/* ===================================
   公共样式 - Common Styles
   青岛青铜器科技有限公司 BROIT
   配色：VI 标准（黑 + 中国红）+ 科技蓝点缀
   =================================== */

/* ===== 颜色变量（源自官方 VI 手册）===== */
:root {
    --brand-black: #1a1a1a;        /* 品牌主色-墨黑 */
    --brand-red: #bb1b21;          /* 品牌强调色-印章红（VI 取色）*/
    --brand-red-dark: #951116;     /* 红-深 */
    --brand-gold: #c0a062;         /* 辅助色-古铜金 */
    --tech-blue: #009ac0;          /* 科技蓝（项目大屏色）*/
    --tech-blue-deep: #0a2a4a;     /* 深科技蓝 */

    --primary-color: #1a1a1a;
    --accent-color: #bb1b21;
    --text-dark: #1f1f1f;          /* 主文字 */
    --text-medium: #5f5f5f;        /* 次文字 */
    --text-light: #9a9a9a;         /* 辅助文字 */
    --bg-white: #ffffff;
    --bg-light: #f6f5f3;           /* 暖灰背景（青铜质感）*/
    --bg-dark: #161616;            /* 深色区块 */
    --border-color: #e7e4df;
    --shadow-light: rgba(26, 26, 26, 0.08);
    --shadow-medium: rgba(26, 26, 26, 0.16);

    --font-serif: "Songti SC", "STSong", "SimSun", serif;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: var(--text-dark);
    background-color: var(--bg-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ===== 容器布局 ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 导航栏样式 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(22, 22, 22, 0.92);
    backdrop-filter: saturate(160%) blur(12px);
    -webkit-backdrop-filter: saturate(160%) blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background-color: rgba(18, 18, 18, 0.98);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.28);
}

.navbar-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 74px;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

/* Logo 区域 */
.navbar-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.navbar-logo-img {
    height: 48px;
    width: auto;
    display: block;
}

.navbar-logo-text {
    font-size: 19px;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: 1px;
}

.navbar-logo-text .en {
    color: var(--brand-gold);
}

/* 导航菜单 */
.navbar-menu {
    display: flex;
    align-items: center;
    gap: 36px;
}

.navbar-menu a {
    font-size: 15.5px;
    color: rgba(255, 255, 255, 0.82);
    font-weight: 500;
    position: relative;
    padding: 10px 0;
    transition: color 0.3s ease;
}

.navbar-menu a:hover,
.navbar-menu a.active {
    color: #ffffff;
}

.navbar-menu a::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--brand-red), var(--brand-gold));
    transition: width 0.3s ease;
}

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

/* 移动端菜单按钮 */
.navbar-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.navbar-toggle span {
    width: 26px;
    height: 2.5px;
    background-color: #ffffff;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.navbar-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

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

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

/* ===== 页脚样式 ===== */
.footer {
    background-color: var(--bg-dark);
    color: #ffffff;
    padding: 72px 0 28px;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--brand-red), var(--brand-gold), var(--tech-blue));
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.3fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand-logo {
    height: 46px;
    margin-bottom: 20px;
}

.footer-section h3 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 22px;
    color: #ffffff;
}

.footer-section p,
.footer-section li {
    font-size: 14px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.62);
    margin-bottom: 10px;
}

.footer-section ul {
    list-style: none;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.62);
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--brand-gold);
}

.footer-bottom {
    padding-top: 28px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 13.5px;
    color: rgba(255, 255, 255, 0.45);
}

.footer-bottom p {
    margin-bottom: 8px;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.45);
    transition: color 0.3s ease;
}

.footer-bottom a:hover {
    color: var(--brand-gold);
}

/* ===== 返回顶部按钮 ===== */
.back-to-top {
    position: fixed;
    right: 32px;
    bottom: 32px;
    width: 48px;
    height: 48px;
    background-color: var(--brand-red);
    color: #ffffff;
    border: none;
    border-radius: 6px;
    font-size: 22px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 6px 18px rgba(187, 27, 33, 0.4);
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--brand-red-dark);
    transform: translateY(-4px);
}

/* ===== 通用按钮样式 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 34px;
    font-size: 15.5px;
    font-weight: 600;
    text-align: center;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    letter-spacing: 0.5px;
}

.btn-primary {
    background-color: var(--brand-red);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--brand-red-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 22px rgba(187, 27, 33, 0.36);
}

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

.btn-outline:hover {
    background-color: #ffffff;
    color: var(--brand-black);
    border-color: #ffffff;
    transform: translateY(-2px);
}

.btn-dark {
    background-color: var(--brand-black);
    color: #ffffff;
}

.btn-dark:hover {
    background-color: #000000;
    transform: translateY(-2px);
    box-shadow: 0 8px 22px var(--shadow-medium);
}

/* ===== 通用标题样式 ===== */
.section-title {
    text-align: center;
    margin-bottom: 56px;
}

.section-title .eyebrow {
    display: inline-block;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--brand-red);
    margin-bottom: 14px;
}

.section-title h2 {
    font-size: 38px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.section-title .subtitle {
    font-size: 17px;
    color: var(--text-medium);
    max-width: 720px;
    margin: 0 auto;
}

.section-title.light h2 {
    color: #ffffff;
}

.section-title.light .subtitle {
    color: rgba(255, 255, 255, 0.7);
}

.section-title::after {
    content: '';
    display: block;
    width: 56px;
    height: 3px;
    background: linear-gradient(90deg, var(--brand-red), var(--brand-gold));
    margin: 22px auto 0;
    border-radius: 2px;
}

/* ===== 区块样式 ===== */
.section {
    padding: 96px 0;
}

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

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

.section-dark {
    background-color: var(--bg-dark);
    color: #ffffff;
}

/* ===== 页面通用 Banner（内页头部）===== */
.page-banner {
    position: relative;
    height: 380px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: #ffffff;
    background: linear-gradient(135deg, #161616 0%, #2a1416 55%, var(--tech-blue-deep) 100%);
    overflow: hidden;
    margin-top: 0;
}

.page-banner::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(187, 27, 33, 0.22), transparent 42%),
        radial-gradient(circle at 80% 70%, rgba(0, 154, 192, 0.20), transparent 45%);
}

.page-banner-content {
    position: relative;
    z-index: 2;
    padding: 0 24px;
}

.page-banner h1 {
    font-size: 46px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.page-banner p {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.78);
    letter-spacing: 1px;
}

.page-banner .breadcrumb {
    margin-top: 20px;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

.page-banner .breadcrumb a {
    color: rgba(255, 255, 255, 0.6);
}

.page-banner .breadcrumb a:hover {
    color: var(--brand-gold);
}

/* ===== 卡片通用 ===== */
.card {
    background-color: var(--bg-white);
    border-radius: 10px;
    box-shadow: 0 6px 22px var(--shadow-light);
    transition: all 0.35s ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 14px 36px var(--shadow-medium);
}

/* ===== 工具类 ===== */
.text-center { text-align: center; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mt-48 { margin-top: 48px; }
.mt-64 { margin-top: 64px; }

/* ===== 滚动动画初始态 ===== */
[data-animate] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

[data-animate].fade-in {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 懒加载图片 ===== */
img[data-src] {
    opacity: 0;
    transition: opacity 0.5s ease;
}

img.loaded {
    opacity: 1;
}

/* ===== 响应式设计 ===== */
@media (max-width: 1200px) {
    .container { max-width: 960px; }
    .footer-content { grid-template-columns: 1fr 1fr; gap: 36px; }
}

@media (max-width: 992px) {
    .container { max-width: 720px; }

    .navbar-menu {
        position: fixed;
        top: 74px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 74px);
        background-color: rgba(18, 18, 18, 0.98);
        flex-direction: column;
        justify-content: flex-start;
        padding: 36px 24px;
        gap: 26px;
        transition: left 0.3s ease;
    }

    .navbar-menu.active { left: 0; }
    .navbar-toggle { display: flex; }

    .section-title h2 { font-size: 32px; }
    .section { padding: 72px 0; }
    .page-banner { height: 320px; }
    .page-banner h1 { font-size: 38px; }
}

@media (max-width: 768px) {
    .container { max-width: 540px; padding: 0 18px; }
    .navbar-container { height: 64px; padding: 0 18px; }
    .navbar-logo-text { font-size: 16px; }
    .navbar-menu { top: 64px; height: calc(100vh - 64px); }

    .section-title h2 { font-size: 27px; }
    .section-title .subtitle { font-size: 15.5px; }
    .section { padding: 56px 0; }

    .footer-content { grid-template-columns: 1fr; gap: 32px; }
    .footer { padding: 56px 0 24px; }

    .page-banner { height: 280px; }
    .page-banner h1 { font-size: 30px; }
    .page-banner p { font-size: 16px; }

    .back-to-top { width: 44px; height: 44px; right: 18px; bottom: 18px; font-size: 20px; }
    .btn { padding: 12px 26px; font-size: 14.5px; }
}