/* ============================================
   Sentinel Template — 哨兵警戒守护风格 (Sentinel Guardian Watch)
   Colors: Alert Red #EF4444 + Deep Charcoal #0D0D0F
   Font: Trebuchet MS headings + system sans body
   CSS Prefix: stl
   ============================================ */
:root {
    --stl-red: #EF4444; --stl-red-light: #F87171; --stl-red-dim: #B91C1C;
    --stl-red-glow: rgba(239,68,68,0.22);
    --stl-amber: #F59E0B;
    --stl-bg: #0D0D0F; --stl-bg2: #141417; --stl-bg3: #1A1A1E;
    --stl-card: rgba(239,68,68,0.035); --stl-card-h: rgba(239,68,68,0.08);
    --stl-text: #E8E8EC; --stl-text-sec: #9CA0AA; --stl-text-muted: #5C6068;
    --stl-border: rgba(239,68,68,0.14); --stl-border-h: rgba(239,68,68,0.32);
    --stl-radius: 4px; --stl-radius-lg: 6px;
    --stl-font-heading: "Trebuchet MS","Lucida Sans","Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
    --stl-font-body: -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
    --stl-transition: all 0.25s cubic-bezier(0.4,0,0.2,1);
}
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}
body{font-family:var(--stl-font-body);font-size:16px;line-height:1.7;color:var(--stl-text);background:var(--stl-bg);overflow-x:hidden;-webkit-font-smoothing:antialiased}
a{text-decoration:none;color:inherit;transition:var(--stl-transition)}
img{max-width:100%;height:auto;display:block}
ul{list-style:none}
h1,h2,h3,h4{font-family:var(--stl-font-heading);font-weight:700;line-height:1.25;color:var(--stl-text);letter-spacing:.3px}
.stl-container{max-width:1200px;margin:0 auto;padding:0 24px}
.stl-nav{position:fixed;top:0;left:0;right:0;z-index:1000;display:flex;align-items:center;justify-content:space-between;padding:14px 24px;background:rgba(13,13,15,0.82);backdrop-filter:blur(14px);border-bottom:1px solid var(--stl-border);transition:var(--stl-transition)}
.stl-nav.scrolled{background:rgba(13,13,15,0.97);border-bottom-color:var(--stl-border-h);box-shadow:0 2px 20px rgba(239,68,68,0.06)}
.stl-logo{display:flex;align-items:center;gap:10px;font-family:var(--stl-font-heading);font-weight:700;font-size:1.15rem;color:var(--stl-text)}
.stl-logo-icon{width:34px;height:34px;display:flex;align-items:center;justify-content:center;color:var(--stl-red);flex-shrink:0;filter:drop-shadow(0 0 6px var(--stl-red-glow))}
.stl-logo-icon svg{width:24px;height:24px}
.stl-nav-links{display:flex;gap:28px}
.stl-nav-links a{font-size:.88rem;font-weight:500;color:var(--stl-text-sec);position:relative}
.stl-nav-links a::after{content:'';position:absolute;bottom:-4px;left:0;width:0;height:2px;background:var(--stl-red);transition:width .25s;box-shadow:0 0 6px var(--stl-red-glow)}
.stl-nav-links a:hover{color:var(--stl-red-light)}
.stl-nav-links a:hover::after{width:100%}
.stl-nav-cta{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;background:var(--stl-red);color:#fff;border-radius:var(--stl-radius);font-size:.84rem;font-weight:700;cursor:pointer;transition:var(--stl-transition)}
.stl-nav-cta:hover{background:var(--stl-red-dim);box-shadow:0 0 16px var(--stl-red-glow);transform:translateY(-1px)}
.stl-mobile-btn{display:none;background:none;border:none;cursor:pointer;color:var(--stl-red);padding:4px}
.stl-hero{position:relative;min-height:100vh;display:flex;align-items:center;padding:120px 0 80px;overflow:hidden}
.stl-hero-bg-wrap{position:absolute;inset:0;z-index:0}
.stl-hero-bg-img{width:100%;height:100%;object-fit:cover;filter:grayscale(.6) brightness(.4)}
.stl-hero-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(13,13,15,.93) 0%,rgba(13,13,15,.83) 50%,rgba(13,13,15,.97) 100%)}
.stl-hero-overlay::after{content:'';position:absolute;inset:0;background:repeating-linear-gradient(45deg,rgba(239,68,68,.02) 0,rgba(239,68,68,.02) 10px,transparent 10px,transparent 20px);pointer-events:none}
.stl-hero-inner{position:relative;z-index:1;max-width:720px}
.stl-hero-badge{display:inline-flex;align-items:center;gap:8px;padding:6px 14px;background:rgba(239,68,68,0.08);border:1px solid var(--stl-border-h);border-radius:var(--stl-radius);font-size:.76rem;font-weight:600;color:var(--stl-red-light);margin-bottom:22px;letter-spacing:1px;text-transform:uppercase}
.stl-hero-badge .stl-dot{width:6px;height:6px;background:var(--stl-red);border-radius:50%;animation:stl-pulse 2s infinite;box-shadow:0 0 8px var(--stl-red)}
@keyframes stl-pulse{0%,100%{opacity:1}50%{opacity:.3}}
.stl-hero h1{font-size:2.8rem;margin-bottom:20px}
.stl-hero h1 .stl-accent{color:var(--stl-red)}
.stl-hero-desc{font-size:1rem;color:var(--stl-text-sec);margin-bottom:32px;max-width:540px;line-height:1.85}
.stl-hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:44px}
.stl-btn-cta{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;background:var(--stl-red);color:#fff;border-radius:var(--stl-radius);font-weight:700;font-size:.9rem;cursor:pointer;border:none;transition:var(--stl-transition);box-shadow:0 4px 20px var(--stl-red-glow)}
.stl-btn-cta:hover{background:var(--stl-red-dim);transform:translateY(-2px);box-shadow:0 8px 28px rgba(239,68,68,.4)}
.stl-btn-ghost{display:inline-flex;align-items:center;gap:8px;padding:14px 28px;background:transparent;color:var(--stl-text-sec);border:1px solid var(--stl-border-h);border-radius:var(--stl-radius);font-weight:500;font-size:.9rem;cursor:pointer}
.stl-btn-ghost:hover{border-color:var(--stl-red);color:var(--stl-red-light);background:var(--stl-card)}
.stl-hero-nums{display:flex;align-items:center;gap:30px}
.stl-hn-v{display:block;font-size:1.6rem;font-weight:700;color:var(--stl-red-light);font-family:var(--stl-font-heading)}
.stl-hn-l{font-size:.72rem;color:var(--stl-text-muted);letter-spacing:.5px}
.stl-hn-sep{width:1px;height:34px;background:var(--stl-border)}
.stl-trust{padding:20px 0;background:var(--stl-bg2);border-bottom:1px solid var(--stl-border);border-top:1px solid var(--stl-border)}
.stl-trust-inner{display:flex;justify-content:center;gap:36px;flex-wrap:wrap}
.stl-trust-item{display:flex;align-items:center;gap:8px;font-size:.82rem;font-weight:500;color:var(--stl-text-sec)}
.stl-trust-item svg{color:var(--stl-red);flex-shrink:0}
.stl-section{padding:90px 0}
.stl-section-alt{background:var(--stl-bg2)}
.stl-sec-header{text-align:center;margin-bottom:54px}
.stl-sec-tag{display:inline-block;padding:4px 14px;background:rgba(239,68,68,0.08);color:var(--stl-red-light);border:1px solid var(--stl-border);border-radius:var(--stl-radius);font-size:.72rem;font-weight:600;letter-spacing:1.5px;text-transform:uppercase;margin-bottom:14px}
.stl-sec-header h2{font-size:2rem;margin-bottom:12px}
.stl-sec-header h2 .stl-h-accent{color:var(--stl-red)}
.stl-sec-header p{font-size:.9rem;color:var(--stl-text-sec);max-width:560px;margin:0 auto}
.stl-feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.stl-feat-card{padding:28px 24px;background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);transition:var(--stl-transition);cursor:pointer;position:relative;overflow:hidden}
.stl-feat-card::before{content:'';position:absolute;top:0;left:0;width:0;height:2px;background:var(--stl-red);transition:width .3s;box-shadow:0 0 6px var(--stl-red-glow)}
.stl-feat-card:hover{border-color:var(--stl-border-h);transform:translateY(-4px);background:var(--stl-bg3)}
.stl-feat-card:hover::before{width:100%}
.stl-feat-icon{width:44px;height:44px;display:flex;align-items:center;justify-content:center;background:rgba(239,68,68,0.06);border:1px solid var(--stl-border);border-radius:var(--stl-radius);margin-bottom:16px}
.stl-feat-icon svg{width:22px;height:22px;stroke:var(--stl-red-light)}
.stl-feat-card h3{font-size:1rem;margin-bottom:8px}
.stl-feat-card p{font-size:.84rem;color:var(--stl-text-sec);line-height:1.75}
.stl-svc-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.stl-svc-card{display:flex;flex-direction:column;background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);overflow:hidden;transition:var(--stl-transition);cursor:pointer}
.stl-svc-card:hover{border-color:var(--stl-border-h);transform:translateY(-3px);box-shadow:0 8px 24px rgba(239,68,68,.08)}
.stl-svc-img{height:180px;overflow:hidden;position:relative}
.stl-svc-img img{width:100%;height:100%;object-fit:cover;transition:transform .4s;filter:grayscale(.5) brightness(.7)}
.stl-svc-img::after{content:'';position:absolute;inset:0;background:linear-gradient(180deg,transparent 50%,rgba(13,13,15,.7) 100%);pointer-events:none}
.stl-svc-card:hover .stl-svc-img img{transform:scale(1.05);filter:grayscale(0) brightness(.85)}
.stl-svc-body{padding:22px 24px}
.stl-svc-body h3{font-size:1rem;margin-bottom:8px}
.stl-svc-body p{font-size:.84rem;color:var(--stl-text-sec);line-height:1.75;margin-bottom:12px}
.stl-svc-link{color:var(--stl-red-light);font-size:.82rem;font-weight:600;display:inline-flex;align-items:center;gap:4px;transition:var(--stl-transition)}
.stl-svc-link:hover{gap:8px;color:var(--stl-red)}
.stl-about-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}
.stl-about-img{position:relative;border-radius:var(--stl-radius);overflow:hidden;border:1px solid var(--stl-border)}
.stl-about-img img{width:100%;height:380px;object-fit:cover;filter:grayscale(.5) brightness(.7);transition:filter .4s}
.stl-about-img:hover img{filter:grayscale(0) brightness(.85)}
.stl-about-img::before{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(239,68,68,.06),transparent 60%);z-index:1;pointer-events:none}
.stl-about-float{position:absolute;bottom:-14px;right:-14px;background:var(--stl-red);color:#fff;border-radius:var(--stl-radius);padding:14px 20px;text-align:center;z-index:2;box-shadow:0 4px 20px var(--stl-red-glow)}
.stl-about-float .stl-af-num{font-size:1.4rem;font-weight:800;display:block;font-family:var(--stl-font-heading)}
.stl-about-float .stl-af-label{font-size:.68rem;text-transform:uppercase;letter-spacing:.5px}
.stl-about-text .stl-sec-tag{margin-bottom:12px}
.stl-about-text h2{font-size:1.8rem;margin-bottom:16px}
.stl-about-text p{color:var(--stl-text-sec);margin-bottom:14px;font-size:.88rem;line-height:1.85}
.stl-link{display:inline-flex;align-items:center;gap:6px;color:var(--stl-red-light);font-weight:600;font-size:.88rem}
.stl-link:hover{gap:10px;color:var(--stl-red)}
.stl-steps-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.stl-step-card{text-align:center;padding:30px 16px;background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);transition:var(--stl-transition)}
.stl-step-card:hover{border-color:var(--stl-border-h);transform:translateY(-4px)}
.stl-step-num{font-size:2.2rem;font-weight:700;color:rgba(239,68,68,.2);margin-bottom:8px;font-family:var(--stl-font-heading)}
.stl-step-card h3{font-size:.95rem;margin-bottom:6px}
.stl-step-card p{font-size:.8rem;color:var(--stl-text-muted)}
.stl-testi-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.stl-testi-card{padding:26px 22px;background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);transition:var(--stl-transition)}
.stl-testi-card:hover{transform:translateY(-3px);border-color:var(--stl-border-h)}
.stl-testi-stars{color:var(--stl-red);font-size:.84rem;margin-bottom:12px;letter-spacing:2px}
.stl-testi-card>p{font-size:.84rem;color:var(--stl-text-sec);line-height:1.8;margin-bottom:16px;font-style:italic}
.stl-testi-author{display:flex;align-items:center;gap:10px}
.stl-ta-avatar{width:34px;height:34px;border-radius:50%;background:var(--stl-red);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.78rem}
.stl-testi-author strong{font-size:.82rem;display:block;color:var(--stl-text)}
.stl-testi-author span{font-size:.72rem;color:var(--stl-text-muted)}
.stl-faq-layout{display:grid;grid-template-columns:1fr 2fr;gap:60px}
.stl-faq-side{position:sticky;top:100px;align-self:start}
.stl-faq-side .stl-sec-tag{margin-bottom:12px}
.stl-faq-side h2{font-size:1.7rem;margin-bottom:14px}
.stl-faq-side p{font-size:.84rem;color:var(--stl-text-sec);line-height:1.8}
.stl-faq-main{display:flex;flex-direction:column;gap:10px}
.stl-faq-item{background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);overflow:hidden;transition:border-color .2s}
.stl-faq-item:hover{border-color:var(--stl-border-h)}
.stl-faq-q{display:flex;align-items:center;justify-content:space-between;padding:14px 20px;cursor:pointer;font-weight:500;font-size:.88rem;color:var(--stl-text)}
.stl-faq-q svg{flex-shrink:0;stroke:var(--stl-red);transition:transform .3s}
.stl-faq-item.active .stl-faq-q svg{transform:rotate(180deg)}
.stl-faq-a{padding:0 20px;max-height:0;overflow:hidden;transition:max-height .3s,padding .3s;font-size:.83rem;color:var(--stl-text-sec);line-height:1.8}
.stl-faq-item.active .stl-faq-a{padding:0 20px 14px;max-height:240px}
.stl-recommend{padding:70px 0}
.stl-recommend-grid{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
.stl-recommend-grid a{display:inline-block;padding:8px 16px;background:var(--stl-bg2);border:1px solid var(--stl-border);border-radius:var(--stl-radius);font-size:.82rem;color:var(--stl-text-sec);transition:var(--stl-transition);cursor:pointer}
.stl-recommend-grid a:hover{color:var(--stl-red-light);border-color:var(--stl-red);transform:translateY(-2px);background:var(--stl-card-h)}
.stl-cta-sec{padding:80px 0;background:var(--stl-bg2)}
.stl-cta-box{text-align:center;max-width:620px;margin:0 auto;padding:60px 40px;border:1px solid var(--stl-border);border-radius:var(--stl-radius-lg);position:relative;overflow:hidden;background:linear-gradient(135deg,rgba(239,68,68,.04),rgba(239,68,68,.01))}
.stl-cta-box::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;background:linear-gradient(90deg,transparent,var(--stl-red),transparent);box-shadow:0 0 8px var(--stl-red-glow)}
.stl-cta-box h2{font-size:1.8rem;margin-bottom:12px}
.stl-cta-box p{font-size:.9rem;color:var(--stl-text-sec);margin-bottom:28px}
.stl-footer{padding:50px 0 0;border-top:1px solid var(--stl-border);background:var(--stl-bg)}
.stl-footer-top{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px;padding-bottom:34px;border-bottom:1px solid var(--stl-border)}
.stl-footer-desc{font-size:.8rem;color:var(--stl-text-muted);margin-top:14px;line-height:1.8;max-width:400px}
.stl-footer-nav h4{color:var(--stl-red-light);font-size:.86rem;margin-bottom:14px;font-family:var(--stl-font-heading)}
.stl-footer-nav li{margin-bottom:8px}
.stl-footer-nav a{font-size:.8rem;color:var(--stl-text-muted)}
.stl-footer-nav a:hover{color:var(--stl-red-light)}
.stl-footer-bottom{padding:20px 0;text-align:center;font-size:.74rem;color:var(--stl-text-muted)}
.stl-page-hero{padding:150px 0 60px;text-align:center}
.stl-page-hero h1{font-size:2.4rem;margin-bottom:12px}
.stl-page-hero p{font-size:.92rem;color:var(--stl-text-sec)}
@media(max-width:1024px){.stl-hero h1{font-size:2.2rem}.stl-feat-grid{grid-template-columns:repeat(2,1fr)}.stl-svc-grid{grid-template-columns:1fr}.stl-about-grid{grid-template-columns:1fr}.stl-faq-layout{grid-template-columns:1fr}.stl-faq-side{position:static;text-align:center}.stl-footer-top{grid-template-columns:1fr 1fr}.stl-steps-grid{grid-template-columns:repeat(2,1fr)}.stl-testi-grid{grid-template-columns:1fr}}
@media(max-width:768px){.stl-nav{padding:10px 16px;flex-wrap:wrap}.stl-nav-links{display:none;position:absolute;top:100%;left:0;right:0;flex-direction:column;background:rgba(13,13,15,.98);border-bottom:1px solid var(--stl-border);border-top:1px solid var(--stl-border);padding:12px 16px;gap:0}.stl-nav-links.active{display:flex}.stl-nav-links li{border-bottom:1px solid var(--stl-border)}.stl-nav-links li:last-child{border-bottom:none}.stl-nav-links a{display:block;padding:12px 0}.stl-nav-cta{display:none}.stl-mobile-btn{display:block}.stl-hero{padding:100px 0 60px;min-height:auto}.stl-hero h1{font-size:1.8rem}.stl-hero-actions{flex-direction:column}.stl-btn-cta,.stl-btn-ghost{width:100%;justify-content:center}.stl-hero-nums{flex-wrap:wrap;gap:16px}.stl-hn-sep{display:none}.stl-feat-grid{grid-template-columns:1fr}.stl-sec-header h2{font-size:1.5rem}.stl-section{padding:60px 0}.stl-cta-box{padding:40px 20px}.stl-footer-top{grid-template-columns:1fr;gap:28px}.stl-page-hero h1{font-size:1.8rem}}
@media(max-width:480px){.stl-steps-grid{grid-template-columns:1fr}.stl-trust-inner{gap:14px}}