/* ========================================
   残鑫软件工作室 - 手机优先扁平化设计
   ======================================== */

/* --- Variables --- */
:root {
    --c-primary: #2563eb;
    --c-primary-dark: #1d4ed8;
    --c-primary-light: #eff6ff;
    --c-bg: #fff;
    --c-bg-alt: #f8fafc;
    --c-text: #0f172a;
    --c-text-light: #475569;
    --c-text-lighter: #94a3b8;
    --c-border: #e2e8f0;
    --c-green: #10b981;
    --c-green-light: #ecfdf5;
    --c-orange: #f59e0b;
    --c-red: #ef4444;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    --font-mono: "SF Mono", "Fira Code", Menlo, Courier, monospace;
    --radius: 8px;
    --radius-lg: 12px;
    --max-w: 960px;
    --header-h: 56px;
}

/* --- Reset --- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px;-webkit-text-size-adjust:100%}
body{font-family:var(--font);color:var(--c-text);background:var(--c-bg);line-height:1.6;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}
button,input{font:inherit;border:none;outline:none;background:none}
code{font-family:var(--font-mono);font-size:0.875em}

/* --- Header --- */
.header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.95);border-bottom:1px solid var(--c-border);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}
.header-inner{max-width:var(--max-w);margin:0 auto;padding:0 16px;height:var(--header-h);display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:6px;font-weight:700;font-size:1rem;color:var(--c-text)}
.logo-icon{font-size:1.2rem;color:var(--c-primary)}
.nav{display:flex;gap:4px}
.nav-link{font-size:.875rem;font-weight:500;color:var(--c-text-light);padding:6px 12px;border-radius:6px;transition:color .15s,background .15s}
.nav-link:hover,.nav-link.active{color:var(--c-primary);background:var(--c-primary-light)}
.menu-btn{display:none;flex-direction:column;gap:4px;padding:8px;border-radius:6px}
.menu-btn span{display:block;width:20px;height:2px;background:var(--c-text);border-radius:2px;transition:.25s}
.menu-btn.active span:nth-child(1){transform:rotate(45deg) translate(4px,4px)}
.menu-btn.active span:nth-child(2){opacity:0}
.menu-btn.active span:nth-child(3){transform:rotate(-45deg) translate(4px,-4px)}

/* --- Section Common --- */
section{padding:48px 0}
section .section-head,.hero,.product-list,.cooperation,.doc-tabs,.docs-contact,.search-box,.faq-list,.api-section,.changelog-list{max-width:var(--max-w);margin-left:auto;margin-right:auto;padding-left:16px;padding-right:16px}
.section-head{margin-bottom:32px}
.section-head h2{font-size:1.5rem;font-weight:800;margin-bottom:6px}
.section-head p{font-size:.9rem;color:var(--c-text-light)}

/* --- Buttons --- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:12px 24px;font-size:.9rem;font-weight:600;border-radius:var(--radius);border:2px solid transparent;cursor:pointer;transition:all .15s;white-space:nowrap}
.btn-primary{background:var(--c-primary);color:#fff;border-color:var(--c-primary)}
.btn-primary:hover{background:var(--c-primary-dark);border-color:var(--c-primary-dark)}
.btn-outline{background:transparent;color:var(--c-primary);border-color:var(--c-primary)}
.btn-outline:hover{background:var(--c-primary);color:#fff}
.btn-sm{padding:8px 16px;font-size:.813rem;border-radius:6px}

/* ==================== Hero ==================== */
.hero{padding:40px 0 48px;text-align:center}
.hero-badge{display:inline-block;font-size:.75rem;font-weight:600;color:var(--c-primary);background:var(--c-primary-light);padding:4px 12px;border-radius:20px;margin-bottom:16px}
.hero-title{font-size:1.65rem;font-weight:900;line-height:1.3;margin-bottom:12px;letter-spacing:-.5px}
.hl{color:var(--c-primary)}
.hero-sub{font-size:.9rem;color:var(--c-text-light);max-width:360px;margin:0 auto 28px;line-height:1.65}
.hero-cta{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-bottom:32px}

/* Demo Mockup */
.hero-demo{max-width:420px;margin:0 auto}
.demo-mockup{background:#1e293b;border-radius:var(--radius-lg);overflow:hidden;box-shadow:0 4px 24px rgba(0,0,0,.12)}
.demo-bar{display:flex;align-items:center;gap:6px;padding:10px 14px;background:#0f172a}
.demo-dot{width:10px;height:10px;border-radius:50%;background:#334155}
.demo-dot:nth-child(1){background:#ef4444}
.demo-dot:nth-child(2){background:#f59e0b}
.demo-dot:nth-child(3){background:#10b981}
.demo-url{font-size:.65rem;color:#64748b;margin-left:auto}
.demo-screen{display:flex;height:200px;padding:10px;gap:10px}
.demo-sidebar{display:flex;flex-direction:column;gap:8px;width:36px}
.demo-side-item{height:8px;background:#334155;border-radius:3px}
.demo-side-item.active{background:var(--c-primary)}
.demo-main{flex:1;display:flex;flex-direction:column;gap:8px;overflow:hidden}
.demo-card{background:#334155;border-radius:4px}
.demo-card-lg{height:64px}
.demo-row{display:flex;gap:8px}
.demo-card-sm{flex:1;height:40px}
.demo-table{display:flex;flex-direction:column;gap:5px}
.demo-table-row{height:6px;background:#334155;border-radius:2px;width:100%}
.demo-table-row.short{width:60%}

/* ==================== Products ==================== */
.products{background:var(--c-bg-alt)}
.product-list{display:grid;grid-template-columns:1fr;gap:16px;margin-bottom:40px}
.product-card{background:var(--c-bg);border:1px solid var(--c-border);border-radius:var(--radius-lg);padding:20px;transition:border-color .2s}
.product-card:hover{border-color:var(--c-primary)}
.product-card-free{border-color:var(--c-green);background:var(--c-green-light)}
.product-header{display:flex;align-items:flex-start;gap:10px;margin-bottom:10px}
.product-icon{font-size:1.5rem;flex-shrink:0}
.product-header h3{font-size:1rem;font-weight:700;margin-bottom:2px}
.product-tag{font-size:.75rem;color:var(--c-primary);font-weight:600}
.product-tag-free{color:var(--c-green)}
.product-desc{font-size:.813rem;color:var(--c-text-light);margin-bottom:14px;line-height:1.6}
.product-price{margin-bottom:14px;display:flex;align-items:baseline;gap:4px}
.price-num{font-size:1.5rem;font-weight:900;color:var(--c-primary)}
.price-free{color:var(--c-green)}
.price-unit{font-size:.8rem;color:var(--c-text-light)}
.product-features{display:grid;grid-template-columns:1fr;gap:6px;margin-bottom:16px}
.product-features li{font-size:.8rem;color:var(--c-text-light);padding-left:16px;position:relative}
.product-features li::before{content:'';position:absolute;left:0;top:8px;width:6px;height:6px;border-radius:50%;background:var(--c-primary)}
.product-actions{display:flex;gap:8px;flex-wrap:wrap}

/* ==================== Core Products (Dark Geek Theme) ==================== */
.core-products{background:#0f172a;color:#e2e8f0;padding:56px 0}
.core-products .section-head h2{color:#f1f5f9}
.core-products .section-head p{color:#94a3b8}
.core-product-list{display:grid;grid-template-columns:1fr;gap:20px;max-width:var(--max-w);margin:0 auto;padding:0 16px}

/* Core Card */
.core-card{background:linear-gradient(135deg, #1e293b 0%, #1a2332 100%);border:1px solid #334155;border-radius:var(--radius-lg);padding:28px 24px;position:relative;overflow:hidden;transition:border-color .25s, box-shadow .25s}
.core-card::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;background:linear-gradient(90deg, #38bdf8, #818cf8);opacity:0;transition:opacity .25s}
.core-card:hover{border-color:#475569;box-shadow:0 8px 32px rgba(0,0,0,.3)}
.core-card:hover::before{opacity:1}
.core-card-badge{position:absolute;top:16px;right:16px;font-size:.65rem;font-weight:700;letter-spacing:.5px;text-transform:uppercase;padding:3px 10px;border-radius:20px;background:rgba(56,189,248,.15);color:#38bdf8;border:1px solid rgba(56,189,248,.25)}
.core-badge-desktop{background:rgba(129,140,248,.15);color:#818cf8;border-color:rgba(129,140,248,.25)}
.core-card-icon{font-size:2.5rem;margin-bottom:8px;line-height:1}
.core-card-tagline{font-size:.75rem;color:#38bdf8;font-weight:600;letter-spacing:.5px;text-transform:uppercase;margin-bottom:6px}
.core-card-title{font-size:1.35rem;font-weight:800;color:#f1f5f9;margin-bottom:10px;letter-spacing:-.3px}
.core-card-desc{font-size:.85rem;color:#94a3b8;line-height:1.65;margin-bottom:18px}
.core-card-features{display:flex;flex-direction:column;gap:8px;margin-bottom:20px}
.core-card-features li{display:flex;align-items:flex-start;gap:8px;font-size:.82rem;color:#cbd5e1;line-height:1.5}
.core-feat-icon{color:#38bdf8;font-size:.55rem;flex-shrink:0;margin-top:5px}
.core-card-price{display:flex;align-items:baseline;gap:10px;margin-bottom:18px;padding:12px 0;border-top:1px solid #334155;border-bottom:1px solid #334155}
.core-price-label{font-size:1.3rem;font-weight:900;color:#fbbf24}
.core-price-divider{width:1px;height:14px;background:#475569}
.core-price-start{font-size:.78rem;color:#94a3b8}
.core-card-note{font-size:.73rem;color:#64748b;margin-bottom:18px;line-height:1.5}
.core-card-btn{display:inline-flex;align-items:center;gap:6px;font-size:.85rem;font-weight:600;color:#38bdf8;padding:10px 20px;border:1.5px solid #38bdf8;border-radius:6px;transition:all .2s;margin-bottom:20px;width:100%;justify-content:center;text-align:center}
.core-card-btn:hover{background:#38bdf8;color:#0f172a}
.core-btn-arrow{transition:transform .2s;font-size:1rem}
.core-card-btn:hover .core-btn-arrow{transform:translateX(3px)}
.core-card-techs{display:flex;flex-wrap:wrap;gap:6px}
.core-card-techs span{font-size:.68rem;font-family:var(--font-mono);color:#64748b;background:#1a2332;padding:3px 8px;border-radius:4px;border:1px solid #334155;letter-spacing:.2px}

/* Core Free Entry */
.core-free-entry{display:flex;align-items:center;gap:12px;max-width:var(--max-w);margin:24px auto 0;padding:14px 18px;background:linear-gradient(135deg, rgba(16,185,129,.08) 0%, rgba(16,185,129,.04) 100%);border:1px solid rgba(16,185,129,.2);border-radius:var(--radius);transition:border-color .2s, background .2s;text-decoration:none;color:inherit}
.core-free-entry:hover{border-color:rgba(16,185,129,.4);background:linear-gradient(135deg, rgba(16,185,129,.12) 0%, rgba(16,185,129,.06) 100%)}
.core-free-icon{font-size:1.4rem;flex-shrink:0}
.core-free-text{flex:1;display:flex;flex-direction:column;gap:2px;min-width:0}
.core-free-text strong{font-size:.82rem;color:#10b981}
.core-free-text small{font-size:.72rem;color:#94a3b8;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.core-free-arrow{font-size:1rem;color:#10b981;flex-shrink:0;transition:transform .2s}
.core-free-entry:hover .core-free-arrow{transform:translateX(3px)}

/* ==================== Core Products Responsive ==================== */
@media (min-width: 640px) {
    .core-product-list{grid-template-columns:repeat(2,1fr);gap:24px}
    .core-card{padding:32px 28px}
    .core-card-btn{width:auto}
    .core-free-text small{white-space:normal}
}

@media (min-width: 900px) {
    .core-products{padding:72px 0}
    .core-product-list{gap:28px}
    .core-card{padding:36px 32px}
    .core-card-title{font-size:1.5rem}
}

/* Cooperation */
.cooperation{padding:32px 0 0;border-top:1px solid var(--c-border);margin-top:8px}
.cooperation h3{font-size:1.1rem;font-weight:700;margin-bottom:16px;text-align:center}
.coop-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.coop-item{background:var(--c-bg);border:1px solid var(--c-border);border-radius:var(--radius);padding:14px;display:flex;flex-direction:column;gap:4px}
.coop-num{font-size:1.1rem;font-weight:900;color:var(--c-primary)}
.coop-item strong{font-size:.85rem}
.coop-item span{font-size:.75rem;color:var(--c-text-light)}

/* ==================== Docs ==================== */
.search-box{position:relative;margin-bottom:20px}
.search-input{width:100%;padding:12px 40px 12px 40px;font-size:.9rem;border:2px solid var(--c-border);border-radius:var(--radius-lg);background:var(--c-bg);color:var(--c-text);transition:border-color .2s}
.search-input:focus{border-color:var(--c-primary)}
.search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);font-size:1rem;opacity:.4}
.search-shortcut{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-size:.7rem;color:var(--c-text-lighter);background:var(--c-bg-alt);padding:2px 8px;border-radius:4px;border:1px solid var(--c-border);pointer-events:none}
.search-results{background:var(--c-bg);border:1px solid var(--c-border);border-radius:var(--radius-lg);padding:16px;margin-bottom:20px;margin-top:-12px;box-shadow:0 4px 16px rgba(0,0,0,.06)}
.search-results-header{font-size:.8rem;color:var(--c-text-lighter);margin-bottom:10px}
.search-result-item{padding:10px 0;border-bottom:1px solid var(--c-border)}
.search-result-item:last-child{border-bottom:none}
.search-result-item strong{display:block;font-size:.85rem;margin-bottom:2px}
.search-result-item span{font-size:.75rem;color:var(--c-text-lighter)}
.search-hit{background:#fef08a;padding:0 2px;border-radius:2px}

.doc-tabs{display:flex;gap:0;margin-bottom:24px;border-bottom:2px solid var(--c-border)}
.doc-tab{flex:1;padding:10px 0;font-size:.85rem;font-weight:600;color:var(--c-text-light);border-bottom:2px solid transparent;margin-bottom:-2px;cursor:pointer;transition:color .15s,border-color .15s;text-align:center}
.doc-tab:hover{color:var(--c-text)}
.doc-tab.active{color:var(--c-primary);border-bottom-color:var(--c-primary)}
.doc-panel{display:none}
.doc-panel.active{display:block}

/* FAQ */
.faq-item{border:1px solid var(--c-border);border-radius:var(--radius);margin-bottom:8px;overflow:hidden}
.faq-item summary{padding:14px 16px;font-size:.9rem;font-weight:600;cursor:pointer;list-style:none;display:flex;justify-content:space-between;align-items:center;user-select:none}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:'+';font-size:1.2rem;color:var(--c-text-lighter);transition:transform .2s}
.faq-item[open] summary::after{content:'−';color:var(--c-primary)}
.faq-answer{padding:0 16px 16px;font-size:.85rem;color:var(--c-text-light);line-height:1.7}
.faq-answer strong{color:var(--c-text)}

/* API */
.api-section{margin-bottom:24px}
.api-section h4{font-size:.95rem;font-weight:700;margin-bottom:10px;padding-bottom:6px;border-bottom:1px solid var(--c-border)}
.api-block{display:flex;align-items:center;gap:10px;padding:8px 0;font-size:.85rem;border-bottom:1px solid var(--c-border);flex-wrap:wrap}
.api-block:last-child{border-bottom:none}
.api-method{font-size:.65rem;font-weight:700;padding:2px 8px;border-radius:4px;color:#fff;text-transform:uppercase;flex-shrink:0}
.api-method.get{background:#10b981}
.api-method.post{background:#2563eb}
.api-method.put{background:#f59e0b}
.api-method.del{background:#ef4444}
.api-block code{font-size:.8rem;color:var(--c-text)}
.api-desc{font-size:.78rem;color:var(--c-text-lighter);margin-left:auto}
.code-block{background:#1e293b;border-radius:var(--radius);padding:14px;overflow-x:auto;margin-bottom:8px}
.code-block code,.code-block pre{color:#e2e8f0;font-size:.78rem;line-height:1.7;white-space:pre-wrap;word-break:break-all}
.api-note{font-size:.78rem;color:var(--c-text-lighter)}

/* Changelog */
.changelog-item{border-left:3px solid var(--c-primary);padding:0 0 20px 16px;position:relative;margin-left:8px}
.changelog-item:last-child{padding-bottom:0}
.changelog-item::before{content:'';position:absolute;left:-8px;top:4px;width:13px;height:13px;border-radius:50%;background:var(--c-primary);border:2px solid var(--c-bg)}
.cl-version{font-weight:700;font-size:.85rem;margin-right:10px}
.cl-date{font-size:.75rem;color:var(--c-text-lighter)}
.changelog-item ul{margin-top:8px;margin-left:16px}
.changelog-item li{font-size:.8rem;color:var(--c-text-light);margin-bottom:4px;list-style:disc}

/* Docs Contact */
.docs-contact{text-align:center;padding:24px;margin-top:32px;background:var(--c-primary-light);border-radius:var(--radius-lg)}
.docs-contact p{font-size:.85rem;color:var(--c-text-light);margin-bottom:12px}
.docs-contact-links{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}

/* ==================== About ==================== */
.about{background:var(--c-bg-alt);padding:48px 0;border-top:1px solid var(--c-border)}
.about-inner{max-width:var(--max-w);margin:0 auto;padding:0 16px;display:flex;align-items:flex-start;gap:20px}
.about-avatar{width:52px;height:52px;border-radius:50%;background:var(--c-primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:1.5rem;flex-shrink:0}
.about-text h2{font-size:1.1rem;font-weight:700;margin-bottom:8px}
.about-text p{font-size:.85rem;color:var(--c-text-light);line-height:1.75}
@media (max-width: 639px) {
    .about-inner{flex-direction:column;align-items:center;text-align:center}
    .about-text p{font-size:.82rem}
}

/* ==================== Footer ==================== */
.footer{background:var(--c-text);color:#94a3b8;padding:24px 0}
.footer-inner{max-width:var(--max-w);margin:0 auto;padding:0 16px;display:flex;flex-direction:column;gap:12px;margin-bottom:16px}
.footer-left strong{display:block;color:#fff;font-size:.9rem;margin-bottom:2px}
.footer-left span{font-size:.78rem}
.footer-right{display:flex;gap:16px;flex-wrap:wrap}
.footer-right a{font-size:.8rem;color:#94a3b8;transition:color .15s}
.footer-right a:hover{color:#fff}
.footer-bottom{max-width:var(--max-w);margin:0 auto;padding:12px 16px 0;border-top:1px solid rgba(255,255,255,.1);text-align:center;font-size:.72rem;color:#64748b}

/* ==================== Responsive: Tablet+ ==================== */
@media (min-width: 640px) {
    .hero-title{font-size:2.2rem}
    .product-list{grid-template-columns:repeat(2,1fr)}
    .product-features{grid-template-columns:repeat(2,1fr)}
    .demo-screen{height:240px}
    .coop-grid{grid-template-columns:repeat(4,1fr)}
    .footer-inner{flex-direction:row;justify-content:space-between;align-items:center}
}

@media (min-width: 900px) {
    section{padding:64px 0}
    .hero{padding:60px 0 64px}
    .hero-title{font-size:2.5rem;max-width:600px;margin-left:auto;margin-right:auto}
    .hero-sub{max-width:440px}
    .hero-demo{max-width:520px}
    .demo-screen{height:280px}
    .product-list{grid-template-columns:repeat(2,1fr);gap:20px}
    .product-card{padding:24px}
    .section-head h2{font-size:1.75rem}
}

/* ==================== Mobile Nav ==================== */
@media (max-width: 639px) {
    .menu-btn{display:flex}
    .nav{position:fixed;top:var(--header-h);left:0;right:0;background:var(--c-bg);border-bottom:1px solid var(--c-border);flex-direction:column;padding:12px;transform:translateY(-110%);opacity:0;visibility:hidden;transition:.25s}
    .nav.active{transform:translateY(0);opacity:1;visibility:visible}
    .nav-link{padding:10px 14px;font-size:.9rem}
    .search-shortcut{display:none}
}

/* ==================== Print / Accessibility ==================== */
@media (prefers-reduced-motion:reduce) {
    *,*::before,*::after{animation-duration:0.01ms!important;transition-duration:0.01ms!important}
}