/* Core Variables */
:root {
    /* Colors - Professional Financial Theme */
    --primary-blue: #1E3A8A;  /* Deeper, more professional blue */
    --dark-blue: #1E40AF;
    --light-blue: #EFF6FF;
    --text-dark: #1F2937;
    --text-light: #4B5563;
    --background-light: #F9FAFB;
    --border-color: rgba(0, 0, 0, 0.1);
    --success-green: #059669;
    --warning-yellow: #D97706;
    --error-red: #DC2626;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;
    
    /* Border Radius */
    --border-radius-sm: 4px;
    --border-radius-md: 6px;
    --border-radius-lg: 8px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
}

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

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

body {
    background: #f6f8fa;
    color: #1a2330;
    font-family: 'SF Pro Display', 'Segoe UI', Arial, sans-serif;
    line-height: 1.6;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
    color: #183153;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-light);
    font-size: 1.125rem;
    line-height: 1.7;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    background: #fff;
    border-radius: 10px;
    padding: 1.2rem 1.5rem;
    margin-bottom: 2.2rem;
    box-shadow: none;
}

/* Header */
.main-header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    height: 70px;
}

.logo a {
    font-size: 26px;
    font-weight: 700;
    color: #204080;
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 12px;
    align-items: center;
}

.nav-links li {
    position: relative;
}

.nav-links a {
    color: #333;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    padding: 14px 18px;
    border-radius: 10px;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.nav-links a:hover {
    color: #204080;
    background: rgba(32, 64, 128, 0.08);
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    min-width: 250px;
    padding: 12px;
    margin-top: 8px;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
}

.dropdown-menu a {
    display: block;
    padding: 12px 16px;
    color: #333;
    font-size: 15px;
    border-radius: 8px;
    margin: 2px 0;
}

.dropdown-menu a:hover {
    background: rgba(32, 64, 128, 0.08);
    color: #204080;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: #204080;
    font-size: 22px;
    cursor: pointer;
    padding: 8px;
}

/* Hero Section */
.hero-section {
    background: #f7fafd;
    color: #183153;
    padding: 3rem 0 2rem 0;
    border-bottom: 1px solid #e3e8f0;
    text-align: center;
}

.hero-section h1 {
    max-width: 800px;
    margin: 0 auto var(--spacing-md);
    font-size: 3rem;
    line-height: 1.2;
}

.hero-section p {
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    font-size: 1.25rem;
    color: var(--text-light);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

/* Calculator Categories */
.calculator-categories {
    padding: var(--spacing-xxl) 0;
    background-color: white;
}

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

.category-card {
    background: #fff;
    border-radius: 8px;
    box-shadow: none;
    border: 1px solid #e3e8f0;
    padding: 2rem 1.2rem 1.2rem 1.2rem;
    transition: border 0.2s, transform 0.2s;
    min-height: 180px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: center;
    text-decoration: none;
    color: var(--text-dark);
}

.category-card:hover {
    border: 1px solid #204080;
    transform: translateY(-2px) scale(1.01);
}

.card-icon {
    font-size: 2rem;
    color: #204080;
    background: #f2f5fa;
    border-radius: 50%;
    padding: 0.6rem 0.8rem;
    margin-bottom: 1rem;
    box-shadow: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.category-card:hover .card-icon {
    color: #183153;
    background: #e3e8f0;
}

.category-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.category-card p {
    font-size: 1rem;
    color: var(--text-light);
    margin-bottom: 0;
}

/* Buttons */
.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    border-radius: var(--border-radius-md);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-fast);
    cursor: pointer;
    border: none;
}

.button-primary {
    background: #204080;
    color: #fff;
    border-radius: 6px;
    border: none;
    font-weight: 600;
    box-shadow: none;
}

.button-primary:hover {
    background: #183153;
    color: #fff;
}

.button-secondary {
    background: #fff;
    color: #204080;
    border: 1.5px solid #204080;
    border-radius: 6px;
    font-weight: 600;
}

.button-secondary:hover {
    background: #204080;
    color: #fff;
}

/* Footer */
.main-footer {
    background: #1a1a1a;
    color: white;
    padding: 50px 0 25px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
}

.footer-section h3 {
    color: #204080;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-section p {
    color: #ccc;
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 0;
}

.footer-section ul {
    list-style: none;
    padding: 0;
}

.footer-section li {
    margin-bottom: 12px;
}

.footer-section a {
    color: #ccc;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.2s ease;
}

.footer-section a:hover {
    color: #204080;
}

.footer-bottom {
    border-top: 1px solid #333;
    margin-top: 40px;
    padding-top: 20px;
    text-align: center;
}

.footer-bottom p {
    color: #999;
    font-size: 14px;
    margin: 0;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 25px;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
        gap: 0;
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-links li {
        width: 100%;
        border-bottom: 1px solid #eee;
    }
    
    .nav-links li:last-child {
        border-bottom: none;
    }
    
    .nav-links a {
        display: block;
        padding: 18px 0;
        width: 100%;
        font-size: 18px;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .dropdown-menu {
        position: static;
        transform: none;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        margin: 18px 0 0 25px;
        background: #f8f9fa;
        border: none;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .breadcrumb-container {
        padding: 0 16px;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 16px;
    }
    
    .logo a {
        font-size: 22px;
    }
    
    .breadcrumb-list {
        font-size: 13px;
        flex-wrap: wrap;
    }
}

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

/* Print Styles */
@media print {
    .main-header,
    .mobile-menu-btn,
    .button {
        display: none;
    }

    body {
        color: black;
    }

    a {
        text-decoration: none;
        color: black;
    }

    .category-card,
    .knowledge-card {
        break-inside: avoid;
        border: 1px solid #ddd;
        box-shadow: none;
    }
}

/* 新增知识库卡片网格 */
.knowledge-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.knowledge-card {
    background: white;
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--spacing-md);
    text-decoration: none;
    color: var(--text-dark);
}

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

.knowledge-card .card-icon,
.category-card .card-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
}

.category-card h3, .knowledge-card h3 {
    margin-bottom: var(--spacing-xs);
}

.category-card p, .knowledge-card p {
    margin-bottom: 0;
}

@media (max-width: 1200px) {
    .knowledge-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .knowledge-grid {
        grid-template-columns: 1fr;
    }
}

/* --- Financial/Professional Theme Enhancements --- */
a, .button, .button-primary {
    transition: background 0.2s, color 0.2s, box-shadow 0.2s;
}

.breadcrumb {
    background: #f8f9fa;
    padding: 15px 0;
    margin-bottom: 30px;
    border-bottom: 1px solid #e9ecef;
}

.breadcrumb-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.breadcrumb-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #666;
}

.breadcrumb-list li {
    display: flex;
    align-items: center;
    gap: 8px;
}

.breadcrumb-list a {
    color: #204080;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.breadcrumb-list a:hover {
    color: #1a3366;
    text-decoration: underline;
}

.breadcrumb-separator {
    color: #999;
    font-size: 12px;
}

.breadcrumb-current {
    font-weight: 600;
    color: #333;
}

/* Responsive tweaks for cards */
@media (max-width: 900px) {
    .category-card, .knowledge-card {
        min-height: 180px;
        padding: 1.2rem 1rem 1rem 1rem;
    }
    .container {
        padding: 0.7rem 0.5rem;
    }
}

/* 1. Hide mobile menu button on desktop */
@media (min-width: 769px) {
    .mobile-menu-btn {
        display: none !important;
    }
}

/* FAQ icon color subtle */
.faq-question i {
    color: #204080;
    margin-left: 0.5rem;
}

/* --- Mega Menu Only --- */

/* Mega menu styles */
.has-mega-menu {
    position: relative;
}
.mega-menu {
    display: none;
    position: absolute;
    left: 0;
    top: 100%;
    min-width: 820px;
    background: #fff;
    box-shadow: 0 8px 32px rgba(24,49,83,0.13);
    border-radius: 10px;
    padding: 1.2rem 2.2rem 1.2rem 2.2rem;
    z-index: 1001;
    margin-top: 0.5rem;
    display: flex;
    flex-direction: row;
    gap: 2.5rem;
}
.has-mega-menu:hover .mega-menu,
.has-mega-menu:focus-within .mega-menu,
.mega-menu:hover {
    display: flex;
}
.mega-menu-group {
    min-width: 180px;
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}
.mega-menu-group-title {
    font-weight: 700;
    color: #183153;
    margin-bottom: 0.3rem;
    font-size: 1.05rem;
}
.mega-menu a {
    display: flex;
    align-items: center;
    color: #183153 !important;
    font-weight: 500;
    padding: 0.38rem 0.2rem;
    border-radius: 6px;
    text-decoration: none;
    margin-bottom: 0.1rem;
    font-size: 1.01rem;
    transition: background 0.15s, color 0.15s;
    position: relative;
}
.mega-menu a:hover {
    background: #f2f5fa;
    color: #204080 !important;
}
.mega-menu .important {
    color: #204080 !important;
    font-weight: 700;
}
.mega-menu .star {
    color: #ffd700;
    font-size: 1.1em;
    margin-left: 0.4em;
}
@media (max-width: 1100px) {
    .mega-menu {
        min-width: 98vw;
        padding: 1rem 0.5rem;
        gap: 1.2rem;
    }
    .mega-menu-group {
        min-width: 120px;
    }
}
@media (max-width: 900px) {
    .mega-menu {
        flex-direction: column;
        min-width: 220px;
        padding: 0.7rem 0.7rem;
        gap: 0.7rem;
    }
    .mega-menu-group {
        min-width: 0;
    }
}