/* ============================================================
   RC804 Product Page — Anker Visual Standard
   CSS 3D · Glassmorphism · Precision Typography
   ============================================================ */


:root {
  --bg-deep: #060E1F;
  --bg-mid: #091833;
  --bg-card: rgba(15,45,92,0.35);
  --bg-card-hover: rgba(21,53,104,0.45);
  --blue-glow: #3B9EFF;
  --blue-soft: #5EB8FF;
  --blue-dim: #1A4A7A;
  --text-primary: #F4F7FC;
  --text-secondary: #A0B4D0;
  --text-muted: #64748B;
  --orange: #FF6B35;
  --green: #00C896;
  --border-glass: rgba(255,255,255,0.06);
  --border-active: rgba(59,158,255,0.25);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --font-display: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'SF Mono', 'JetBrains Mono', 'Fira Code', monospace;
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;background:var(--bg-deep)}
body{font-family:var(--font-display);background:var(--bg-deep);color:var(--text-primary);line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}

/* ============================================================
   HERO — CSS 3D Product Model
   ============================================================ */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;justify-content:center;overflow:hidden;padding:80px 32px 120px}
.hero-bg{position:absolute;inset:0;pointer-events:none}
.hero-bg::before{content:'';position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(ellipse 50% 35% at 50% 35%,rgba(59,158,255,0.10) 0%,transparent 50%),radial-gradient(ellipse 40% 30% at 35% 65%,rgba(0,200,150,0.04) 0%,transparent 50%),radial-gradient(ellipse 45% 25% at 65% 55%,rgba(59,158,255,0.06) 0%,transparent 45%)}
.hero-bg::after{content:'';position:absolute;bottom:0;left:0;right:0;height:50%;background:linear-gradient(180deg,transparent 0%,rgba(59,158,255,0.03) 40%,rgba(59,158,255,0.08) 100%)}

.hero-inner{position:relative;z-index:1;max-width:1100px;width:100%;text-align:center}
.hero-eyebrow{font-size:11px;font-weight:700;color:var(--blue-glow);letter-spacing:4px;text-transform:uppercase;margin-bottom:24px;opacity:0;animation:fadeUp 0.8s 0.1s forwards}
.hero h1{font-size:clamp(36px,6vw,64px);font-weight:900;line-height:1.04;letter-spacing:-1.5px;margin-bottom:20px;opacity:0;animation:fadeUp 0.8s 0.2s forwards}
.hero h1 .hl{background:linear-gradient(135deg,var(--blue-glow),#6EC8FF);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-desc{font-size:clamp(15px,1.6vw,18px);color:var(--text-secondary);max-width:520px;margin:0 auto 40px;font-weight:400;line-height:1.6;opacity:0;animation:fadeUp 0.8s 0.3s forwards}
.hero-ctas{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;margin-bottom:72px;opacity:0;animation:fadeUp 0.8s 0.4s forwards}

/* CSS 3D Product Model */
.product-stage{position:relative;width:100%;max-width:800px;margin:0 auto;height:420px;perspective:1200px;perspective-origin:50% 30%}
.product-3d{position:absolute;top:50%;left:50%;transform-style:preserve-3d;transform:translate(-50%,-50%) rotateX(8deg) rotateY(-15deg);transition:transform 0.6s cubic-bezier(.23,1,.32,1)}
.product-3d:hover{transform:translate(-50%,-50%) rotateX(3deg) rotateY(-8deg)}
/* Body */
.product-body{position:relative;width:280px;height:180px;background:linear-gradient(145deg,#1A3A5C 0%,#0F2D5C 40%,#0A2550 70%,#081E42 100%);border-radius:24px;box-shadow:0 30px 80px rgba(0,0,0,0.5),0 0 0 1px rgba(255,255,255,0.04) inset,0 1px 0 rgba(255,255,255,0.03) inset;overflow:visible}
.product-body::after{content:'';position:absolute;inset:1px;border-radius:23px;background:linear-gradient(180deg,rgba(255,255,255,0.03) 0%,transparent 30%,rgba(0,0,0,0.2) 100%);pointer-events:none}
/* Screen */
.product-screen{position:absolute;top:18px;left:50%;transform:translateX(-50%);width:200px;height:95px;background:linear-gradient(180deg,#0A0F1A 0%,#040810 100%);border-radius:14px;border:1px solid rgba(255,255,255,0.06);overflow:hidden}
.product-screen::before{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(59,158,255,0.06) 0%,transparent 50%,rgba(0,200,150,0.03) 100%)}
.screen-content{position:absolute;inset:10px;display:flex;flex-direction:column;align-items:center;justify-content:center}
.screen-pd{font-size:9px;font-weight:700;color:rgba(59,158,255,0.9);letter-spacing:2px;text-transform:uppercase;margin-bottom:4px}
.screen-battery{font-size:38px;font-weight:900;color:#fff;line-height:1;margin-bottom:2px;text-shadow:0 0 20px rgba(59,158,255,0.4)}
.screen-sub{font-size:9px;color:rgba(160,180,208,0.6);letter-spacing:1px}
/* Cable groove */
.cable-groove{position:absolute;bottom:42px;left:15px;right:15px;height:22px;background:rgba(0,0,0,0.3);border-radius:6px;border:1px solid rgba(255,255,255,0.03)}
.cable-groove::after{content:'';position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:60%;height:2px;background:rgba(59,158,255,0.3);border-radius:1px}
/* Ports */
.product-ports{position:absolute;bottom:10px;left:50%;transform:translateX(-50%);display:flex;gap:8px}
.port{width:28px;height:16px;border-radius:5px;background:#050810;border:1px solid rgba(255,255,255,0.06)}
.port.orange{border-color:rgba(255,107,53,0.4)}
/* Reflection */
.product-reflection{position:absolute;bottom:-40px;left:10%;right:10%;height:60px;background:linear-gradient(180deg,rgba(59,158,255,0.12) 0%,rgba(59,158,255,0.04) 40%,transparent 100%);border-radius:50%;filter:blur(20px);transform:rotateX(90deg)}

/* Badges */
.hero-badges{display:flex;flex-wrap:wrap;justify-content:center;gap:40px;margin-top:48px;opacity:0;animation:fadeUp 0.8s 0.5s forwards}
.hero-badge{text-align:center}
.hero-badge .badge-num{font-size:clamp(24px,3vw,32px);font-weight:900;color:var(--text-primary);font-family:var(--font-mono);line-height:1;margin-bottom:4px}
.hero-badge .badge-num.hl{color:var(--blue-glow)}
.hero-badge .badge-label{font-size:10px;color:var(--text-muted);text-transform:uppercase;letter-spacing:1.5px;font-weight:500}

@keyframes fadeUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn{display:inline-flex;align-items:center;gap:8px;padding:16px 40px;border-radius:50px;font-weight:700;font-size:14px;cursor:pointer;text-decoration:none;transition:all .3s cubic-bezier(.23,1,.32,1);border:none;font-family:var(--font-display);white-space:nowrap;letter-spacing:-0.2px}
.btn-primary{background:var(--blue-glow);color:#fff;box-shadow:0 8px 32px rgba(59,158,255,0.25)}
.btn-primary:hover{background:var(--blue-soft);transform:translateY(-2px);box-shadow:0 16px 48px rgba(59,158,255,0.35)}
.btn-outline{background:rgba(255,255,255,0.04);color:var(--text-primary);border:1px solid rgba(255,255,255,0.12);backdrop-filter:blur(10px)}
.btn-outline:hover{background:rgba(255,255,255,0.08);border-color:rgba(255,255,255,0.2);transform:translateY(-2px)}
.btn-accent{background:var(--green);color:#060E1F}
.btn-accent:hover{background:#00E8B0;transform:translateY(-2px);box-shadow:0 12px 40px rgba(0,200,150,0.3)}

/* ============================================================
   SECTION SYSTEM
   ============================================================ */
.section{padding:140px 32px;position:relative}
.section-alt{background:linear-gradient(180deg,var(--bg-deep) 0%,var(--bg-mid) 50%,var(--bg-deep) 100%)}
.section-inner{max-width:1120px;margin:0 auto}
.s-label{font-size:10px;font-weight:700;color:var(--blue-glow);text-transform:uppercase;letter-spacing:3px;margin-bottom:20px}
.s-heading{font-size:clamp(28px,4vw,44px);font-weight:900;line-height:1.08;letter-spacing:-1px;margin-bottom:20px;max-width:640px}
.s-heading .hl{color:var(--blue-glow)}
.s-sub{font-size:17px;color:var(--text-secondary);max-width:520px;line-height:1.6;font-weight:400}

/* ============================================================
   FEATURE ROW — Anker rhythm: big visual + small text
   ============================================================ */
.feature-row{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center;margin-top:80px}
.feature-row.reverse{direction:rtl}
.feature-row.reverse>*{direction:ltr}
.feature-visual{position:relative;display:flex;align-items:center;justify-content:center;min-height:400px}
.feature-visual-inner{position:relative;width:100%;max-width:440px}
.feature-text h2{font-size:clamp(26px,3.5vw,38px);font-weight:900;line-height:1.1;letter-spacing:-0.8px;margin-bottom:16px}
.feature-text h2 .hl{color:var(--blue-glow)}
.feature-text .f-sub{font-size:16px;color:var(--text-secondary);line-height:1.6;margin-bottom:32px;max-width:400px}
.feature-metrics{display:flex;gap:36px;flex-wrap:wrap}
.fm-item .fm-num{font-size:28px;font-weight:900;color:var(--blue-glow);font-family:var(--font-mono);line-height:1;margin-bottom:4px}
.fm-item .fm-label{font-size:12px;color:var(--text-muted);font-weight:500}

/* Device chips */
.device-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px}
.chip{padding:8px 16px;background:rgba(59,158,255,0.06);border:1px solid rgba(59,158,255,0.1);border-radius:50px;font-size:12px;color:var(--text-secondary);font-weight:500;backdrop-filter:blur(10px)}

/* ============================================================
   GLASS CARDS
   ============================================================ */
.glass-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;margin-top:64px}
.glass-card{background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-lg);padding:48px 40px;backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);transition:all .4s cubic-bezier(.23,1,.32,1);position:relative;overflow:hidden}
.glass-card::before{content:'';position:absolute;top:0;left:0;right:0;height:1px;background:linear-gradient(90deg,transparent,rgba(255,255,255,0.06),transparent);opacity:0;transition:opacity .4s}
.glass-card:hover{background:var(--bg-card-hover);border-color:var(--border-active);transform:translateY(-4px);box-shadow:0 20px 60px rgba(0,0,0,0.3),0 0 0 1px rgba(59,158,255,0.1)}
.glass-card:hover::before{opacity:1}
.glass-card .gc-icon{width:52px;height:52px;border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;background:rgba(59,158,255,0.08);margin-bottom:24px;font-size:22px}
.glass-card h3{font-size:18px;font-weight:800;margin-bottom:8px;letter-spacing:-0.3px}
.glass-card p{font-size:14px;color:var(--text-secondary);line-height:1.6}

/* Page dots for glass card carousel */
.page-dots{display:flex;justify-content:center;gap:8px;margin-top:40px}
.page-dot{width:8px;height:8px;border-radius:50%;background:rgba(255,255,255,0.1);border:none;cursor:pointer;transition:all .3s}
.page-dot.active{background:var(--blue-glow);width:24px;border-radius:4px}

/* ============================================================
   CSS 3D Feature Visuals
   ============================================================ */
/* Cable visual */
.cable-3d{position:relative;width:300px;height:300px;margin:0 auto;perspective:600px}
.cable-ring{position:absolute;top:50%;left:50%;width:200px;height:200px;border-radius:50%;border:3px solid rgba(59,158,255,0.15);transform:translate(-50%,-50%) rotateX(60deg);animation:rotateSlow 20s linear infinite}
.cable-ring:nth-child(2){width:140px;height:140px;border-color:rgba(59,158,255,0.2);border-style:dashed;animation-duration:15s;animation-direction:reverse}
.cable-ring:nth-child(3){width:90px;height:90px;border-color:rgba(59,158,255,0.3);animation-duration:10s}
.cable-core{position:absolute;top:50%;left:50%;width:50px;height:50px;border-radius:50%;background:rgba(59,158,255,0.15);border:2px solid rgba(59,158,255,0.4);transform:translate(-50%,-50%);box-shadow:0 0 40px rgba(59,158,255,0.2)}
.cable-label{position:absolute;bottom:0;left:50%;transform:translateX(-50%);font-size:13px;font-weight:700;color:var(--text-secondary);text-align:center}
@keyframes rotateSlow{from{transform:translate(-50%,-50%) rotateX(60deg) rotateZ(0deg)}to{transform:translate(-50%,-50%) rotateX(60deg) rotateZ(360deg)}}

/* Power distribution visual */
.power-visual{position:relative;width:320px;height:320px;margin:0 auto}
.power-hub{position:absolute;top:50%;left:50%;width:70px;height:70px;border-radius:50%;background:rgba(59,158,255,0.1);border:2px solid rgba(59,158,255,0.3);transform:translate(-50%,-50%);box-shadow:0 0 60px rgba(59,158,255,0.15);display:flex;align-items:center;justify-content:center;font-weight:900;font-size:14px;color:var(--blue-glow)}
.power-ray{position:absolute;top:50%;left:50%;height:2px;background:linear-gradient(90deg,rgba(59,158,255,0.4),transparent);transform-origin:left center;border-radius:1px}
.power-ray:nth-child(1){width:100px;transform:translate(35px,-35px) rotate(-45deg)}
.power-ray:nth-child(2){width:100px;transform:translate(35px,35px) rotate(45deg)}
.power-ray:nth-child(3){width:80px;transform:translate(35px,0) rotate(0deg)}
.power-ray:nth-child(4){width:90px;transform:translate(-125px,-20px) rotate(180deg)}
.power-ray:nth-child(5){width:90px;transform:translate(-125px,20px) rotate(200deg)}
.power-device{position:absolute;width:36px;height:36px;border-radius:10px;background:rgba(15,45,92,0.8);border:1px solid rgba(255,255,255,0.08);display:flex;align-items:center;justify-content:center;font-size:16px;backdrop-filter:blur(10px)}
.power-device:nth-child(6){top:20px;right:50px}
.power-device:nth-child(7){bottom:20px;right:60px}
.power-device:nth-child(8){top:50%;right:10px;transform:translateY(-50%)}
.power-device:nth-child(9){bottom:30px;left:30px}
.power-device:nth-child(10){top:30px;left:40px}

/* ============================================================
   ENGINEERING ARCHITECTURE DIAGRAM
   ============================================================ */
.arch-flow{display:flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:0;margin-top:64px}
.arch-node{position:relative;padding:8px}
.arch-node .an-inner{width:120px;padding:20px 14px;background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-md);text-align:center;backdrop-filter:blur(20px);transition:all .3s}
.arch-node .an-inner:hover{border-color:var(--border-active);transform:translateY(-3px);box-shadow:0 12px 40px rgba(0,0,0,0.3)}
.arch-node .an-icon{font-size:24px;margin-bottom:8px}
.arch-node .an-name{font-size:13px;font-weight:700;line-height:1.3}
.arch-node .an-sub{font-size:10px;color:var(--text-muted);margin-top:2px}
.arch-arrow{font-size:20px;color:rgba(59,158,255,0.4);padding:0 2px;font-weight:200}

/* Thermal bar */
.thermal-section{margin-top:64px;padding:40px;background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-lg);backdrop-filter:blur(20px)}
.thermal-section h3{text-align:center;font-size:17px;font-weight:800;margin-bottom:32px}
.thermal-gradient-bar{height:40px;border-radius:20px;background:linear-gradient(90deg,#00C896 0%,#6EDC5A 20%,#FFD93D 40%,#FFA500 60%,#FF6B35 75%,#FF4757 88%,#8B0000 100%);position:relative;overflow:hidden}
.thermal-gradient-bar::after{content:'';position:absolute;inset:0;background:linear-gradient(180deg,rgba(255,255,255,0.1) 0%,transparent 50%,rgba(0,0,0,0.2) 100%)}
.thermal-labels{display:flex;justify-content:space-between;margin-top:14px}
.thermal-labels span{text-align:center;font-size:11px;color:var(--text-muted);flex:1}
.thermal-labels span strong{display:block;font-size:15px;color:var(--text-primary);font-family:var(--font-mono);font-weight:800;margin-bottom:2px}

/* Reliability 3x3 grid */
.reliability-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:48px}
.rel-card{background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-md);padding:28px 20px;text-align:center;backdrop-filter:blur(20px);transition:all .3s}
.rel-card:hover{border-color:var(--border-active);transform:translateY(-2px)}
.rel-card .rl-icon{font-size:28px;margin-bottom:10px}
.rel-card .rl-metric{font-size:24px;font-weight:900;font-family:var(--font-mono);margin-bottom:4px}
.rel-card .rl-name{font-size:13px;font-weight:600;margin-bottom:6px}
.rel-card .rl-badge{display:inline-block;padding:3px 14px;background:rgba(0,200,150,0.1);color:var(--green);border-radius:50px;font-size:10px;font-weight:700;letter-spacing:0.5px}

/* ============================================================
   COMPARISON CARDS
   ============================================================ */
.compare-duo{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin-top:64px;max-width:800px;margin-left:auto;margin-right:auto}
.compare-card{border-radius:var(--radius-lg);padding:48px 36px;position:relative;overflow:hidden}
.compare-card.premium{background:linear-gradient(135deg,rgba(59,158,255,0.08),rgba(59,158,255,0.02));border:1px solid rgba(59,158,255,0.2)}
.compare-card.standard{background:var(--bg-card);border:1px solid var(--border-glass)}
.compare-card .cmp-badge{display:inline-block;padding:4px 14px;border-radius:50px;font-size:10px;font-weight:700;letter-spacing:1px;text-transform:uppercase;margin-bottom:24px}
.compare-card.premium .cmp-badge{background:rgba(59,158,255,0.15);color:var(--blue-glow)}
.compare-card.standard .cmp-badge{background:rgba(255,255,255,0.05);color:var(--text-muted)}
.compare-card h3{font-size:22px;font-weight:900;margin-bottom:24px;letter-spacing:-0.5px}
.compare-card ul{list-style:none}
.compare-card li{padding:10px 0;border-bottom:1px solid rgba(255,255,255,0.03);font-size:13px;color:var(--text-secondary);display:flex;justify-content:space-between;align-items:center}
.compare-card li .cv{font-weight:700;font-family:var(--font-mono);font-size:12px}
.compare-card.premium li .cv{color:var(--blue-glow)}

/* ============================================================
   SPECS ACCORDION
   ============================================================ */
.specs-accordion{max-width:680px;margin:64px auto 0}
.spec-group{border:1px solid var(--border-glass);border-radius:var(--radius-md);margin-bottom:10px;overflow:hidden;background:var(--bg-card);backdrop-filter:blur(20px)}
.spec-group-header{width:100%;background:none;border:none;color:var(--text-primary);font-size:15px;font-weight:700;text-align:left;padding:18px 24px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-family:var(--font-display)}
.spec-group-header::after{content:'+';font-size:18px;color:var(--blue-glow);font-weight:300;transition:transform .3s}
.spec-group-header.open::after{content:'−'}
.spec-group-body{max-height:0;overflow:hidden;transition:max-height .4s ease}
.spec-group-body.open{max-height:600px}
.spec-group-body .spec-row{display:flex;justify-content:space-between;padding:12px 24px;border-top:1px solid rgba(255,255,255,0.03);font-size:13px}
.spec-group-body .spec-row .sk{color:var(--text-muted)}
.spec-group-body .spec-row .sv{font-weight:700;font-family:var(--font-mono);font-size:12px;color:var(--text-primary)}

/* ============================================================
   OEM MATRIX
   ============================================================ */
.oem-matrix{max-width:600px;margin:48px auto;background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-lg);overflow:hidden;backdrop-filter:blur(20px)}
.oem-matrix h3{padding:28px 28px 0;font-size:17px;font-weight:800;text-align:center;letter-spacing:-0.3px}
.oem-matrix .om-row{display:flex;justify-content:space-between;align-items:center;padding:14px 28px;border-bottom:1px solid rgba(255,255,255,0.03);font-size:14px}
.oem-matrix .om-row .om-item{font-weight:600}
.oem-matrix .om-row .om-status{font-weight:700;font-size:14px}
.oem-matrix .om-row .om-status.yes{color:var(--green)}
.oem-matrix .om-row .om-status.opt{color:var(--blue-glow)}

/* ============================================================
   FACTORY PHOTOS
   ============================================================ */
.factory-photos{display:grid;grid-template-columns:repeat(5,1fr);gap:14px;margin-top:48px}
.factory-photo{aspect-ratio:1;background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;flex-direction:column;gap:10px;font-size:32px;transition:all .3s;backdrop-filter:blur(20px);cursor:default}
.factory-photo:hover{border-color:var(--border-active);transform:translateY(-3px)}
.factory-photo .fp-label{font-size:10px;color:var(--text-muted);text-transform:uppercase;letter-spacing:1.5px;font-weight:600}

/* Client card */
.client-card{display:grid;grid-template-columns:180px 1fr;gap:48px;align-items:center;background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-lg);padding:48px;max-width:760px;margin:56px auto 0;backdrop-filter:blur(20px)}
.client-card .client-logo{font-size:80px;font-weight:900;color:rgba(59,158,255,0.5);letter-spacing:-3px;text-align:center;line-height:1}
.client-card .client-tag{display:inline-block;padding:4px 12px;background:rgba(0,200,150,0.1);color:var(--green);border-radius:50px;font-size:10px;font-weight:700;letter-spacing:1px;text-transform:uppercase;margin-bottom:16px}
.client-card h3{font-size:18px;font-weight:800;margin-bottom:10px;letter-spacing:-0.3px}
.client-card p{font-size:14px;color:var(--text-secondary);line-height:1.6}
.client-photo-placeholder{width:100%;height:120px;background:rgba(59,158,255,0.03);border:1px dashed rgba(255,255,255,0.06);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;margin-top:24px;font-size:11px;color:var(--text-muted)}

/* ============================================================
   FAQ
   ============================================================ */
.faq-wrap{max-width:720px;margin:64px auto 0}
.faq-item{border-bottom:1px solid rgba(255,255,255,0.04)}
.faq-q{width:100%;background:none;border:none;color:var(--text-primary);font-size:15px;font-weight:600;text-align:left;padding:20px 0;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-family:var(--font-display);gap:16px}
.faq-q::after{content:'+';font-size:18px;color:var(--blue-glow);font-weight:300;transition:transform .3s;flex-shrink:0}
.faq-q.open::after{content:'−'}
.faq-a{max-height:0;overflow:hidden;transition:max-height .35s ease;font-size:14px;color:var(--text-secondary);line-height:1.7}
.faq-a.open{max-height:400px;padding-bottom:20px}

/* ============================================================
   KNOWLEDGE CARDS
   ============================================================ */
.knowledge-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px;margin-top:64px}
.knowledge-card{background:var(--bg-card);border:1px solid var(--border-glass);border-radius:var(--radius-lg);overflow:hidden;transition:all .3s;text-decoration:none;color:inherit;display:flex;flex-direction:column;backdrop-filter:blur(20px)}
.knowledge-card:hover{border-color:var(--border-active);transform:translateY(-3px);box-shadow:0 16px 48px rgba(0,0,0,0.3)}
.knowledge-card .kc-thumb{height:140px;background:linear-gradient(135deg,rgba(59,158,255,0.06),rgba(0,200,150,0.03));display:flex;align-items:center;justify-content:center;font-size:40px}
.knowledge-card .kc-body{padding:24px}
.knowledge-card .k-tag{display:inline-block;padding:3px 10px;background:rgba(59,158,255,0.08);color:var(--blue-glow);border-radius:50px;font-size:10px;font-weight:700;letter-spacing:1px;text-transform:uppercase;margin-bottom:12px}
.knowledge-card h3{font-size:16px;font-weight:800;margin-bottom:6px;letter-spacing:-0.3px;line-height:1.35}
.knowledge-card p{font-size:13px;color:var(--text-muted);line-height:1.5}

/* ============================================================
   FINAL CTA
   ============================================================ */
.cta-final{position:relative;overflow:hidden;background:linear-gradient(180deg,var(--bg-deep),#0A1530)}
.cta-grid{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center;max-width:1100px;margin:0 auto;padding:120px 32px}
.cta-left h2{font-size:clamp(28px,4.5vw,42px);font-weight:900;line-height:1.08;letter-spacing:-1px;margin-bottom:16px}
.cta-left .cta-sub{font-size:17px;color:var(--text-secondary);max-width:420px;line-height:1.6;margin-bottom:40px}
.cta-buttons{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:48px}
.trust-badges{display:flex;flex-wrap:wrap;gap:24px}
.trust-badges span{font-size:12px;color:var(--text-muted);display:flex;align-items:center;gap:6px}
.cta-right{display:flex;align-items:center;justify-content:center}

/* ============================================================
   MOBILE
   ============================================================ */
.mobile-bar{display:none;position:fixed;bottom:0;left:0;right:0;background:rgba(6,14,31,0.96);backdrop-filter:blur(30px);-webkit-backdrop-filter:blur(30px);border-top:1px solid rgba(255,255,255,0.06);padding:14px 20px;z-index:100}
.mobile-bar .btn-primary{width:100%;justify-content:center}

@media(max-width:900px){
  .feature-row,.compare-duo,.cta-grid{grid-template-columns:1fr;gap:48px}
  .section{padding:80px 20px}
  .hero{padding:60px 20px 100px;min-height:auto}
  .product-stage{height:320px}
  .product-body{width:220px;height:140px;border-radius:20px}
  .product-body::after{border-radius:19px}
  .product-screen{width:160px;height:72px;top:14px;border-radius:11px}
  .screen-battery{font-size:28px}
  .screen-pd{font-size:7px}
  .cable-groove{bottom:32px;left:12px;right:12px;height:18px}
  .product-ports{gap:6px;bottom:8px}
  .port{width:22px;height:13px}
  .hero h1{font-size:30px}
  .hero-badges{gap:20px}
  .glass-grid{grid-template-columns:1fr}
  .factory-photos{grid-template-columns:repeat(3,1fr)}
  .client-card{grid-template-columns:1fr;text-align:center;padding:36px}
  .client-card .client-logo{font-size:56px}
  .mobile-bar{display:block}
  .arch-flow{flex-direction:column;gap:4px}
  .arch-arrow{transform:rotate(90deg)}
  .reliability-grid{grid-template-columns:repeat(2,1fr)}
  .knowledge-grid{grid-template-columns:1fr}
  .cta-right{display:none}
}
@media(max-width:480px){
  .factory-photos{grid-template-columns:repeat(2,1fr)}
  .reliability-grid{grid-template-columns:1fr}
  .hero-badges{flex-wrap:wrap;gap:16px}
}