/* ============================================================
   VoltSource Wholesale — B2B power banks & charging site
   Pure static, zero dependencies. System font stack.
   ============================================================ */
:root{
  --ink:#181f3f;
  --ink-soft:#333d63;
  --indigo:#3c51c6;
  --indigo-deep:#28379b;
  --indigo-tint:#e9edfb;
  --volt:#fdd21e;
  --volt-deep:#a8860b;
  --volt-tint:#fdf6d5;
  --bg:#f9fafd;
  --surface:#ffffff;
  --line:#e2e6ef;
  --muted:#5f6680;
  --shadow:0 1px 2px rgba(24,31,63,.05),0 12px 30px -16px rgba(24,31,63,.25);
  --radius:10px;
  --maxw:1160px;
  --font:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Leelawadee UI","Noto Sans Thai",sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.65;font-size:16.5px}
img,svg{display:block;max-width:100%}
a{color:var(--indigo);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.22;letter-spacing:-.012em;font-weight:800}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.section{padding:76px 0}
.section.alt{background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.eyebrow{display:inline-block;font-size:.76rem;font-weight:800;letter-spacing:.16em;text-transform:uppercase;color:var(--indigo-deep);background:var(--indigo-tint);padding:5px 12px;border-radius:6px;margin-bottom:14px}
.h2{font-size:clamp(1.6rem,3.2vw,2.15rem);margin-bottom:12px}
.lead{color:var(--muted);max-width:640px}
.center{text-align:center}
.center .lead{margin:0 auto}
.section-head{margin-bottom:42px}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 24px;border-radius:8px;font-weight:800;font-size:.98rem;border:2px solid transparent;cursor:pointer;transition:.18s;text-decoration:none!important}
.btn-primary{background:var(--volt);color:#3a2d05;box-shadow:0 8px 20px -8px rgba(253,210,30,.6)}
.btn-primary:hover{background:#ffe15c;transform:translateY(-1px)}
.btn-ghost{border-color:var(--indigo);color:var(--indigo)}
.btn-ghost:hover{background:var(--indigo);color:#fff}
.btn-sm{padding:9px 18px;font-size:.9rem}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:60;background:rgba(249,250,253,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;gap:26px;height:70px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.2rem;color:var(--ink);text-decoration:none!important}
.brand .mark{width:38px;height:38px;border-radius:10px;background:var(--indigo-deep);display:grid;place-items:center;color:var(--volt)}
.brand small{display:block;font-size:.64rem;font-weight:700;letter-spacing:.16em;color:var(--muted);text-transform:uppercase}
.nav-links{display:flex;gap:24px;margin-left:auto;align-items:center}
.nav-links a{color:var(--ink-soft);font-weight:600;font-size:.95rem}
.nav-links a:hover{color:var(--indigo);text-decoration:none}
.nav-cta{margin-left:4px}
.nav-toggle{display:none;margin-left:auto;background:none;border:1.5px solid var(--line);border-radius:8px;padding:8px 10px;cursor:pointer;color:var(--ink)}
.nav-toggle svg{width:20px;height:20px}

/* ---------- hero (dark indigo, volt glow) ---------- */
.hero{position:relative;overflow:hidden;color:#eef0fb;background:
  radial-gradient(700px 380px at 85% -10%,rgba(253,210,30,.16),transparent 60%),
  linear-gradient(125deg,#141a38 0%,#232f86 55%,#3c51c6 100%)}
.hero-inner{display:grid;grid-template-columns:1.12fr .88fr;gap:48px;align-items:center;padding:86px 0 74px}
.hero h1{font-size:clamp(2.1rem,4.6vw,3.2rem);margin:16px 0 18px;color:#fff}
.hero h1 em{font-style:normal;color:var(--volt)}
.hero .lede{font-size:1.12rem;color:rgba(238,240,251,.82);max-width:560px;margin-bottom:28px}
.hero-ctas{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:32px}
.hero-note{font-size:.86rem;color:rgba(238,240,251,.65)}
.hero-note strong{color:var(--volt)}
.hero-panel{background:rgba(255,255,255,.97);border-radius:8px;border-top:3px solid var(--volt);box-shadow:var(--shadow);padding:28px;color:var(--ink)}
.hero-panel h3{font-size:1.02rem;margin-bottom:16px;color:var(--indigo-deep)}
.quote-rows{display:grid;gap:9px}
.quote-row{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:10px 14px;background:var(--bg);border:1px solid var(--line);border-radius:6px;font-size:.93rem}
.quote-row b{font-size:1.02rem;color:var(--indigo-deep);white-space:nowrap}
.quote-row span{color:var(--muted)}
.hero-panel .fine{margin-top:14px;font-size:.8rem;color:var(--muted)}

/* ---------- stats strip ---------- */
.stats{background:var(--ink);color:#cdd3ec}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;padding:26px 0}
.stat{display:flex;flex-direction:column;align-items:center;text-align:center;gap:2px}
.stat b{font-size:1.5rem;color:var(--volt)}
.stat span{font-size:.84rem;opacity:.85}

/* ---------- category cards ---------- */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.cat-card{background:var(--surface);border:1px solid var(--line);border-top:3px solid var(--volt);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow);transition:.2s;display:flex;flex-direction:column;gap:10px}
.cat-card:hover{transform:translateY(-4px);border-top-color:var(--indigo)}
.cat-icon{width:52px;height:52px;border-radius:12px;background:var(--indigo-tint);color:var(--indigo);display:grid;place-items:center;margin-bottom:4px}
.cat-icon svg{width:26px;height:26px}
.cat-card h3{font-size:1.08rem}
.cat-card p{font-size:.92rem;color:var(--muted)}
.cat-card .moq{margin-top:auto;font-size:.8rem;font-weight:800;color:var(--indigo-deep);background:var(--indigo-tint);border-radius:6px;padding:4px 12px;align-self:flex-start}

/* ---------- advantage ---------- */
.adv-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.adv{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.adv .num{font-size:.75rem;font-weight:800;letter-spacing:.1em;color:var(--volt-deep)}
.adv h3{font-size:1.02rem;margin:6px 0 8px}
.adv p{font-size:.9rem;color:var(--muted)}

/* ---------- process ---------- */
.steps{display:grid;grid-template-columns:repeat(6,1fr);gap:14px}
.step{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px 14px;text-align:center}
.step .n{font-size:.72rem;font-weight:800;letter-spacing:.1em;color:var(--indigo)}
.step svg{width:26px;height:26px;margin:6px auto 8px;color:var(--indigo)}
.step b{display:block;font-size:.9rem;margin-bottom:4px}
.step span{font-size:.78rem;color:var(--muted)}

/* ---------- price table ---------- */
.table-wrap{overflow-x:auto;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
table{width:100%;border-collapse:collapse;font-size:.93rem;min-width:640px}
thead th{background:var(--indigo-deep);color:#eef0fb;text-align:left;padding:13px 16px;font-size:.8rem;letter-spacing:.08em;text-transform:uppercase;white-space:nowrap}
tbody td{padding:13px 16px;border-top:1px solid var(--line);vertical-align:top}
tbody tr:nth-child(even){background:var(--bg)}
td b{color:var(--indigo-deep)}
.tag{display:inline-block;font-size:.74rem;font-weight:800;padding:3px 10px;border-radius:6px;background:var(--indigo-tint);color:var(--indigo-deep);white-space:nowrap}
.tag.gold{background:var(--volt-tint);color:var(--volt-deep)}

/* ---------- testimonials ---------- */
.tm-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.tm{background:var(--surface);border:1px solid var(--line);border-left:4px solid var(--volt);border-radius:var(--radius);padding:22px}
.tm p{font-size:.93rem;color:var(--ink-soft)}
.tm .who{margin-top:14px;font-size:.83rem;color:var(--muted)}
.tm .who b{color:var(--ink)}

/* ---------- FAQ ---------- */
.faq{max-width:780px;margin:0 auto;display:grid;gap:12px}
details{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px 20px}
summary{cursor:pointer;font-weight:700;font-size:1rem;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font-size:1.3rem;color:var(--indigo);font-weight:400}
details[open] summary::after{content:"–"}
details p{margin-top:10px;color:var(--muted);font-size:.94rem}

/* ---------- CTA band ---------- */
.cta-band{background:linear-gradient(120deg,#141a38,#28379b);border-radius:10px;color:#eef0fb;padding:46px 44px;display:flex;align-items:center;justify-content:space-between;gap:26px;flex-wrap:wrap;box-shadow:var(--shadow)}
.cta-band h2{font-size:clamp(1.4rem,2.6vw,1.9rem);color:#fff}
.cta-band p{opacity:.85;max-width:520px;margin-top:6px}
.cta-band .btn-primary{background:var(--volt);color:#3a2d05}
.cta-band .btn-primary:hover{background:#ffe15c}
.cta-band .btn-ghost{border-color:#eef0fb;color:#eef0fb}
.cta-band .btn-ghost:hover{background:#eef0fb;color:var(--indigo-deep)}

/* ---------- page hero (subpages) ---------- */
.page-hero{background:
  radial-gradient(700px 300px at 90% -20%,var(--indigo-tint),transparent 60%),var(--bg);
  border-bottom:1px solid var(--line);padding:56px 0 44px}
.page-hero h1{font-size:clamp(1.8rem,3.6vw,2.5rem);margin:14px 0 10px}
.page-hero .lede{color:var(--muted);max-width:680px;font-size:1.05rem}

/* ---------- category section (products page) ---------- */
.cat-block{display:grid;grid-template-columns:.9fr 1.1fr;gap:36px;align-items:start;padding:38px 0;border-bottom:1px solid var(--line)}
.cat-block:last-of-type{border-bottom:none}
.cat-block .info{position:sticky;top:96px}
.cat-block .info h2{font-size:1.45rem;margin:12px 0 10px}
.cat-block .info p{color:var(--muted);font-size:.95rem;margin-bottom:14px}
.cat-block ul{list-style:none;display:grid;gap:8px;margin-bottom:18px}
.cat-block ul li{display:flex;gap:10px;font-size:.93rem;color:var(--ink-soft)}
.cat-block ul li::before{content:"⚡";color:var(--volt-deep);font-size:.8rem;margin-top:2px}

/* ---------- form ---------- */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.form-grid .full{grid-column:1/-1}
.field label{display:block;font-size:.85rem;font-weight:700;margin-bottom:6px}
.field input,.field select,.field textarea{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:8px;font:inherit;background:var(--surface);color:var(--ink);transition:.15s}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--indigo);box-shadow:0 0 0 3px var(--indigo-tint)}
.field textarea{min-height:130px;resize:vertical}
.form-note{font-size:.82rem;color:var(--muted);margin-top:12px}
.contact-wrap{display:grid;grid-template-columns:1.25fr .75fr;gap:34px;align-items:start}
.contact-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);margin-bottom:18px}
.contact-card h3{font-size:1.02rem;margin-bottom:8px;display:flex;gap:9px;align-items:center;color:var(--indigo-deep)}
.contact-card h3 svg{width:19px;height:19px;color:var(--volt-deep)}
.contact-card p{font-size:.92rem;color:var(--muted)}
.contact-card a{font-weight:600;word-break:break-word}
.pill-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px}

/* ---------- OEM / about ---------- */
.split{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}
.check-list{list-style:none;display:grid;gap:12px;margin:18px 0}
.check-list li{display:flex;gap:12px;font-size:.97rem;color:var(--ink-soft)}
.check-list li::before{content:"⚡";flex:none;margin-top:2px;color:var(--volt-deep);font-size:.85rem}
.value-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.value{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.value h3{font-size:1.02rem;margin-bottom:8px}
.value p{font-size:.92rem;color:var(--muted)}
.qc-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.qc-step{background:var(--surface);border:1px solid var(--line);border-top:3px solid var(--volt);border-radius:var(--radius);padding:20px}
.qc-step h3{font-size:.98rem;margin-bottom:6px}
.qc-step p{font-size:.88rem;color:var(--muted)}

/* ---------- footer ---------- */
.site-footer{background:#131835;color:#b9c0dd;margin-top:76px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1.2fr;gap:34px;padding:52px 0 40px}
.site-footer h4{color:#fff;font-size:.95rem;margin-bottom:14px}
.site-footer ul{list-style:none;display:grid;gap:9px}
.site-footer a{color:#b9c0dd;font-size:.92rem}
.site-footer a:hover{color:var(--volt)}
.site-footer .brand{color:#fff}
.site-footer .brand .mark{background:rgba(255,255,255,.1)}
.site-footer p{font-size:.9rem;max-width:300px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding:18px 0;font-size:.83rem;display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}

/* ---------- language dropdown (compact, end of nav) ---------- */
.lang-switch{position:relative;margin-left:2px}
.lang-switch summary{list-style:none;display:inline-flex;align-items:center;gap:6px;padding:4px 8px;border-radius:8px;cursor:pointer;font-size:.74rem;font-weight:700;letter-spacing:.06em;color:var(--muted);background:transparent;transition:.15s;user-select:none}
.lang-switch summary::-webkit-details-marker{display:none}
.lang-switch summary:hover,.lang-switch[open] summary{background:var(--indigo-tint);color:var(--indigo)}
.lang-switch .caret{width:9px;height:5px;transition:.2s;color:currentColor;opacity:.7}
.lang-switch[open] .caret{transform:rotate(180deg)}
.lang-menu{position:absolute;top:calc(100% + 7px);right:0;min-width:176px;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:5px;z-index:90;display:flex;flex-direction:column;gap:1px}
.lang-menu a{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:8px;font-size:.88rem;font-weight:600;color:var(--ink-soft);white-space:nowrap}
.lang-menu a:hover{background:var(--indigo-tint);color:var(--indigo);text-decoration:none}
.lang-menu a[aria-current="true"]{background:var(--indigo-tint);color:var(--indigo)}
.lang-menu a[aria-current="true"]::after{content:"✓";margin-left:auto;font-weight:800}
.flag{width:18px;height:12px;border-radius:2.5px;overflow:hidden;flex:none;display:inline-block;box-shadow:inset 0 0 0 1px rgba(0,0,0,.12)}
.flag svg{width:100%;height:100%;display:block}

/* ---------- whatsapp float ---------- */
.wa-float{position:fixed;right:22px;bottom:22px;z-index:80;width:58px;height:58px;border-radius:50%;background:#25d366;display:grid;place-items:center;color:#fff;box-shadow:0 10px 24px -8px rgba(37,211,102,.65);transition:.2s}
.wa-float:hover{transform:scale(1.07)}
.wa-float svg{width:30px;height:30px}

/* ---------- responsive ---------- */
@media (max-width:1000px){
  .hero-inner{grid-template-columns:1fr;padding:56px 0}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .adv-grid{grid-template-columns:repeat(2,1fr)}
  .steps{grid-template-columns:repeat(3,1fr)}
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .qc-steps{grid-template-columns:repeat(2,1fr)}
  .cat-block{grid-template-columns:1fr}
  .cat-block .info{position:static}
  .contact-wrap,.split{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:700px){
  .nav-links{display:none;position:absolute;top:70px;left:0;right:0;background:var(--surface);border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;padding:14px 24px 20px;gap:14px}
  .nav-links.open{display:flex}
  .nav-links a{padding:6px 0}
  .nav-toggle{display:block}
  .grid-3,.tm-grid{grid-template-columns:1fr}
  .adv-grid,.steps{grid-template-columns:1fr 1fr}
  .form-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .section{padding:54px 0}
  .cta-band{padding:32px 26px}
}