/* VN-JP UAV Delivery Buildathon — hệ thiết kế của web thi.
   Cùng ngôn ngữ với video công bố: nền xanh navy chuyển tối, chữ đậm trắng, MỘT từ nhấn màu cam, viền cyan cho chip,
   bốn bước Build · Test · Certify · Race, huy hiệu khiên-drone. Ảnh là cảnh chụp thật từ GRASP Drone Lab. */
:root{
  --bg:#050d22;--bg2:#0b1f4a;--card:#0c1a3d;--s2:#12285a;--line:#27437f;--line2:#1b3266;
  --ink:#EAF1FF;--dim:#BCCBE6;--faint:#8DA2C8;
  --acc:#FF8A1F;--acc2:rgba(255,138,31,.14);--blue:#5EC8FF;--ok:#22C55E;--bad:#FF5A63;--warn:#F6AD55;--on:#0b1f4a;
  --gold:#F5C542;--silver:#C9D3E3;--bronze:#D08A4E;
  --font:"Be Vietnam Pro","Segoe UI",system-ui,-apple-system,Roboto,Helvetica,Arial,sans-serif;--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --r:16px;--hdr:64px;color-scheme:dark}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:80px}
body{margin:0;min-height:100vh;color:var(--ink);font:16px/1.6 var(--font);background:var(--bg);
  background-image:radial-gradient(1100px 620px at 78% -6%,#12357a 0%,rgba(18,53,122,0) 62%),radial-gradient(900px 520px at -8% 18%,#0e2a66 0%,rgba(14,42,102,0) 60%);background-repeat:no-repeat}
a{color:var(--blue)}a:hover{color:#fff}
img{max-width:100%}
h1,h2,h3,h4{font-weight:800;line-height:1.15;margin:0}
h1{font-size:clamp(30px,4.4vw,46px);letter-spacing:-.4px}h2{font-size:clamp(24px,3vw,32px);letter-spacing:-.3px}h3{font-size:19px}
.o,h1 em,h2 em{color:var(--acc);font-style:normal}
.lead{color:var(--dim);font-size:18px;max-width:760px;margin:10px 0 0}
.mono,.eyebrow{font-family:var(--mono)}
.eyebrow{display:inline-block;font-size:12.5px;letter-spacing:1.6px;text-transform:uppercase;color:var(--blue);margin:0 0 12px}
.dim{color:var(--dim)}.faint{color:var(--faint)}.hint{font-size:13.5px;color:var(--dim);margin:4px 0}.sm{font-size:14px}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:8px;z-index:100;background:var(--acc);color:var(--on);padding:8px 12px;border-radius:8px}
:focus-visible{outline:2px solid var(--blue);outline-offset:2px;border-radius:6px}

/* ---------- khung trang */
.wrap{max-width:1160px;margin:0 auto;padding:0 20px}
main{display:block}
main.page{max-width:1160px;margin:0 auto;padding:44px 20px 80px}
.blk{max-width:1160px;margin:0 auto;padding:68px 20px 0}
.blk.tight{padding-top:44px}
.blk>.head{margin-bottom:26px}.blk>.head p{color:var(--dim);font-size:17px;max-width:720px;margin:10px 0 0}
.split{display:grid;gap:36px;grid-template-columns:1fr 1fr;align-items:center}
.grid{display:grid;gap:16px}.g2{grid-template-columns:repeat(auto-fit,minmax(min(300px,100%),1fr))}.g3{grid-template-columns:repeat(auto-fit,minmax(250px,1fr))}.g5{grid-template-columns:repeat(auto-fit,minmax(min(190px,100%),1fr))}.g4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.sp{justify-content:space-between}
.stack>*+*{margin-top:14px}

/* ---------- đầu trang */
.hdr{position:sticky;top:0;z-index:50;background:rgba(5,13,34,.82);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line2)}
.hdr .in{max-width:1160px;margin:0 auto;padding:0 20px;height:var(--hdr);display:flex;align-items:center;gap:18px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-weight:800;letter-spacing:.9px;font-size:14.5px;white-space:nowrap}
.brand svg{width:30px;height:34px;flex:none}.brand>span{display:flex;flex-direction:column;line-height:1.05}.brand small{font-weight:600;letter-spacing:1.4px;color:var(--blue);font-size:9.5px;margin-top:3px}
.brand b{color:var(--acc);font-weight:800}
.hdr nav{display:flex;gap:2px;margin-left:auto;align-items:center}
.hdr nav a{color:var(--dim);text-decoration:none;padding:8px 11px;border-radius:9px;font-size:14.5px;font-weight:600;white-space:nowrap}
.hdr nav a:hover{color:#fff;background:rgba(255,255,255,.07)}.hdr nav a.on{color:#fff;background:rgba(94,200,255,.14);box-shadow:inset 0 -2px 0 var(--acc)}
.hdr .tools{display:flex;gap:8px;align-items:center;margin-left:8px}
.lang{border:1px solid var(--line);background:none;color:var(--dim);border-radius:9px;padding:6px 10px;cursor:pointer;font:600 12.5px var(--font);letter-spacing:.5px}.lang:hover{color:#fff;border-color:var(--blue)}
.signin{background:var(--acc);color:var(--on)!important;font-weight:800!important;border-radius:99px!important;padding:8px 16px!important;box-shadow:none!important}
.burger{display:none;margin-left:auto;background:none;border:1px solid var(--line);color:#fff;border-radius:9px;width:42px;height:38px;font-size:20px;cursor:pointer}
@media (max-width:1120px){
  .burger{display:block}.hdr nav{display:none;position:absolute;left:0;right:0;top:var(--hdr);flex-direction:column;align-items:stretch;gap:2px;padding:10px 16px 16px;background:rgba(5,13,34,.97);border-bottom:1px solid var(--line2);margin:0}
  .hdr.open nav{display:flex}.hdr nav a{padding:12px 12px}.hdr .tools{margin:8px 0 0;padding-top:10px;border-top:1px solid var(--line2);flex-wrap:wrap}}

/* ---------- nút, chip */
.btn{display:inline-flex;align-items:center;gap:8px;border:0;background:var(--acc);color:var(--on);font:800 15.5px var(--font);padding:12px 22px;border-radius:12px;cursor:pointer;text-decoration:none;transition:transform .12s,box-shadow .12s}
.btn:hover{color:var(--on);transform:translateY(-1px);box-shadow:0 8px 26px rgba(255,138,31,.28)}
.btn.sec{background:transparent;color:#fff;border:1.5px solid var(--blue)}.btn.sec:hover{background:rgba(94,200,255,.12);color:#fff;box-shadow:none}
.btn.ghost{background:rgba(255,255,255,.06);color:#fff;border:1px solid var(--line)}.btn.ghost:hover{color:#fff;box-shadow:none;background:rgba(255,255,255,.1)}
.btn.sm{padding:6px 12px;font-size:14px;border-radius:9px}.btn.danger{background:var(--bad);color:#fff}.btn[disabled]{opacity:.5;cursor:default;transform:none;box-shadow:none}
.chip{display:inline-flex;align-items:center;gap:6px;padding:5px 13px;border-radius:99px;background:rgba(5,12,30,.8);border:1.5px solid var(--blue);font-size:13.5px;font-weight:700;color:#fff}
.chip.ok{border-color:var(--ok)}.chip.bad{border-color:var(--bad)}.chip.warn{border-color:var(--warn)}.chip.o{border-color:var(--acc);color:var(--acc)}
.pill{display:inline-block;border-radius:99px;padding:2px 10px;font-size:12.5px;background:var(--s2);color:var(--dim);font-weight:700;border:1px solid var(--line)}
.pill.ok{background:rgba(34,197,94,.14);color:var(--ok);border-color:rgba(34,197,94,.4)}.pill.bad{background:rgba(255,90,99,.14);color:var(--bad);border-color:rgba(255,90,99,.4)}.pill.warn{background:rgba(246,173,85,.14);color:var(--warn);border-color:rgba(246,173,85,.4)}

/* ---------- thẻ, bảng */
.card{background:linear-gradient(180deg,rgba(18,40,90,.55),rgba(12,26,61,.9));border:1px solid var(--line);border-radius:var(--r);padding:22px}
.card.hero{background:linear-gradient(135deg,var(--s2),var(--card))}
.card h3{margin-bottom:6px}.card p{margin:0;color:var(--dim)}
.card.flat{background:rgba(12,26,61,.7)}
.callout{border-left:4px solid var(--acc);background:var(--acc2);border-radius:0 12px 12px 0;padding:14px 18px;color:#ffe3c4}.callout.info{border-left-color:var(--blue);background:rgba(94,200,255,.1);color:#d4eeff}
.callout b{color:#fff}
table{border-collapse:collapse;width:100%;font-size:15px}th,td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line2);vertical-align:top}
th{font:700 12px var(--mono);color:var(--faint);text-transform:uppercase;letter-spacing:1px;white-space:nowrap}
td.n,th.n{text-align:right;font-variant-numeric:tabular-nums}.scroll{overflow-x:auto}
.tbl{border:1px solid var(--line);border-radius:var(--r);overflow:hidden;background:rgba(12,26,61,.7)}.tbl th{background:rgba(5,13,34,.5)}.tbl tr:last-child td{border-bottom:0}
.kv{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px}.kv div{border:1px solid var(--line);border-radius:14px;padding:14px 16px;background:rgba(12,26,61,.7)}
.kv b{display:block;font-size:26px;font-weight:800;line-height:1.1}.kv span{font:600 12px var(--mono);letter-spacing:1px;color:var(--faint);text-transform:uppercase}
.kv small{display:block;color:var(--dim);font-size:13px;margin-top:4px}
.shot{margin:0;border:1px solid var(--line);border-radius:var(--r);overflow:hidden;background:var(--card);box-shadow:0 24px 70px rgba(0,0,0,.45)}.shot img{display:block;width:100%;height:auto}
.shot figcaption{padding:10px 14px;font-size:13px;color:var(--dim);border-top:1px solid var(--line2)}

/* ---------- hero trang chủ */
.hero{padding:64px 0 28px}
.hero .wrap{display:grid;gap:44px;grid-template-columns:1.04fr 1fr;align-items:center}
.hero .emblem{width:84px;height:94px;filter:drop-shadow(0 0 22px rgba(94,200,255,.5));margin-bottom:12px}
.hero h1{font-size:clamp(38px,6vw,70px);line-height:1.02;letter-spacing:1px;font-weight:800;text-transform:uppercase}
.hero .tag{font-size:clamp(18px,2.3vw,24px);color:var(--blue);font-weight:700;margin:16px 0 0}
.hero .sub{color:var(--dim);font-size:17.5px;max-width:560px;margin:16px 0 26px}
.stats{display:flex;gap:26px;flex-wrap:wrap;margin-top:34px;padding-top:22px;border-top:1px solid var(--line2)}
.stats b{display:block;font-size:30px;font-weight:800}.stats span{font:600 12px var(--mono);letter-spacing:1px;text-transform:uppercase;color:var(--faint)}
@media (max-width:900px){.hero .wrap,.split{grid-template-columns:1fr}.hero{padding-top:40px}}
.pagehead{padding:58px 0 8px}.pagehead .wrap{max-width:1160px}
.pagehead h1{max-width:900px}.pagehead .crumb{font:600 12.5px var(--mono);color:var(--faint);letter-spacing:1.2px;text-transform:uppercase;margin-bottom:12px}.pagehead .crumb a{color:var(--blue);text-decoration:none}
.pagehead.track{position:relative;padding:80px 0 56px;border-bottom:1px solid var(--line2);overflow:hidden}
.pagehead.track::before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(5,13,34,.96) 20%,rgba(5,13,34,.55)),var(--bgimg) center/cover;z-index:-1}
.pagehead.track .wrap{position:relative}

/* ---------- đường đi Build · Test · Certify · Race */
.pipe{display:grid;gap:14px;grid-template-columns:repeat(4,1fr);counter-reset:p}
.pipe .st{position:relative;border:1px solid var(--line);border-radius:var(--r);padding:20px 20px 22px;background:linear-gradient(180deg,rgba(18,40,90,.55),rgba(12,26,61,.9));counter-increment:p;text-decoration:none;color:inherit;display:block;transition:border-color .15s,transform .15s}
.pipe a.st:hover{border-color:var(--blue);transform:translateY(-2px);color:inherit}
.pipe .st .num{display:inline-flex;width:34px;height:34px;border-radius:50%;align-items:center;justify-content:center;background:var(--acc);color:var(--on);font-weight:800;font-size:16px}
.pipe .st h3{margin:14px 0 6px;font-size:20px}.pipe .st p{margin:0;color:var(--dim);font-size:14.5px}
.pipe .st:not(:last-child)::after{content:"";position:absolute;right:-15px;top:38px;width:16px;height:2px;background:var(--line)}
@media (max-width:900px){.pipe{grid-template-columns:1fr 1fr}.pipe .st::after{display:none}}@media (max-width:520px){.pipe{grid-template-columns:1fr}}

/* ---------- thẻ track */
.tracks{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(min(340px,100%),1fr))}
.tk{border:1px solid var(--line);border-radius:20px;overflow:hidden;background:var(--card);display:flex;flex-direction:column;text-decoration:none;color:inherit;transition:border-color .15s,transform .15s}
a.tk:hover{border-color:var(--acc);transform:translateY(-3px);color:inherit}
.tk .ph{aspect-ratio:16/9;overflow:hidden;position:relative}.tk .ph img{display:block;width:100%;height:100%;object-fit:cover}
.tk .ph .chip{position:absolute;left:14px;top:14px}
.tk .bd{padding:20px 22px 24px;display:flex;flex-direction:column;gap:10px;flex:1}.tk h3{font-size:25px}.tk p{margin:0;color:var(--dim)}
.tk ul{padding:0;margin:4px 0 0;list-style:none;display:flex;flex-wrap:wrap;gap:8px}.tk li{border:1px solid var(--line);border-radius:99px;padding:4px 12px;font-size:13.5px;background:rgba(5,13,34,.5);color:var(--dim)}
.tk .go{margin-top:auto;padding-top:10px;color:var(--acc);font-weight:800}

/* ---------- lịch, mốc */
.days{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(min(340px,100%),1fr))}
.day{border:1px solid var(--line);border-radius:var(--r);padding:22px;background:rgba(12,26,61,.75)}.day h3{margin-bottom:12px}
.tl{margin:0;padding:0;list-style:none}.tl li{display:flex;gap:16px;padding:10px 0;border-top:1px solid var(--line2)}.tl li:first-child{border-top:0}
.tl b{min-width:54px;color:var(--acc);font:700 14.5px var(--mono)}.tl span{color:var(--dim)}.tl em{display:block;color:var(--faint);font-style:normal;font-size:13.5px}
.rounds{display:flex;gap:10px;flex-wrap:wrap}.rd{border:1px solid var(--line);border-radius:12px;padding:8px 14px;background:rgba(12,26,61,.75);font-size:14px;color:var(--dim)}

/* ---------- accordion hỏi đáp */
details.qa{border:1px solid var(--line);border-radius:14px;background:rgba(12,26,61,.7);margin:0 0 10px}
details.qa summary{cursor:pointer;list-style:none;padding:16px 50px 16px 20px;font-weight:700;position:relative}
details.qa summary::-webkit-details-marker{display:none}
details.qa summary::after{content:"+";position:absolute;right:20px;top:50%;transform:translateY(-50%);font:400 24px var(--font);color:var(--acc)}
details.qa[open] summary::after{content:"–"}details.qa[open]{border-color:var(--blue)}
details.qa .ans{padding:0 20px 18px;color:var(--dim)}details.qa .ans p{margin:0 0 10px}details.qa .ans ul{margin:6px 0 0;padding-left:20px}
.qa .by{font:600 11.5px var(--mono);color:var(--faint);letter-spacing:.8px;text-transform:uppercase}

/* ---------- biểu mẫu */
label{display:block;font-weight:700;font-size:14px;margin:14px 0 5px;color:#fff}
input,select,textarea{width:100%;font:inherit;color:var(--ink);background:rgba(5,13,34,.7);border:1.5px solid var(--line);border-radius:11px;padding:11px 13px}
input:focus,select:focus,textarea:focus{outline:0;border-color:var(--blue);box-shadow:0 0 0 3px rgba(94,200,255,.18)}
textarea{min-height:110px;resize:vertical}
input[type=checkbox],input[type=radio]{width:auto;margin-right:9px;accent-color:var(--acc)}.chk{display:flex;align-items:flex-start;font-weight:400;font-size:14.5px;color:var(--dim)}
input[type=file]{padding:8px;font-size:14px}
.formcard{max-width:520px;margin:0 auto}.formcard.wide{max-width:760px}
.msg{padding:11px 14px;border-radius:11px;margin:12px 0;font-size:15px}.msg.bad{background:rgba(255,90,99,.12);color:#ffb1b6;border:1px solid rgba(255,90,99,.35)}.msg.ok{background:rgba(34,197,94,.12);color:#9cf0bd;border:1px solid rgba(34,197,94,.35)}.msg.info{background:rgba(94,200,255,.1);color:#cdeaff;border:1px solid rgba(94,200,255,.3)}
.code{font:800 34px/1 var(--mono);letter-spacing:7px;background:var(--acc2);color:var(--acc);padding:14px 20px;border-radius:12px;display:inline-block}
.steps{display:flex;gap:8px;margin:0 0 20px;flex-wrap:wrap}.steps span{font:700 12px var(--mono);letter-spacing:1px;text-transform:uppercase;padding:6px 12px;border-radius:99px;border:1px solid var(--line);color:var(--faint)}.steps span.on{background:var(--acc);color:var(--on);border-color:var(--acc)}.steps span.done{color:var(--ok);border-color:rgba(34,197,94,.5)}

/* ---------- tab, huy chương, bảng xếp hạng */
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin:6px 0 18px}.tabs button{border:1px solid var(--line);background:rgba(12,26,61,.7);color:var(--ink);padding:9px 18px;border-radius:99px;font:700 14.5px var(--font);cursor:pointer}
.tabs button.on{background:var(--acc);color:var(--on);border-color:var(--acc)}.tabs .tabbtn{border:1px solid var(--line);background:rgba(12,26,61,.7);color:var(--ink);padding:9px 18px;border-radius:99px;font:700 14.5px var(--font);text-decoration:none}.tabs .tabbtn.on{background:var(--acc);color:var(--on);border-color:var(--acc)}.tabs .tabbtn:hover:not(.on){border-color:var(--blue)}
.tabs button:hover:not(.on){border-color:var(--blue)}
.podium{display:grid;gap:14px;grid-template-columns:repeat(3,1fr);margin:6px 0 22px;align-items:end}
.pod{border:1px solid var(--line);border-radius:var(--r);padding:18px;background:linear-gradient(180deg,rgba(18,40,90,.55),rgba(12,26,61,.9));text-align:center}
.pod .rk{font:800 40px var(--font);line-height:1}.pod.p1{padding-top:34px;padding-bottom:30px;border-color:var(--gold)}.pod.p1 .rk{color:var(--gold)}.pod.p2 .rk{color:var(--silver)}.pod.p3 .rk{color:var(--bronze)}
.pod h3{margin:8px 0 2px;word-break:break-word}.pod .sc{font:700 15px var(--mono);color:var(--dim)}
@media (max-width:640px){.podium{grid-template-columns:1fr}}
.medal{display:inline-block;padding:2px 10px;border-radius:99px;font:800 12px var(--font);color:#1a1200}.medal.gold{background:var(--gold)}.medal.silver{background:var(--silver)}.medal.bronze{background:var(--bronze)}
.live{display:inline-flex;align-items:center;gap:7px;font:700 12px var(--mono);letter-spacing:1px;color:var(--ok);text-transform:uppercase}.live::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--ok);box-shadow:0 0 0 0 rgba(34,197,94,.6);animation:pulse 1.8s infinite}
@keyframes pulse{70%{box-shadow:0 0 0 9px rgba(34,197,94,0)}100%{box-shadow:0 0 0 0 rgba(34,197,94,0)}}
.dot{display:inline-block;width:14px;height:14px;border-radius:50%;margin-right:8px;vertical-align:-2px;border:2px solid #fff}
.ev{font:12.5px/1.45 var(--mono);white-space:pre-wrap;word-break:break-word}.ev .ty{font-weight:700}.ev .tm{color:var(--dim)}
.ag td:first-child{white-space:nowrap;font-variant-numeric:tabular-nums;color:var(--dim)}
.tv .hdr nav,.tv .hdr .tools,.tv .burger{display:none}.tv main.page{max-width:none}.tv h1{font-size:44px}.tv table{font-size:24px}.tv th{font-size:16px}.tv .foot{display:none}

/* ---------- chân trang */
.foot{margin-top:90px;border-top:1px solid var(--line2);background:rgba(3,8,22,.7)}
.foot .in{max-width:1160px;margin:0 auto;padding:40px 20px 30px;display:grid;gap:28px;grid-template-columns:1.5fr 1fr 1fr 1fr}
.foot h4{font:700 12px var(--mono);letter-spacing:1.4px;text-transform:uppercase;color:var(--faint);margin-bottom:12px}.foot a{display:block;color:var(--dim);text-decoration:none;padding:3px 0;font-size:14.5px}.foot a:hover{color:#fff}
.foot p{color:var(--faint);font-size:13.5px;margin:10px 0 0;max-width:340px}
.foot .bot{max-width:1160px;margin:0 auto;padding:16px 20px 36px;border-top:1px solid var(--line2);color:var(--faint);font-size:12.5px}
@media (max-width:800px){.foot .in{grid-template-columns:1fr 1fr}}@media (max-width:480px){.foot .in{grid-template-columns:1fr}}
.modal{position:fixed;inset:0;z-index:80;background:rgba(3,8,22,.78);backdrop-filter:blur(6px);display:flex;align-items:center;justify-content:center;padding:16px}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);z-index:90;background:var(--s2);border:1px solid var(--blue);padding:12px 18px;border-radius:12px;box-shadow:0 12px 40px rgba(0,0,0,.5);font-weight:600}
.toast.upd{border-color:var(--acc)}.toast button{margin-left:12px}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media print{.hdr,.foot{display:none}body{background:#fff;color:#000}}

/* ---------- dải logo */
.plogos{display:flex;flex-wrap:wrap;gap:12px;align-items:center}
.plogo{background:#fff;border-radius:12px;height:64px;padding:8px 14px;display:flex;align-items:center;justify-content:center;min-width:92px}
.plogo img{display:block;height:100%;max-height:48px;width:auto;object-fit:contain}
.plogo.txt{color:#0b1f4a;font:800 19px var(--font);letter-spacing:.3px}
.plogo.own{background:rgba(12,26,61,.8);border:1px solid var(--line);gap:10px;color:#fff;text-decoration:none;font:800 13px var(--font);letter-spacing:.9px}.plogo.own svg{width:30px;height:34px}.plogo.own b{color:var(--acc)}
.plogos.lg .plogo{height:80px;padding:10px 16px}.plogos.lg .plogo img{max-height:58px}.plogos.lg .plogo.own{font-size:13.5px}.plogos.lg .plogo.own svg{width:38px;height:42px}.plogos.lg .plogo.txt{font-size:22px}
.foot .logos{max-width:1160px;margin:0 auto;padding:30px 20px 0}.foot .logos .cap{font:700 12px var(--mono);letter-spacing:1.4px;text-transform:uppercase;color:var(--faint);margin-bottom:12px}