/**
 * FERS Retirement Calculator - main stylesheet
 * Global layout, tokens, and components.
 */

/* ========== Design tokens ========== */
:root {
    
    --color-primary: #1E3A8A;          
    --color-primary-light: #2563EB;    
    --color-primary-dark: #1E40AF;     
    --color-secondary: #F59E0B;        
    --color-secondary-light: #FBBF24;  
    --color-success: #10B981;          
    --color-danger: #EF4444;           
    --color-warning: #F97316;          
    --color-text: #111827;             
    --color-text-light: #6B7280;       
    --color-text-lighter: #9CA3AF;     
    --color-bg: #FFFFFF;               
    --color-bg-alt: #F9FAFB;           
    --color-bg-dark: #1F2937;          
    --color-border: #E5E7EB;           
    --color-border-light: #F3F4F6;     

    
    --spacing-xs: 0.25rem;   
    --spacing-sm: 0.375rem;  
    --spacing-md: 0.75rem;   
    --spacing-lg: 1rem;      
    --spacing-xl: 1.5rem;    
    --spacing-2xl: 2rem;     
    --spacing-3xl: 2.5rem;   
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-heading: 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    
    --text-xs: 0.75rem;      
    --text-sm: 0.875rem;     
    --text-base: 1rem;       
    --text-lg: 1.125rem;     
    --text-xl: 1.25rem;      
    --text-2xl: 1.5rem;      
    --text-3xl: 1.875rem;    
    --text-4xl: 2.25rem;     
    --text-5xl: 3rem;        
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;

    
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;

    --page-rhythm: var(--spacing-2xl);
    --surface-elevated: var(--color-bg);
    --shadow-card: var(--shadow-md);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

/* ========== Skip link (accessibility) ========== */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: 8px 16px;
    z-index: 10000;
    font-weight: 600;
    text-decoration: none;
    transition: top 0.3s ease;
}

.skip-link:focus {
    top: 0;
}

body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: var(--leading-relaxed);
    color: var(--color-text);
    background-color: var(--color-bg);
    background-image: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 16rem);
    background-repeat: no-repeat;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========== Typography ========== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: var(--font-bold);
    line-height: var(--leading-tight);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--text-4xl);
}

h2 {
    font-size: var(--text-3xl);
}

h3 {
    font-size: var(--text-2xl);
}

h4 {
    font-size: var(--text-xl);
}

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

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

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

/* ========== Container ========== */
.container {
    width: 100%;
    max-width: var(--container-xl);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
}

.container-sm {
    max-width: var(--container-sm);
}

.container-md {
    max-width: var(--container-md);
}

.container-lg {
    max-width: var(--container-lg);
}

/* ========== Header navigation ========== */
.header {
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-md);
    padding-bottom: var(--spacing-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    color: var(--color-primary);
    text-decoration: none;
}

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

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.nav-menu {
    display: none;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-menu > li {
    position: relative;
}

.nav-menu a {
    color: var(--color-text);
    font-weight: var(--font-medium);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    display: block;
}

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

.nav-menu a.active {
    color: var(--color-primary);
    background-color: rgba(30, 58, 138, 0.08);
    font-weight: var(--font-semibold);
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 220px;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) 0;
    margin-top: 0;
    z-index: 9999;
    list-style: none;
    border: 1px solid var(--color-border);
}

.nav-menu > li:hover .dropdown-menu {
    display: block;
}

/* Keep parent li active while hovering dropdown */
.nav-menu > li {
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.dropdown-menu li a {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.9rem;
    white-space: nowrap;
    color: var(--color-text);
}

.dropdown-menu li a:hover {
    background-color: var(--color-bg-alt);
    color: var(--color-primary);
}

.mobile-menu-toggle {
    display: block;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    position: relative;
    transition: all var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    transition: all var(--transition-fast);
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

/* Mobile navigation: open panel + stacked dropdowns (matches site-nav.js .active toggle) */
@media (max-width: 767px) {
    .header .container {
        flex-wrap: wrap;
        align-items: center;
    }

    .header .logo {
        order: 1;
    }

    .header .mobile-menu-toggle {
        order: 2;
        margin-left: auto;
        z-index: 101;
        min-width: 44px;
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .header nav {
        order: 3;
        flex: 1 1 100%;
        width: 100%;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        gap: 0;
        width: 100%;
        padding: var(--spacing-sm) 0;
        margin: 0;
        list-style: none;
        background: var(--color-bg);
        border-top: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu > li {
        width: 100%;
        padding-bottom: 0;
        border-bottom: 1px solid var(--color-border-light);
    }

    .nav-menu > li:last-child {
        border-bottom: none;
    }

    .nav-menu a {
        padding: var(--spacing-md) var(--spacing-lg);
    }

    .nav-menu.active .dropdown-menu {
        display: block !important;
        position: static;
        min-width: 0;
        margin: 0;
        padding: 0 0 var(--spacing-sm) 0;
        border: none;
        box-shadow: none;
        background: var(--color-bg-alt);
    }

    .nav-menu.active .dropdown-menu li a {
        padding: var(--spacing-sm) var(--spacing-md) var(--spacing-sm) var(--spacing-xl);
        font-size: var(--text-sm);
    }
}

/* ========== Hero Section ========== */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero h1 {
    color: white;
    font-size: var(--text-3xl);
    margin-bottom: var(--spacing-sm);
}

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

.hero-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background-color: rgba(255, 255, 255, 0.15);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    backdrop-filter: blur(10px);
}

/* ========== Main content area ========== */
main {
    padding: var(--spacing-xl) 0;
}

section {
    margin-bottom: var(--spacing-2xl);
}

section h2 {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

section h3 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

/* ========== Cards ========== */
.card {
    background-color: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-xl);
    transition: box-shadow var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border-light);
}

.card-title {
    font-size: var(--text-xl);
    font-weight: var(--font-semibold);
    color: var(--color-primary);
    margin: 0;
}

/* ========== Buttons ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-family: var(--font-body);
    font-size: var(--text-base);
    font-weight: var(--font-semibold);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    min-height: 48px; 
}

.btn:hover {
    text-decoration: none;
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
    box-shadow: var(--shadow-md);
}

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

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

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

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

.btn-lg {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: var(--text-lg);
}

.btn-block {
    width: 100%;
}

/* ========== Forms ========== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

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

.form-label .required {
    color: var(--color-danger);
    margin-left: var(--spacing-xs);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--spacing-md);
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--color-text);
    background-color: var(--color-bg);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(30, 58, 138, 0.1);
}

.form-input::placeholder {
    color: var(--color-text-lighter);
}

.form-help {
    display: block;
    font-size: var(--text-sm);
    color: var(--color-text-light);
    margin-top: var(--spacing-xs);
}

.form-error {
    display: block;
    font-size: var(--text-sm);
    color: var(--color-danger);
    margin-top: var(--spacing-xs);
}

.slider-container {
    margin-top: var(--spacing-sm);
}

.slider {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: var(--radius-full);
    background: var(--color-border);
    outline: none;
    transition: all var(--transition-fast);
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.slider::-webkit-slider-thumb:hover {
    background: var(--color-primary-light);
    transform: scale(1.1);
}

.slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-md);
}

.slider-value {
    display: inline-block;
    margin-left: var(--spacing-sm);
    font-weight: var(--font-semibold);
    color: var(--color-primary);
}

.radio-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.radio-item {
    flex: 1;
    min-width: 120px;
}

.radio-item input[type="radio"] {
    display: none;
}

.radio-item label {
    display: block;
    padding: var(--spacing-md);
    text-align: center;
    background-color: var(--color-bg-alt);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-weight: var(--font-medium);
}

.radio-item input[type="radio"]:checked + label {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.radio-item label:hover {
    border-color: var(--color-primary);
}

/* ========== Result cards ========== */
.results-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.result-card {
    background: linear-gradient(135deg, var(--color-bg-alt), white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border-left: 4px solid var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.result-card.highlight {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: white;
    border-left-color: var(--color-secondary);
}

.result-card.highlight .result-label,
.result-card.highlight .result-value {
    color: white;
}

.result-label {
    font-size: var(--text-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
}

.result-value {
    font-size: var(--text-3xl);
    font-weight: var(--font-bold);
    color: var(--color-primary);
}

.result-value.sm {
    font-size: var(--text-2xl);
}

.result-note {
    font-size: var(--text-sm);
    color: var(--color-text-light);
    margin-top: var(--spacing-sm);
}

/* ========== FAQ accordion ========== */
.faq-list {
    margin-top: var(--spacing-xl);
}

.faq-item {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-alt);
    border: none;
    text-align: left;
    font-size: var(--text-base);
    font-weight: var(--font-semibold);
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color var(--transition-fast);
}

.faq-question:hover {
    background-color: var(--color-border-light);
}

.faq-question::after {
    content: '+';
    font-size: var(--text-2xl);
    color: var(--color-primary);
    transition: transform var(--transition-fast);
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 var(--spacing-lg);
    max-height: 0;
    overflow: hidden;
    transition: all var(--transition-normal);
}

.faq-item.active .faq-answer {
    padding: var(--spacing-lg);
    max-height: 500px;
}

/* ========== Footer ========== */
.footer {
    background-color: var(--color-bg-dark);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
    color: white;
    font-size: var(--text-lg);
    margin-bottom: var(--spacing-md);
}

.footer-section ul {
    list-style: none;
}

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

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

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

.disclaimer {
    background-color: rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
}

.disclaimer strong {
    color: var(--color-secondary);
}

.footer-bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: var(--text-sm);
    color: rgba(255, 255, 255, 0.6);
}

.trust-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.trust-badges img {
    height: 40px;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.trust-badges img:hover {
    opacity: 1;
}

/* ========== Partner / friend links ========== */
.partner-links {
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.partner-links h4 {
    color: white;
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.partner-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    justify-items: center;
}

.partner-link {
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
    width: 100%;
    max-width: 280px;
    justify-content: center;
}

.partner-link:hover {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.partner-link svg {
    flex-shrink: 0;
}

.partner-link span {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ========== Ad slots ========== */
.ad-container {
    margin: var(--spacing-xl) 0;
    text-align: center;
    min-height: 0;
    overflow: hidden;
}

.ad-container:empty,
.ad-container ins.adsbygoogle[data-ad-status="unfilled"] {
    display: none !important;
    height: 0 !important;
    margin: 0 !important;
}

/* ========== Utility classes ========== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

.hidden { display: none !important; }
.visible { display: block !important; }

/* ========== Loading spinner ========== */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(30, 58, 138, 0.2);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ========== Accessibility helpers ========== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

*:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ========== Guide article layout ========== */
.guide-article {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-md) 0;
}

.article-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 3px solid var(--color-primary);
}

.article-header h1 {
    font-size: var(--text-4xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.article-meta {
    color: var(--color-text-light);
    font-size: var(--text-sm);
}

.article-section {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

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

.article-section h2 {
    font-size: var(--text-2xl);
    color: var(--color-primary);
    margin-top: 0;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-secondary);
}

.article-section h3 {
    font-size: var(--text-xl);
    color: var(--color-primary-dark);
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.article-section h4 {
    font-size: var(--text-lg);
    color: var(--color-text);
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.article-section p {
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.article-section ul,
.article-section ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

.article-section li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.7;
}

.article-section table,
.guide-section table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-md) 0;
    background: white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    border-radius: var(--radius-md);
}

.article-section thead,
.guide-section thead {
    background-color: var(--color-primary);
    color: white;
}

.article-section th,
.guide-section th {
    padding: 12px 14px;
    text-align: left;
    font-weight: 600;
}

.article-section td,
.guide-section td {
    padding: 10px 12px;
    border: 1px solid var(--color-border);
}

.article-section tbody tr:nth-child(even),
.guide-section tbody tr:nth-child(even) {
    background-color: #f9fafb;
}

.article-section a {
    color: var(--color-primary-light);
    text-decoration: underline;
}

.article-section a:hover {
    color: var(--color-primary-dark);
}

.guide-section a {
    color: var(--color-primary-light);
    text-decoration: underline;
}

.guide-section a:hover {
    color: var(--color-primary-dark);
}

/* Guide / tool prose: reusable blocks (replaces inline styles) */
.article-note-info {
    background-color: rgba(219, 234, 254, 0.95);
    border-left: 4px solid var(--color-primary-light);
    padding: var(--spacing-md) var(--spacing-lg);
    margin: var(--spacing-md) 0;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.article-note-info p:last-child {
    margin-bottom: 0;
}

.article-list-disc {
    list-style: disc;
    padding-left: 1.5rem;
    line-height: 1.8;
}

.article-td-label {
    font-weight: var(--font-semibold);
}

.article-td-accent-positive {
    color: var(--color-primary);
    font-weight: var(--font-semibold);
}

.article-td-accent-negative {
    color: var(--color-danger);
    font-weight: var(--font-semibold);
}

.article-td-accent-success {
    color: var(--color-success);
    font-weight: var(--font-semibold);
}

.article-tr-muted {
    background-color: #f3f4f6;
}

.article-tr-highlight {
    background-color: #fef3c7;
}

.article-tr-mint {
    background-color: #f0fdf4;
}

.article-tr-subtle-blue {
    background: #dbeafe;
}

.article-tr-subtle-green {
    background: #dcfce7;
}

.article-tr-head-green {
    background-color: #16a34a;
    color: white;
}

.article-tr-head-amber {
    background-color: #f59e0b;
    color: white;
}

.article-tr-orange-tint {
    background-color: rgba(245, 158, 11, 0.1);
}

.article-tr-total-row {
    background-color: #f3f4f6;
    font-weight: var(--font-bold);
}

.formula-box {
    background: #f0f9ff;
    border: 2px solid var(--color-primary);
    padding: var(--spacing-lg);
    margin: var(--spacing-md) 0;
    text-align: center;
    font-size: var(--text-lg);
}

.example-box {
    background: #fef3c7;
    border-left: 4px solid #f59e0b;
    padding: var(--spacing-lg);
    margin: var(--spacing-md) 0;
}

.example-box ul {
    margin-top: 0.5rem;
}

/* CTA Section — unified call-to-action band (guides + calculators) */
.cta-section {
    margin: var(--spacing-2xl) 0;
    padding: var(--spacing-xl) var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: var(--radius-xl);
    text-align: center;
    color: white;
    box-shadow: var(--shadow-lg);
}

.cta-section h2 {
    color: white;
    margin-bottom: var(--spacing-md);
    border-bottom: none;
    padding-bottom: 0;
    font-size: var(--text-2xl);
}

.cta-section p {
    color: rgba(255, 255, 255, 0.92);
    max-width: 42rem;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: var(--spacing-md);
}

.cta-section a:not(.btn) {
    color: var(--color-secondary-light);
    font-weight: var(--font-semibold);
    text-decoration: underline;
}

.cta-section a:not(.btn):hover {
    color: white;
}

.cta-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-md);
}

.cta-buttons .btn {
    min-width: 180px;
}

/* Primary = light button on blue band for contrast */
.cta-section .btn-primary {
    background: white;
    color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.cta-section .btn-primary:hover {
    background: var(--color-bg-alt);
    color: var(--color-primary-dark);
}

.cta-section a.btn:not(.btn-primary):not(.btn-secondary):not(.btn-outline) {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--color-secondary);
    color: var(--color-text);
    font-weight: var(--font-bold);
    border-radius: var(--radius-md);
    text-decoration: none;
}

.cta-section a.btn:not(.btn-primary):not(.btn-secondary):not(.btn-outline):hover {
    background: var(--color-secondary-light);
    color: var(--color-text);
    text-decoration: none;
}

/* Breadcrumb */
.breadcrumb {
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-xs) 0;
}

.breadcrumb ol {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    font-size: var(--text-sm);
}

.breadcrumb li + li::before {
    content: ">";
    margin-right: var(--spacing-sm);
    color: var(--color-text-light);
}

.breadcrumb a {
    color: var(--color-primary-light);
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb [aria-current="page"] {
    color: var(--color-text-light);
}

/* Responsive adjustments for guide articles */
@media (max-width: 768px) {
    .article-header h1 {
        font-size: var(--text-3xl);
    }

    .article-section h2 {
        font-size: var(--text-xl);
    }

    .article-section h3 {
        font-size: var(--text-lg);
    }

    .article-section table,
    .guide-section table {
        font-size: var(--text-sm);
    }

    .article-section th,
    .article-section td,
    .guide-section th,
    .guide-section td {
        padding: 8px;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .cta-buttons .btn {
        width: 100%;
    }
}

.tool-five-tier {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.tool-five-tier:first-of-type {
    margin-top: var(--spacing-lg);
    border-top: none;
    padding-top: 0;
}

.tool-five-tier__h2 {
    font-size: var(--text-2xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-secondary);
    display: inline-block;
    width: 100%;
}

.tool-five-tier__h2:first-child,
.tool-five-tier > .tool-five-tier__h2:first-of-type {
    margin-top: 0;
}

.tool-five-tier .tier-lead {
    font-size: var(--text-lg);
    color: var(--color-text-light);
    max-width: 65ch;
    margin-bottom: var(--spacing-lg);
}

.tier-card-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

@media (min-width: 768px) {
    .tier-card-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .tier-card-grid--2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

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

.tier-card h3 {
    font-size: var(--text-lg);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.tier-card p:last-child {
    margin-bottom: 0;
}

.meta-source-note {
    font-size: var(--text-sm);
    color: var(--color-text-light);
    background: linear-gradient(90deg, rgba(30, 58, 138, 0.06), transparent);
    border-left: 4px solid var(--color-primary);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.tool-five-tier__links {
    list-style: none;
    padding: 0;
    margin: 0 0 var(--spacing-lg);
}

.tool-five-tier__links li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-lg);
    position: relative;
}

.tool-five-tier__links li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--color-secondary);
    font-weight: var(--font-bold);
}

.tool-hero-subtle {
    background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    border-radius: 0 0 var(--radius-xl) var(--radius-xl);
}

.calculator-page .page-header h1 {
    scroll-margin-top: 5rem;
}

.content-hub-strip {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-sm) var(--spacing-lg);
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    font-size: var(--text-sm);
}

.content-hub-strip a {
    font-weight: var(--font-semibold);
    color: var(--color-primary);
    text-decoration: none;
}

.content-hub-strip a:hover {
    text-decoration: underline;
}

.content-hub-strip__label {
    color: var(--color-text-light);
    font-weight: var(--font-semibold);
    font-size: var(--text-xs);
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.content-end-dual {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--color-border);
}

@media (min-width: 900px) {
    .content-end-dual {
        grid-template-columns: 1fr 1fr;
        align-items: start;
    }
}

.content-end-dual__col h2 {
    font-size: var(--text-xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.content-end-dual__col .tier-lead {
    margin-bottom: var(--spacing-md);
}

.content-end-dual__col {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

/* Hub listing pages (guides index, calculators index) */
.page-header {
    text-align: center;
    max-width: 42rem;
    margin: 0 auto var(--page-rhythm);
    padding: var(--spacing-lg) 0 var(--spacing-sm);
}

.page-header h1 {
    font-size: clamp(1.85rem, 4vw, 2.35rem);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.page-header p {
    font-size: var(--text-lg);
    color: var(--color-text-light);
    margin-bottom: 0;
    line-height: var(--leading-relaxed);
}

.calculator-grid,
.guides-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

@media (min-width: 640px) {
    .calculator-grid,
    .guides-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .calculator-grid,
    .guides-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.calculator-card,
.guide-card {
    background: var(--surface-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    min-height: 100%;
    transition: box-shadow var(--transition-normal), border-color var(--transition-fast);
}

.calculator-card:hover,
.guide-card:hover {
    box-shadow: var(--shadow-card);
    border-color: rgba(30, 58, 138, 0.2);
}

.calculator-card h3,
.guide-card h3 {
    font-size: var(--text-xl);
    color: var(--color-primary);
    margin-bottom: 0;
}

.calculator-card p,
.guide-card p {
    flex: 1 1 auto;
    color: var(--color-text-light);
    margin-bottom: 0;
    font-size: var(--text-base);
    line-height: 1.6;
}

.calculator-card .btn,
.guide-card .btn {
    align-self: flex-start;
    margin-top: auto;
}

.calculator-card.featured,
.guide-card.featured {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-md);
    background: linear-gradient(165deg, rgba(37, 99, 235, 0.06) 0%, var(--color-bg) 55%);
}

/* Guide / blog: two-column article shell */
.article-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--spacing-lg);
    align-items: start;
    margin-bottom: var(--spacing-lg);
}

.article-layout__main {
    min-width: 0;
}

@media (min-width: 1100px) {
    .article-layout {
        grid-template-columns: minmax(0, 1fr) 17.5rem;
        gap: var(--spacing-xl);
    }

    .article-layout__aside {
        position: sticky;
        top: 6rem;
    }
}

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

.article-aside-card__kicker {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-light);
    margin: 0 0 var(--spacing-sm);
}

.article-aside-card__links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.article-aside-card__links li {
    margin-bottom: var(--spacing-sm);
}

.article-aside-card__links a {
    font-weight: var(--font-medium);
}

.article-toc {
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.article-toc__title {
    font-size: var(--text-sm);
    font-weight: var(--font-bold);
    color: var(--color-primary);
    margin: 0 0 var(--spacing-md);
}

.article-toc__list {
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: var(--text-sm);
}

.article-toc__list li {
    margin-bottom: 0;
    padding-left: 0;
}

.article-toc__list a {
    color: var(--color-text);
    text-decoration: none;
    display: block;
    padding: var(--spacing-xs) 0;
    border-bottom: 1px solid var(--color-border-light);
}

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

/* Article content patterns (replace inline styles) */
.article-lead {
    color: var(--color-text-light);
    font-size: var(--text-lg);
    line-height: var(--leading-relaxed);
}

.article-callout-banner {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    margin: var(--spacing-xl) 0;
    text-align: center;
}

.article-callout-banner h2,
.article-callout-banner h3 {
    color: white;
    margin-bottom: var(--spacing-md);
    border: none;
    padding: 0;
}

.article-callout-banner > p:first-of-type {
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    margin-bottom: var(--spacing-md);
}

.article-callout-banner p {
    opacity: 0.95;
    margin-bottom: var(--spacing-md);
}

.article-callout-banner a {
    color: white;
    text-decoration: underline;
    font-weight: var(--font-semibold);
}

.article-formula-card {
    text-align: center;
    padding: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
}

.article-formula-card p {
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    color: var(--color-primary);
    margin: 0;
}

.article-mono-block {
    background-color: var(--color-bg-alt);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin: var(--spacing-md) 0;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: var(--text-base);
}

.resource-grid-3 {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

@media (min-width: 768px) {
    .resource-grid-3 {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

h4.resource-card-min {
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

h4.resource-card-min--spaced {
    margin-top: var(--spacing-xl);
}

.resource-grid-3 .card p {
    font-size: var(--text-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
}

.resource-grid-3 .card a {
    font-weight: var(--font-semibold);
}

.flatpickr-calendar {
    z-index: 12000;
}