/* GearVN Back-to-School 2026 — "Đổi điểm thi" micro-site. Mobile-first. */
:root{
  --gvn-red:#d71920; --gvn-red-dark:#b7151b; --gvn-red-press:#b42318;
  --gvn-ink:#172033; --gvn-ink-2:#111827; --gvn-muted:#53657f; --gvn-muted-2:#6a7890;
  --gvn-bg:#fff; --gvn-bg-soft:#f6f8fb; --gvn-line:#d5dde8;
  --gvn-success:#0f766e; --gvn-success-bg:#e8f7f1; --gvn-warn-bg:#fff7df;
  --gvn-error:#b42318; --gvn-error-bg:#fff0ef; --gvn-gold:#e3b341;
  --radius:14px; --shadow:0 6px 24px rgba(23,32,51,.08); --shadow-lg:0 12px 40px rgba(23,32,51,.16);
  --font:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI","Be Vietnam Pro",sans-serif;
}
*{box-sizing:border-box}
/* the [hidden] attribute must win over component display rules (khối toggle, CCCD field, countdown) */
[hidden]{display:none!important}
html,body{margin:0;padding:0}
body{font-family:var(--font);color:var(--gvn-ink);background:var(--gvn-bg-soft);font-size:15px;line-height:1.5;-webkit-font-smoothing:antialiased}
img{max-width:100%}
a{color:var(--gvn-red-dark)}
.wrap{max-width:520px;margin:0 auto;padding:0 16px}

/* DEMO ribbon */
.demo-ribbon{background:repeating-linear-gradient(45deg,#1f2937,#1f2937 14px,#111827 14px,#111827 28px);color:#ffd76a;font-size:12.5px;font-weight:600;text-align:center;padding:7px 10px;letter-spacing:.2px}
.demo-ribbon[hidden]{display:none}

/* Header */
header.site{position:sticky;top:0;z-index:30;background:var(--gvn-red);color:#fff;box-shadow:0 2px 10px rgba(0,0,0,.12)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:54px}
.logo{font-weight:800;font-size:20px;letter-spacing:.5px;color:#fff;text-decoration:none}
.logo span{color:var(--gvn-gold)}
.hotline{color:#fff;text-decoration:none;font-weight:600;font-size:14px;background:rgba(255,255,255,.15);padding:6px 12px;border-radius:999px}

/* Stepper */
.stepper{position:sticky;top:54px;z-index:20;background:#fff;border-bottom:1px solid var(--gvn-line)}
.stepper .wrap{display:flex;gap:6px;padding:10px 16px}
.step-pill{flex:1;display:flex;align-items:center;gap:7px;font-size:12.5px;color:var(--gvn-muted);font-weight:600}
.step-pill .dot{width:22px;height:22px;border-radius:50%;display:grid;place-items:center;background:var(--gvn-bg-soft);border:1.5px solid var(--gvn-line);font-size:12px;flex:none}
.step-pill.active{color:var(--gvn-ink)}
.step-pill.active .dot{background:var(--gvn-red);border-color:var(--gvn-red);color:#fff}
.step-pill.done .dot{background:var(--gvn-success);border-color:var(--gvn-success);color:#fff}

/* Hero */
.hero{background:radial-gradient(120% 120% at 80% 0,#e23b2c 0,var(--gvn-red) 38%,#7d0f14 100%);color:#fff;padding:30px 0 34px;text-align:center}
.hero .eyebrow{font-weight:700;letter-spacing:2px;font-size:12.5px;opacity:.92}
.hero h1{font-size:27px;line-height:1.18;margin:10px 0 8px;font-weight:800}
.hero h1 .amount{color:var(--gvn-gold)}
.hero p{margin:0 auto;max-width:380px;opacity:.94;font-size:14.5px}
.hero .cta-row{margin-top:18px}
.hero .chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:16px}
.hero .chip{background:rgba(255,255,255,.16);border-radius:999px;padding:5px 11px;font-size:12px;font-weight:600}
.countdown{margin-top:14px;font-size:13px;background:rgba(0,0,0,.18);display:inline-block;padding:8px 14px;border-radius:10px}

/* Cards / sections */
main{padding:18px 0 40px}
.card{background:#fff;border:1px solid var(--gvn-line);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px 18px;margin:14px 0}
.card[hidden]{display:none}
.card h2{font-size:19px;margin:0 0 4px;font-weight:700}
.card .sub{color:var(--gvn-muted);font-size:13.5px;margin:0 0 16px}
.step-tag{display:inline-block;font-size:12px;font-weight:700;color:var(--gvn-red);letter-spacing:.5px;margin-bottom:6px}

/* Form */
label.field{display:block;margin:14px 0}
label.field > .lab{display:block;font-size:13.5px;font-weight:600;margin-bottom:6px}
.input,select.input{width:100%;font:inherit;font-size:16px;padding:12px 13px;border:1.5px solid var(--gvn-line);border-radius:10px;background:#fff;color:var(--gvn-ink)}
.input:focus,select.input:focus{outline:none;border-color:var(--gvn-red);box-shadow:0 0 0 3px rgba(215,25,32,.12)}
.hint{font-size:12.5px;color:var(--gvn-muted-2);margin-top:6px}
.err{font-size:12.5px;color:var(--gvn-error);margin-top:6px;display:flex;gap:5px;align-items:flex-start}
.err[hidden]{display:none}
.two{display:flex;gap:12px}.two > *{flex:1}
.radio-row{display:flex;flex-direction:column;gap:8px;margin-top:6px}
.radio{display:flex;gap:10px;align-items:flex-start;border:1.5px solid var(--gvn-line);border-radius:10px;padding:11px 12px;cursor:pointer}
.radio input{margin-top:3px;accent-color:var(--gvn-red)}
.radio.sel{border-color:var(--gvn-red);background:#fff6f6}
.radio b{font-size:14.5px}.radio small{display:block;color:var(--gvn-muted);font-size:12.5px}
.score-row{display:flex;gap:8px;align-items:center;margin:8px 0}
.score-row .sc-lab{flex:1;font-size:14px;font-weight:600}
.score-row select.input{flex:1}
.score-row .sc{max-width:110px}
#selfScoreBlock[hidden],#dobBlock[hidden],#lookupModeField[hidden]{display:none}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;width:100%;font:inherit;font-size:16px;font-weight:600;padding:14px 18px;border-radius:11px;border:0;cursor:pointer;min-height:48px;transition:filter .15s,transform .05s}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--gvn-red);color:#fff}
.btn-primary:hover{filter:brightness(1.05)}
.btn-primary:disabled{background:#e3a9ac;cursor:not-allowed}
.btn-ghost{background:#fff;color:var(--gvn-ink);border:1.5px solid var(--gvn-line)}
.btn-gold{background:linear-gradient(135deg,#f6c453,#e3b341);color:#3a2a00}
.btn-row{display:flex;gap:10px;margin-top:14px}
.btn.sm{width:auto;font-size:14px;padding:9px 14px;min-height:0}
.reassure{font-size:12.5px;color:var(--gvn-muted);margin-top:10px;text-align:center}

/* Result reveal */
.avg-box{text-align:center;padding:8px 0 4px}
.avg-box .avg-num{font-size:46px;font-weight:800;line-height:1;color:var(--gvn-ink)}
.avg-box .avg-cap{font-size:13px;color:var(--gvn-muted);margin-top:4px}
.chips-subj{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;margin:12px 0}
.chip-subj{background:var(--gvn-bg-soft);border:1px solid var(--gvn-line);border-radius:999px;padding:4px 11px;font-size:12.5px;font-weight:600}
.tier-card{margin-top:14px;border:2px solid var(--gvn-red);border-radius:14px;padding:16px;text-align:center;background:linear-gradient(180deg,#fff6f6,#fff)}
.tier-card.gold{border-color:var(--gvn-gold);background:linear-gradient(180deg,#fffaf0,#fff)}
.tier-card .t-head{font-size:14px;font-weight:600;color:var(--gvn-ink)}
.tier-card .t-amt{font-size:34px;font-weight:800;color:var(--gvn-red);margin:4px 0}
.tier-card.gold .t-amt{color:#b9881a}
.tier-card .t-band{font-size:13px;color:var(--gvn-muted)}
.applies{font-size:12.5px;color:var(--gvn-muted);text-align:center;margin-top:10px}

/* Voucher */
.voucher{margin-top:8px;border:2px dashed var(--gvn-red);border-radius:14px;background:#fff6f6;padding:16px;text-align:center}
.voucher .vlabel{font-size:12.5px;color:var(--gvn-muted);font-weight:600}
.voucher .vcode{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:22px;font-weight:700;letter-spacing:1px;color:var(--gvn-ink);margin:6px 0 10px;word-break:break-all}
.howto{margin-top:16px;background:var(--gvn-bg-soft);border-radius:12px;padding:14px}
.howto h3{margin:0 0 8px;font-size:14px}
.howto ol{margin:0;padding-left:20px;font-size:13.5px;color:var(--gvn-ink)}
.howto li{margin:4px 0}

/* State banners */
.banner{border-radius:12px;padding:16px;margin:14px 0;display:flex;gap:12px;align-items:flex-start}
.banner .ic{font-size:22px;flex:none}
.banner h3{margin:0 0 4px;font-size:15.5px}
.banner p{margin:0;font-size:13.5px}
.banner.warn{background:var(--gvn-warn-bg);border:1px solid #f0d98a}
.banner.error{background:var(--gvn-error-bg);border:1px solid #f3c2bf}
.banner.info{background:var(--gvn-success-bg);border:1px solid #b9e6d8}
.banner[hidden]{display:none}

/* FAQ / Terms */
.accordion{border-top:1px solid var(--gvn-line)}
.accordion details{border-bottom:1px solid var(--gvn-line)}
.accordion summary{cursor:pointer;padding:13px 2px;font-weight:600;font-size:14.5px;list-style:none;display:flex;justify-content:space-between;gap:10px}
.accordion summary::-webkit-details-marker{display:none}
.accordion summary::after{content:"+";color:var(--gvn-red);font-weight:700}
.accordion details[open] summary::after{content:"–"}
.accordion .body{padding:0 2px 13px;font-size:13.5px;color:var(--gvn-muted)}
.terms ul{padding-left:18px;margin:8px 0}
.terms li{margin:4px 0;font-size:13px;color:var(--gvn-ink)}
.tier-list{font-size:13px;color:var(--gvn-ink);background:var(--gvn-bg-soft);border-radius:10px;padding:12px;margin:8px 0}

/* Footer */
footer.site{background:var(--gvn-ink);color:#c8d2e0;padding:22px 0;font-size:13px;text-align:center}
footer.site a{color:#fff}
footer.site .row{margin:4px 0}

/* Toast */
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--gvn-ink);color:#fff;padding:11px 18px;border-radius:10px;font-size:14px;box-shadow:var(--shadow-lg);opacity:0;pointer-events:none;transition:opacity .2s}
.toast.show{opacity:1}

.spin{display:inline-block;width:16px;height:16px;border:2px solid rgba(255,255,255,.4);border-top-color:#fff;border-radius:50%;animation:sp .7s linear infinite}
@keyframes sp{to{transform:rotate(360deg)}}
.reveal{animation:rv .35s ease}
@keyframes rv{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@media (prefers-reduced-motion:reduce){.reveal,.spin{animation:none}}
@media(min-width:560px){.hero h1{font-size:31px}}