/* ============================================================
   福鹊消防维保 SaaS 平台 · 官网样式
   设计约束：科技风 / 无圆角 / 无渐变 / 深色主题 / 直角元素
   ============================================================ */

:root {
    --bg: #0a1428;
    --bg-2: #0d1a33;
    --bg-3: #101f3d;
    --line: #1d2e52;
    --line-2: #29406e;
    --cyan: #00d9ff;
    --blue: #2f6bff;
    --text: #e8f1ff;
    --muted: #8fa6c9;
    --danger: #ff4d4f;
    --ok: #2ee6a8;
    --mono: 'Courier New', 'Consolas', monospace;
}

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

html { scroll-behavior: smooth; }

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    font-size: 15px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

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

/* ---------- 按钮（直角、无渐变） ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 42px;
    padding: 0 22px;
    border: 1px solid var(--line-2);
    border-radius: 0;
    background: transparent;
    color: var(--text);
    font-size: 14px;
    letter-spacing: 1px;
    cursor: pointer;
    transition: background .2s, border-color .2s, color .2s;
}
.btn-lg { height: 50px; padding: 0 30px; font-size: 15px; }
.btn-primary {
    background: var(--cyan);
    border-color: var(--cyan);
    color: #06213a;
    font-weight: 700;
}
.btn-primary:hover { background: #66eaff; border-color: #66eaff; }
.btn-ghost:hover { background: rgba(0, 217, 255, .08); border-color: var(--cyan); color: var(--cyan); }

/* ---------- 顶部导航 ---------- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(10, 20, 40, .92);
    border-bottom: 1px solid var(--line);
    transition: border-color .2s;
}
.site-header.scrolled { border-bottom-color: var(--line-2); }
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; }
.brand-mark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--cyan);
    background: var(--bg-3);
    color: var(--cyan);
    font-family: var(--mono);
    font-weight: 700;
    font-size: 13px;
}
.brand-text {
    font-size: 17px;
    font-weight: 700;
    letter-spacing: 1px;
}
.brand-sub {
    display: block;
    font-family: var(--mono);
    font-size: 9px;
    letter-spacing: 2px;
    color: var(--muted);
    font-weight: 400;
}
.main-nav { display: flex; gap: 34px; }
.main-nav a {
    font-size: 14px;
    color: var(--muted);
    transition: color .2s;
    position: relative;
}
.main-nav a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 0;
    height: 2px;
    background: var(--cyan);
    transition: width .2s;
}
.main-nav a:hover { color: var(--text); }
.main-nav a:hover::after { width: 100%; }
.header-actions { display: flex; gap: 10px; }
.nav-toggle {
    display: none;
    background: none;
    border: 1px solid var(--line-2);
    color: var(--cyan);
    width: 42px;
    height: 42px;
    font-size: 20px;
    cursor: pointer;
}

/* ---------- Hero ---------- */
.hero {
    position: relative;
    padding: 180px 0 100px;
    background: var(--bg);
    overflow: hidden;
    border-bottom: 1px solid var(--line);
}
.hero-grid {
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='48'%3E%3Cpath d='M48 0H0V48' fill='none' stroke='%231d2e52' stroke-width='1'/%3E%3C/svg%3E");
    background-size: 48px 48px;
    opacity: .5;
    pointer-events: none;
}
.hero-scan {
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    height: 2px;
    background: var(--cyan);
    opacity: .6;
    animation: scan 6s linear infinite;
    pointer-events: none;
}
@keyframes scan {
    0% { transform: translateY(0); }
    50% { transform: translateY(560px); }
    100% { transform: translateY(0); }
}
.hero-inner {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: 60px;
    align-items: center;
}
.hero-tag {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 3px;
    color: var(--cyan);
    margin-bottom: 22px;
}
.tag-block {
    width: 14px;
    height: 14px;
    background: var(--cyan);
    display: inline-block;
}
.hero-title {
    font-size: 52px;
    line-height: 1.18;
    font-weight: 800;
    letter-spacing: 2px;
}
.hero-desc {
    margin: 24px 0 34px;
    max-width: 520px;
    color: var(--muted);
    font-size: 16px;
}
.hero-btns { display: flex; gap: 14px; }
.hero-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 40px;
    font-family: var(--mono);
    font-size: 12px;
    color: var(--muted);
}
.hero-meta i {
    width: 4px;
    height: 4px;
    background: var(--cyan);
    display: inline-block;
}
.hero-visual { position: relative; }
.hero-frame {
    position: relative;
    border: 1px solid var(--line-2);
    background: var(--bg-3);
    padding: 10px;
}
.hero-frame img { width: 100%; }
.frame-corner {
    position: absolute;
    width: 18px;
    height: 18px;
    border: 2px solid var(--cyan);
    pointer-events: none;
}
.frame-corner.tl { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.frame-corner.tr { top: -1px; right: -1px; border-left: 0; border-bottom: 0; }
.frame-corner.bl { bottom: -1px; left: -1px; border-right: 0; border-top: 0; }
.frame-corner.br { bottom: -1px; right: -1px; border-left: 0; border-top: 0; }
.hero-chip {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    border: 1px solid var(--cyan);
    background: var(--bg-3);
    box-shadow: 0 0 0 4px rgba(10, 20, 40, .9);
}
.hero-chip b { font-family: var(--mono); font-size: 26px; color: var(--cyan); }
.hero-chip span { font-size: 12px; color: var(--muted); }
.chip-a { top: -22px; right: 16px; }
.chip-b { bottom: -22px; left: 16px; }

/* ---------- 数据条 ---------- */
.stats { border-bottom: 1px solid var(--line); }
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
}
.stat-cell {
    padding: 34px 24px;
    border-left: 1px solid var(--line);
    text-align: center;
}
.stat-cell:first-child { border-left: 0; }
.stat-cell b {
    display: block;
    font-family: var(--mono);
    font-size: 40px;
    color: var(--cyan);
    font-weight: 700;
}
.stat-cell span { color: var(--muted); font-size: 13px; letter-spacing: 1px; }

/* ---------- 通用区块 ---------- */
.section { padding: 96px 0; border-bottom: 1px solid var(--line); }
.section-alt { background: var(--bg-2); }
.sec-head { text-align: center; margin-bottom: 60px; }
.sec-kicker {
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 4px;
    color: var(--cyan);
    margin-bottom: 10px;
}
.sec-title {
    font-size: 36px;
    font-weight: 800;
    letter-spacing: 2px;
}
.sec-desc { color: var(--muted); margin-top: 14px; }

/* ---------- 核心能力 ---------- */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.feat-card {
    position: relative;
    border: 1px solid var(--line);
    background: var(--bg-3);
    padding: 30px 26px 26px;
    transition: border-color .2s, transform .2s;
}
.feat-card::before {
    content: '';
    position: absolute;
    top: -1px;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--cyan);
    transition: width .25s;
}
.feat-card:hover { border-color: var(--line-2); transform: translateY(-4px); }
.feat-card:hover::before { width: 100%; }
.feat-icon {
    width: 44px;
    height: 44px;
    margin-bottom: 18px;
    border: 1px solid var(--cyan);
    background: rgba(0, 217, 255, .06);
    position: relative;
}
/* 纯 CSS 直角图标 */
.ic-report::before {
    content: '';
    position: absolute;
    inset: 8px 9px;
    border: 1px solid var(--cyan);
    border-top: 6px solid var(--cyan);
}
.ic-report::after {
    content: '';
    position: absolute;
    left: 9px;
    right: 9px;
    top: 22px;
    height: 1px;
    background: var(--cyan);
    box-shadow: 0 4px 0 var(--cyan), 0 8px 0 var(--cyan), 0 12px 0 var(--cyan);
}
.ic-check::before {
    content: '';
    position: absolute;
    inset: 8px;
    border: 1px solid var(--cyan);
}
.ic-check::after {
    content: '';
    position: absolute;
    left: 12px;
    top: 21px;
    width: 10px;
    height: 5px;
    border-left: 2px solid var(--cyan);
    border-bottom: 2px solid var(--cyan);
    transform: rotate(-45deg);
}
.ic-sign::before {
    content: '';
    position: absolute;
    inset: 10px 12px;
    border: 1px solid var(--cyan);
    border-radius: 50%;
}
.ic-sign::after {
    content: '';
    position: absolute;
    left: 8px;
    right: 8px;
    top: 27px;
    height: 2px;
    background: var(--cyan);
}
.ic-audit::before {
    content: '';
    position: absolute;
    inset: 9px;
    border: 1px solid var(--cyan);
}
.ic-audit::after {
    content: '';
    position: absolute;
    inset: 15px 15px 6px;
    border: 1px solid var(--cyan);
    background: rgba(0, 217, 255, .1);
}
.ic-repair::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 10px;
    width: 6px;
    height: 22px;
    background: var(--cyan);
}
.ic-repair::after {
    content: '';
    position: absolute;
    left: 10px;
    top: 30px;
    width: 22px;
    height: 6px;
    background: var(--cyan);
    box-shadow: 14px -14px 0 var(--cyan);
}
.ic-location::before {
    content: '';
    position: absolute;
    inset: 9px;
    border: 1px solid var(--cyan);
}
.ic-location::after {
    content: '';
    position: absolute;
    inset: 16px;
    background: var(--cyan);
}
.feat-card h3 { font-size: 18px; margin-bottom: 10px; letter-spacing: 1px; }
.feat-card p { color: var(--muted); font-size: 14px; }

/* ---------- 平台展示 ---------- */
.show-row {
    display: grid;
    grid-template-columns: 1.15fr 1fr;
    gap: 56px;
    align-items: center;
    margin-bottom: 72px;
}
.show-row:last-child { margin-bottom: 0; }
.show-row-reverse .show-visual { order: 2; }
.show-row-reverse .show-copy { order: 1; }
.show-visual {
    border: 1px solid var(--line-2);
    background: var(--bg-3);
    padding: 10px;
}
.show-visual img { width: 100%; }
.show-no {
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 3px;
    color: var(--cyan);
    margin-bottom: 12px;
}
.show-copy h3 { font-size: 26px; margin-bottom: 14px; letter-spacing: 1px; }
.show-copy > p { color: var(--muted); margin-bottom: 18px; }
.show-list li {
    position: relative;
    padding: 8px 0 8px 26px;
    color: var(--text);
    font-size: 14px;
    border-bottom: 1px dashed var(--line);
}
.show-list li::before {
    content: '▣';
    position: absolute;
    left: 0;
    top: 8px;
    color: var(--cyan);
    font-size: 12px;
}

/* ---------- 架构安全 ---------- */
.sec-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.sec-cell {
    border: 1px solid var(--line);
    padding: 26px 22px;
    background: var(--bg-3);
    transition: border-color .2s;
}
.sec-cell:hover { border-color: var(--cyan); }
.sec-cell-no {
    font-family: var(--mono);
    font-size: 13px;
    color: var(--cyan);
    margin-bottom: 14px;
}
.sec-cell h3 { font-size: 17px; margin-bottom: 10px; }
.sec-cell p { color: var(--muted); font-size: 13px; }

/* ---------- 实施流程 ---------- */
.flow {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
}
.flow-step {
    position: relative;
    border: 1px solid var(--line);
    background: var(--bg-3);
    padding: 26px 20px;
}
.flow-step::after {
    content: '→';
    position: absolute;
    right: -15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--cyan);
    font-family: var(--mono);
    z-index: 2;
}
.flow-step:last-child::after { display: none; }
.flow-no {
    font-family: var(--mono);
    font-size: 14px;
    color: var(--cyan);
    display: block;
    margin-bottom: 14px;
}
.flow-step h4 { font-size: 16px; margin-bottom: 8px; }
.flow-step p { color: var(--muted); font-size: 13px; }

/* ---------- CTA ---------- */
.cta {
    padding: 110px 0;
    border-bottom: 1px solid var(--line);
    position: relative;
    overflow: hidden;
}
.cta::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='48'%3E%3Cpath d='M48 0H0V48' fill='none' stroke='%231d2e52' stroke-width='1'/%3E%3C/svg%3E");
    background-size: 48px 48px;
    opacity: .4;
}
.cta-inner { position: relative; text-align: center; }
.cta-title { font-size: 34px; font-weight: 800; letter-spacing: 2px; }
.cta-desc { color: var(--muted); margin: 18px 0 34px; }
.cta-btns { display: flex; justify-content: center; gap: 14px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg-2); }
.footer-inner {
    display: flex;
    justify-content: space-between;
    gap: 40px;
    padding-top: 56px;
    padding-bottom: 40px;
}
.footer-brand p { color: var(--muted); font-size: 13px; margin-top: 12px; }
.footer-links { display: flex; gap: 70px; }
.footer-col h4 {
    font-size: 14px;
    color: var(--text);
    margin-bottom: 14px;
    letter-spacing: 2px;
}
.footer-col a {
    display: block;
    color: var(--muted);
    font-size: 13px;
    padding: 4px 0;
    transition: color .2s;
}
.footer-col a:hover { color: var(--cyan); }
.footer-bottom {
    border-top: 1px solid var(--line);
    padding: 18px 0;
    color: var(--muted);
    font-size: 12px;
    font-family: var(--mono);
}

/* ---------- 滚动渐显（仅 JS 可用时启用；opacity/位移过渡，非渐变） ---------- */
.js-ready .feat-card,
.js-ready .sec-cell,
.js-ready .flow-step,
.js-ready .show-row {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .6s ease, transform .6s ease;
}
.js-ready .in-view {
    opacity: 1;
    transform: translateY(0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
    .hero { padding: 150px 0 80px; }
    .hero-inner { grid-template-columns: 1fr; gap: 60px; }
    .hero-visual { order: -1; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .sec-grid { grid-template-columns: repeat(2, 1fr); }
    .flow { grid-template-columns: repeat(2, 1fr); }
    .flow-step::after { display: none; }
    .show-row { grid-template-columns: 1fr; gap: 32px; }
    .show-row-reverse .show-visual { order: 0; }
    .show-row-reverse .show-copy { order: 0; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .stat-cell:nth-child(3) { border-left: 0; }
}
@media (max-width: 720px) {
    .hero-title { font-size: 36px; }
    .sec-title { font-size: 28px; }
    .feature-grid { grid-template-columns: 1fr; }
    .sec-grid { grid-template-columns: 1fr; }
    .flow { grid-template-columns: 1fr; }
    .main-nav {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-2);
        border-bottom: 1px solid var(--line-2);
        padding: 12px 24px 20px;
        gap: 14px;
    }
    .main-nav.open { display: flex; }
    .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
    .header-actions .btn { display: none; }
    .footer-inner { flex-direction: column; }
    .footer-links { gap: 40px; }
}