:root {
    --ink: #172026;
    --muted: #5c6870;
    --line: #d8e1e6;
    --paper: #ffffff;
    --soft: #f0f5f4;
    --deep: #0d1c24;
    --brand: #0e766e;
    --accent: #a83c32;
    --gold: #c7983b;
    --steel: #2d5668;
}

* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: "Microsoft YaHei", Arial, sans-serif;
    color: var(--ink);
    background:
        linear-gradient(180deg, rgba(240,245,244,.8), rgba(255,255,255,0) 260px),
        var(--paper);
    line-height: 1.7;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 12px 5vw 12px 18px;
    background: rgba(255,255,255,.92);
    border-bottom: 1px solid var(--line);
    backdrop-filter: blur(12px);
}
.brand {
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
}
.brand img {
    width: 108px;
    height: 42px;
    object-fit: contain;
    object-position:left;
}
.brand span {
    max-width: 260px;
    line-height: 1.25;
}
.nav { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
.nav a { padding: 8px 12px; border-radius: 6px; color: #34424a; }
.nav a:hover { background: var(--soft); color: var(--brand); }
.menu-toggle { display: none; border: 1px solid var(--line); background: #fff; border-radius: 6px; padding: 8px 10px; }
.phone-link {
    min-height: 38px;
    display: inline-flex;
    align-items: center;
    padding: 0 12px;
    border: 1px solid rgba(14,118,110,.24);
    border-radius: 6px;
    color: var(--brand);
    font-weight: 700;
    background: rgba(14,118,110,.08);
}

.hero {
    min-height: 680px;
    display: grid;
    align-items: center;
    padding: 8vw 5vw;
    color: #fff;
    background:
        radial-gradient(circle at 74% 34%, rgba(199,152,59,.24), transparent 28%),
        linear-gradient(90deg, rgba(8,18,24,.92), rgba(8,18,24,.64), rgba(8,18,24,.12)),
        url("../media/hero-engineering.jpg") center/cover;
}
.hero-copy { max-width: 720px; }
.hero h1, .page-hero h1 { margin: 0 0 16px; font-size: clamp(42px, 7vw, 84px); line-height: 1.05; letter-spacing: 0; }
.hero p { max-width: 660px; font-size: 18px; }
.eyebrow { margin: 0 0 10px; color: var(--gold); font-weight: 700; letter-spacing: 0; }
.hero-actions { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.hero-metrics {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 26px;
}
.hero-metrics span {
    min-width: 132px;
    padding: 12px 14px;
    border: 1px solid rgba(255,255,255,.22);
    border-radius: 8px;
    background: rgba(255,255,255,.1);
}
.hero-metrics strong { display: block; font-size: 26px; line-height: 1.1; color: #fff; }
.button, .search-box button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 18px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fff;
    color: var(--ink);
    cursor: pointer;
    font-weight: 700;
    transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}
.button.primary, .search-box button, .contact-form button { background: var(--brand); color: #fff; border-color: var(--brand); }
.button:hover, .search-box button:hover { transform: translateY(-1px); box-shadow: 0 12px 26px rgba(23,32,38,.16); }

.band { padding: 78px 5vw; }
.band.muted { background: var(--soft); }
.section-head { max-width: 760px; margin-bottom: 28px; }
.section-head p:not(.eyebrow) { color: var(--muted); margin: 12px 0 0; }
.section-head h1, .section-head h2, .split h2, .contact h1 { margin: 0; font-size: clamp(30px, 4vw, 48px); line-height: 1.15; letter-spacing: 0; }
.feature-grid, .card-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.feature {
    min-height: 162px;
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background:
        linear-gradient(135deg, rgba(14,118,110,.08), rgba(255,255,255,0) 42%),
        #fff;
}
.feature span, .card span { display: block; font-size: 20px; font-weight: 700; margin: 12px 0 6px; }
.feature p, .card p, .split p, .footer p { margin: 0; color: var(--muted); }
.card {
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    transition: transform .2s ease, box-shadow .2s ease;
    position: relative;
}
.card:hover { transform: translateY(-3px); box-shadow: 0 16px 40px rgba(23,32,38,.12); }
.card img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.card small {
    display: inline-flex;
    margin: 16px 18px 0;
    color: var(--brand);
    font-weight: 700;
}
.card span, .card p { padding-left: 18px; padding-right: 18px; }
.card p { padding-bottom: 20px; }
.split, .contact {
    display: grid;
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
    gap: 42px;
    align-items: start;
    padding: 78px 5vw;
}
.mini-list { display: grid; gap: 12px; }
.mini-list a { padding: 18px; border-left: 4px solid var(--brand); background: var(--soft); border-radius: 6px; font-weight: 700; }
.mini-list span { display: block; color: var(--muted); font-weight: 400; }

.page-hero {
    min-height: 390px;
    display: grid;
    align-content: end;
    padding: 8vw 5vw 58px;
    color: #fff;
    background:
        linear-gradient(0deg, rgba(8,18,24,.82), rgba(8,18,24,.34)),
        var(--hero-image) center/cover;
}
.article { max-width: 1060px; margin: 0 auto; padding: 56px 5vw 80px; }
.article-cover { width: 100%; max-height: 520px; object-fit: cover; border-radius: 8px; }
.article-body { max-width: 820px; margin: 34px auto 0; }
.article h1 { font-size: clamp(34px, 5vw, 58px); line-height: 1.12; margin: 0 0 12px; letter-spacing: 0; }
.lead { color: var(--muted); font-size: 18px; }
.content { margin-top: 28px; font-size: 17px; }
.related-list {
    display: grid;
    gap: 10px;
    margin-top: 34px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
}
.related-list h2 {
    margin: 0 0 4px;
    font-size: 24px;
}
.related-list a {
    display: grid;
    gap: 4px;
    padding: 14px 16px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
}
.related-list a:hover {
    border-color: rgba(14,118,110,.32);
    box-shadow: 0 12px 28px rgba(23,32,38,.08);
}
.related-list span {
    color: var(--muted);
}

.search-box, .contact-form { display: grid; gap: 14px; }
.search-box { grid-template-columns: minmax(0, 1fr) auto; max-width: 760px; margin-bottom: 28px; }
input, textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 12px 14px;
    font: inherit;
}
select {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 12px 14px;
    font: inherit;
    background: #fff;
}
.contact-form {
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 18px 50px rgba(23,32,38,.08);
}
.contact-form label { display: grid; gap: 6px; color: var(--muted); }
.notice { margin: 0; padding: 10px 12px; background: var(--soft); border-radius: 6px; color: var(--brand); }
.qr { width: 140px; margin-top: 18px; border: 1px solid var(--line); border-radius: 8px; }

.footer {
    display: grid;
    grid-template-columns: .8fr 1.2fr;
    gap: 24px;
    padding: 38px 5vw;
    background: var(--deep);
    color: #fff;
}
.footer-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px 18px; color: #cdd8dd; }

.admin-shell {
    min-height: 100vh;
    padding: 34px 5vw 70px;
    background: #f4f7f7;
}
.admin-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 22px;
}
.admin-head h1 {
    margin: 0;
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.15;
}
.admin-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 18px;
}
.admin-tabs a {
    min-height: 40px;
    display: inline-flex;
    align-items: center;
    padding: 0 14px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fff;
    color: var(--muted);
    font-weight: 700;
}
.admin-tabs a.active {
    background: var(--brand);
    border-color: var(--brand);
    color: #fff;
}
.admin-grid {
    display: grid;
    grid-template-columns: minmax(320px, .85fr) minmax(0, 1.35fr);
    gap: 18px;
    align-items: start;
}
.admin-panel {
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 14px 36px rgba(23,32,38,.08);
}
.admin-panel h2 {
    margin: 0 0 16px;
    font-size: 22px;
}
.admin-panel-title {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}
.admin-panel-title h2 {
    margin: 0;
}
.admin-panel-title span {
    color: var(--muted);
    font-size: 13px;
}
.admin-panel label {
    display: grid;
    gap: 6px;
    margin-bottom: 12px;
    color: var(--muted);
}
.admin-filters {
    display: grid;
    grid-template-columns: minmax(140px, .7fr) minmax(130px, .55fr) minmax(220px, 1fr) auto;
    gap: 10px;
    align-items: end;
    margin-bottom: 16px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--soft);
}
.admin-filters label {
    margin: 0;
}
.admin-filter-actions {
    display: flex;
    gap: 8px;
    align-items: center;
    padding-bottom: 0;
}
.admin-form-section {
    margin-bottom: 18px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--line);
}
.admin-form-section h3 {
    margin: 0 0 12px;
    font-size: 18px;
}
.admin-mini-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 12px;
}
.admin-help {
    margin-top: 0;
    color: var(--muted);
}
.admin-upload-form {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}
.admin-panel .checkline {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--ink);
}
.admin-panel .checkline input {
    width: 18px;
    height: 18px;
}
.html-editor {
    margin: -4px 0 14px;
    border: 1px solid var(--line);
    border-radius: 8px;
    overflow: hidden;
    background: #fff;
}
.html-editor-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 8px;
    border-bottom: 1px solid var(--line);
    background: var(--soft);
}
.html-editor-toolbar button {
    min-width: 34px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fff;
    color: var(--ink);
    padding: 6px 9px;
    font: inherit;
    cursor: pointer;
}
.html-editor-surface {
    min-height: 220px;
    padding: 14px;
    outline: none;
    line-height: 1.8;
}
.html-editor-surface:focus {
    box-shadow: inset 0 0 0 2px rgba(14,118,110,.18);
}
.admin-login,
.admin-narrow {
    max-width: 560px;
}
.admin-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}
.admin-table th,
.admin-table td {
    padding: 10px;
    border-bottom: 1px solid var(--line);
    text-align: left;
    vertical-align: top;
}
.admin-table th {
    color: var(--muted);
    background: var(--soft);
}
.admin-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}
.admin-actions a,
.admin-actions button {
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fff;
    color: var(--brand);
    padding: 6px 9px;
    font: inherit;
    cursor: pointer;
}
.admin-actions form {
    margin: 0;
}
.status-pill {
    display: inline-flex;
    align-items: center;
    min-height: 28px;
    padding: 0 10px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 700;
    background: rgba(14,118,110,.1);
    color: var(--brand);
}
.status-pill.off {
    background: #eef1f2;
    color: var(--muted);
}

@media (max-width: 860px) {
    .menu-toggle { display: inline-flex; }
    .nav { display: none; width: 100%; }
    .nav.open { display: grid; }
    .topbar { flex-wrap: wrap; padding-left: 12px; }
    .brand img { width: 55px; height: 38px; }
    .brand span { max-width: calc(100vw - 133px); font-size: 14px; }
    .phone-link { order: 4; }
    .feature-grid, .card-grid, .split, .contact, .footer { grid-template-columns: 1fr; }
    .admin-grid { grid-template-columns: 1fr; }
    .admin-head { align-items: flex-start; flex-direction: column; }
    .admin-table { display: block; overflow-x: auto; }
    .admin-filters { grid-template-columns: 1fr; }
    .admin-mini-grid { grid-template-columns: 1fr; }
    .admin-panel-title { align-items: flex-start; flex-direction: column; }
    .hero { min-height: 560px; }
    .search-box { grid-template-columns: 1fr; }
}