/* ===== Battery App — Global Styles ===== */
:root {
  --clr-primary: #FF6B00;
  --clr-primary-dark: #E05E00;
  --clr-accent: #FFB800;
  --clr-dark: #1A1A2E;
  --clr-darker: #0F0F23;
  --clr-surface: #16213E;
  --clr-surface-light: #1E2D50;
  --clr-text: #F0F0F5;
  --clr-text-muted: #A0A0B8;
  --clr-success: #00C853;
  --clr-border: rgba(255,255,255,.08);
  --font-main: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Poppins', var(--font-main);
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,.35);
  --max-w: 1140px;
  --transition: .25s ease;
}

/* ===== Reset ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:var(--font-main);background:var(--clr-darker);color:var(--clr-text);line-height:1.6;min-height:100vh;overflow-x:hidden}
img{max-width:100%;height:auto;display:block}
a{color:var(--clr-accent);text-decoration:none;transition:color var(--transition)}
a:hover{color:var(--clr-primary)}
ul,ol{list-style:none}
h1,h2,h3,h4,h5,h6{font-family:var(--font-display);line-height:1.25;color:#fff}

/* ===== Utility ===== */
.container{width:100%;max-width:var(--max-w);margin:0 auto;padding:0 20px}
.sr-only{position:absolute;width:1px;height:1px;clip:rect(0,0,0,0);overflow:hidden}
.text-center{text-align:center}
.text-gradient{background:linear-gradient(135deg,var(--clr-primary),var(--clr-accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

/* ===== Header / Navbar ===== */
.header{position:sticky;top:0;z-index:100;background:rgba(15,15,35,.92);backdrop-filter:blur(14px);border-bottom:1px solid var(--clr-border)}
.nav{display:flex;align-items:center;justify-content:space-between;height:64px}
.nav__logo{font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:#fff;display:flex;align-items:center;gap:8px}
.nav__logo .logo-icon{width:36px;height:36px;background:linear-gradient(135deg,var(--clr-primary),var(--clr-accent));border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;font-size:1.1rem}
.nav__links{display:flex;gap:24px;align-items:center}
.nav__links a{color:var(--clr-text-muted);font-size:.9rem;font-weight:500;transition:color var(--transition)}
.nav__links a:hover,.nav__links a.active{color:#fff}
.nav__lang{display:flex;gap:6px}
.nav__lang a{padding:4px 10px;border-radius:4px;font-size:.8rem;font-weight:600;border:1px solid var(--clr-border);color:var(--clr-text-muted)}
.nav__lang a.active{background:var(--clr-primary);color:#fff;border-color:var(--clr-primary)}
.nav__burger{display:none;flex-direction:column;gap:5px;cursor:pointer;background:none;border:none;padding:4px}
.nav__burger span{width:24px;height:2px;background:#fff;border-radius:2px;transition:var(--transition)}

/* ===== Hero ===== */
.hero{padding:80px 0 60px;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-120px;left:50%;transform:translateX(-50%);width:600px;height:600px;background:radial-gradient(circle,rgba(255,107,0,.15),transparent 70%);pointer-events:none}
.hero__badge{display:inline-block;padding:6px 16px;background:rgba(255,107,0,.12);border:1px solid rgba(255,107,0,.25);border-radius:50px;font-size:.8rem;color:var(--clr-accent);font-weight:600;margin-bottom:20px}
.hero h1{font-size:clamp(2rem,5vw,3.2rem);margin-bottom:16px;position:relative}
.hero p{font-size:1.1rem;color:var(--clr-text-muted);max-width:640px;margin:0 auto 32px}

/* ===== CTA Button ===== */
.cta-btn{display:inline-flex;align-items:center;gap:10px;padding:16px 36px;background:linear-gradient(135deg,var(--clr-primary),var(--clr-primary-dark));color:#fff;font-size:1.05rem;font-weight:700;border-radius:50px;border:none;cursor:pointer;box-shadow:0 4px 20px rgba(255,107,0,.35);transition:transform var(--transition),box-shadow var(--transition);text-transform:uppercase;letter-spacing:.5px}
.cta-btn:hover{transform:translateY(-2px);box-shadow:0 8px 30px rgba(255,107,0,.45);color:#fff}
.cta-btn:active{transform:translateY(0)}
.cta-btn svg{width:20px;height:20px;fill:currentColor}
.cta-btn--secondary{background:transparent;border:2px solid var(--clr-primary);box-shadow:none}
.cta-btn--secondary:hover{background:var(--clr-primary);box-shadow:0 4px 20px rgba(255,107,0,.35)}
.cta-btn--sm{padding:12px 24px;font-size:.9rem}

/* ===== Features / Cards ===== */
.section{padding:60px 0}
.section__title{font-size:clamp(1.6rem,3.5vw,2.2rem);margin-bottom:12px}
.section__sub{color:var(--clr-text-muted);max-width:600px;margin:0 auto 40px;font-size:1rem}

.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px}
.card{background:var(--clr-surface);border:1px solid var(--clr-border);border-radius:var(--radius);padding:28px 24px;transition:transform var(--transition),border-color var(--transition)}
.card:hover{transform:translateY(-4px);border-color:rgba(255,107,0,.3)}
.card__icon{width:48px;height:48px;background:linear-gradient(135deg,var(--clr-primary),var(--clr-accent));border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;margin-bottom:16px;font-size:1.5rem}
.card h3{font-size:1.15rem;margin-bottom:8px}
.card p{color:var(--clr-text-muted);font-size:.92rem}

/* ===== Steps ===== */
.steps{counter-reset:step}
.step{display:flex;gap:20px;align-items:flex-start;margin-bottom:32px;counter-increment:step}
.step__num{flex-shrink:0;width:44px;height:44px;background:var(--clr-surface);border:2px solid var(--clr-primary);border-radius:50%;display:flex;align-items:center;justify-content:center;font-family:var(--font-display);font-weight:700;color:var(--clr-primary);font-size:1.1rem}
.step__num::before{content:counter(step)}
.step__body h3{font-size:1.05rem;margin-bottom:4px}
.step__body p{color:var(--clr-text-muted);font-size:.92rem}

/* ===== Table ===== */
.info-table{width:100%;border-collapse:collapse;margin:24px 0;background:var(--clr-surface);border-radius:var(--radius);overflow:hidden;border:1px solid var(--clr-border)}
.info-table th,.info-table td{padding:14px 18px;text-align:left;font-size:.92rem}
.info-table th{background:var(--clr-surface-light);color:var(--clr-accent);font-weight:600;text-transform:uppercase;font-size:.8rem;letter-spacing:.5px}
.info-table td{border-top:1px solid var(--clr-border);color:var(--clr-text-muted)}

/* ===== FAQ / Accordion ===== */
.faq{max-width:760px;margin:0 auto}
.faq__item{border:1px solid var(--clr-border);border-radius:var(--radius-sm);margin-bottom:12px;overflow:hidden;background:var(--clr-surface)}
.faq__q{width:100%;display:flex;justify-content:space-between;align-items:center;padding:16px 20px;background:none;border:none;color:#fff;font-size:1rem;font-weight:600;cursor:pointer;text-align:left;font-family:var(--font-main)}
.faq__q::after{content:'+';font-size:1.4rem;color:var(--clr-primary);transition:transform var(--transition)}
.faq__item.open .faq__q::after{transform:rotate(45deg)}
.faq__a{max-height:0;overflow:hidden;transition:max-height .35s ease,padding .35s ease}
.faq__item.open .faq__a{max-height:500px;padding:0 20px 16px}
.faq__a p{color:var(--clr-text-muted);font-size:.92rem;line-height:1.7}

/* ===== Promo Box ===== */
.promo-box{background:linear-gradient(135deg,var(--clr-surface),var(--clr-surface-light));border:2px dashed var(--clr-primary);border-radius:var(--radius);padding:32px;text-align:center;margin:32px 0}
.promo-box__code{display:inline-block;padding:10px 28px;background:var(--clr-darker);border:2px solid var(--clr-accent);border-radius:var(--radius-sm);font-family:monospace;font-size:1.3rem;color:var(--clr-accent);letter-spacing:2px;margin:16px 0}

/* ===== Footer ===== */
.footer{background:var(--clr-dark);border-top:1px solid var(--clr-border);padding:40px 0 24px}
.footer__grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:32px;margin-bottom:32px}
.footer__col h4{font-size:.95rem;margin-bottom:12px;color:var(--clr-accent)}
.footer__col p,.footer__col a{color:var(--clr-text-muted);font-size:.88rem;display:block;margin-bottom:6px}
.footer__bottom{border-top:1px solid var(--clr-border);padding-top:20px;display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;font-size:.82rem;color:var(--clr-text-muted)}
.footer__badges{display:flex;gap:12px;align-items:center}
.footer__badges span{padding:4px 12px;border:1px solid var(--clr-border);border-radius:4px;font-size:.75rem;color:var(--clr-text-muted)}

/* ===== Disclaimer ===== */
.disclaimer{background:rgba(255,107,0,.06);border:1px solid rgba(255,107,0,.15);border-radius:var(--radius-sm);padding:16px 20px;margin:24px 0;font-size:.82rem;color:var(--clr-text-muted);line-height:1.7}

/* ===== Breadcrumbs ===== */
.breadcrumbs{padding:12px 0;font-size:.85rem;color:var(--clr-text-muted)}
.breadcrumbs a{color:var(--clr-text-muted)}
.breadcrumbs a:hover{color:var(--clr-accent)}
.breadcrumbs span{margin:0 6px;opacity:.5}

/* ===== Author Box (E-E-A-T) ===== */
.author-box{display:flex;gap:16px;align-items:center;background:var(--clr-surface);border:1px solid var(--clr-border);border-radius:var(--radius);padding:20px;margin:32px 0}
.author-box__avatar{width:56px;height:56px;border-radius:50%;background:linear-gradient(135deg,var(--clr-primary),var(--clr-accent));display:flex;align-items:center;justify-content:center;font-size:1.4rem;color:#fff;font-weight:700;flex-shrink:0}
.author-box__info h4{font-size:.95rem;margin-bottom:2px}
.author-box__info p{font-size:.82rem;color:var(--clr-text-muted)}

/* ===== "Last Updated" Tag ===== */
.updated-tag{font-size:.82rem;color:var(--clr-text-muted);margin-bottom:20px}
.updated-tag time{color:var(--clr-accent)}

/* ===== Responsive ===== */
@media(max-width:768px){
  .nav__links{position:fixed;top:64px;left:0;right:0;background:rgba(15,15,35,.98);flex-direction:column;padding:24px;gap:16px;transform:translateY(-120%);transition:transform .3s ease;z-index:99}
  .nav__links.open{transform:translateY(0)}
  .nav__burger{display:flex}
  .hero{padding:48px 0 40px}
  .hero h1{font-size:1.8rem}
  .section{padding:40px 0}
  .footer__grid{grid-template-columns:1fr}
  .author-box{flex-direction:column;text-align:center}
}
@media(max-width:480px){
  .cta-btn{width:100%;justify-content:center;padding:14px 24px;font-size:.95rem}
  .cards{grid-template-columns:1fr}
}