/* ========================================
   尧图网络科技 - 全局样式表
   商务便捷风 | 浅蓝 + 浅灰 + 纯白
   ======================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul, ol {
    list-style: none;
}

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

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 80px 0;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 50px;
    color: #1a3a5c;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #4a90e2, #6fb3f2);
    margin: 15px auto 0;
    border-radius: 2px;
}

/* ========================================
   顶部导航栏
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.4s ease;
}

.header.scrolled {
    background: rgba(255, 255, 255, 1);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.12);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo img {
    height: 45px;
    width: auto;
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: #1a3a5c;
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    gap: 35px;
}

.nav-menu li {
    position: relative;
}

.nav-menu a {
    font-size: 15px;
    font-weight: 500;
    color: #444;
    padding: 8px 0;
    position: relative;
    display: inline-block;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #4a90e2, #6fb3f2);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #4a90e2;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 28px;
    height: 3px;
    background: #1a3a5c;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* 移动端菜单 */
@media (max-width: 992px) {
    .nav-menu {
        position: fixed;
        top: 75px;
        right: -100%;
        width: 280px;
        height: calc(100vh - 75px);
        background: #fff;
        flex-direction: column;
        padding: 30px;
        gap: 20px;
        box-shadow: -5px 0 20px rgba(0, 0, 0, 0.1);
        transition: right 0.4s ease;
    }

    .nav-menu.active {
        right: 0;
    }

    .hamburger {
        display: flex;
    }
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: linear-gradient(135deg, #1a3a5c 0%, #2c5282 100%);
    color: #fff;
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #6fb3f2;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: #6fb3f2;
}

.footer-col p,
.footer-col a {
    color: #e0e8f0;
    font-size: 14px;
    line-height: 2;
}

.footer-col a:hover {
    color: #6fb3f2;
    padding-left: 5px;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    padding-top: 25px;
    text-align: center;
    font-size: 14px;
    color: #b0c4de;
}

@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   动画效果
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   按钮样式
   ======================================== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 4px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #4a90e2, #6fb3f2);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(74, 144, 226, 0.4);
}

.btn-outline {
    background: transparent;
    border: 2px solid #4a90e2;
    color: #4a90e2;
}

.btn-outline:hover {
    background: #4a90e2;
    color: #fff;
}

/* ========================================
   卡片样式
   ======================================== */
.card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
}

.card-img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

.card-body {
    padding: 25px;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: #1a3a5c;
    margin-bottom: 12px;
}

.card-text {
    font-size: 14px;
    color: #666;
    line-height: 1.8;
    margin-bottom: 15px;
}

.card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: #999;
}

/* ========================================
   硬朗折线分割
   ======================================== */
.divider-diagonal {
    position: relative;
    margin: 60px 0;
    height: 60px;
    background: transparent;
    overflow: hidden;
}

.divider-diagonal::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f8f9fa 50%, #e9ecef 50%);
    clip-path: polygon(0 0, 100% 0, 100% 50%, 0 100%);
}

/* ========================================
   响应式网格
   ======================================== */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

@media (max-width: 992px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
}