/* ========================================
   湖南恒顺新材料有限公司 - 全局样式
   影视复古风：黑色 + 银灰 + 暗红
   ======================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    background-color: #0a0a0a;
    color: #c0c0c0;
    line-height: 1.6;
    overflow-x: hidden;
    font-size: 16px;
}

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 {
    --color-black: #0a0a0a;
    --color-dark: #1a1a1a;
    --color-silver: #c0c0c0;
    --color-red: #8b1a1a;
    --color-red-light: #a52a2a;
    --color-white: #f5f5f5;
    --color-gray: #666666;
}

/* ========================================
   顶部导航栏
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(10, 10, 10, 0.9);
    backdrop-filter: blur(10px);
    transition: all 0.4s ease;
    border-bottom: 1px solid rgba(139, 26, 26, 0.3);
}

.header.scrolled {
    background: rgba(10, 10, 10, 0.98);
    border-bottom: 2px solid var(--color-red);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
}

.logo {
    font-size: 28px;
    font-weight: bold;
    color: var(--color-white);
    letter-spacing: 2px;
}

.logo span {
    color: var(--color-red);
}

.nav-menu {
    display: flex;
    gap: 40px;
}

.nav-menu li {
    position: relative;
}

.nav-menu a {
    color: var(--color-silver);
    font-size: 15px;
    letter-spacing: 1px;
    padding: 10px 0;
    position: relative;
    transition: all 0.3s ease;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-red);
    transition: width 0.3s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--color-white);
}

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

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 30px;
    height: 3px;
    background: var(--color-silver);
    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);
}

/* 移动端菜单 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: var(--color-black);
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        padding-top: 60px;
        gap: 30px;
        transition: left 0.4s ease;
    }

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

    .hamburger {
        display: flex;
    }

    .nav-container {
        padding: 20px;
    }

    .logo {
        font-size: 22px;
    }
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: linear-gradient(135deg, var(--color-black) 0%, var(--color-dark) 100%);
    border-top: 2px solid var(--color-red);
    padding: 60px 0 30px;
    margin-top: 100px;
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

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

.footer-section h3 {
    color: var(--color-white);
    font-size: 18px;
    margin-bottom: 20px;
    letter-spacing: 1px;
    position: relative;
    padding-bottom: 10px;
}

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

.footer-section p,
.footer-section li {
    color: var(--color-silver);
    font-size: 14px;
    line-height: 2;
}

.footer-section ul li {
    transition: all 0.3s ease;
}

.footer-section ul li:hover {
    color: var(--color-red-light);
    padding-left: 10px;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(192, 192, 192, 0.2);
}

.footer-bottom p {
    color: var(--color-gray);
    font-size: 13px;
}

@media (max-width: 768px) {
    .footer-container {
        padding: 0 20px;
    }

    .footer {
        padding: 40px 0 20px;
    }
}

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

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

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

/* 滚动渐入动画类 */
.scroll-animate {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease;
}

.scroll-animate.show {
    opacity: 1;
    transform: translateY(0);
}

/* Hover 动画 */
.hover-card {
    transition: all 0.4s ease;
    overflow: hidden;
}

.hover-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(139, 26, 26, 0.3);
}

.hover-card img {
    transition: transform 0.6s ease;
}

.hover-card:hover img {
    transform: scale(1.1);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 35px;
    background: linear-gradient(135deg, var(--color-red) 0%, var(--color-red-light) 100%);
    color: var(--color-white);
    font-size: 15px;
    letter-spacing: 1px;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(139, 26, 26, 0.5);
}

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

.btn-outline:hover {
    background: var(--color-red);
}

/* 通用容器 */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
}

/* 章节标题 */
.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 42px;
    color: var(--color-white);
    margin-bottom: 15px;
    letter-spacing: 3px;
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--color-red), transparent);
}

.section-title p {
    color: var(--color-silver);
    font-size: 16px;
    margin-top: 25px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}