/* =====================================================================
   智网畅联官网 · 共享设计系统 (site.css) v3.0
   去AI味重设计：工业精密感，冷暖分离，无发光
   ===================================================================== */

:root {
    /* —— 暗色主题（默认）—— */
    --bg-primary: #0d1117;
    --bg-secondary: #131820;
    --bg-tertiary: #1a1f2a;
    --bg-elevated: #212735;

    --text-primary: #e8ecf1;
    --text-secondary: #8b96a8;
    --text-muted: #5e6a7c;

    /* 双引擎主色 —— 独立使用，不再混融 */
    --sim: #0ea5e9;
    --sim-deep: #0284c7;
    --x: #8b5cf6;
    --x-deep: #7c3aed;
    --accent: #38bdf8;

    /* 单色渐变，冷暖不交叉 */
    --grad-brand: linear-gradient(135deg, #0ea5e9, #0284c7);
    --grad-sim: linear-gradient(135deg, #0ea5e9, #0284c7);
    --grad-x: linear-gradient(135deg, #8b5cf6, #7c3aed);
    --grad-text: linear-gradient(110deg, #0ea5e9, #38bdf8);

    --border: rgba(255, 255, 255, 0.06);
    --border-strong: rgba(255, 255, 255, 0.12);
    --card-bg: rgba(255, 255, 255, 0.02);
    --card-bg-hover: rgba(255, 255, 255, 0.045);

    /* 普通投影，无发光 */
    --shadow-soft: 0 8px 30px rgba(0, 0, 0, 0.35);
    --shadow-glow: 0 4px 16px rgba(0, 0, 0, 0.2);

    --radius: 20px;
    --radius-sm: 14px;
    --maxw: 1220px;
    --nav-h: 70px;

    --font: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI",
        "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

[data-theme="light"] {
    --bg-primary: #f7f8fa;
    --bg-secondary: #eef0f4;
    --bg-tertiary: #e4e7ed;
    --bg-elevated: #ffffff;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #7a8699;

    --sim: #0284c7;
    --x: #7c3aed;
    --accent: #0ea5e9;

    --grad-text: linear-gradient(110deg, #0284c7, #0ea5e9);

    --border: rgba(15, 23, 42, 0.08);
    --border-strong: rgba(15, 23, 42, 0.14);
    --card-bg: #ffffff;
    --card-bg-hover: #ffffff;

    --shadow-soft: 0 8px 30px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.65;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    transition: background .4s ease, color .4s ease;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* —— 文字渐变 / 强调 —— */
.gradient-text {
    background: var(--grad-text);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.text-sim { color: var(--sim); }
.text-x { color: var(--x); }

/* =====================================================================
   导航栏
   ===================================================================== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    height: var(--nav-h);
    display: flex; align-items: center;
    background: transparent;
    transition: background .35s ease, backdrop-filter .35s ease, border-color .35s ease;
    border-bottom: 1px solid transparent;
}
.navbar.scrolled {
    background: color-mix(in srgb, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(20px) saturate(150%);
    -webkit-backdrop-filter: blur(20px) saturate(150%);
    border-bottom: 1px solid var(--border);
}
.nav-container {
    max-width: var(--maxw); width: 100%; margin: 0 auto; padding: 0 24px;
    display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.logo {
    display: flex; align-items: center; gap: 10px;
    font-weight: 800; font-size: 1.25rem; letter-spacing: .5px;
    white-space: nowrap;
}
.logo .logo-mark {
    width: 32px; height: 32px; border-radius: 10px;
    background: var(--sim);
    display: grid; place-items: center;
    font-size: .9rem; color: #fff; font-weight: 900;
    box-shadow: none;
}
.logo .logo-sub { color: var(--text-muted); font-weight: 500; font-size: .72rem; letter-spacing: 1px; }

/* 导航中的ZNetX徽标 */
.nav-brand-x {
    display: flex; align-items: center; gap: 8px;
}
.nav-brand-x img {
    height: 28px; width: auto;
    opacity: .85;
    transition: opacity .3s;
}
.nav-brand-x:hover img { opacity: 1; }

.nav-menu { display: flex; align-items: center; gap: 28px; }
.nav-link {
    position: relative; font-size: .94rem; font-weight: 500;
    color: var(--text-secondary); transition: color .25s;
}
.nav-link::after {
    content: ""; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
    background: var(--sim); transition: width .3s ease; border-radius: 2px;
}
.nav-link:hover { color: var(--text-primary); }
.nav-link:hover::after { width: 100%; }

.nav-actions { display: flex; align-items: center; gap: 14px; }

.cta-button {
    padding: 9px 20px; border-radius: 999px; font-weight: 600; font-size: .9rem;
    color: #fff; background: var(--sim);
    box-shadow: none; white-space: nowrap;
    transition: transform .25s, box-shadow .25s, background .25s;
}
.cta-button:hover { transform: translateY(-2px); background: var(--sim-deep); box-shadow: 0 6px 20px rgba(2, 132, 199, .3); }

.icon-btn {
    width: 38px; height: 38px; border-radius: 10px; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    background: var(--card-bg); border: 1px solid var(--border);
    color: var(--text-secondary); transition: all .25s;
    padding: 0;
}
.icon-btn:hover { border-color: var(--border-strong); color: var(--text-primary); transform: translateY(-2px); }
.icon-btn #theme-icon { display: flex; line-height: 0; }

.menu-toggle {
    display: none; flex-direction: column; gap: 5px; cursor: pointer;
    background: none; border: none; padding: 6px;
}
.menu-toggle span { width: 24px; height: 2px; background: var(--text-primary); border-radius: 2px; transition: .3s; }

/* =====================================================================
   按钮
   ===================================================================== */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 13px 28px; border-radius: 999px; font-weight: 600; font-size: .98rem;
    cursor: pointer; border: 1px solid transparent; transition: all .28s ease;
    white-space: nowrap;
}
.btn-primary { color: #fff; background: var(--sim); box-shadow: none; }
.btn-primary:hover { transform: translateY(-3px); background: var(--sim-deep); box-shadow: 0 8px 24px rgba(2, 132, 199, .3); }
.btn-ghost { color: var(--text-primary); border-color: var(--border-strong); background: var(--card-bg); }
.btn-ghost:hover { transform: translateY(-3px); border-color: var(--sim); color: var(--sim); }
.btn-sim { background: var(--grad-sim); color: #fff; }
.btn-x { background: var(--grad-x); color: #fff; }
.btn-arrow::after { content: "→"; transition: transform .25s; }
.btn-arrow:hover::after { transform: translateX(4px); }

/* SaaS badge */
.saas-badge {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 6px 14px; border-radius: 999px;
    font-size: .82rem; font-weight: 600;
    background: color-mix(in srgb, var(--x) 10%, transparent);
    border: 1px solid color-mix(in srgb, var(--x) 25%, transparent);
    color: var(--x);
    transition: all .25s;
}
.saas-badge:hover {
    transform: translateY(-2px);
    border-color: var(--x);
    box-shadow: 0 4px 12px rgba(139, 92, 246, .15);
}
.saas-badge .dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--x);
    box-shadow: none;
    animation: saasPulse 2s infinite;
}
@keyframes saasPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: .4; }
}

/* =====================================================================
   通用区块 / 标题
   ===================================================================== */
.section { padding: 110px 0; position: relative; }
.section-alt { background: var(--bg-secondary); }

.eyebrow {
    display: inline-flex; align-items: center; gap: 8px;
    font-size: .82rem; font-weight: 600; letter-spacing: 2px; text-transform: uppercase;
    color: var(--sim); margin-bottom: 16px;
}
.eyebrow::before, .eyebrow::after { content: ""; width: 22px; height: 2px; background: var(--sim); border-radius: 2px; }

.section-header { max-width: 780px; margin: 0 auto 60px; text-align: center; }
.section-header.left { margin-left: 0; text-align: left; }
.section-title { font-size: clamp(1.8rem, 3.4vw, 2.6rem); font-weight: 800; line-height: 1.25; letter-spacing: -.5px; }
.section-subtitle { margin-top: 16px; font-size: 1.05rem; color: var(--text-secondary); }

/* =====================================================================
   卡片
   ===================================================================== */
.card {
    background: var(--card-bg); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 30px;
    transition: transform .35s ease, border-color .35s ease, background .35s ease, box-shadow .35s ease;
    position: relative; overflow: hidden;
}
.card:hover {
    transform: translateY(-6px); background: var(--card-bg-hover);
    border-color: var(--border-strong); box-shadow: var(--shadow-soft);
}
.card-icon {
    width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center;
    font-size: 1.6rem; margin-bottom: 20px;
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    border: 1px solid var(--border);
}
.card h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 10px; }
.card p { color: var(--text-secondary); font-size: .96rem; }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* 渐变描边卡（强调用）—— 改为单色 */
.card-glow::before {
    content: ""; position: absolute; inset: 0; border-radius: var(--radius); padding: 1px;
    background: var(--sim); opacity: 0; transition: opacity .3s;
    -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
    -webkit-mask-composite: xor; mask-composite: exclude; pointer-events: none;
}
.card-glow:hover::before { opacity: .5; }

/* =====================================================================
   Logo展示区
   ===================================================================== */
.logo-showcase {
    display: flex; align-items: center; justify-content: center;
    padding: 40px;
    position: relative;
}
.logo-showcase .logo-main {
    max-height: 180px; width: auto;
    filter: none;
    transition: transform .5s ease;
}
.logo-showcase:hover .logo-main {
    transform: scale(1.05);
    filter: none;
}
.logo-showcase .logo-glow {
    position: absolute; inset: 0;
    background: radial-gradient(ellipse 60% 50% at 50% 50%, color-mix(in srgb, var(--x) 8%, transparent), transparent 70%);
    pointer-events: none;
}
.logo-showcase.compact .logo-main { max-height: 100px; }
.logo-showcase.compact { padding: 24px; }

/* =====================================================================
   页脚
   ===================================================================== */
.footer { background: var(--bg-secondary); border-top: 1px solid var(--border); padding: 70px 0 28px; }
.footer-top { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 50px; }
.footer-brand .logo { margin-bottom: 16px; }
.footer-brand p { color: var(--text-secondary); font-size: .92rem; max-width: 320px; }
.footer-col h4 { font-size: .95rem; font-weight: 700; margin-bottom: 18px; color: var(--text-primary); }
.footer-col a { display: block; color: var(--text-secondary); font-size: .9rem; margin-bottom: 12px; transition: color .2s; }
.footer-col a:hover { color: var(--sim); }
.footer-bottom {
    border-top: 1px solid var(--border); padding-top: 24px;
    text-align: center; color: var(--text-muted); font-size: .82rem; line-height: 1.9;
}
.footer-bottom a { color: var(--text-muted); }
.footer-bottom img { height: 13px; display: inline; margin: 0 2px; vertical-align: -2px; }

/* =====================================================================
   滚动入场动画
   ===================================================================== */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .08s; }
.reveal.d2 { transition-delay: .16s; }
.reveal.d3 { transition-delay: .24s; }
.reveal.d4 { transition-delay: .32s; }

/* 背景光斑 —— 减弱 */
.glow-orb { position: absolute; border-radius: 50%; filter: blur(100px); opacity: .25; pointer-events: none; z-index: 0; }

/* =====================================================================
   响应式
   ===================================================================== */
@media (max-width: 992px) {
    .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 768px) {
    .section { padding: 72px 0; }
    .nav-menu {
        position: fixed; top: var(--nav-h); left: 0; right: 0;
        flex-direction: column; gap: 0; align-items: stretch;
        background: var(--bg-secondary); border-bottom: 1px solid var(--border);
        padding: 10px 0; transform: translateY(-130%); transition: transform .35s ease;
        max-height: calc(100vh - var(--nav-h)); overflow-y: auto;
    }
    .nav-menu.open { transform: translateY(0); }
    .nav-menu li { padding: 0 24px; }
    .nav-link { display: block; padding: 14px 0; border-bottom: 1px solid var(--border); }
    .nav-link::after { display: none; }
    .menu-toggle { display: flex; }
    .cta-button.nav-cta-text { display: none; }
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .footer-top { grid-template-columns: 1fr 2fr; }
    .logo-showcase .logo-main { max-height: 120px; }
}
@media (max-width: 480px) {
    .footer-top { grid-template-columns: 1fr; }
    .logo .logo-sub { display: none; }
    .logo-showcase .logo-main { max-height: 100px; }
}

/* ===== 图标系统 ===== */
.ic { display:inline-flex; align-items:center; justify-content:center; width:1.3em; height:1.3em; flex-shrink:0; }
.ic svg { width:100%; height:100%; }
.ic-stroke { stroke:currentColor; fill:none; stroke-width:1.5; stroke-linecap:round; stroke-linejoin:round; }

/* ===== 引擎卡片水印logo ===== */
.engine-logo { position: absolute; top: 28px; right: 28px; width: 48px; height: 48px; opacity: .1; pointer-events: none; }
.engine-logo img { width: 100%; height: 100%; object-fit: contain; }

/* ===== 页脚品牌矩阵 ===== */
.footer-brand .brand-matrix { margin-top: 16px; display: flex; align-items: center; gap: 12px; opacity: .6; }
.footer-brand .brand-matrix img { height: 28px; width: auto; }
.footer-brand .brand-matrix span { font-size: .75rem; color: var(--text-muted); letter-spacing: 1px; }

/* ===== 解决方案页面图标容器 ===== */
.sol-head .ic { width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center; background: color-mix(in srgb, var(--accent) 12%, transparent); border: 1px solid var(--border); color: var(--sim); }
.sol-head .ic.x { color: var(--x); background: color-mix(in srgb, var(--x) 12%, transparent); }

/* ===== 对比卡片 ===== */
.why-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.why { padding: 30px; border-radius: var(--radius); border: 1px solid var(--border); }
.why.no { background: color-mix(in srgb, #ef4444 5%, transparent); }
.why.yes { background: color-mix(in srgb, var(--x) 6%, transparent); }
.why h4 { font-size: 1.05rem; margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }
.why h4 .mark { width: 20px; height: 20px; border-radius: 50%; display: grid; place-items: center; font-size: .7rem; font-weight: 800; flex-shrink: 0; }
.why.no h4 .mark { background: color-mix(in srgb, #ef4444 18%, transparent); color: #f87171; }
.why.yes h4 .mark { background: color-mix(in srgb, #34d399 18%, transparent); color: #34d399; }

/* ===== 联系信息行 ===== */
.contact-row { display: flex; align-items: center; justify-content: center; gap: 24px; flex-wrap: wrap; color: var(--text-secondary); font-size: .95rem; }
.contact-row .ci { width: 18px; height: 18px; color: var(--text-muted); }

@media(max-width:768px){ .why-grid{grid-template-columns:1fr;} .contact-row{gap:12px;} }
.subhero {
    position: relative; padding: calc(var(--nav-h) + 90px) 0 70px; overflow: hidden;
}
.subhero::before {
    content: ""; position: absolute; inset: 0; z-index: 0; opacity: .35;
    background:
        radial-gradient(50% 60% at 15% 0%, color-mix(in srgb, var(--sim) 12%, transparent), transparent 70%),
        radial-gradient(50% 60% at 90% 20%, color-mix(in srgb, var(--x) 10%, transparent), transparent 70%);
}
.subhero .container { position: relative; z-index: 1; }
.subhero .crumb { font-size: .85rem; color: var(--text-muted); margin-bottom: 18px; }
.subhero .crumb a:hover { color: var(--sim); }
.subhero h1 { font-size: clamp(2rem, 4.6vw, 3.2rem); font-weight: 900; line-height: 1.2; letter-spacing: -1px; max-width: 900px; }
.subhero .lead { margin-top: 20px; font-size: 1.1rem; color: var(--text-secondary); max-width: 760px; }
.subhero .hero-buttons { margin-top: 32px; display: flex; gap: 14px; flex-wrap: wrap; }

.prose h3 { font-size: 1.3rem; font-weight: 700; margin: 0 0 12px; }
.prose p { color: var(--text-secondary); margin-bottom: 14px; }

/* 详情块（产品/方案）*/
.detail {
    display: grid; grid-template-columns: 200px 1fr; gap: 36px; padding: 40px 0; border-top: 1px solid var(--border);
    scroll-margin-top: 90px;
}
.detail:first-of-type { border-top: none; }
.detail .d-side .d-ic { font-size: 2.4rem; margin-bottom: 14px; }
.detail .d-side .d-tag { font-size: .78rem; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: var(--text-muted); }
.detail .d-side h3 { font-size: 1.5rem; font-weight: 800; margin: 6px 0; }
.detail .d-side .d-sub { color: var(--text-secondary); font-size: .92rem; }
.detail .d-body { color: var(--text-secondary); }
.detail .d-body > p { margin-bottom: 18px; }
.feat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.feat-grid h4 { font-size: .95rem; font-weight: 700; color: var(--text-primary); margin-bottom: 10px; }
.feat-list li { display: flex; gap: 9px; align-items: flex-start; margin-bottom: 9px; font-size: .92rem; }
.feat-list li::before { content: "▹"; color: var(--sim); margin-top: 1px; }
.feat-list.x li::before { color: var(--x); }

.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip { padding: 9px 16px; border-radius: 999px; border: 1px solid var(--border); background: var(--card-bg); font-size: .9rem; color: var(--text-secondary); transition: all .25s; }
.chip:hover { border-color: var(--sim); color: var(--text-primary); }

.cta-band { text-align: center; }
.cta-band h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 800; margin-bottom: 14px; }
.cta-band p { color: var(--text-secondary); max-width: 620px; margin: 0 auto 28px; }
.cta-band .hero-buttons { display: inline-flex; gap: 14px; flex-wrap: wrap; justify-content: center; }

@media (max-width: 768px) {
    .detail { grid-template-columns: 1fr; gap: 18px; padding: 30px 0; }
    .feat-grid { grid-template-columns: 1fr; }
}