/* ============================================
   CalcHub - Enhanced Styles
   ============================================ */

/* CSS Variables */
:root {
    --color-primary: #1a73e8;
    --color-primary-dark: #1557b0;
    --color-primary-light: #e8f0fe;
    --color-secondary: #0f9d58;
    --color-accent: #f57c00;
    --color-danger: #d93025;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-text-muted: #999999;
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-border: #e0e0e0;
    --color-border-light: #f0f0f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --max-width: 1200px;
    --header-height: 64px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
    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);
}

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

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
}

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

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 24px;
}

.main-nav a {
    color: var(--color-text);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

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

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width 0.2s;
}

.main-nav a:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
}

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

/* ============================================
   Main Content Layout
   ============================================ */
.main-content {
    flex: 1;
    padding: 30px 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 30px;
}

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

.sidebar {
    position: sticky;
    top: calc(var(--header-height) + 20px);
    align-self: start;
}

/* ============================================
   Breadcrumb
   ============================================ */
.breadcrumb {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 16px;
}

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

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

.breadcrumb .separator {
    margin: 0 8px;
}

/* ============================================
   Page Title
   ============================================ */
.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 24px;
    color: var(--color-text);
}

/* ============================================
   Calculator Widget
   ============================================ */
.calculator-widget {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
}

.calc-form {
    display: grid;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--color-text);
}

.form-group input,
.form-group select {
    padding: 12px 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-sans);
    transition: border-color 0.2s, box-shadow 0.2s;
    background: var(--color-bg);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-row-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 16px;
}

.input-with-suffix {
    position: relative;
    display: flex;
    align-items: center;
}

.input-with-suffix input {
    width: 100%;
    padding-right: 40px;
}

.input-suffix {
    position: absolute;
    right: 12px;
    color: var(--color-text-muted);
    font-size: 0.875rem;
    pointer-events: none;
}

.input-toggle {
    display: flex;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.input-toggle input {
    border: none;
    border-radius: 0;
    border-right: 1px solid var(--color-border);
}

.input-toggle .toggle-btn {
    padding: 12px 16px;
    background: var(--color-bg-alt);
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--color-text);
    transition: background 0.2s;
}

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

.input-toggle .toggle-btn:hover:not(.active) {
    background: var(--color-border-light);
}

.calc-button {
    background: var(--color-primary);
    color: white;
    border: none;
    padding: 14px 24px;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
    width: 100%;
}

.calc-button:hover {
    background: var(--color-primary-dark);
}

.calc-button:active {
    transform: scale(0.98);
}

.calc-button.secondary {
    background: var(--color-bg-alt);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.calc-button.secondary:hover {
    background: var(--color-border-light);
}

/* ============================================
   Section Headers
   ============================================ */
.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    user-select: none;
    margin-top: 16px;
}

.section-header:hover {
    background: var(--color-border-light);
}

.section-header h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: 8px;
}

.section-header .toggle-icon {
    transition: transform 0.2s;
}

.section-header.expanded .toggle-icon {
    transform: rotate(180deg);
}

/* ============================================
   Calculator Results
   ============================================ */
.calc-result {
    background: var(--color-primary-light);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-top: 20px;
    text-align: center;
}

.calc-result .result-label {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: 4px;
}

.calc-result .result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

.calc-result .result-value.large {
    font-size: 2.5rem;
}

.calc-result .result-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 16px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--color-border);
}

.result-item {
    text-align: center;
}

.result-item .label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.result-item .value {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
}

.result-item .value.positive {
    color: var(--color-secondary);
}

.result-item .value.negative {
    color: var(--color-danger);
}

/* ============================================
   Pie Chart
   ============================================ */
.pie-chart-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    margin: 20px 0;
    flex-wrap: wrap;
}

.pie-chart {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    flex-shrink: 0;
}

.pie-legend {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
}

.legend-color {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    flex-shrink: 0;
}

.legend-label {
    color: var(--color-text-light);
}

.legend-value {
    font-weight: 600;
    color: var(--color-text);
    margin-left: auto;
}

/* ============================================
   Amortization Schedule
   ============================================ */
.amortization-section {
    margin-top: 30px;
}

.amortization-section h3 {
    font-size: 1.25rem;
    margin-bottom: 16px;
    color: var(--color-text);
}

.schedule-controls {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.schedule-controls .calc-button {
    width: auto;
    padding: 8px 20px;
    font-size: 0.875rem;
}

.schedule-controls .calc-button.active {
    background: var(--color-primary);
    color: white;
}

.schedule-table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    max-height: 500px;
    overflow-y: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.schedule-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.schedule-table th,
.schedule-table td {
    padding: 10px 12px;
    text-align: right;
    border-bottom: 1px solid var(--color-border);
    white-space: nowrap;
}

.schedule-table th {
    background: var(--color-bg-alt);
    font-weight: 600;
    color: var(--color-text);
    position: sticky;
    top: 0;
}

.schedule-table th:first-child,
.schedule-table td:first-child {
    text-align: left;
}

.schedule-table tbody tr:hover {
    background: var(--color-bg-alt);
}

.schedule-table tbody tr:nth-child(even) {
    background: var(--color-bg-alt);
}

.schedule-table tbody tr:nth-child(even):hover {
    background: var(--color-border-light);
}

/* ============================================
   Summary Table
   ============================================ */
.summary-table {
    width: 100%;
    margin-top: 16px;
    border-collapse: collapse;
}

.summary-table td {
    padding: 8px 0;
    font-size: 0.875rem;
}

.summary-table td:first-child {
    color: var(--color-text-light);
}

.summary-table td:last-child {
    text-align: right;
    font-weight: 600;
    color: var(--color-text);
}

.summary-table tr.total td {
    font-size: 1rem;
    font-weight: 700;
    border-top: 2px solid var(--color-border);
    padding-top: 12px;
}

/* ============================================
   Calculator Explanation
   ============================================ */
.calculator-explanation {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid var(--color-border);
}

.calculator-explanation h2 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--color-text);
}

.calculator-explanation h3 {
    font-size: 1.125rem;
    margin: 24px 0 12px;
    color: var(--color-text);
}

.calculator-explanation p {
    margin-bottom: 12px;
    color: var(--color-text-light);
    line-height: 1.8;
}

.calculator-explanation ul,
.calculator-explanation ol {
    margin: 12px 0;
    padding-left: 24px;
    color: var(--color-text-light);
}

.calculator-explanation li {
    margin-bottom: 8px;
}

.calculator-explanation .formula-box {
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 16px;
    margin: 16px 0;
    font-family: 'Courier New', monospace;
    font-size: 1rem;
    text-align: center;
}

/* ============================================
   Sidebar
   ============================================ */
.sidebar-widget {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 20px;
}

.sidebar-widget h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--color-border);
}

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

.category-list li {
    margin-bottom: 4px;
}

.category-list a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 0.875rem;
    transition: background 0.2s;
}

.category-list a:hover {
    background: var(--color-bg-alt);
    color: var(--color-primary);
}

/* ============================================
   Ad Placements
   ============================================ */
.ad-header,
.ad-footer {
    text-align: center;
    padding: 10px 0;
}

.ad-in-content {
    margin: 20px 0;
    text-align: center;
}

.ad-sidebar {
    margin-bottom: 20px;
    text-align: center;
}

/* ============================================
   404 Error Page
   ============================================ */
.error-page {
    text-align: center;
    padding: 80px 20px;
    max-width: 500px;
    margin: 0 auto;
}

.error-code {
    font-size: 6rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: 16px;
}

.error-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--color-text);
}

.error-message {
    font-size: 1rem;
    color: var(--color-text-light);
    margin-bottom: 32px;
}

.error-page .calc-button {
    display: inline-block;
    width: auto;
    padding: 14px 32px;
}

/* ============================================
   Homepage Specific
   ============================================ */
.hero {
    text-align: center;
    padding: 40px 0;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.hero p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

.category-section {
    margin-bottom: 40px;
}

.category-section h2 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.calc-grid.small {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}

.calc-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px 16px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

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

.calc-card .icon {
    font-size: 2rem;
    margin-bottom: 8px;
}

.calc-card .name {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--color-text);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    padding: 40px 0 0;
    margin-top: auto;
}

.footer-inner {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    padding-bottom: 30px;
}

.footer-section h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.footer-section p {
    color: var(--color-text-light);
    font-size: 0.875rem;
}

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

.footer-section li {
    margin-bottom: 6px;
}

.footer-section a {
    color: var(--color-text-light);
    font-size: 0.875rem;
}

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

.footer-bottom {
    background: var(--color-border-light);
    padding: 16px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: static;
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 20px;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 56px;
    }
    
    .main-nav {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
    }
    
    .main-nav.active {
        display: block;
    }
    
    .main-nav ul {
        flex-direction: column;
        padding: 16px;
        gap: 0;
    }
    
    .main-nav li {
        border-bottom: 1px solid var(--color-border-light);
    }
    
    .main-nav a {
        display: block;
        padding: 12px 0;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .form-row,
    .form-row-3 {
        grid-template-columns: 1fr;
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    .calc-result .result-value {
        font-size: 1.5rem;
    }
    
    .calc-result .result-value.large {
        font-size: 2rem;
    }
    
    .calc-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    }
    
    .pie-chart-container {
        flex-direction: column;
        align-items: center;
    }
    
    .schedule-table {
        font-size: 0.75rem;
    }
    
    .schedule-table th,
    .schedule-table td {
        padding: 8px 6px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .calculator-widget {
        padding: 16px;
    }
    
    .calc-card {
        padding: 16px 12px;
    }
    
    .calc-card .icon {
        font-size: 1.5rem;
    }
}

/* ============================================
   Utility Classes
   ============================================ */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.hidden { display: none !important; }