:root{
  --bg:#F5F6F8; --surface:#FFFFFF; --ink:#161A23; --muted:#5E6675; --rule:#E2E5EA;
  --blue:#2451D6; --blue-ink:#FFFFFF; --blue-soft:#EAF0FF; --red:#C62F2F; --ok:#18794E;
  --shadow:0 1px 2px rgba(16,24,40,.06);
  --font:"Be Vietnam Pro",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;
  box-sizing:border-box;
  padding-top:env(safe-area-inset-top,0px);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0F1218; --surface:#171B23; --ink:#E8EAEF; --muted:#9BA3B2; --rule:#272D38;
    --blue:#7C9CFF; --blue-ink:#0F1218; --blue-soft:#1B2440; --red:#FF7B72; --ok:#4CC38A; --shadow:none;
  }
}
:root[data-theme="dark"]{
  --bg:#0F1218; --surface:#171B23; --ink:#E8EAEF; --muted:#9BA3B2; --rule:#272D38;
  --blue:#7C9CFF; --blue-ink:#0F1218; --blue-soft:#1B2440; --red:#FF7B72; --ok:#4CC38A; --shadow:none;
}
*,*::before,*::after{box-sizing:inherit}
body{overflow-x:clip;margin:0;background:var(--bg);color:var(--ink);font:400 16px/1.6 var(--font);-webkit-font-smoothing:antialiased}
a{color:var(--blue)}
svg{flex:none}
:focus-visible{outline:2px solid var(--blue);outline-offset:2px}
.vh{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{max-width:1080px;margin:0 auto;padding:0 20px}
[hidden]{display:none!important}

/* Đầu trang */
.site{background:var(--surface);border-bottom:1px solid var(--rule)}
.site .wrap{display:flex;align-items:center;gap:24px;height:64px}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:19px;color:var(--ink);text-decoration:none}
.logo-mark{width:34px;height:34px;border-radius:9px;background:var(--blue);color:var(--blue-ink);display:grid;place-items:center}
.logo-mark svg{width:20px;height:20px}
.logo b{color:var(--blue);font-weight:700}
.site nav{display:flex;gap:22px;margin-left:auto}
.site nav a{color:var(--muted);text-decoration:none;font-weight:500;font-size:15px}
.site nav a:hover{color:var(--blue)}
@media (max-width:640px){.site nav{display:none}}

/* Trang chủ */
.hero{text-align:center;padding:52px 0 8px}
.hero h1{font-size:clamp(28px,4.6vw,44px);line-height:1.2;margin:0 auto 12px;max-width:20ch;letter-spacing:-.02em}
.hero p{color:var(--muted);font-size:18px;margin:0 auto;max-width:54ch}
.notice{display:inline-flex;align-items:center;gap:10px;margin-top:22px;padding:10px 18px;border-radius:999px;background:var(--surface);border:1px solid var(--rule);font-weight:500;font-size:15px;text-align:left}
.notice svg{width:20px;height:20px;color:var(--ok)}
.cat{margin-top:44px;scroll-margin-top:16px}
.cat h2{font-size:20px;margin:0 0 14px;letter-spacing:-.01em}
.cat .grid{grid-template-columns:repeat(auto-fill,minmax(300px,1fr))}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.card{display:flex;flex-direction:column;gap:12px;padding:20px;background:var(--surface);border:1px solid var(--rule);border-radius:14px;text-decoration:none;color:inherit;box-shadow:var(--shadow);transition:border-color .15s,transform .15s}
.card:hover{border-color:var(--c);transform:translateY(-2px)}
.card h3{margin:0;font-size:17px;line-height:1.35}
.card p{margin:0;color:var(--muted);font-size:15px;line-height:1.5}
.ico{width:48px;height:48px;border-radius:12px;display:grid;place-items:center;color:#fff;background:var(--c)}
.card{background:color-mix(in srgb,var(--c) 8%,var(--surface));border-color:color-mix(in srgb,var(--c) 22%,var(--surface))}
.ico svg{width:26px;height:26px}
@media (max-width:540px){
  .grid,.cat .grid{grid-template-columns:1fr 1fr;gap:10px}
  .card{padding:14px;gap:10px}
  .card h3{font-size:15.5px}
  .card p{font-size:13.5px}
  .ico{width:42px;height:42px}
}
@media (prefers-reduced-motion:reduce){.card{transition:none}.card:hover{transform:none}}

/* Trang công cụ */
#tool{--blue:var(--cd);--blue-ink:#fff;--blue-soft:color-mix(in srgb,var(--c) 12%,var(--surface))}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) #tool{--blue:var(--c);--blue-ink:#10131A}}
:root[data-theme="dark"] #tool{--blue:var(--c);--blue-ink:#10131A}
.tool-top{margin:0 calc(50% - 50vw) 22px;padding:2px calc(50vw - 50%) 24px;background:color-mix(in srgb,var(--c) 10%,var(--bg));border-bottom:1px solid color-mix(in srgb,var(--c) 20%,var(--bg))}
.tool-top .lede{margin-bottom:0}
.pc-note{display:none}
.picks{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
.drop.compact .picks{justify-content:flex-start}
.cam{display:none!important}
@media (pointer:coarse){.cam{display:inline-flex!important}}
.more-m{display:none}
@media (max-width:720px){
  .cat .card.pc,.cat.all-pc{display:none}
  .more-m{display:block;margin-top:36px}
  .more-m summary{display:flex;justify-content:space-between;align-items:center;padding:15px 18px;background:var(--surface);border:1px solid var(--rule);border-radius:12px;font-weight:600;cursor:pointer;list-style:none}
  .more-m summary::-webkit-details-marker{display:none}
  .more-m summary::after{content:"";width:9px;height:9px;border-right:2px solid var(--muted);border-bottom:2px solid var(--muted);transform:translateY(-3px) rotate(45deg);transition:transform .2s}
  .more-m[open] summary::after{transform:translateY(2px) rotate(-135deg)}
  .more-m .hint{color:var(--muted);font-size:14px;margin:12px 2px}
  .pc-note{display:block;margin:12px 0 0;font-size:14px;color:var(--muted)}
}
.crumbs{font-size:14px;color:var(--muted);margin:22px 0 18px}
.crumbs a{color:var(--muted);text-decoration:none}
.crumbs a:hover{color:var(--blue)}
.tool-head{display:flex;gap:16px;align-items:center}
.tool-head .ico{width:56px;height:56px;border-radius:14px}
.tool-head .ico svg{width:30px;height:30px}
.tool-head h1{font-size:clamp(24px,3.6vw,32px);line-height:1.2;margin:0;letter-spacing:-.015em}
.lede{color:var(--muted);margin:12px 0 22px;max-width:68ch}

.drop{display:flex;flex-direction:column;align-items:center;gap:12px;padding:44px 20px;border:2px dashed color-mix(in srgb,var(--c) 40%,var(--rule));border-radius:16px;background:color-mix(in srgb,var(--c) 4%,var(--surface));text-align:center;transition:border-color .15s,background .15s}
.drop.over{border-color:var(--blue);background:var(--blue-soft)}
.drop .up{width:48px;height:48px;color:var(--blue)}
.drop small{color:var(--muted);font-size:15px}
.drop.compact{flex-direction:row;justify-content:flex-start;padding:12px 14px;border-style:solid;border-width:1px}
.drop.compact .up{display:none}
.drop.compact .btn{padding:9px 16px;font-size:15px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--blue);color:var(--blue-ink);border:1px solid var(--blue);border-radius:10px;padding:12px 22px;font:600 16px var(--font);cursor:pointer;text-decoration:none;white-space:nowrap}
.btn svg{width:18px;height:18px}
.btn:hover:not([disabled]){filter:brightness(1.08)}
[tabindex="-1"]:focus{outline:none}
.btn[disabled]{opacity:.4;cursor:not-allowed}
.btn.ghost{background:var(--surface);color:var(--ink);border-color:var(--rule)}
.btn.ghost:hover:not([disabled]){border-color:var(--blue);color:var(--blue);filter:none}
.btn.sm{padding:8px 14px;font-size:14.5px;border-radius:8px}
.btn.big{padding:14px 28px;font-size:17px}
label.btn:focus-within{outline:2px solid var(--blue);outline-offset:3px}

.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:14px;margin-top:16px}
.tile{position:relative;background:var(--surface);border:1px solid var(--rule);border-radius:12px;padding:10px;display:flex;flex-direction:column;gap:6px;min-width:0}
.thumb{aspect-ratio:3/4;background:var(--bg);border-radius:6px;display:grid;place-items:center;overflow:hidden}
.thumb canvas,.thumb img{max-width:100%;max-height:100%;object-fit:contain;display:block;background:#fff;box-shadow:0 0 0 1px var(--rule)}
.thumb .ph{font-weight:700;color:var(--muted);font-size:14px}
.tile .nm{font-size:14px;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.tile .mt{font-size:13px;color:var(--muted)}
.ctl{display:flex;gap:6px}
.ctl .del{margin-left:auto}
.icon-btn{display:grid;place-items:center;border:1px solid var(--rule);background:var(--surface);color:var(--ink);width:34px;height:34px;border-radius:8px;cursor:pointer;padding:0}
.icon-btn svg{width:18px;height:18px}
.icon-btn:hover:not([disabled]){border-color:var(--blue);color:var(--blue)}
.icon-btn.del:hover{border-color:var(--red);color:var(--red)}
.icon-btn[disabled]{opacity:.35;cursor:default}
.badge{position:absolute;top:4px;left:4px;z-index:1;background:var(--blue);color:var(--blue-ink);font-size:13px;font-weight:700;min-width:26px;height:26px;border-radius:13px;display:grid;place-items:center;padding:0 7px}

.page{position:relative;background:var(--surface);border:2px solid var(--rule);border-radius:12px;padding:8px;display:flex;flex-direction:column;gap:6px;cursor:pointer;font:inherit;color:inherit;text-align:center}
.page:hover{border-color:color-mix(in srgb,var(--blue) 50%,var(--rule))}
.page[aria-pressed="true"]{border-color:var(--blue);background:var(--blue-soft)}
.page .check{position:absolute;top:6px;right:6px;z-index:1;width:26px;height:26px;border-radius:50%;border:2px solid var(--rule);background:var(--surface);display:grid;place-items:center;color:transparent}
.page .check svg{width:16px;height:16px}
.page[aria-pressed="true"] .check{background:var(--blue);border-color:var(--blue);color:var(--blue-ink)}
.page .pn{font-size:13.5px;color:var(--muted);font-weight:500}
.page[aria-pressed="true"] .pn{color:var(--blue)}

.bar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between;margin-top:16px}
.bar .grp{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.fileinfo b{display:block;font-weight:600;overflow-wrap:anywhere}
.fileinfo span{color:var(--muted);font-size:14px}
.quick{display:flex;gap:8px}
.quick input{width:170px}

.actionbar{position:sticky;bottom:0;z-index:5;margin-top:22px;padding:14px 0 calc(14px + env(safe-area-inset-bottom,0px));background:var(--bg);border-top:1px solid var(--rule);display:flex;flex-wrap:wrap;gap:12px;align-items:center}
.actionbar .status{flex:1;min-width:200px}
.actionbar .btns{display:flex;gap:10px;flex-wrap:wrap}
.status{font-size:15px;color:var(--muted)}
.status[data-kind="err"]{color:var(--red)}
.status[data-kind="ok"]{color:var(--ok);font-weight:500}

.panel{background:var(--surface);border:1px solid var(--rule);border-radius:14px;padding:18px}
.split2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media (max-width:760px){.split2{grid-template-columns:1fr}}
.box-h{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:10px;font-weight:600;min-height:36px}
textarea,input[type="text"]{width:100%;font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:12px 14px}
textarea{min-height:220px;resize:vertical;line-height:1.55}
textarea:focus,input[type="text"]:focus{outline:2px solid var(--blue);outline-offset:0;border-color:transparent}
.check-line{display:inline-flex;gap:8px;align-items:center;cursor:pointer;margin-top:12px}
input[type="radio"],input[type="checkbox"]{accent-color:var(--blue);width:18px;height:18px}

.seg{display:inline-flex;border:1px solid var(--rule);border-radius:10px;padding:3px;background:var(--surface)}
.seg label{position:relative}
.seg input{position:absolute;opacity:0;pointer-events:none}
.seg span{display:block;padding:8px 14px;border-radius:8px;cursor:pointer;font-weight:500;font-size:15px;color:var(--muted)}
.seg input:checked + span{background:var(--blue-soft);color:var(--blue)}
.seg input:focus-visible + span{outline:2px solid var(--blue)}

.bignum{font-size:26px;font-weight:600;padding:16px 18px;letter-spacing:.01em}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.chip{border:1px solid var(--rule);background:var(--surface);color:var(--ink);border-radius:999px;padding:6px 14px;font:500 14.5px var(--font);cursor:pointer}
.chip:hover{border-color:var(--blue);color:var(--blue)}
.result{margin-top:18px;padding:20px;border-radius:14px;background:var(--blue-soft)}
.result .lbl{font-size:14px;color:var(--muted);margin-bottom:6px}
.result .words{font-size:22px;line-height:1.45;font-weight:500;min-height:32px}
.result .words:empty::before{content:"Nhập số tiền ở ô phía trên";color:var(--muted);font-size:17px;font-weight:400}

.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:14px}
.stats div{background:var(--surface);border:1px solid var(--rule);border-radius:12px;padding:12px 14px}
.stats b{display:block;font-size:26px;font-weight:700;line-height:1.2}
.stats span{color:var(--muted);font-size:13.5px}
@media (max-width:600px){.stats{grid-template-columns:repeat(2,1fr)}}

.more{margin-top:48px}
.more h2{font-size:18px;margin:0 0 12px}
.more .card{flex-direction:row;align-items:center;padding:14px}
.more .card p{display:none}
.more .ico{width:40px;height:40px;border-radius:10px}
.more .ico svg{width:22px;height:22px}
.more .card h3{font-size:15.5px}

/* Bổ sung cho giai đoạn 1 */
.opts{display:flex;flex-wrap:wrap;gap:18px 28px;margin-top:14px}
.opt .t{display:block;font-weight:600;font-size:14.5px;margin-bottom:8px}
.opt input[type="number"]{width:130px}
input[type="number"],select{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:9px 12px}
input[type="range"]{accent-color:var(--blue);width:170px;vertical-align:middle}
.btn-row{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px;align-items:center}
.fld{display:block;margin-top:14px}
.fld > span{display:block;font-weight:600;font-size:14.5px;margin-bottom:6px}
.hint{color:var(--muted);font-size:14px}
.rotbox canvas{transform:rotate(var(--r,0deg));transition:transform .2s}
.rotbox.q canvas{transform:rotate(var(--r,0deg)) scale(.75)}
.pager{display:flex;align-items:center;gap:10px;font-weight:500}
.stage{position:relative;margin:12px auto 0;max-width:680px;touch-action:none;user-select:none;-webkit-user-select:none;background:#fff;box-shadow:0 0 0 1px var(--rule),0 4px 16px rgba(16,24,40,.08)}
.stage canvas{display:block;width:100%;height:auto}
.stage .ov{position:absolute;max-width:none;cursor:move;outline:2px dashed var(--blue);outline-offset:2px;touch-action:none}
.stage .placed{position:absolute;max-width:none;pointer-events:none}
.pad canvas{display:block;width:100%;height:200px;background:#fff;border:1px solid var(--rule);border-radius:10px;touch-action:none;margin-top:12px}
.chip-x{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--rule);background:var(--surface);border-radius:999px;padding:5px 8px 5px 14px;font-size:14.5px}
.chip-x button{border:0;background:none;color:var(--muted);cursor:pointer;display:grid;place-items:center;padding:2px}
.chip-x svg{width:15px;height:15px}
.diff{white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.75;padding:18px;background:var(--surface);border:1px solid var(--rule);border-radius:12px;max-height:65vh;overflow:auto;margin-top:12px}
.diff del,.legend del{background:#FFE3E3;color:#9B1C1C;text-decoration:line-through;border-radius:3px;padding:0 2px}
.diff ins,.legend ins{background:#D9F5E3;color:#135C33;text-decoration:none;border-radius:3px;padding:0 2px}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .diff del,:root:not([data-theme="light"]) .legend del{background:rgba(255,90,90,.18);color:#FF9A92}:root:not([data-theme="light"]) .diff ins,:root:not([data-theme="light"]) .legend ins{background:rgba(70,200,120,.18);color:#7EE2A8}}
.legend{display:flex;flex-wrap:wrap;gap:16px;margin-top:18px;font-size:14.5px;color:var(--muted)}
.qr-out{display:grid;place-items:center;min-height:220px;background:var(--bg);border-radius:10px;padding:14px}
.qr-out canvas{width:min(260px,100%);height:auto;image-rendering:pixelated;border-radius:6px}
footer{border-top:1px solid var(--rule);margin-top:56px;padding:24px 0 calc(28px + env(safe-area-inset-bottom,0px));color:var(--muted);font-size:14px;background:var(--surface)}
/* Trang nội dung hướng dẫn */
.guide{margin-top:48px;max-width:760px}
.guide h2{font-size:20px;margin:0 0 12px;letter-spacing:-.01em}
.guide ol{margin:0;padding-left:22px}
.guide li{margin:6px 0}
.faq{margin-top:32px}
.faq details{border-bottom:1px solid var(--rule)}
.faq summary{padding:14px 0;font-weight:600;cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--muted);font-weight:400;font-size:22px;line-height:1}
.faq details[open] summary::after{content:"−"}
.faq p{margin:0 0 16px;color:var(--muted)}
.notfound{text-align:center;padding:56px 0 8px}
.notfound h1{font-size:clamp(26px,4vw,36px);margin:0 0 10px}
.notfound p{color:var(--muted);margin:0 0 22px}
/* Giai đoạn 2a */
select{width:100%}
input[type="date"]{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:10px 12px;width:100%}
.crop{position:relative;width:min(300px,100%);margin:14px auto 0;overflow:hidden;border-radius:6px;background:#eee;box-shadow:0 0 0 1px var(--rule)}
.crop canvas{display:block;width:100%;height:100%;touch-action:none;cursor:grab}
.crop-guide{position:absolute;inset:0;pointer-events:none;background:radial-gradient(ellipse 34% 30% at 50% 40%,transparent 97%,rgba(255,255,255,.55) 100%)}
.editor{margin-top:12px;max-width:900px}
.editor canvas{display:block;width:100%;height:auto;touch-action:none;cursor:crosshair;border-radius:8px;box-shadow:0 0 0 1px var(--rule)}
.fest-row{display:flex;flex-wrap:wrap;justify-content:space-between;gap:4px 16px;padding:10px 0;border-bottom:1px solid var(--rule)}
.fest-row:last-child{border-bottom:0}
.fest-row span{color:var(--muted);font-size:14.5px}
.result .words.plain:empty::before{content:""}
/* Giai đoạn 2b */
.kv{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px solid var(--rule);font-size:15px}
.kv b{font-weight:600;white-space:nowrap}
.kv.sub span{color:var(--muted)}
.kv.sub2 span{padding-left:14px;font-size:14px}
.kv.sub2 b{font-weight:400;color:var(--muted);font-size:14px}
.kv.total{font-size:17px}
.kv.net{background:var(--blue-soft);margin:6px -10px;padding:12px 10px;border-radius:8px;border:0;font-size:19px}
.kv.net b{color:var(--blue)}
.tbl{overflow-x:auto;border:1px solid var(--rule);border-radius:10px;background:var(--surface)}
.tbl table{border-collapse:collapse;font-size:14px;min-width:100%}
.tbl th,.tbl td{border-bottom:1px solid var(--rule);padding:7px 10px;text-align:left;white-space:nowrap;max-width:240px;overflow:hidden;text-overflow:ellipsis}
.tbl th{background:var(--bg);font-weight:600}
.install{margin-left:12px}