:root {
    --primary-color: #0056b3;
    --secondary-color: #004494;
    --text-color: #333333;
    --bg-color: #f8f9fa;
    --light-bg: #ffffff;
    --border-color: #e0e0e0;
    --font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.8;
    font-size: 18px;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header */
#main-header {
    background-color: var(--light-bg);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

#main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 15px;
}

.logo a {
    font-size: 28px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    transition: color 0.3s;
}

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

.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 4px 0;
}

/* Hero Section */
.hero {
    background-color: var(--primary-color);
    color: white;
    padding: 150px 0;
    min-height: 60vh;
    display: flex;
    align-items: center;
    text-align: center;
    position: relative;
}

.hero-large {
    min-height: 85vh;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    position: relative;
    display: flex;
    align-items: center;
    text-align: center;
}

.hero-large::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5); /* 半透明遮罩，保证文字可读 */
    z-index: 1;
}

.hero-large .container {
    position: relative;
    z-index: 2;
    color: white;
}

.hero-large h1 {
    font-size: 64px;
    margin-bottom: 24px;
    text-shadow: 2px 2px 6px rgba(0,0,0,0.6);
}

.hero-large p {
    font-size: 26px;
    max-width: 900px;
    margin: 0 auto;
    text-shadow: 1px 1px 4px rgba(0,0,0,0.6);
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 22px;
    max-width: 800px;
    margin: 0 auto;
}

/* Content Sections */
.section {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.section.alt-bg {
    background-color: var(--bg-color);
}

.section h2 {
    font-size: 36px;
    color: var(--primary-color);
    margin-bottom: 30px;
    text-align: center;
}

.section h3 {
    font-size: 28px;
    margin-top: 40px;
    margin-bottom: 20px;
    color: var(--secondary-color);
}

.section p {
    margin-bottom: 30px;
    text-align: justify;
    font-size: 18px;
    color: #444;
}

.section ul {
    margin-bottom: 30px;
    margin-left: 20px;
}

.section li {
    margin-bottom: 15px;
    font-size: 18px;
}

/* Inline Links */
.inline-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    border-bottom: 1px dashed var(--primary-color);
    transition: all 0.3s ease;
}

.inline-link:hover {
    color: var(--secondary-color);
    border-bottom: 1px solid var(--secondary-color);
    background-color: rgba(0, 86, 179, 0.05);
}

/* Text Layouts */
.lead-text {
    font-size: 22px;
    font-weight: 500;
    color: var(--secondary-color);
    margin-bottom: 40px;
    text-align: center;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.text-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
    margin-top: 30px;
    margin-bottom: 30px;
}

.text-columns-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-bottom: 30px;
}

@media (max-width: 768px) {
    .text-columns-2 {
        grid-template-columns: 1fr;
    }
}

.text-card {
    background: var(--light-bg);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

.text-card:hover {
    transform: translateY(-5px);
}

.section.alt-bg .text-card {
    background: var(--light-bg);
}

.section:not(.alt-bg) .text-card {
    background: #fdfdfd;
    border: 1px solid var(--border-color);
    box-shadow: none;
}

.text-card h3 {
    margin-top: 0;
    font-size: 24px;
    color: var(--primary-color);
}

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

.text-box {
    padding: 20px;
    border-left: 4px solid var(--primary-color);
    background: rgba(0, 86, 179, 0.05);
    margin-bottom: 30px;
}

/* FAQ Sidebar Layout */
.faq-layout {
    display: flex;
    gap: 40px;
    margin-top: 40px;
}

.faq-sidebar {
    width: 250px;
    flex-shrink: 0;
}

.faq-sidebar h3 {
    margin-top: 0;
    font-size: 20px;
    color: var(--secondary-color);
    margin-bottom: 20px;
}

.faq-categories {
    list-style: none;
    margin: 0;
    padding: 0;
}

.faq-categories li {
    margin-bottom: 10px;
}

.faq-categories button {
    width: 100%;
    text-align: left;
    padding: 12px 15px;
    background: var(--light-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    color: var(--text-color);
    transition: all 0.3s ease;
}

.faq-categories button:hover {
    background: #f0f7ff;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.faq-categories button.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.faq-content {
    flex-grow: 1;
}

@media (max-width: 768px) {
    .faq-layout {
        flex-direction: column;
    }
    .faq-sidebar {
        width: 100%;
    }
}

/* Forms */
.form-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--light-bg);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: bold;
}

.form-group input, 
.form-group select, 
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
    font-family: var(--font-family);
}

button[type="submit"] {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 30px;
    border: none;
    border-radius: 4px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}

button[type="submit"]:hover {
    background-color: var(--secondary-color);
}

/* Global Buttons */
.btn-global {
    display: inline-block;
    padding: 12px 25px;
    border-radius: 5px;
    font-size: 16px;
    font-weight: bold;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
    color: #fff;
}

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

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

.cross-links-section {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.cross-links-section h3 {
    margin-top: 0;
    margin-bottom: 25px;
    color: var(--secondary-color);
}

.cross-links-container {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
}

/* Footer */
#main-footer {
    background-color: #222;
    color: #fff;
    padding: 60px 0 20px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h3 {
    margin-bottom: 20px;
    font-size: 22px;
}

.footer-col p {
    margin-bottom: 15px;
    color: #ccc;
    font-size: 16px;
}

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

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-col a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    border-top: 1px solid #444;
    padding-top: 20px;
    color: #888;
}

/* Responsive */
@media (max-width: 768px) {
    .main-nav {
        display: none;
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background-color: var(--light-bg);
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }

    .main-nav.active {
        display: block;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 0;
    }

    .main-nav a {
        display: block;
        padding: 15px 20px;
        border-bottom: 1px solid var(--border-color);
    }

    .menu-toggle {
        display: flex;
    }
    
    .hero h1 {
        font-size: 36px;
    }
    
    .feature-row, .feature-row:nth-child(even) {
        flex-direction: column;
        text-align: center;
        gap: 30px;
        margin-bottom: 60px;
    }
    
    .hero {
        min-height: 50vh;
        padding: 100px 0;
    }
}

/* Alternating Feature Rows */
.feature-row {
    display: flex;
    align-items: center;
    gap: 60px;
    margin-bottom: 80px;
}

.feature-row:last-child {
    margin-bottom: 0;
}

.feature-row:nth-child(even) {
    flex-direction: row-reverse;
}

.feature-row .text-content {
    flex: 1;
}

.feature-row .text-content h3 {
    color: var(--secondary-color);
    font-size: 28px;
    margin-bottom: 20px;
    margin-top: 0;
}

.feature-row .text-content p {
    font-size: 18px;
    color: #444;
    line-height: 1.8;
    margin-bottom: 0;
}

.feature-row .image-content {
    flex: 1;
}

.feature-row .img-placeholder {
    margin: 0;
    min-height: 350px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

/* Parallax Backgrounds */
.parallax {
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.parallax::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5); /* Dark overlay for better text readability */
    z-index: 1;
}

.parallax > * {
    position: relative;
    z-index: 2;
}

/* Image Placeholders (Unique Markers) */
.img-placeholder {
    width: 100%;
    min-height: 400px;
    background-color: #ddd;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 40px 0;
    border-radius: 8px;
    color: #666;
    font-size: 24px;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 2px;
    border: 2px dashed #bbb;
    position: relative;
    overflow: hidden;
}

/* Specific Placeholder Backgrounds */
.ph-home-hero { background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%); color: white; border: none; }
.ph-home-inline { background: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%); }

.ph-hr-hero { background: linear-gradient(135deg, #2b5876 0%, #4e4376 100%); color: white; border: none; }
.ph-hr-inline { background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%); }

.ph-peo-hero { background: linear-gradient(135deg, #0ba360 0%, #3cba92 100%); color: white; border: none; }
.ph-peo-inline { background: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%); }

.ph-faq-hero { background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%); color: white; border: none; }
.ph-faq-inline { background: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%); }

.ph-survey-hero { background: linear-gradient(135deg, #89f7fe 0%, #66a6ff 100%); color: white; border: none; }
.ph-survey-inline { background: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%); }

.ph-contact-hero { background: linear-gradient(135deg, #f6d365 0%, #fda085 100%); color: white; border: none; }
.ph-contact-inline { background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%); }

.img-placeholder::after {
    content: attr(data-marker);
    position: absolute;
    bottom: 20px;
    right: 20px;
    font-size: 14px;
    background: rgba(255,255,255,0.8);
    color: #333;
    padding: 5px 10px;
    border-radius: 4px;
    font-family: monospace;
}