/* ==========================================
   CALCULATOR BODY CSS
   Layout and component styles for calculator pages.
   Header/footer/nav are handled by site-shell.css.
   ========================================== */
:root {
    /* Primary Palette - Navy (matches site theme) */
    --primary-900: #0a1628;
    --primary-800: #0f2240;
    --primary-700: #153058;
    --primary-600: #1a3d6e;
    --primary-500: #1e4d8c;
    --primary-400: #3366aa;
    --primary-300: #5588cc;
    --primary-200: #88aadd;
    --primary-100: #c4d6ee;
    --primary-50: #e8f0f8;

    /* Accent - Teal (matches site theme) */
    --accent-500: #00d4aa;
    --accent-400: #00e6b8;
    --accent-300: #33ecc6;
    --accent-glow: rgba(0, 212, 170, 0.4);

    /* Neutrals */
    --gray-900: #111827;
    --gray-800: #1f2937;
    --gray-700: #374151;
    --gray-600: #4b5563;
    --gray-500: #6b7280;
    --gray-400: #9ca3af;
    --gray-300: #d1d5db;
    --gray-200: #e5e7eb;
    --gray-100: #f3f4f6;
    --gray-50: #f9fafb;

    /* Semantic */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    /* Shadows */
    --shadow-sm: 0 1px 2px 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);
    --shadow-glow: 0 0 40px rgba(0, 212, 170, 0.15);

    /* Typography - Inter to match site-shell.css */
    --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

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

html {
    height: 100%;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: #0f172a;
    background: #f8fafc;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* ==========================================
   MAIN CONTAINER
   ========================================== */
.page-container {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--space-6);
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--space-6);
    width: 100%;
}

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

/* Breadcrumb */
.breadcrumb {
    font-size: 13px;
    color: var(--primary-400);
    margin-bottom: var(--space-4);
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.breadcrumb a {
    color: var(--accent-500);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.breadcrumb a:hover {
    color: var(--accent-400);
    text-decoration: underline;
}

.breadcrumb span {
    color: var(--gray-400);
}

/* ==========================================
   CALCULATOR CARD
   ========================================== */
.calculator-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: 0 14px 28px rgba(15, 23, 42, 0.08);
    border: 1px solid var(--gray-200);
    position: relative;
}

.calculator-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-500) 0%, var(--accent-500) 50%, var(--primary-400) 100%);
}

.calculator-header {
    background: linear-gradient(135deg, var(--primary-800) 0%, var(--primary-600) 100%);
    padding: var(--space-6) var(--space-6) var(--space-5);
    position: relative;
    overflow: hidden;
}

.calculator-header::before {
    display: none;
}

.calculator-header h1 {
    font-family: var(--font-display);
    font-size: 26px;
    font-weight: 700;
    color: #f8fafc;
    margin: 0;
    position: relative;
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.calculator-header h1 .icon {
    width: 44px;
    height: 44px;
    background: var(--accent-500);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    box-shadow: 0 6px 14px rgba(0, 212, 170, 0.3);
}

.calculator-header p {
    color: #cbd5e1;
    font-size: 15px;
    margin: var(--space-3) 0 0;
    position: relative;
    max-width: 100%;
}

.calculator-body {
    padding: var(--space-6);
}

/* ==========================================
   CALCULATOR LAYOUT
   ========================================== */
.calculator-layout {
    display: grid;
    grid-template-columns: 1fr 280px;
    gap: var(--space-6);
    align-items: start;
}

.calculator-inputs {
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

/* ==========================================
   INPUT GRID
   ========================================== */
.input-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-5) var(--space-5);
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

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

.input-label {
    font-size: 13px;
    font-weight: 600;
    color: #334155;
    margin-bottom: var(--space-2);
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.input-label .hint-icon {
    width: 16px;
    height: 16px;
    background: var(--gray-200);
    color: var(--gray-500);
    border-radius: 50%;
    font-size: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: help;
    transition: all var(--transition-fast);
}

.input-label .hint-icon:hover {
    background: var(--accent-500);
    color: white;
}

.input-wrapper {
    position: relative;
    display: flex;
    gap: var(--space-2);
    align-items: center;
}

.input-field {
    flex: 1;
    width: 100%;
    min-width: 0;
    padding: var(--space-4);
    padding-right: calc(var(--space-12) + 4px);
    font-size: 16px;
    font-family: var(--font-body);
    font-weight: 500;
    color: #0f172a;
    background: #ffffff;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    outline: none;
    transition: all var(--transition-fast);
    -moz-appearance: textfield;
}

.input-field::-webkit-outer-spin-button,
.input-field::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.input-field:hover {
    border-color: var(--gray-300);
}

.input-field:focus {
    border-color: var(--accent-400);
    background: white;
    box-shadow: 0 0 0 3px rgba(0, 212, 170, 0.15);
}

.prefix,
.suffix {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-500);
    pointer-events: none;
    white-space: nowrap;
    line-height: 1;
}

.prefix {
    left: var(--space-4);
}

.suffix {
    right: var(--space-4);
}

.input-wrapper .prefix ~ .input-field {
    padding-left: calc(var(--space-10) + 4px);
}

/* Select styling */
.select-field {
    min-width: 120px;
    padding: var(--space-4);
    font-size: 16px;
    font-family: var(--font-body);
    font-weight: 500;
    color: var(--gray-800);
    background: var(--gray-50);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    outline: none;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--space-3) center;
    padding-right: calc(var(--space-8) + 8px);
    transition: all var(--transition-fast);
}

.select-field:hover {
    border-color: var(--gray-300);
}

.select-field:focus {
    border-color: var(--primary-500);
    background-color: white;
    box-shadow: 0 0 0 4px rgba(30, 77, 140, 0.1);
}

/* Quick Facts Panel */
.quick-facts {
    background: linear-gradient(135deg, var(--primary-50) 0%, #f0f7ff 100%);
    border: 1px solid var(--primary-200);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    box-shadow: var(--shadow-sm);
}

.quick-facts h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-700);
    margin: 0 0 var(--space-4);
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.quick-facts h4 i {
    color: var(--accent-500);
}

.fact-item {
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--primary-100);
}

.fact-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.fact-item .fact-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--gray-500);
    margin-bottom: 2px;
}

.fact-item .fact-value {
    font-size: 15px;
    font-weight: 600;
    color: var(--primary-700);
}

.fact-item .fact-note {
    font-size: 11px;
    color: var(--gray-500);
    margin-top: 2px;
}

/* ==========================================
   BUTTONS
   ========================================== */
.button-group {
    display: flex;
    gap: var(--space-3);
    margin-top: var(--space-8);
    padding-top: var(--space-2);
}

.btn {
    flex: 1;
    padding: var(--space-4) var(--space-6);
    font-size: 16px;
    font-family: var(--font-body);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
}

.btn-primary {
    background: var(--accent-500);
    color: white;
    box-shadow: 0 8px 18px rgba(0, 212, 170, 0.25);
}

.btn-primary:hover {
    background: var(--accent-400);
    transform: translateY(-1px);
    box-shadow: 0 10px 22px rgba(0, 212, 170, 0.35);
}

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

.btn-secondary {
    background: #f1f5f9;
    color: #475569;
    border: 1px solid var(--gray-200);
}

.btn-secondary:hover {
    background: #e2e8f0;
    border-color: var(--gray-300);
}

/* ==========================================
   RESULTS SECTION
   ========================================== */
.results-section {
    margin-top: var(--space-8);
    display: none;
    animation: slideUp 0.4s ease-out;
    padding: var(--space-6);
    border-radius: var(--radius-xl);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.98) 0%, rgba(248, 250, 252, 0.98) 100%);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow-md);
}

.results-section.visible {
    display: block;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-6);
    padding-bottom: var(--space-4);
    border-bottom: 2px solid var(--gray-100);
    flex-wrap: wrap;
}

.results-header h2 {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 600;
    color: var(--gray-800);
    margin: 0;
}

.results-header .badge {
    background: var(--accent-500);
    color: white;
    font-size: 11px;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Results cards */
.results-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
}

.result-card {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: var(--radius-lg);
    padding: var(--space-5) var(--space-6);
    text-align: center;
    transition: all var(--transition-fast);
}

.result-card:hover {
    border-color: var(--primary-200);
    box-shadow: 0 6px 16px rgba(15, 23, 42, 0.08);
}

.result-card.highlight {
    background: linear-gradient(135deg, var(--primary-50) 0%, #e8f4ff 100%);
    border-color: var(--primary-200);
}

.result-card .label {
    font-size: 12px;
    font-weight: 600;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--space-2);
}

.result-card .value {
    font-family: var(--font-display);
    font-size: 26px;
    font-weight: 700;
    color: var(--primary-700);
    line-height: 1.2;
}

.result-card .value.value-break {
    overflow-wrap: anywhere;
    word-break: break-word;
    font-size: 22px;
    line-height: 1.35;
}

.result-card.highlight .value {
    color: var(--primary-600);
}

.result-card .subtext {
    font-size: 12px;
    color: var(--gray-500);
    margin-top: var(--space-1);
}

/* Risk indicator */
.risk-indicator {
    margin-top: var(--space-8);
    padding: var(--space-5);
    border-radius: var(--radius-lg);
    text-align: center;
}

.risk-indicator.low {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border: 1px solid #86efac;
}

.risk-indicator.moderate {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    border: 1px solid #fcd34d;
}

.risk-indicator.high {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border: 1px solid #fca5a5;
}

.risk-indicator.extreme {
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border: 1px solid #f87171;
}

.risk-indicator h3 {
    font-size: 18px;
    margin: 0 0 var(--space-2);
}

.risk-indicator.low h3 { color: #166534; }
.risk-indicator.moderate h3 { color: #92400e; }
.risk-indicator.high h3 { color: #991b1b; }
.risk-indicator.extreme h3 { color: #7f1d1d; }

.risk-indicator p {
    font-size: 14px;
    color: var(--gray-600);
    margin: 0;
}

/* ==========================================
   COPY/SHARE SECTION
   ========================================== */
.share-section {
    margin-top: var(--space-8);
    padding-top: var(--space-6);
    border-top: 1px solid var(--gray-200);
    text-align: center;
}

.share-section p {
    font-size: 13px;
    color: var(--gray-500);
    margin-bottom: var(--space-4);
}

.share-buttons {
    display: flex;
    justify-content: center;
    gap: var(--space-3);
}

.share-btn {
    padding: var(--space-3) var(--space-5);
    font-size: 13px;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    border: none;
}

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

.share-btn.widget:hover {
    background: #0ea572;
}

.share-btn.link {
    background: var(--primary-500);
    color: white;
}

.share-btn.link:hover {
    background: var(--primary-400);
}

/* ==========================================
   CONTENT SECTION
   ========================================== */
.content-section {
    margin-top: var(--space-8);
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
}

.content-section h2 {
    font-family: var(--font-display);
    font-size: 22px;
    font-weight: 600;
    color: var(--gray-800);
    margin: 0 0 var(--space-5);
    line-height: 1.3;
}

.content-section h3 {
    font-family: var(--font-display);
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-800);
    margin: var(--space-8) 0 var(--space-3);
    line-height: 1.35;
}

.content-section p {
    color: var(--gray-600);
    margin-bottom: var(--space-5);
    max-width: 72ch;
}

.content-section ul {
    color: var(--gray-600);
    margin: var(--space-5) 0;
    padding-left: var(--space-6);
    max-width: 72ch;
}

.content-section ol {
    color: var(--gray-700);
    margin: var(--space-4) 0 var(--space-6);
    padding-left: calc(var(--space-6) + 2px);
    list-style: decimal;
    list-style-position: outside;
    max-width: 72ch;
}

.content-section li {
    margin-bottom: var(--space-2);
}

.content-section ol li {
    padding-left: var(--space-1);
    margin-bottom: var(--space-3);
    line-height: 1.55;
}

.content-section ol li:last-child {
    margin-bottom: 0;
}

/* Formula box */
.formula-box {
    background: linear-gradient(135deg, var(--primary-50) 0%, var(--primary-100) 100%);
    border: 1px solid var(--primary-200);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    margin: var(--space-6) 0;
    text-align: center;
}

.formula-box code {
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 16px;
    color: var(--primary-700);
    font-weight: 600;
    display: block;
    word-break: break-word;
}

.formula-box .legend {
    margin-top: var(--space-4);
    font-size: 13px;
    color: var(--gray-600);
}

.formula-box .legend-item {
    display: inline-block;
    margin: var(--space-1) var(--space-3);
}

/* Key Takeaways Box */
.key-takeaways {
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    border: 1px solid #86efac;
    border-left: 4px solid #22c55e;
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    margin-bottom: var(--space-8);
}

.key-takeaways h3 {
    color: #166534;
    font-size: 16px;
    margin: 0 0 var(--space-3);
}

.key-takeaways h3 i {
    color: #22c55e;
    margin-right: var(--space-2);
}

.key-takeaways ul {
    margin: 0;
    padding-left: var(--space-5);
}

.key-takeaways li {
    margin-bottom: var(--space-2);
    color: var(--gray-700);
}

/* Warning Box */
.warning-box {
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border: 1px solid #fca5a5;
    border-left: 4px solid #ef4444;
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    margin: var(--space-5) 0;
}

.warning-box h4 {
    color: #991b1b;
    font-size: 14px;
    margin: 0 0 var(--space-3);
}

.warning-box h4 i {
    color: #ef4444;
    margin-right: var(--space-2);
}

.warning-box p {
    margin: 0;
    color: var(--gray-700);
    font-size: 14px;
}

.insight-box {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border: 1px solid #93c5fd;
    border-left: 4px solid #3b82f6;
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    margin: var(--space-6) 0;
}

.insight-box h4 {
    color: #1e40af;
    font-size: 15px;
    margin: 0 0 var(--space-3);
}

.insight-box h4 i {
    color: #2563eb;
    margin-right: var(--space-2);
}

.insight-box p {
    margin: 0;
    color: var(--gray-700);
    font-size: 14px;
}

.comparison-table-wrapper {
    overflow-x: auto;
    margin: var(--space-5) 0;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 640px;
    margin: 0;
    font-size: 14px;
}

.comparison-table th,
.comparison-table td {
    border-bottom: 1px solid var(--gray-200);
    padding: var(--space-3);
    text-align: left;
    vertical-align: top;
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

.comparison-table th {
    background: var(--primary-50);
    color: var(--primary-700);
    font-weight: 600;
}

.comparison-table td {
    color: var(--gray-700);
}

/* ==========================================
   SIDEBAR
   ========================================== */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
}

.sidebar-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.08);
    border: 1px solid var(--gray-200);
    position: relative;
    overflow: hidden;
}

.sidebar-card::before {
    content: "";
    display: block;
    height: 4px;
    margin: calc(-1 * var(--space-5)) calc(-1 * var(--space-5)) var(--space-4);
    background: linear-gradient(90deg, var(--accent-500) 0%, var(--accent-300) 100%);
}

.sidebar-card h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-800);
    margin: 0 0 var(--space-4);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    line-height: 1.4;
}

.sidebar-card h3 i {
    color: var(--accent-500);
}

/* Quick tools */
.quick-tool {
    margin-bottom: var(--space-4);
    padding-bottom: var(--space-4);
    border-bottom: 1px solid var(--gray-100);
}

.quick-tool:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.quick-tool label {
    font-size: 12px;
    font-weight: 500;
    color: var(--gray-500);
    margin-bottom: var(--space-2);
    display: block;
}

.quick-tool-inputs {
    display: flex;
    gap: var(--space-2);
    align-items: center;
    width: 100%;
}

.quick-tool-inputs input,
.quick-tool-inputs select {
    flex: 1;
    min-width: 0;
    max-width: 100%;
    padding: var(--space-2) var(--space-3);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 13px;
    box-sizing: border-box;
}

.quick-tool-inputs span {
    flex-shrink: 0;
    font-size: 12px;
    color: var(--gray-500);
}

.quick-tool-result {
    margin-top: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    color: #047857;
    text-align: center;
}

/* Popular calculators */
.popular-calc-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.popular-calc-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--gray-50);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--gray-700);
    font-size: 13px;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.popular-calc-item:hover {
    background: #f1f5f9;
    border-color: #e2e8f0;
    color: var(--primary-600);
    transform: translateX(4px);
}

.popular-calc-item i {
    color: var(--accent-500);
    width: 18px;
    text-align: center;
}

/* Related calculators grid */
.related-section {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.08);
    border: 1px solid var(--gray-200);
    position: relative;
    overflow: hidden;
}

.related-section::before {
    content: "";
    display: block;
    height: 4px;
    margin: calc(-1 * var(--space-5)) calc(-1 * var(--space-5)) var(--space-4);
    background: linear-gradient(90deg, var(--primary-500) 0%, var(--accent-500) 100%);
}

.related-header {
    background: transparent;
    color: #0f172a;
    padding: 0;
    margin: 0 0 var(--space-4);
    border-radius: 0;
    font-weight: 600;
    font-size: 14px;
    text-align: left;
}

.related-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2);
}

.related-grid a {
    font-size: 13px;
    color: var(--primary-700);
    text-decoration: none;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    transition: all var(--transition-fast);
}

.related-grid a:hover {
    background: #f1f5f9;
    color: var(--primary-500);
    border-color: #e2e8f0;
}

/* Link list used for pairs/related/more */
.link-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.link-list a {
    display: block;
    font-size: 13px;
    color: var(--primary-700);
    text-decoration: none;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    background: #f8fafc;
    transition: all var(--transition-fast);
}

.link-list a:hover {
    background: #f1f5f9;
    color: var(--primary-500);
    border-color: #e2e8f0;
}

.related-footer {
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--gray-100);
    text-align: center;
}

.related-footer a {
    color: var(--accent-500);
    text-decoration: none;
    font-size: 13px;
}

/* ==========================================
   TOAST NOTIFICATION
   ========================================== */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--gray-900);
    color: white;
    padding: var(--space-4) var(--space-6);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-xl);
    z-index: 9999;
    opacity: 0;
    transition: all var(--transition-base);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* ==========================================
   RESPONSIVE STYLES
   ========================================== */
@media (max-width: 1180px) {
    .calculator-layout {
        grid-template-columns: 1fr;
    }

    .quick-facts {
        margin-top: var(--space-2);
    }
}

@media (max-width: 1024px) {
    .page-container {
        grid-template-columns: 1fr 280px;
    }
}

@media (max-width: 900px) {
    .page-container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        display: none;
    }

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

@media (max-width: 768px) {
    .page-container {
        padding: var(--space-4);
    }

    .calculator-header {
        padding: var(--space-6);
    }

    .calculator-header h1 {
        font-size: 22px;
    }

    .calculator-body {
        padding: var(--space-5);
    }

    .calculator-layout {
        grid-template-columns: 1fr;
    }

    .quick-facts {
        display: none;
    }

    .input-grid {
        grid-template-columns: 1fr;
        gap: var(--space-4);
    }

    .button-group {
        flex-direction: column;
    }

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

    .result-card .value {
        font-size: 22px;
    }

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

    .share-btn {
        width: 100%;
        justify-content: center;
    }

    .breadcrumb {
        display: none;
    }
}

@media (max-width: 480px) {
    .calculator-header h1 {
        font-size: 20px;
    }

    .calculator-header h1 .icon {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }

    .content-section {
        padding: var(--space-5);
    }

    .results-section {
        padding: var(--space-5);
    }
}

/* Sidebar share block */
.social-share {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--space-2);
}

.social-share a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 36px;
    border-radius: var(--radius-sm);
    color: white;
    text-decoration: none;
    transition: transform var(--transition-fast), filter var(--transition-fast);
}

.social-share a:hover {
    transform: translateY(-1px);
    filter: brightness(1.05);
}

.social-share .facebook { background: #1877f2; }
.social-share .twitter { background: #1da1f2; }
.social-share .email { background: var(--gray-600); }
.social-share .linkedin { background: #0a66c2; }