/* ================================================================
   styles.css — 企业官网全局样式
   说明：所有颜色/字号/间距集中定义在 CSS 变量中，方便全局替换
   ================================================================ */

/* =========================================
   CSS 变量（全局主题配置，修改一处全局生效）
   ========================================= */
:root {
    /* --- 主色调 [可改] --- */
    --color-primary:        #2563eb;   /* 主色 */
    --color-primary-dark:   #1d4ed8;   /* 主色深（hover/active） */
    --color-primary-light:  #dbeafe;   /* 主色浅（背景高亮） */

    /* --- 中性色 [可改] --- */
    --color-bg:             #ffffff;   /* 页面背景 */
    --color-bg-alt:         #f8fafc;   /* 交替区块背景 */
    --color-bg-dark:        #1e293b;   /* 深色背景（页脚） */
    --color-text:           #1e293b;   /* 主文字色 */
    --color-text-light:     #64748b;   /* 辅助文字色 */
    --color-text-inverse:   #f1f5f9;   /* 深色背景上的文字 */
    --color-border:         #e2e8f0;   /* 边框色 */

    /* --- 排版 [可改] --- */
    --font-family:          -apple-system, BlinkMacSystemFont, "Segoe UI",
                            "PingFang SC", "Microsoft YaHei", "Helvetica Neue",
                            Arial, sans-serif;
    --font-size-base:       16px;
    --line-height-base:     1.7;
    --max-width:            1200px;    /* 内容最大宽度 */

    /* --- 间距 [可改] --- */
    --space-section:        80px;      /* 区块上下间距 */
    --space-card-gap:       24px;      /* 卡片网格间距 */
    --space-container-pad:  20px;      /* 容器左右内边距 */

    /* --- 圆角 [可改] --- */
    --radius-sm:            6px;
    --radius-md:            10px;
    --radius-lg:            16px;

    /* --- 阴影 [可改] --- */
    --shadow-card:          0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
    --shadow-card-hover:    0 2px 8px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.06);
    --shadow-nav:           0 1px 3px rgba(0,0,0,0.08);

    /* --- 过渡 [可改] --- */
    --transition-fast:      0.2s ease;
    --transition-base:      0.3s ease;
}

/* =========================================
   全局重置 & 基础样式
   ========================================= */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-family);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: var(--line-height-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-dark);
}

/* =========================================
   通用容器
   ========================================= */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding-left: var(--space-container-pad);
    padding-right: var(--space-container-pad);
}

/* =========================================
   区块通用样式
   ========================================= */
.section {
    padding: var(--space-section) 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 12px;
    color: var(--color-text);
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--color-text-light);
    text-align: center;
    max-width: 560px;
    margin: 0 auto 48px;
}

/* =========================================
   按钮
   ========================================= */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: 2px solid transparent;
    transition:
        background var(--transition-fast),
        color var(--transition-fast),
        border-color var(--transition-fast),
        transform var(--transition-fast);
    text-decoration: none;
    user-select: none;
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    color: #fff;
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: #fff;
    border-color: rgba(255,255,255,0.5);
}

.btn-outline:hover {
    background: #fff;
    color: var(--color-primary);
    border-color: #fff;
    transform: translateY(-1px);
}

.btn-block {
    width: 100%;
}

/* =========================================
   导航栏 (固定顶部)
   ========================================= */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition:
        background var(--transition-base),
        border-color var(--transition-base),
        box-shadow var(--transition-base);
}

.site-header.scrolled {
    border-bottom-color: var(--color-border);
    box-shadow: var(--shadow-nav);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

/* --- Logo --- */
.nav-logo {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--color-text);
    letter-spacing: -0.5px;
}

.nav-logo:hover {
    color: var(--color-primary);
}

/* --- 导航菜单链接 --- */
.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    display: inline-block;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-light);
    transition:
        color var(--transition-fast),
        background var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
    background: var(--color-primary-light);
}

/* --- 移动端菜单按钮（桌面端隐藏） --- */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}

.toggle-bar {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 1px;
    transition:
        transform var(--transition-fast),
        opacity var(--transition-fast);
}

/* 菜单打开时按钮变成 X */
.nav-toggle.open .toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle.open .toggle-bar:nth-child(2) {
    opacity: 0;
}
.nav-toggle.open .toggle-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* =========================================
   首页横幅 (Hero)
   ========================================= */
.hero {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 100px 0 60px;
    /* ▼ [可改] 背景：纯色改为渐变或替换为图片 ▼ */
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #7c3aed 100%);
    overflow: hidden;
}

/* 叠加装饰层（可选删掉） */
.hero-overlay {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(255,255,255,0.06) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255,255,255,0.04) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: #fff;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: 0.5px;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.2rem);
    opacity: 0.9;
    max-width: 560px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 向下滚动指示器（纯装饰） */
.scroll-indicator {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}
.scroll-indicator span {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255,255,255,0.5);
    border-radius: 12px;
    position: relative;
}
.scroll-indicator span::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: rgba(255,255,255,0.7);
    border-radius: 2px;
    animation: scrollDot 1.6s ease-in-out infinite;
}
@keyframes scrollDot {
    0%, 100% { top: 8px; opacity: 1; }
    50%     { top: 20px; opacity: 0.3; }
}

/* =========================================
   卡片网格
   ========================================= */
.card-grid {
    display: grid;
    gap: var(--space-card-gap);
}

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

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

/* =========================================
   业务介绍卡片 (Feature Card)
   ========================================= */
.feature-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px 24px;
    text-align: center;
    transition:
        transform var(--transition-base),
        box-shadow var(--transition-base);
}

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

.card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 72px;
    height: 72px;
    border-radius: var(--radius-md);
    background: var(--color-primary-light);
    margin-bottom: 20px;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-text);
}

.card-desc {
    font-size: 0.92rem;
    color: var(--color-text-light);
    margin-bottom: 12px;
    line-height: 1.6;
}

.card-link {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--color-primary);
}

.card-link:hover {
    color: var(--color-primary-dark);
}

/* =========================================
   产品卡片 (Product Card)
   ========================================= */
.product-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    transition:
        transform var(--transition-base),
        box-shadow var(--transition-base);
}

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

.product-card .card-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
}

.product-card .card-title {
    margin-bottom: 8px;
}

.product-card .card-desc {
    margin-bottom: 0;
}

/* =========================================
   关于我们
   ========================================= */
.about-layout {
    display: flex;
    gap: 56px;
    align-items: center;
    margin-top: 16px;
}

.about-image {
    flex: 1;
    min-width: 0;
}

.about-text {
    flex: 1;
    min-width: 0;
}

/* --- 图片占位符（替换为真实图片后删除此块） --- */
.image-placeholder {
    aspect-ratio: 4 / 3;
    background: var(--color-bg);
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-light);
    font-size: 0.9rem;
}

.about-heading {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--color-text);
}

.about-desc {
    font-size: 0.95rem;
    color: var(--color-text-light);
    margin-bottom: 12px;
    line-height: 1.8;
}

/* --- 数据指标 --- */
.about-stats {
    display: flex;
    gap: 32px;
    margin-top: 28px;
    flex-wrap: wrap;
}

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

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1.2;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--color-text-light);
    margin-top: 4px;
}

/* =========================================
   联系我们
   ========================================= */
.contact-layout {
    display: flex;
    gap: 48px;
    margin-top: 16px;
}

/* --- 表单 --- */
.contact-form {
    flex: 1.2;
    min-width: 0;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--color-text);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.92rem;
    font-family: var(--font-family);
    color: var(--color-text);
    background: var(--color-bg);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #94a3b8;
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* --- 联系信息 --- */
.contact-info {
    flex: 0.8;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.info-item {
    display: flex;
    gap: 14px;
    align-items: flex-start;
}

.info-icon {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--color-primary-light);
    border-radius: var(--radius-sm);
}

.info-item strong {
    display: block;
    font-size: 0.88rem;
    color: var(--color-text);
    margin-bottom: 2px;
}

.info-item p {
    font-size: 0.88rem;
    color: var(--color-text-light);
}

/* =========================================
   页脚
   ========================================= */
.site-footer {
    background: var(--color-bg-dark);
    color: var(--color-text-inverse);
    padding: 32px 0;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-logo {
    font-size: 1.2rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.footer-copy {
    font-size: 0.85rem;
    color: #94a3b8;
    margin-top: 6px;
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    font-size: 0.85rem;
    color: #94a3b8;
}

.footer-links a:hover {
    color: #fff;
}

/* =========================================
   响应式 — 平板 (≤ 900px)
   ========================================= */
@media (max-width: 900px) {
    :root {
        --space-section: 60px;
    }

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

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

    .about-layout {
        flex-direction: column;
        gap: 32px;
    }

    .contact-layout {
        flex-direction: column;
        gap: 36px;
    }
}

/* =========================================
   响应式 — 手机 (≤ 640px)
   ========================================= */
@media (max-width: 640px) {
    :root {
        --space-section: 48px;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .section-subtitle {
        font-size: 0.95rem;
        margin-bottom: 32px;
    }

    /* --- 导航 --- */
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 260px;
        height: 100vh;
        flex-direction: column;
        background: var(--color-bg);
        padding: 80px 28px 28px;
        gap: 4px;
        box-shadow: -4px 0 20px rgba(0,0,0,0.08);
        transition: right var(--transition-base);
    }

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

    .nav-link {
        width: 100%;
        padding: 12px 16px;
        font-size: 1rem;
    }

    .nav-toggle {
        display: flex;
    }

    /* 菜单打开时背景遮罩 */
    .nav-overlay {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0,0,0,0.3);
        z-index: 999;
    }

    .nav-overlay.show {
        display: block;
    }

    /* --- 卡片网格降为单列 --- */
    .grid-4, .grid-3 {
        grid-template-columns: 1fr;
    }

    /* --- 关于我们 --- */
    .about-stats {
        gap: 20px;
        justify-content: space-around;
    }

    .stat-number {
        font-size: 1.6rem;
    }

    /* --- Hero --- */
    .hero-title {
        font-size: 1.8rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    /* --- 页脚 --- */
    .footer-container {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }
}