/* =================================================================
   西东智能官网 - 公共样式
   配色：白底 + 深蓝主色 + 少量亮色点缀
   字体：系统字体（无外网依赖，加载快）
   ================================================================= */

/* ----- 重置 ----- */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue",
                 Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.65;
    color: #1a1a1a;
    background: #ffffff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font: inherit; cursor: pointer; border: none; background: none; }

:root {
    --c-primary:        #0a2540;        /* 深蓝主色（西门子风） */
    --c-primary-light:  #1e4db7;        /* 辅助蓝 */
    --c-accent:         #00bfa6;        /* 点缀：青绿 */
    --c-accent-warm:    #ff6b35;        /* 极少使用的暖色 */
    --c-bg:             #ffffff;
    --c-bg-soft:        #f5f7fa;        /* 浅灰底 */
    --c-bg-dark:        #0a2540;        /* 深色块 */
    --c-border:         #e6e9ee;
    --c-text:           #1a1a1a;
    --c-text-light:     #5a6678;
    --c-text-muted:     #8a93a3;
    --maxw:             1200px;
    --pad-x:            24px;
    --radius:           8px;
    --radius-lg:        12px;
    --shadow-sm:        0 1px 3px rgba(10, 37, 64, 0.06);
    --shadow-md:        0 8px 24px rgba(10, 37, 64, 0.08);
}

/* ----- 容器 ----- */
.container {
    width: 100%;
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 var(--pad-x);
}

/* =================================================================
   HEADER / NAV
   ================================================================= */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    z-index: 100;
    transition: border-color .25s, box-shadow .25s;
}
.header.scrolled {
    border-bottom-color: var(--c-border);
    box-shadow: var(--shadow-sm);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
    gap: 24px;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    color: var(--c-primary);
    font-size: 1.05rem;
    white-space: nowrap;
}
.logo-mark {
    width: 32px; height: 32px;
    background: var(--c-primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    font-weight: 700;
    font-size: 1rem;
}
.logo-en { color: var(--c-text-muted); font-size: .85rem; font-weight: 400; }

.nav {
    display: flex;
    align-items: center;
    gap: 32px;
}
.nav a {
    color: var(--c-text);
    font-size: 0.95rem;
    font-weight: 500;
    position: relative;
    padding: 6px 0;
    transition: color .2s;
}
.nav a:hover { color: var(--c-primary-light); }
.nav a.active { color: var(--c-primary); }
.nav a.active::after {
    content: '';
    position: absolute;
    bottom: -4px; left: 0; right: 0;
    height: 2px;
    background: var(--c-primary);
    border-radius: 2px;
}

.lang-switch {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: 8px;
    padding-left: 24px;
    border-left: 1px solid var(--c-border);
    font-size: 0.9rem;
    color: var(--c-text-light);
}
.lang-switch a {
    color: var(--c-text-light);
    padding: 4px 8px;
    border-radius: 4px;
    transition: all .2s;
}
.lang-switch a.active,
.lang-switch a:hover {
    color: var(--c-primary);
    background: var(--c-bg-soft);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}
.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--c-primary);
    border-radius: 2px;
    transition: all .25s;
}

/* =================================================================
   BUTTONS
   ================================================================= */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius);
    transition: all .2s;
    cursor: pointer;
    border: 1px solid transparent;
    white-space: nowrap;
}
.btn-primary {
    background: var(--c-primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--c-primary-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}
.btn-outline {
    background: transparent;
    color: var(--c-primary);
    border-color: var(--c-primary);
}
.btn-outline:hover {
    background: var(--c-primary);
    color: #fff;
}
.btn-ghost {
    background: transparent;
    color: var(--c-primary);
    padding: 8px 0;
}
.btn-ghost:hover { color: var(--c-primary-light); }

/* =================================================================
   HERO (首页大标题)
   ================================================================= */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(180deg, #f5f7fa 0%, #ffffff 100%);
    position: relative;
    overflow: hidden;
}
.hero-grid {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 64px;
    align-items: center;
}
.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    background: rgba(10, 37, 64, 0.06);
    color: var(--c-primary);
    border-radius: 100px;
    font-size: 0.82rem;
    font-weight: 500;
    margin-bottom: 24px;
}
.hero-eyebrow .dot {
    width: 6px; height: 6px;
    background: var(--c-accent);
    border-radius: 50%;
}
.hero h1 {
    font-size: clamp(2.2rem, 4.2vw, 3.4rem);
    font-weight: 700;
    line-height: 1.2;
    color: var(--c-primary);
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}
.hero h1 .accent { color: var(--c-primary-light); }
.hero p.lead {
    font-size: 1.1rem;
    color: var(--c-text-light);
    margin-bottom: 36px;
    max-width: 540px;
}
.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 48px;
}
.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    padding-top: 32px;
    border-top: 1px solid var(--c-border);
    max-width: 540px;
}
.hero-stat .num {
    font-size: 1.7rem;
    font-weight: 700;
    color: var(--c-primary);
    line-height: 1;
    margin-bottom: 6px;
}
.hero-stat .label {
    font-size: 0.85rem;
    color: var(--c-text-light);
}

.hero-visual {
    position: relative;
    aspect-ratio: 4 / 3;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}
.hero-visual .img-tag {
    position: absolute;
    bottom: 12px; right: 12px;
    background: rgba(255, 255, 255, 0.92);
    color: var(--c-text-muted);
    padding: 4px 10px;
    font-size: 0.75rem;
    border-radius: 4px;
    backdrop-filter: blur(6px);
}

/* =================================================================
   SECTIONS
   ================================================================= */
.section {
    padding: 96px 0;
}
.section-sm {
    padding: 64px 0;
}
.section-bg-soft {
    background: var(--c-bg-soft);
}
.section-bg-dark {
    background: var(--c-primary);
    color: #fff;
}
.section-bg-dark h2,
.section-bg-dark h3 { color: #fff; }
.section-bg-dark .eyebrow { color: var(--c-accent); }
.section-bg-dark .lead { color: rgba(255,255,255,0.8); }

.section-header {
    text-align: center;
    margin-bottom: 56px;
}
.section-header.left {
    text-align: left;
}
.eyebrow {
    display: inline-block;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--c-primary-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
}
.section-header h2 {
    font-size: clamp(1.8rem, 3vw, 2.4rem);
    font-weight: 700;
    color: var(--c-primary);
    margin-bottom: 16px;
    letter-spacing: -0.01em;
}
.section-header p {
    font-size: 1.05rem;
    color: var(--c-text-light);
    max-width: 640px;
    margin: 0 auto;
}

/* =================================================================
   PRODUCT CARDS
   ================================================================= */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.product-card {
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all .25s;
    display: flex;
    flex-direction: column;
}
.product-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: transparent;
}
.product-visual {
    position: relative;
    aspect-ratio: 4 / 3;
    background: linear-gradient(135deg, #eef2f7 0%, #dde4ee 100%);
    overflow: hidden;
}
.product-visual svg { width: 100%; height: 100%; }
.product-visual .img-tag {
    position: absolute;
    top: 12px; left: 12px;
    background: rgba(255,255,255,0.92);
    color: var(--c-text-muted);
    padding: 4px 10px;
    font-size: 0.72rem;
    border-radius: 4px;
}
.product-status {
    position: absolute;
    top: 12px; right: 12px;
    padding: 4px 10px;
    font-size: 0.72rem;
    border-radius: 100px;
    font-weight: 500;
}
.status-dev {
    background: rgba(0, 191, 166, 0.12);
    color: #008876;
}
.status-plan {
    background: rgba(255, 107, 53, 0.12);
    color: #c44a1f;
}
.status-tbd {
    background: rgba(138, 147, 163, 0.18);
    color: var(--c-text-muted);
}

.product-info {
    padding: 28px;
    flex: 1;
    display: flex;
    flex-direction: column;
}
.product-info .cat {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--c-primary-light);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 10px;
}
.product-info h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--c-primary);
    margin-bottom: 12px;
}
.product-info .desc {
    color: var(--c-text-light);
    font-size: 0.92rem;
    margin-bottom: 16px;
    flex: 1;
}
.product-info .meta {
    font-size: 0.82rem;
    color: var(--c-text-muted);
    padding-top: 12px;
    border-top: 1px solid var(--c-border);
    display: flex;
    flex-wrap: wrap;
    gap: 6px 12px;
}
.product-info .meta strong {
    color: var(--c-text);
    font-weight: 500;
}

/* =================================================================
   FEATURE / STAT LIST
   ================================================================= */
.feature-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.feature-item {
    padding: 24px;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--c-border);
}
.feature-item .num {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--c-primary);
    margin-bottom: 8px;
}
.feature-item h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--c-primary);
    margin-bottom: 6px;
}
.feature-item p {
    font-size: 0.85rem;
    color: var(--c-text-light);
    line-height: 1.5;
}

/* =================================================================
   APPLICATION CARDS
   ================================================================= */
.app-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}
.app-card {
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all .25s;
}
.app-card:hover {
    border-color: var(--c-primary-light);
    box-shadow: var(--shadow-md);
}
.app-card .visual {
    aspect-ratio: 16 / 9;
    background: linear-gradient(135deg, #eef2f7 0%, #dde4ee 100%);
    position: relative;
}
.app-card .body {
    padding: 28px;
}
.app-card .stage {
    display: inline-block;
    padding: 4px 10px;
    background: var(--c-bg-soft);
    color: var(--c-primary);
    border-radius: 4px;
    font-size: 0.78rem;
    font-weight: 500;
    margin-bottom: 12px;
}
.app-card h3 {
    font-size: 1.15rem;
    color: var(--c-primary);
    margin-bottom: 10px;
}
.app-card p {
    color: var(--c-text-light);
    font-size: 0.92rem;
    margin-bottom: 14px;
}
.app-card .products {
    font-size: 0.85rem;
    color: var(--c-text-muted);
    border-top: 1px solid var(--c-border);
    padding-top: 12px;
}
.app-card .products strong {
    color: var(--c-primary);
}

/* =================================================================
   PLACEHOLDER CALLOUT - 待补充
   ================================================================= */
.tbd-banner {
    background: #fff8e6;
    border: 1px dashed #d4a73a;
    border-radius: var(--radius);
    padding: 14px 18px;
    color: #8a5a00;
    font-size: 0.88rem;
    margin: 24px 0;
    display: flex;
    align-items: center;
    gap: 10px;
}
.tbd-banner::before {
    content: '!';
    flex-shrink: 0;
    width: 22px; height: 22px;
    border-radius: 50%;
    background: #d4a73a;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
}

/* =================================================================
   CONTACT PAGE
   ================================================================= */
.contact-grid {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 56px;
    align-items: start;
}
.contact-list {
    display: flex;
    flex-direction: column;
    gap: 28px;
}
.contact-item {
    display: flex;
    gap: 16px;
    padding: 20px 0;
    border-bottom: 1px solid var(--c-border);
}
.contact-item:last-child { border-bottom: none; }
.contact-icon {
    flex-shrink: 0;
    width: 44px; height: 44px;
    background: var(--c-bg-soft);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--c-primary);
}
.contact-icon svg { width: 22px; height: 22px; }
.contact-item .info h4 {
    font-size: 0.95rem;
    color: var(--c-primary);
    margin-bottom: 6px;
    font-weight: 600;
}
.contact-item .info p {
    color: var(--c-text-light);
    font-size: 0.92rem;
    line-height: 1.6;
}
.contact-item .info .tbd {
    color: var(--c-text-muted);
    font-style: italic;
}
.contact-form {
    background: var(--c-bg-soft);
    border-radius: var(--radius-lg);
    padding: 36px;
}
.contact-form h3 {
    font-size: 1.2rem;
    color: var(--c-primary);
    margin-bottom: 8px;
}
.contact-form p.form-note {
    color: var(--c-text-light);
    font-size: 0.85rem;
    margin-bottom: 24px;
}
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}
.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--c-text);
    font-weight: 500;
    margin-bottom: 6px;
}
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--c-border);
    border-radius: var(--radius);
    background: #fff;
    font: inherit;
    color: var(--c-text);
    transition: border-color .2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--c-primary-light);
}
.form-group textarea { min-height: 120px; resize: vertical; }
.form-msg {
    background: #f0fbf7;
    border: 1px solid #b8e6d4;
    color: #008876;
    padding: 14px 18px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    margin-top: 12px;
    display: none;
}
.form-msg.show { display: block; }

/* =================================================================
   PAGE HEADER (内页顶部)
   ================================================================= */
.page-hero {
    padding: 140px 0 60px;
    background: linear-gradient(180deg, #f5f7fa 0%, #ffffff 100%);
    text-align: center;
}
.page-hero .eyebrow { color: var(--c-primary-light); }
.page-hero h1 {
    font-size: clamp(2rem, 3.6vw, 2.8rem);
    color: var(--c-primary);
    margin-bottom: 16px;
    font-weight: 700;
    letter-spacing: -0.01em;
}
.page-hero p {
    font-size: 1.05rem;
    color: var(--c-text-light);
    max-width: 640px;
    margin: 0 auto;
}

/* =================================================================
   CTA SECTION
   ================================================================= */
.cta-section {
    background: var(--c-primary);
    color: #fff;
    text-align: center;
    padding: 80px 0;
}
.cta-section h2 {
    font-size: clamp(1.6rem, 2.6vw, 2.1rem);
    margin-bottom: 16px;
    color: #fff;
}
.cta-section p {
    color: rgba(255,255,255,0.75);
    font-size: 1.02rem;
    max-width: 540px;
    margin: 0 auto 32px;
}
.cta-section .btn-primary {
    background: #fff;
    color: var(--c-primary);
}
.cta-section .btn-primary:hover {
    background: var(--c-accent);
    color: #fff;
}

/* =================================================================
   FOOTER
   ================================================================= */
.footer {
    background: #0a2540;
    color: rgba(255,255,255,0.7);
    padding: 64px 0 24px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}
.footer-brand h3 {
    color: #fff;
    font-size: 1.05rem;
    margin-bottom: 12px;
    font-weight: 600;
}
.footer-brand p {
    font-size: 0.88rem;
    line-height: 1.7;
    margin-bottom: 16px;
    color: rgba(255,255,255,0.6);
}
.footer h4 {
    color: #fff;
    font-size: 0.92rem;
    margin-bottom: 16px;
    font-weight: 600;
}
.footer ul li {
    margin-bottom: 10px;
    font-size: 0.88rem;
}
.footer ul li a {
    color: rgba(255,255,255,0.6);
    transition: color .2s;
}
.footer ul li a:hover {
    color: #fff;
}
.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,0.12);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 0.82rem;
    color: rgba(255,255,255,0.5);
}

/* =================================================================
   UTILITIES
   ================================================================= */
.divider {
    height: 1px;
    background: var(--c-border);
    margin: 48px 0;
}
.text-muted { color: var(--c-text-light); }
.text-center { text-align: center; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }

/* =================================================================
   RESPONSIVE
   ================================================================= */
@media (max-width: 1024px) {
    .hero-grid { grid-template-columns: 1fr; gap: 48px; }
    .hero-visual { order: -1; max-width: 600px; margin: 0 auto; width: 100%; }
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-list { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .contact-grid { grid-template-columns: 1fr; gap: 32px; }
    .app-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
    .section { padding: 64px 0; }
    .section-sm { padding: 48px 0; }
    .hero { padding: 120px 0 64px; }
    .hero-stats { grid-template-columns: 1fr 1fr; }

    .nav {
        position: fixed;
        top: 68px; left: 0; right: 0;
        background: #fff;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 12px 24px 24px;
        border-bottom: 1px solid var(--c-border);
        transform: translateY(-12px);
        opacity: 0;
        pointer-events: none;
        transition: all .2s;
    }
    .nav.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }
    .nav a {
        padding: 12px 0;
        border-bottom: 1px solid var(--c-border);
    }
    .lang-switch {
        border-left: none;
        padding-left: 0;
        margin-left: 0;
        padding-top: 12px;
        margin-top: 8px;
        border-top: 1px solid var(--c-border);
    }
    .menu-toggle { display: flex; }

    .products-grid { grid-template-columns: 1fr; }
    .feature-list { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
    .form-row { grid-template-columns: 1fr; gap: 0; margin-bottom: 0; }
    .form-group { margin-bottom: 16px; }
    .footer-bottom { flex-direction: column; text-align: center; }
    .page-hero { padding: 110px 0 40px; }
    .contact-form { padding: 24px; }
    .hero-actions .btn { flex: 1; }
}

/* =================================================================
   FADE IN (轻微入场动画，不影响阅读)
   ================================================================= */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity .6s ease, transform .6s ease;
}
.fade-up.in {
    opacity: 1;
    transform: translateY(0);
}