/* ========================================
   拓冰建站 - 全局样式表
   数码Ins风 | 银灰 + 浅蓝 + 纯白
   ======================================== */

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #404040;
    background-color: #ffffff;
    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;
}

/* ========================================
   颜色变量
   ======================================== */
:root {
    --silver: #c0c0c0;
    --silver-light: #e8e8e8;
    --silver-dark: #909090;
    --light-blue: #add8e6;
    --light-blue-dark: #87ceeb;
    --white: #ffffff;
    --dark-gray: #404040;
    --medium-gray: #808080;
    --gradient-primary: linear-gradient(135deg, #c0c0c0 0%, #add8e6 100%);
    --gradient-secondary: linear-gradient(135deg, #add8e6 0%, #ffffff 100%);
}

/* ========================================
   导航栏样式
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1680px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

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

.logo img {
    height: 50px;
    width: auto;
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: var(--dark-gray);
    letter-spacing: 2px;
}

.nav-menu {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 12px 20px;
    font-size: 15px;
    color: var(--dark-gray);
    position: relative;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width 0.3s ease;
}

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

.nav-link:hover {
    color: var(--light-blue-dark);
    background: rgba(173, 216, 230, 0.1);
}

.nav-link.active {
    color: var(--light-blue-dark);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--dark-gray);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* ========================================
   页脚样式
   ======================================== */
.footer {
    background: var(--dark-gray);
    color: var(--white);
    padding: 80px 0 40px;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 60px;
}

.footer-section h3 {
    font-size: 18px;
    margin-bottom: 25px;
    color: var(--light-blue);
    position: relative;
    padding-bottom: 12px;
}

.footer-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--gradient-primary);
}

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

.footer-links a {
    color: var(--silver-light);
    font-size: 14px;
    transition: all 0.3s ease;
}

.footer-links a:hover {
    color: var(--light-blue);
    padding-left: 8px;
}

.contact-info li {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 15px;
    color: var(--silver-light);
    font-size: 14px;
}

.footer-bottom {
    max-width: 1400px;
    margin: 60px auto 0;
    padding: 30px 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: var(--silver);
    font-size: 14px;
}

/* ========================================
   通用组件
   ======================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

.section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 42px;
    color: var(--dark-gray);
    margin-bottom: 15px;
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--gradient-primary);
}

.section-title p {
    color: var(--medium-gray);
    font-size: 18px;
    margin-top: 25px;
}

.btn {
    display: inline-block;
    padding: 15px 40px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--dark-gray);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(173, 216, 230, 0.4);
}

.btn-secondary {
    background: transparent;
    border: 2px solid var(--light-blue);
    color: var(--dark-gray);
}

.btn-secondary:hover {
    background: var(--light-blue);
    color: var(--white);
}

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

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

.slide-in-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: all 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(50px);
    transition: all 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1200px) {
    .nav-container {
        padding: 0 25px;
    }
    
    .container {
        padding: 0 25px;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px;
    }
}

@media (max-width: 992px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: var(--white);
        flex-direction: column;
        padding: 40px;
        gap: 0;
        transition: left 0.3s ease;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-link {
        padding: 20px;
        font-size: 18px;
        border-bottom: 1px solid var(--silver-light);
    }
    
    .nav-link::after {
        display: none;
    }
    
    .section-title h2 {
        font-size: 36px;
    }
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title h2 {
        font-size: 28px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .logo-text {
        font-size: 20px;
    }
}

@media (max-width: 576px) {
    .nav-container {
        padding: 0 15px;
        height: 70px;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .btn {
        padding: 12px 30px;
        font-size: 14px;
    }
}