/* ===== styles.css ===== */
:root{color-scheme:dark;--bg:#0d1117;--card:#161b22;--line:#30363d;--text:#e6edf3;--muted:#8b949e;--accent:#f2a900;--danger:#ff7b72;--green:#3fb950}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.55 system-ui,-apple-system,Segoe UI,sans-serif}.shell{max-width:1100px;margin:auto;padding:36px 20px 56px}header{margin-bottom:24px}h1{font-size:clamp(2rem,5vw,3.4rem);line-height:1.05;margin:.2em 0}h2{margin-top:0}.eyebrow{color:var(--accent);font-size:.75rem;font-weight:700;letter-spacing:.14em}.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:22px;margin:16px 0}.warning{border-color:#806000;background:#211b0b}.controls{display:flex;gap:18px;flex-wrap:wrap;margin-bottom:18px}label{display:block;font-weight:650;flex:1;min-width:230px}select,textarea{display:block;width:100%;margin-top:7px;border:1px solid var(--line);border-radius:7px;background:#0d1117;color:var(--text);padding:11px;font:inherit}textarea{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;resize:vertical}button{background:var(--accent);border:0;border-radius:7px;color:#161b22;cursor:pointer;font-weight:750;margin-top:14px;padding:11px 18px}button:hover{filter:brightness(1.1)}.help{color:var(--muted);font-size:.92rem}.error{color:var(--danger);min-height:1.5em}.hidden{display:none}.summary{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:10px}.summary div{border:1px solid var(--line);padding:12px;border-radius:8px}.summary strong{display:block;color:var(--accent);font-size:1.2rem}.formula,.mnemonic{background:#0d1117;border-radius:8px;padding:14px;overflow-wrap:anywhere;font-family:ui-monospace,monospace}.mnemonic{color:var(--green);font-size:1.05rem}.table-wrap{overflow:auto}table{border-collapse:collapse;width:100%;min-width:620px}th,td{text-align:left;border-bottom:1px solid var(--line);padding:9px}th{color:var(--muted);font-size:.85rem}.address-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:14px}.address-group{border:1px solid var(--line);border-radius:8px;padding:14px}.address-group h3{margin:0 0 8px;color:var(--accent)}.address{font:12px ui-monospace,monospace;overflow-wrap:anywhere;padding:7px 0;border-bottom:1px solid var(--line)}.address:last-child{border-bottom:0}code{color:#d2a8ff}footer{color:var(--muted);font-size:.85rem;text-align:center;margin-top:24px}

/* ===== rows.css ===== */
.roll-rows{display:grid;gap:8px;margin:14px 0}.roll-row{display:grid;grid-template-columns:42px minmax(180px,1fr) 170px 80px 80px minmax(120px,1fr);gap:8px;align-items:center;border-bottom:1px solid var(--line);padding:6px 0}.roll-row input{margin:0;font:15px ui-monospace,monospace;padding:8px}.roll-row .bits{letter-spacing:.08em;white-space:nowrap}.roll-row .pending{color:var(--muted)}.roll-row .word{color:var(--green);font-weight:700}@media(max-width:760px){.roll-row{grid-template-columns:30px 1fr 130px 65px 65px}.roll-row .word{grid-column:2/-1}}

/* ===== checksum.css ===== */
.checksum-input{display:block;width:100%;max-width:360px;margin-top:7px;border:1px solid var(--line);border-radius:7px;background:#0d1117;color:var(--text);padding:11px;font:18px ui-monospace,monospace;letter-spacing:.2em}mark{background:#806000;color:var(--text);padding:2px 0}

/* ===== polish.css ===== */
:root{--accent-soft:#ffd166;--panel:#1c232d}body{background:linear-gradient(180deg,#0b1016 0%,#101720 100%)}.shell{max-width:1280px;padding:48px 28px 72px}header{max-width:850px;margin-bottom:30px}header p:not(.eyebrow){color:#b8c4d0;font-size:1.08rem}.card{border-radius:14px;padding:28px;margin:20px 0;box-shadow:0 8px 24px #0002}h2{font-size:1.35rem;margin-bottom:10px}.lesson-intro{background:var(--panel)}.lesson-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.lesson-steps div{border:1px solid var(--line);border-radius:10px;padding:15px;background:#151b23}.lesson-steps strong{display:block;color:var(--accent-soft);margin-bottom:7px}.lesson-steps span{display:block;color:#b8c4d0;font-size:.92rem}.worksheet-head,.roll-row{display:grid;grid-template-columns:58px minmax(230px,1fr) 180px 90px 105px minmax(150px,1fr);gap:10px;align-items:center}.worksheet-head{color:var(--muted);font-size:.76rem;font-weight:750;letter-spacing:.05em;text-transform:uppercase;padding:0 10px 7px}.roll-row{background:#121820;border:1px solid var(--line);border-radius:9px;padding:8px 10px}.roll-row input{width:100%;border:1px solid #536170;border-radius:7px;background:#0b1016;color:var(--accent-soft);font-size:1.06rem;font-weight:700;letter-spacing:.22em;text-align:center}.roll-row input:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}.roll-row .bits{color:#b8c4d0}.roll-row .total,.roll-row .index{color:#d7e0e8;text-align:center}.roll-row .word{font-size:1.03rem}.roll-row>strong{color:var(--muted);text-align:center}.formula{line-height:1.8}.formula code{word-break:break-all}.table-wrap table{min-width:760px}.table-wrap th{background:#111820;position:sticky;top:0}.table-wrap td{vertical-align:top}.address-grid{grid-template-columns:repeat(2,minmax(360px,1fr))}.address-group{background:#121820}.button-row{display:flex;gap:10px;flex-wrap:wrap}@media(max-width:900px){.lesson-steps{grid-template-columns:repeat(2,1fr)}.worksheet-head,.roll-row{grid-template-columns:42px minmax(190px,1fr) 150px 75px 90px minmax(120px,1fr)}}@media(max-width:650px){.shell{padding:28px 14px 48px}.card{padding:18px}.lesson-steps{grid-template-columns:1fr}.worksheet-head{display:none}.worksheet-head,.roll-row{grid-template-columns:34px 1fr 120px 62px 78px}.roll-row .word{grid-column:2/-1}.address-grid{grid-template-columns:1fr}.roll-row input{font-size:.95rem;letter-spacing:.13em}}

/* ===== links.css ===== */
.wordlist-link{margin:10px 0 14px;font-size:.92rem}.wordlist-link a{color:var(--accent-soft);font-weight:750}.wordlist-link span{color:var(--muted);margin-left:8px}

/* ===== device-note.css ===== */
.device-note{border-left:4px solid var(--accent);background:#211b0b;border-radius:6px;padding:12px 14px;color:#e6d7a7}.device-note strong{color:var(--accent-soft)}

/* ===== education.css ===== */
.conversion-note{margin-top:20px;border:1px solid #3b4652;border-radius:9px;background:#111820;padding:14px;color:#c7d1db}.conversion-note strong{color:var(--accent-soft)}.conversion-note code{color:var(--green);font-size:1rem}.address-section{padding:0;overflow:hidden}.address-section summary{cursor:pointer;padding:20px 28px;color:var(--accent-soft);font-size:1.15rem;font-weight:750}.address-section summary::marker{color:var(--accent)}.summary-hint{color:var(--muted);font-size:.8rem;font-weight:400;margin-left:8px}.address-content{padding:0 28px 28px}

/* ===== bitboxes.css ===== */
.bit-entry{display:grid;grid-template-columns:repeat(11,minmax(34px,1fr));gap:8px}.bit-cell{text-align:center;position:relative}.bit-cell:not(:last-child)::after{content:'+';position:absolute;right:-12px;top:58px;transform:translateY(-50%);color:var(--muted);font-size:1.25rem;font-weight:700;z-index:2}.multiplier{display:block;color:var(--accent-soft);font:700 14px ui-monospace,monospace;margin-bottom:5px;line-height:16px;white-space:nowrap}.times{display:block;color:var(--muted);font-size:13px;line-height:12px}.bit-input{width:100%;height:46px!important;margin:0!important;padding:3px!important;letter-spacing:0!important;text-align:center;font-size:1.25rem!important;font-weight:800!important}.checksum-slot{display:flex;height:46px;align-items:center;justify-content:center;border:1px dashed #5c6773;border-radius:7px;color:var(--accent);font-size:1.25rem;font-weight:700}.roll-row .bits{font-size:.82rem;word-break:break-all}@media(max-width:1100px){.bit-entry{gap:5px}.bit-cell:not(:last-child)::after{right:-9px}.multiplier{font-size:12px}.times{font-size:11px}}@media(max-width:900px){.bit-entry{gap:3px}.bit-cell:not(:last-child)::after{top:52px;right:-7px}.multiplier{font-size:10px}.times{font-size:10px}.bit-input,.checksum-slot{height:40px!important}}@media(max-width:650px){.bit-entry{grid-template-columns:repeat(11,minmax(22px,1fr));gap:2px;grid-column:2/-1}.multiplier{font-size:8px}.times{font-size:8px}.bit-input,.checksum-slot{height:36px!important;font-size:1rem!important}.bit-cell:not(:last-child)::after{top:47px;right:-5px;font-size:1rem}.roll-row .bits{grid-column:2/-1}.roll-row .total,.roll-row .index{margin-top:4px}}



/* merged layout fixes */
.shell{max-width:1280px}.roll-row{column-gap:14px}.bit-entry{column-gap:12px}.bit-cell:not(:last-child)::after{right:-16px;top:58px}.checksum-slot{background:#171d25;color:#ffd166;border:2px dashed #687789}.roll-row:last-child .bits{color:#ffd166;font-weight:700}
@media(max-width:900px){.roll-row{grid-template-columns:36px minmax(0,1fr);row-gap:10px}.roll-row .bit-entry,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:2}.bit-entry{min-width:0;overflow-x:auto;padding:0 8px 2px}.roll-row .bits{text-align:left}.roll-row .total,.roll-row .index,.roll-row .word{text-align:left}.bit-cell:not(:last-child)::after{right:-10px}}
@media(max-width:650px){.roll-row{grid-template-columns:30px minmax(0,1fr)}.bit-entry{column-gap:8px;padding-left:4px;padding-right:12px}.bit-cell:not(:last-child)::after{right:-8px;top:47px}.roll-row .bits{white-space:normal}}

/* Keep the worksheet readable when the viewport is narrower than the full 11-bit row. */
@media(max-width:1200px){.roll-row{grid-template-columns:38px minmax(0,1fr);row-gap:12px}.roll-row .bit-entry,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:2}.bit-entry{width:100%;min-width:0;overflow-x:auto;padding:0 12px 4px 2px}.roll-row .bits{white-space:normal;overflow-wrap:anywhere;line-height:1.4}.roll-row .total,.roll-row .index,.roll-row .word{text-align:left}.roll-row .word{min-height:1.5em}.bit-cell:not(:last-child)::after{right:-10px;top:58px}}
@media(max-width:650px){.roll-row{grid-template-columns:30px minmax(0,1fr);padding:10px 8px}.bit-entry{column-gap:8px;padding-right:14px}.bit-cell:not(:last-child)::after{right:-8px;top:47px}}

/* Keep operators in the gaps and keep the summary text inside its own column. */
.bit-entry{column-gap:22px}.bit-cell:not(:last-child)::after{right:-15px;top:58px}.roll-row .bits{white-space:normal;overflow:hidden;overflow-wrap:anywhere;line-height:1.35;max-width:100%}
@media(max-width:1200px){.bit-entry{column-gap:20px}.bit-cell:not(:last-child)::after{right:-14px}}
@media(max-width:650px){.bit-entry{column-gap:16px;padding-right:18px}.bit-cell:not(:last-child)::after{right:-12px;top:47px}}

/* Equal operator gaps and local validation feedback. */
.bit-entry{column-gap:28px;min-width:0;overflow:visible}.bit-cell:not(:last-child)::after{right:-18px;top:58px}.roll-row,.roll-row .bits{min-width:0}.roll-row .bits{overflow:hidden;overflow-wrap:anywhere;white-space:normal}.bit-cell.invalid .bit-input{border:2px solid var(--danger);box-shadow:0 0 0 2px #ff7b7233}.input-popover{position:absolute;z-index:20;left:50%;bottom:calc(100% + 8px);transform:translateX(-50%);width:max-content;max-width:160px;border:1px solid var(--danger);border-radius:6px;background:#3a1618;color:#fff;padding:5px 8px;font:700 11px/1.25 system-ui,sans-serif;white-space:normal;box-shadow:0 5px 14px #0008}.input-popover::after{content:'';position:absolute;left:50%;bottom:-6px;transform:translateX(-50%);border:6px solid transparent;border-top-color:var(--danger);border-bottom:0}
@media(max-width:1200px){.bit-entry{column-gap:24px}.bit-cell:not(:last-child)::after{right:-16px}}
@media(max-width:650px){.bit-entry{column-gap:20px;padding-right:20px}.bit-cell:not(:last-child)::after{right:-14px;top:47px}.input-popover{max-width:130px;font-size:10px}}

/* Use the available screen without letting the worksheet columns collide. */
.shell{width:95vw;max-width:1600px}.roll-row,.worksheet-head{min-width:0}.roll-row{grid-template-columns:52px minmax(0,1fr) minmax(150px,190px) 90px 105px minmax(150px,200px)}.bit-entry{min-width:0;overflow-x:auto}.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{min-width:0}
@media(max-width:1400px){.worksheet-head{display:none}.roll-row{grid-template-columns:42px minmax(0,1fr);row-gap:12px}.roll-row .bit-entry,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:2}.bit-entry{width:100%;min-width:0;overflow-x:auto}.roll-row .bits{white-space:normal;overflow-wrap:anywhere}.roll-row .total,.roll-row .index,.roll-row .word{text-align:left}}
@media(max-width:650px){.shell{width:96vw}.roll-row{grid-template-columns:30px minmax(0,1fr)}}

/* Header and data rows must share exactly the same column tracks. */
@media(min-width:1401px){.worksheet-head{grid-template-columns:52px minmax(0,1fr) minmax(150px,190px) 90px 105px minmax(150px,200px);column-gap:14px}.roll-row{grid-template-columns:52px minmax(0,1fr) minmax(150px,190px) 90px 105px minmax(150px,200px);column-gap:14px}}

/* Fluid worksheet and result tables for tablets and phones. */
html,body{max-width:100%;overflow-x:hidden}.shell,.card,.roll-rows,.roll-row{max-width:100%}.table-wrap{width:100%;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch}.table-wrap table{width:100%;min-width:0;table-layout:auto}.table-wrap th,.table-wrap td{overflow-wrap:anywhere;word-break:normal}.address-grid{width:100%;grid-template-columns:repeat(auto-fit,minmax(min(100%,360px),1fr))}.address{overflow-wrap:anywhere;word-break:break-word}
@media(max-width:1400px){.roll-row{width:100%}.bit-entry{width:100%;max-width:100%;overflow-x:auto;overflow-y:visible}.roll-row .bits{width:100%;max-width:100%}}
@media(max-width:700px){.shell{width:96vw;padding-left:8px;padding-right:8px}.card{padding:16px;margin:14px 0}.controls{gap:10px}label{min-width:0}.lesson-steps{grid-template-columns:1fr}.table-wrap table{font-size:.86rem}.table-wrap th,.table-wrap td{padding:7px 6px}.address-grid{grid-template-columns:1fr}.address-section summary{padding:16px}.address-content{padding:0 16px 18px}.bit-entry{column-gap:16px;padding-left:2px;padding-right:18px}.bit-cell:not(:last-child)::after{right:-12px}.input-popover{max-width:120px}}
@media(max-width:1000px){.table-wrap table{min-width:0;width:100%;table-layout:fixed}.table-wrap th,.table-wrap td{overflow-wrap:anywhere}}

/* Center every value outside the bit-entry strip and keep headers on the same tracks. */
.worksheet-head{justify-items:center;text-align:center}.roll-row{justify-items:center}.roll-row>strong,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{justify-self:stretch;text-align:center}.roll-row .bit-entry{justify-self:stretch}.roll-row .word{overflow-wrap:anywhere}.roll-row .bits{font-family:ui-monospace,monospace}
@media(max-width:1400px){.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{text-align:center}.roll-row .word{justify-self:stretch}}
.address-section{display:none!important}

/* Primary reference layout: 1200px viewport. */
.shell{width:95vw;max-width:1200px}
@media(min-width:1001px) and (max-width:1400px){.worksheet-head{display:grid;grid-template-columns:42px minmax(0,1fr) 120px 70px 85px 130px;column-gap:10px}.roll-row{display:grid;grid-template-columns:42px minmax(0,1fr) 120px 70px 85px 130px;column-gap:10px;row-gap:8px}.roll-row .bit-entry{grid-column:auto;grid-row:auto;display:grid;grid-template-columns:repeat(11,minmax(28px,1fr));column-gap:12px;overflow:visible;padding:0}.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:auto;grid-row:auto;min-width:0}.roll-row .bits{white-space:normal;overflow-wrap:anywhere}.bit-cell:not(:last-child)::after{right:-9px;top:54px}.multiplier{font-size:11px}.times{font-size:10px}.bit-input,.checksum-slot{height:42px!important;font-size:1.1rem!important}}
@media(min-width:1001px) and (max-width:1400px){.roll-row .bit-entry{grid-template-columns:repeat(11,minmax(26px,1fr));column-gap:16px}.bit-cell:not(:last-child)::after{right:-11px;top:51px;font-size:1rem}.multiplier{font-size:10px;margin-bottom:3px}.times{font-size:9px;line-height:10px}.bit-input,.checksum-slot{height:38px!important;font-size:1rem!important}.roll-row .bits{font-size:.75rem}}

/* Put each plus sign at the exact center of the gap between two boxes. */
.bit-cell:not(:last-child)::after{left:calc(100% + 14px);right:auto;transform:translate(-50%,-50%)}
@media(max-width:1400px){.bit-cell:not(:last-child)::after{left:calc(100% + 8px);right:auto}}
@media(max-width:650px){.bit-cell:not(:last-child)::after{left:calc(100% + 10px);right:auto}}

/* Give the 11-bit strip the full row on screens up to 1400px. */
@media(max-width:1400px){.worksheet-head{display:none!important}.roll-row{grid-template-columns:42px minmax(0,1fr)!important;grid-template-rows:auto;row-gap:12px}.roll-row .bit-entry,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:2!important;grid-row:auto!important}.roll-row .bit-entry{display:grid!important;grid-template-columns:repeat(11,minmax(30px,1fr))!important;column-gap:16px;width:100%!important;overflow:visible!important}.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{text-align:center}.bit-cell:not(:last-child)::after{left:calc(100% + 8px);right:auto}}
@media(max-width:650px){.roll-row{grid-template-columns:30px minmax(0,1fr)!important}.roll-row .bit-entry{grid-template-columns:repeat(11,minmax(24px,1fr))!important;column-gap:14px;overflow-x:auto!important;padding-right:16px}.bit-cell:not(:last-child)::after{left:calc(100% + 7px);right:auto}}
@media(min-width:1401px){.shell{width:95vw;max-width:1600px}}

/* Always keep the worksheet headings and row metadata on one aligned row. */
.worksheet-head{display:grid!important;grid-template-columns:42px minmax(110px,1fr) 120px 70px 85px 130px!important;column-gap:10px;align-items:center}.roll-row{display:grid!important;grid-template-columns:42px minmax(110px,1fr) 120px 70px 85px 130px!important;column-gap:10px;align-items:center;grid-template-rows:auto!important}.roll-row .bit-entry,.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{grid-column:auto!important;grid-row:auto!important}.roll-row .bit-entry{width:100%!important;min-width:0!important;overflow-x:auto!important;overflow-y:visible!important;display:grid!important;grid-template-columns:repeat(11,minmax(30px,1fr))!important;column-gap:16px}.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{min-width:0;text-align:center;justify-self:stretch}.roll-row .bits{overflow-wrap:anywhere;white-space:normal}
@media(max-width:700px){.worksheet-head{display:grid!important;grid-template-columns:34px minmax(95px,1fr) 92px 58px 70px 100px!important;font-size:.62rem}.roll-row{grid-template-columns:34px minmax(95px,1fr) 92px 58px 70px 100px!important;padding:8px 5px}.roll-row .bit-entry{grid-template-columns:repeat(11,minmax(24px,1fr))!important;column-gap:14px}.roll-row .bits,.roll-row .total,.roll-row .index,.roll-row .word{font-size:.78rem}.wordlist-link span{display:none}}

/* One digit needs a compact fixed box; every operator gap is identical. */
.roll-row .bit-entry{grid-template-columns:repeat(11,60px)!important;column-gap:20px!important;justify-content:start}.roll-row .bit-cell:not(:last-child)::after{left:calc(100% + 10px)!important;right:auto!important}.roll-row .bit-input,.roll-row .checksum-slot{width:32px!important;min-width:32px!important}.multiplier{text-align:center}
@media(max-width:700px){.roll-row .bit-entry{grid-template-columns:repeat(11,27px)!important;column-gap:16px!important}.roll-row .bit-cell:not(:last-child)::after{left:calc(100% + 8px)!important}.roll-row .bit-input,.roll-row .checksum-slot{width:27px!important;min-width:27px!important}}
@media(max-width:430px){h1{font-size:2rem}.shell{width:98vw}.table-wrap table{font-size:.78rem}.table-wrap th,.table-wrap td{padding:6px 4px}.roll-row{padding:8px 5px}.bit-entry{column-gap:14px}.multiplier{font-size:9px}.times{font-size:8px}.bit-input,.checksum-slot{height:36px!important}.button-row,button{max-width:100%}}

/* Use identical tracks for editable and checksum cells. */
.roll-row .bit-entry{grid-template-columns:repeat(11,60px)!important;column-gap:20px!important}.roll-row .bit-input,.roll-row .checksum-slot{box-sizing:border-box!important;width:60px!important;min-width:32px!important;height:46px!important;margin:0!important;padding:3px!important}.roll-row .checksum-slot{display:flex!important;align-items:center;justify-content:center}
@media(max-width:700px){.roll-row .bit-entry{grid-template-columns:repeat(11,27px)!important;column-gap:16px!important}.roll-row .bit-input,.roll-row .checksum-slot{width:27px!important;min-width:27px!important;height:36px!important}}