/*
 * 江西万驰汽车零部件有限公司 官网 CSS样式表
 * 设计基调：天窗系统专业展示、结构图解、研发与专利可信度
 */

/* ==========================================================================
   1. CSS 变量系统 (CSS Variables)
   ========================================================================== */
:root {
    --color-primary: #0b2c54; /* 深科技蓝 */
    --color-secondary: #1f6feb; /* 亮蓝 - 互动与链接 */
    --color-accent: #ff7a18; /* 活力橙 - CTA/强调 */
    --color-surface: #ffffff;
    --color-surface-alt: #f3f7fb;
    --color-border: #e0e6ef;
    --color-text-dark: #1f2a3d;
    --color-text-light: #6b778c;
    --color-success: #2fbf71;

    --font-family-main: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;

    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 6rem;

    --border-radius-sm: 6px;
    --border-radius-md: 10px;
    --border-radius-lg: 16px;
    --shadow-sm: 0 4px 12px rgba(12, 37, 79, 0.06);
    --shadow-md: 0 14px 38px rgba(12, 37, 79, 0.12);
    --shadow-strong: 0 20px 60px rgba(8, 27, 58, 0.18);
    --transition-speed: 0.3s;
}

/* ==========================================================================
   2. 全局基础样式 (Global Base Styles)
   ========================================================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-main);
    line-height: 1.6;
    color: var(--color-text-dark);
    background: linear-gradient(180deg, #f7f9fc 0%, #f4f6fb 100%);
}

a {
    color: var(--color-secondary);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--color-accent);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-dark);
}

ul {
    margin-left: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

li {
    margin-bottom: var(--spacing-xs);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: var(--border-radius-lg);
}

.container {
    max-width: 1220px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.main-content {
    padding-top: 76px; /* 固定导航栏留白 */
}

/* ==========================================================================
   3. 头部与导航 (Header & Navigation)
   ========================================================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: linear-gradient(120deg, #0b2c54 0%, #0f3f72 60%, #0b2c54 100%);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 76px;
}

.logo a {
    color: #ffffff;
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 0.5px;
}

.nav-menu {
    list-style: none;
    display: flex;
    gap: var(--spacing-sm);
    margin: 0;
    padding: 0;
}

.nav-item {
    position: relative;
}

.nav-item > a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: #ffffff;
    border-radius: var(--border-radius-sm);
    transition: background var(--transition-speed), color var(--transition-speed);
}

.nav-item > a:hover {
    background: rgba(255, 255, 255, 0.1);
}

.dropdown-menu {
    list-style: none;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    min-width: 180px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-sm) 0;
    display: none;
    margin: 0;
}

.nav-item:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-lg);
    color: var(--color-text-dark);
}

.dropdown-menu li a:hover {
    background: var(--color-surface-alt);
    color: var(--color-secondary);
}

.menu-toggle {
    display: none;
    color: #ffffff;
    font-size: 1.7rem;
    cursor: pointer;
}

/* ==========================================================================
   4. 按钮与标签 (Buttons & Badges)
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 999px;
    font-weight: 700;
    cursor: pointer;
    border: none;
    transition: all var(--transition-speed);
    box-shadow: var(--shadow-sm);
}

.btn-primary {
    background: linear-gradient(135deg, #ff8a1c 0%, #ff6a00 100%);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: #113763;
    color: #fff;
}

.btn-secondary:hover {
    background: #1f4f88;
    transform: translateY(-2px);
}

.btn-outline {
    border: 1px solid rgba(255, 255, 255, 0.35);
    color: #fff;
    background: transparent;
}

.btn-outline:hover {
    border-color: #fff;
    background: rgba(255, 255, 255, 0.1);
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 6px 12px;
    background: rgba(31, 111, 235, 0.12);
    color: #0f3f72;
    border-radius: 999px;
    font-weight: 600;
    font-size: 0.9rem;
}

.pill {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 999px;
    background: var(--color-surface-alt);
    color: var(--color-text-light);
    font-size: 0.85rem;
    margin-right: var(--spacing-sm);
}

/* ==========================================================================
   5. 版式与网格 (Layouts & Grids)
   ========================================================================== */
.section-padding {
    padding: var(--spacing-xxl) 0;
}

.section-title {
    text-align: center;
    max-width: 820px;
    margin: 0 auto var(--spacing-xl) auto;
}

.section-title h2 {
    font-size: 2.6rem;
}

.section-title p {
    color: var(--color-text-light);
    font-size: 1.05rem;
}

.grid {
    display: grid;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.grid-1 { grid-template-columns: 1fr; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

.split {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--spacing-xl);
    align-items: center;
}

@media (max-width: 960px) {
    .split { grid-template-columns: 1fr; }
}

/* ==========================================================================
   6. 模块化组件 (Cards, Hero, Timeline etc.)
   ========================================================================== */
.card {
    background: var(--color-surface);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.card-contrast {
    background: #0f2748;
    color: #dbe7ff;
    border-color: rgba(255, 255, 255, 0.08);
}

.card-contrast h3,
.card-contrast p {
    color: #dbe7ff;
}

.hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    padding: calc(var(--spacing-xxl) + 30px) 0 var(--spacing-xxl);
    background-size: cover;
    background-position: center;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(120deg, rgba(11, 44, 84, 0.82) 10%, rgba(15, 63, 114, 0.76) 45%, rgba(11, 44, 84, 0.9) 90%);
}

.hero .container {
    position: relative;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    align-items: center;
}

.hero h1 {
    color: #fff;
    font-size: 2.8rem;
    margin-bottom: var(--spacing-md);
}

.hero p {
    color: #e6efff;
    font-size: 1.05rem;
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.stat {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md);
    color: #fff;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat strong {
    display: block;
    font-size: 1.6rem;
    margin-bottom: var(--spacing-xs);
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-md);
}

.feature-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-md);
    align-items: start;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: rgba(31, 111, 235, 0.12);
    color: #0f3f72;
    font-size: 1.3rem;
    font-weight: 700;
}

.highlight-card {
    position: relative;
    overflow: hidden;
    border-top: 4px solid var(--color-accent);
}

.highlight-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 20%, rgba(31, 111, 235, 0.08), transparent 35%);
    pointer-events: none;
}

.component-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-md);
}

.component-card {
    position: relative;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    overflow: hidden;
}

.component-card:hover {
    border-color: var(--color-secondary);
    box-shadow: var(--shadow-md);
}

.component-detail {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(15, 63, 114, 0.9), rgba(11, 44, 84, 0.95));
    color: #fff;
    padding: var(--spacing-lg);
    opacity: 0;
    transition: opacity var(--transition-speed);
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--spacing-sm);
}

.component-card:hover .component-detail {
    opacity: 1;
}

.text-center { text-align: center; }
.bg-light { background: var(--color-surface-alt); }
.muted { color: var(--color-text-light); }
.eyebrow {
    display: inline-block;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--color-text-light);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tag {
    padding: 6px 10px;
    border-radius: 10px;
    background: var(--color-surface-alt);
    color: var(--color-text-light);
    font-size: 0.9rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: var(--spacing-md);
}

.data-table th,
.data-table td {
    padding: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
    text-align: left;
}

.data-table th {
    color: var(--color-text-light);
    font-weight: 600;
}

.timeline {
    position: relative;
    padding-left: 26px;
    list-style: none;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(180deg, #1f6feb, #0b2c54);
}

.timeline li {
    position: relative;
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-md);
}

.timeline li::before {
    content: '';
    position: absolute;
    left: -2px;
    top: 6px;
    width: 12px;
    height: 12px;
    background: var(--color-surface);
    border: 3px solid #1f6feb;
    border-radius: 50%;
    box-shadow: var(--shadow-sm);
}

.news-card {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.news-card h4 a {
    color: var(--color-primary);
}

.news-meta {
    color: var(--color-text-light);
    font-size: 0.95rem;
}

.partner-logos {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: var(--spacing-md);
    align-items: center;
}

.partner-logos div {
    background: var(--color-surface);
    border: 1px dashed var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md);
    text-align: center;
    color: var(--color-text-light);
}

.cta-panel {
    background: linear-gradient(135deg, #0f3f72, #0b2c54);
    color: #fff;
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    box-shadow: var(--shadow-md);
}

@media (max-width: 900px) {
    .cta-panel { grid-template-columns: 1fr; }
}

.form-grid {
    display: grid;
    gap: var(--spacing-md);
}

.form-row-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

@media (max-width: 720px) {
    .form-row-2 { grid-template-columns: 1fr; }
}

.form-group label {
    display: block;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-dark);
}

.form-control,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    background: #fff;
    font-size: 1rem;
    transition: border var(--transition-speed), box-shadow var(--transition-speed);
}

.form-control:focus,
.form-select:focus,
.form-textarea:focus {
    border-color: var(--color-secondary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(31, 111, 235, 0.15);
}

/* ==========================================================================
   7. 底部 (Footer)
   ========================================================================== */
.footer {
    background: #0b1d36;
    color: #e3edff;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    font-size: 0.95rem;
    margin-top: var(--spacing-xl);
}

.footer p {
    color: #f1f5ff;
    line-height: 1.8;
    margin-bottom: var(--spacing-sm);
}

.footer-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer h4 {
    color: #fff;
    margin-bottom: var(--spacing-md);
}

.footer ul {
    list-style: none;
}

.footer ul li {
    margin-bottom: var(--spacing-sm);
}

.footer ul li a {
    color: #eef2ff;
    font-weight: 600;
}

.footer ul li a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    color: #fff;
    font-weight: 600;
}

.footer-bottom a {
    color: #fff;
    font-weight: 700;
}

/* ==========================================================================
   8. 响应式调整 (Responsive)
   ========================================================================== */
@media (max-width: 900px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 76px;
        right: 0;
        left: 0;
        background: #0b2c54;
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
    }

    .nav-menu.active { display: flex; }

    .dropdown-menu {
        position: static;
        box-shadow: none;
        border: none;
        background: transparent;
        padding: 0 var(--spacing-sm);
    }

    .dropdown-menu li a {
        color: #dbe7ff;
        padding-left: var(--spacing-lg);
        background: rgba(255, 255, 255, 0.04);
        margin-bottom: 6px;
        border-radius: var(--border-radius-sm);
    }

    .menu-toggle { display: block; }
}