:root {
    --primary-blue: #1e4d8c;
    --secondary-blue: #2c6fbb;
    --accent-gold: #c9a227;
    --light-gold: #f4e4a6;
    --dark-blue: #0f2b52;
    --text-dark: #2c3e50;
    --text-light: #5a6c7d;
    --bg-light: #f8f9fa;
    --bg-section: #ffffff;
    --border-light: #e2e8f0;
    --shadow-sm: 0 2px 8px rgba(30, 77, 140, 0.08);
    --shadow-md: 0 8px 24px rgba(30, 77, 140, 0.12);
    --shadow-lg: 0 16px 48px rgba(30, 77, 140, 0.16);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
    color: var(--text-dark);
    background-color: var(--bg-light);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 导航栏样式 - 深蓝色学术风格 */
.navbar-custom {
    background: linear-gradient(135deg, var(--dark-blue) 0%, var(--primary-blue) 100%);
    padding: 0.8rem 0;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 1030;
    transition: var(--transition);
}

.navbar-custom.scrolled {
    padding: 0.5rem 0;
    box-shadow: var(--shadow-lg);
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.logo-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-sm);
}

.logo-icon::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    transform: rotate(45deg);
    transition: var(--transition);
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-main {
    color: #fff;
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo-sub {
    color: var(--light-gold);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 2px;
    margin-top: 2px;
}

.nav-link-custom {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    padding: 0.5rem 1.2rem !important;
    margin: 0 0.2rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
    font-size: 0.95rem;
}

.nav-link-custom:hover, .nav-link-custom.active {
    color: #fff !important;
    background: rgba(255, 255, 255, 0.1);
}

.nav-link-custom::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--accent-gold);
    transition: var(--transition);
}

.nav-link-custom:hover::after, .nav-link-custom.active::after {
    width: 60%;
}

/* Banner区域 - 学术庄重风格 */
.hero-section {
    background: linear-gradient(135deg, var(--dark-blue) 0%, var(--primary-blue) 50%, var(--secondary-blue) 100%);
    position: relative;
    padding: 5rem 0;
    overflow: hidden;
    min-height: 500px;
    display: flex;
    align-items: center;
}

.hero-pattern {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.05;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content h1 {
    color: #fff;
    font-size: 2.8rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    text-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.hero-content .highlight {
    color: var(--accent-gold);
    position: relative;
    display: inline-block;
}

.hero-content .lead {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 2rem;
    max-width: 600px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(201, 162, 39, 0.2);
    border: 1px solid rgba(201, 162, 39, 0.4);
    color: var(--light-gold);
    padding: 0.5rem 1.2rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    backdrop-filter: blur(10px);
}

.hero-stats {
    display: flex;
    gap: 2.5rem;
    margin-top: 2.5rem;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--accent-gold);
    line-height: 1;
}

.stat-label {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

.hero-image-wrapper {
    position: relative;
    z-index: 1;
}

.hero-image {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 4px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.hero-image:hover {
    transform: translateY(-5px) scale(1.02);
}

/* 材料导航区域 - 核心功能区 */
.materials-section {
    background: linear-gradient(to bottom, #fff 0%, var(--bg-light) 100%);
    padding: 5rem 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
    margin-top: 2rem;
}

.section-tag {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    color: #fff;
    padding: 0.4rem 1.2rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
    letter-spacing: 1px;
}

.section-title {
    font-size: 2.2rem;
    font-weight: 900;
    color: var(--text-dark);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-gold));
    border-radius: 2px;
}

.section-desc {
    color: var(--text-light);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 1.5rem auto 0;
}

/* 材料卡片网格 */
.material-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
}

/* 四个一行的布局 */
.material-grid-4 {
    grid-template-columns: repeat(4, 1fr);
    margin-top: 2rem;
}

/* 三个一行的布局 */
.material-grid-3 {
    grid-template-columns: repeat(3, 1fr);
    margin-top: 2rem;
}

/* 两个一行的布局 */
.material-grid-2 {
    grid-template-columns: repeat(2, 1fr);
    margin-top: 2rem;
}

.material-card {
    background: #fff;
    border-radius: var(--radius-md);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}

.material-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-blue), var(--secondary-blue));
    transition: var(--transition);
}

.material-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--secondary-blue);
}

.material-card:hover::before {
    width: 6px;
    background: linear-gradient(to bottom, var(--accent-gold), var(--primary-blue));
}

.material-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, rgba(30, 77, 140, 0.1) 0%, rgba(44, 111, 187, 0.1) 100%);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: 1.25rem;
    transition: var(--transition);
}

.material-card:hover .material-icon {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-blue) 100%);
    color: #fff;
    transform: scale(1.1);
}

.material-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.material-desc {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.6;
}

.material-badge {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: var(--accent-gold);
    color: var(--dark-blue);
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
}

/* PDF预览模态框 */
.pdf-modal .modal-dialog {
    max-width: 90vw;
    height: 90vh;
}

.pdf-modal .modal-content {
    height: 100%;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.pdf-modal .modal-header {
    background: linear-gradient(135deg, var(--dark-blue), var(--primary-blue));
    color: #fff;
    border: none;
    padding: 1rem 1.5rem;
}

.pdf-container {
    height: calc(100% - 60px);
    background: #525659;
    display: flex;
}

.pdf-sidebar {
    width: 280px;
    background: #f5f5f5;
    border-right: 1px solid #ddd;
    overflow-y: auto;
    padding: 1rem;
}

.pdf-nav-item {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.pdf-nav-item:hover, .pdf-nav-item.active {
    background: var(--primary-blue);
    color: #fff;
}

.pdf-nav-item i {
    font-size: 1.1rem;
}

.pdf-viewer {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.pdf-toolbar {
    height: 48px;
    background: #323639;
    display: flex;
    align-items: center;
    padding: 0 1rem;
    gap: 1rem;
    color: #fff;
}

.pdf-toolbar button {
    background: transparent;
    border: 1px solid rgba(255,255,255,0.2);
    color: #fff;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
}

.pdf-toolbar button:hover {
    background: rgba(255,255,255,0.1);
}

.pdf-frame {
    flex: 1;
    width: 100%;
    border: none;
}

/* 项目简介区域 */
.intro-section {
    padding: 5rem 0;
    background: #fff;
}

.intro-card {
    background: linear-gradient(135deg, #f8fafc 0%, #fff 100%);
    border-radius: var(--radius-lg);
    padding: 3rem;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    height: 100%;
    transition: var(--transition);
}

.intro-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.intro-card h3 {
    color: var(--primary-blue);
    font-weight: 700;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.intro-card h3 i {
    color: var(--accent-gold);
    font-size: 1.5rem;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    padding: 0.75rem 0;
    padding-left: 2rem;
    position: relative;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.feature-list li::before {
    content: '\F26A';
    font-family: 'bootstrap-icons';
    position: absolute;
    left: 0;
    color: var(--accent-gold);
    font-weight: 900;
}

.feature-list li:last-child {
    border-bottom: none;
}

/* 验收标准表格 */
.standards-section {
    padding: 5rem 0;
    background: linear-gradient(to bottom, var(--bg-light) 0%, #fff 100%);
}

.table-custom {
    background: #fff;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.table-custom thead th {
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    color: #fff;
    font-weight: 600;
    padding: 1.25rem 1.5rem;
    border: none;
    font-size: 0.95rem;
}

.table-custom tbody td {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-light);
    vertical-align: middle;
    font-size: 0.95rem;
}

.table-custom tbody tr:hover {
    background: rgba(30, 77, 140, 0.03);
}

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

.standard-tag {
    display: inline-block;
    padding: 0.35rem 0.9rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

.tag-excellent {
    background: rgba(40, 167, 69, 0.1);
    color: #28a745;
}

.tag-good {
    background: rgba(30, 77, 140, 0.1);
    color: var(--primary-blue);
}

.tag-pass {
    background: rgba(255, 193, 7, 0.1);
    color: #856404;
}

/* 页脚 */
.footer-custom {
    background: linear-gradient(135deg, var(--dark-blue) 0%, #0a1f3d 100%);
    color: rgba(255, 255, 255, 0.8);
    padding: 4rem 0 2rem;
    position: relative;
    overflow: hidden;
}

.footer-custom::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-gold), var(--primary-blue), var(--accent-gold));
}

.footer-title {
    color: #fff;
    font-weight: 700;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.footer-link {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    display: block;
    padding: 0.4rem 0;
    transition: var(--transition);
    font-size: 0.95rem;
}

.footer-link:hover {
    color: var(--accent-gold);
    padding-left: 5px;
}

.footer-contact-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.footer-contact-item i {
    color: var(--accent-gold);
    margin-top: 0.25rem;
}

.footer-bottom {
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.9rem;
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-blue);
    border-radius: 4px;
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.1s; opacity: 0; }
.delay-2 { animation-delay: 0.2s; opacity: 0; }
.delay-3 { animation-delay: 0.3s; opacity: 0; }

/* 响应式调整 */
@media (max-width: 992px) {
    .material-grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2rem;
    }
    .hero-stats {
        gap: 1.5rem;
    }
    .stat-number {
        font-size: 1.8rem;
    }
    .material-grid,
    .material-grid-3,
    .material-grid-2 {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 1.75rem;
    }
    .pdf-sidebar {
        display: none;
    }
}

/* Banner区域 - 简化版 */
.hero-section {
    background: linear-gradient(135deg, var(--dark-blue) 0%, var(--primary-blue) 50%, var(--secondary-blue) 100%);
    position: relative;
    padding: 3rem 0;
    overflow: hidden;
    min-height: auto;
}

/* 轮播图片容器 */
.carousel-image-wrapper {
    position: relative;
    overflow: hidden;
}

.carousel-image-wrapper img {
    transition: transform 0.6s ease;
}

.carousel-item.active .carousel-image-wrapper img {
    transform: scale(1.02);
}

/* 底部文字 */
.carousel-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(15, 43, 82, 0.9) 0%, rgba(15, 43, 82, 0.6) 60%, transparent 100%);
    padding: 2.5rem 1.5rem 1rem;
    text-align: center;
}

.carousel-caption p {
    color: #fff;
    font-size: 1.1rem;
    font-weight: 500;
    letter-spacing: 1px;
}

/* 指示器样式 */
.carousel-indicators button {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    margin: 0 5px;
    background-color: rgba(255, 255, 255, 0.4);
    border: 2px solid transparent;
}

.carousel-indicators button.active {
    background-color: var(--accent-gold);
    border-color: rgba(255, 255, 255, 0.5);
    transform: scale(1.2);
}

/* 控制按钮 */
.carousel-control-prev,
.carousel-control-next {
    width: 8%;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.hero-section:hover .carousel-control-prev,
.hero-section:hover .carousel-control-next {
    opacity: 0.8;
}

.carousel-control-prev:hover,
.carousel-control-next:hover {
    opacity: 1 !important;
}

/* 响应式 */
@media (max-width: 768px) {
    .hero-section {
        padding: 1.5rem 0;
    }
    
    .carousel-inner img {
        height: 250px !important;
    }
    
    .carousel-caption p {
        font-size: 0.95rem;
    }
}