.hero-search {
    max-width: 500px;
    margin: 0 auto;
}

.hero-search .search-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
    border: none;
    box-shadow: var(--shadow-lg);
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
    .header,
    .footer,
    .toc,
    .btn-group,
    .search-container,
    .related-grid,
    .accordion-group,
    .year-selector-wrapper,
    .menu-toggle {
        display: none !important;
    }

    body {
        background: white;
        color: black;
        font-size: 12pt;
    }

    .main-wrapper {
        max-width: 100%;
        padding: 0;
    }

    .card {
        border: 1px solid #ccc;
        box-shadow: none;
        page-break-inside: avoid;
    }

    .result-row {
        border-bottom-color: #ccc;
    }

    h1, h2, h3 {
        page-break-after: avoid;
    }

    a {
        color: black;
        text-decoration: underline;
    }

    .results-card {
        background: #f5f5f5;
    }
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 1024px) {
    .toc {
        display: none;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 56px;
    }

    .menu-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--color-bg-alt);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: 0;
        transform: translateX(-100%);
        transition: transform 0.3s;
        overflow-y: auto;
    }

    .nav-menu.active {
        transform: translateX(0);
    }

    .nav-dropdown {
        width: 100%;
    }

    .nav-link {
        display: block;
        padding: var(--spacing-md);
        border-bottom: 1px solid var(--color-border);
    }

    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: none;
        background: var(--color-bg);
        display: none;
    }

    .nav-dropdown.active .dropdown-menu {
        display: block;
    }

    .search-container {
        display: none;
    }

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

    .hero {
        padding: var(--spacing-xl) var(--spacing-md);
        margin: calc(-1 * var(--spacing-md));
        margin-bottom: var(--spacing-lg);
    }

    .hero h1 {
        font-size: 1.75rem;
    }

    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.25rem;
    }

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

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .category-grid {
        grid-template-columns: 1fr;
    }

    .result-total .result-value {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .btn-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }
}