:root{--gradient-start:#585cf6;--gradient-end:#8b3de7;--brand:#724def;--brand-surface:#ede9fe;--brand-gradient:linear-gradient(135deg, var(--gradient-start), var(--gradient-end));--accent:#0e7c74;--background:#f6f5fa;--surface:#fff;--ink:#1c1b22;--ink-secondary:#6b6879;--separator:#e5e3ec;--right:#0e7c74;--wrong:#dc2626;--pen-right:#2563eb;--column:760px}*{box-sizing:border-box}body{background:var(--background);color:var(--ink);-webkit-font-smoothing:antialiased;-webkit-text-size-adjust:100%;margin:0;font-family:-apple-system,BlinkMacSystemFont,SF Pro Text,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:16px;line-height:1.45}h1{margin:0;font-size:30px}h2{margin:0 0 12px;font-size:18px}a{color:var(--brand)}button{font:inherit;cursor:pointer}button:disabled{cursor:default;opacity:.5}input,textarea{font:inherit;color:inherit;border:1px solid var(--separator);background:var(--surface);border-radius:10px;padding:8px 10px}textarea{resize:vertical;width:100%}.column{max-width:var(--column);margin:0 auto;padding:24px 16px 64px}.page-head{margin:8px 0 20px}.eyebrow{letter-spacing:.04em;text-transform:uppercase;color:var(--brand);margin:0 0 4px;font-size:13px;font-weight:600}.card{background:var(--surface);border:1px solid var(--separator);border-radius:16px;margin-bottom:16px;padding:20px}.card-head{justify-content:space-between;align-items:baseline;gap:12px;display:flex}.muted{color:var(--ink-secondary)}.small{font-size:14px}.notice{background:var(--brand-surface);border-radius:10px;padding:10px 12px}.notice.failed,.failed{color:var(--wrong)}.notice.failed{background:#fef2f2}.save-note{color:var(--ink-secondary);font-size:13px}.save-note.failed{color:var(--wrong)}.primary,.secondary,a.button,label.button{text-align:center;border-radius:12px;padding:12px 20px;font-weight:600;text-decoration:none;display:inline-block}.primary{color:#fff;background:var(--brand-gradient);border:0;min-width:160px}.secondary,a.button.secondary,label.button.secondary{border:1px solid var(--brand);color:var(--brand);background:var(--surface)}.link{color:var(--brand);background:0 0;border:0;padding:0;font-weight:500}.icon{color:var(--ink-secondary);background:0 0;border:0;padding:4px 8px;font-size:20px;line-height:1}.actions{flex-wrap:wrap;gap:12px;display:flex}.week-row{border-top:1px solid var(--separator);gap:12px;padding:8px 0;display:flex}.week-row:first-child{border-top:0}.week-day{flex:none;width:44px;padding-top:8px;font-weight:600}.week-slots{flex-wrap:wrap;align-items:center;gap:8px 16px;display:flex}.slot{align-items:center;gap:6px;display:inline-flex}.dash{color:var(--ink-secondary);font-size:14px}.day-strip{flex-wrap:wrap;gap:8px;margin-bottom:8px;display:flex}.chip{border:1px solid var(--separator);background:var(--surface);border-radius:999px;padding:6px 12px;font-size:14px;position:relative}.chip.selected{border-color:var(--brand);background:var(--brand-surface);color:var(--brand);font-weight:600}.chip .dot{background:var(--brand);border-radius:50%;width:6px;height:6px;position:absolute;top:2px;right:6px}.items{margin:0 0 8px;padding:0;list-style:none}.items li{gap:4px;margin-bottom:8px;display:flex}.items input{flex:1}ul.plain{margin:0 0 16px;padding-left:20px}.sessions{margin:0;padding:0;list-style:none}.sessions li{border-top:1px solid var(--separator);flex-wrap:wrap;gap:4px 12px;padding:8px 0;display:flex}.sessions li:first-child{border-top:0}.add-student{gap:8px;margin-top:16px;display:flex}.add-student input{flex:1}.steps{padding-left:20px}.steps li{margin-bottom:16px}.steps p{margin:0 0 8px}.watching{text-align:center}.live{color:var(--accent)}.live-dot{background:var(--accent);border-radius:50%;width:10px;height:10px;margin-right:4px;animation:1.6s ease-in-out infinite pulse;display:inline-block}@keyframes pulse{50%{opacity:.3}}.now{margin:12px 0 20px;font-size:20px}.so-far{margin:0;padding:0;list-style:none}.so-far li{border-top:1px solid var(--separator);align-items:baseline;gap:10px;padding:6px 0;display:flex}.so-far li:first-child{border-top:0}.so-far .time{margin-left:auto}.key{color:var(--brand);font-weight:700}.time{font-variant-numeric:tabular-nums;color:var(--ink-secondary)}.mark{font-weight:700}.mark.right{color:var(--right)}.mark.wrong{color:var(--wrong)}.mark.none{color:var(--ink-secondary)}.photo-code{text-align:center}.photo-code ol{text-align:left;margin:0 0 8px;display:inline-block}.qr img{width:300px;max-width:80vw;height:auto;image-rendering:pixelated}.stats{flex-wrap:wrap;gap:24px;margin-bottom:8px;display:flex}.stats div{flex-direction:column;display:flex}.stats strong{font-size:24px}.stats span{color:var(--ink-secondary);font-size:13px}.problem-head{align-items:baseline;gap:10px;display:flex}.problem-head .skill{font-weight:600}.problem-head .time{margin-left:auto}.problem-text{margin:8px 0 4px;font-size:18px}.regions{flex-wrap:wrap;gap:12px;margin-top:12px;display:flex}.regions figure{max-width:100%;margin:0}.regions figcaption{color:var(--ink-secondary);font-size:13px}.crop{border:1px solid var(--separator);border-radius:8px;max-width:100%;max-height:420px;display:block}.placeholder{width:240px;height:160px;color:var(--ink-secondary);background:var(--background);place-items:center;font-size:13px;display:grid}.photos{flex-wrap:wrap;gap:8px;display:flex}.photo{border:1px solid var(--separator);border-radius:8px;width:160px;height:auto}.frames{border-collapse:collapse;width:100%;font-size:14px}.frames td{vertical-align:top;border-top:1px solid var(--separator);padding:6px 8px 6px 0}.frame-image{border:1px solid var(--separator);max-width:100%;margin-top:8px;display:block}.phone{color:#fff;background:#000;flex-direction:column;display:flex;position:fixed;inset:0}.phone.center{text-align:center;justify-content:center;align-items:center;padding:24px}.phone .big{font-size:24px;font-weight:700}.phone-sent{flex-direction:column;align-items:center;gap:16px;max-width:360px;display:flex}.phone-sent p{margin:0}.phone-label{top:calc(12px + env(safe-area-inset-top));z-index:1;background:#0009;border-radius:999px;margin:0;padding:4px 12px;font-size:14px;font-weight:600;position:absolute;left:50%;transform:translate(-50%)}.viewfinder{object-fit:cover;flex:1;width:100%;min-height:0;transition:opacity .12s}.viewfinder.flash{opacity:.2}.phone-fallback{text-align:center;flex-direction:column;flex:1;justify-content:center;align-items:center;gap:16px;padding:24px;display:flex}.phone-bar{padding:16px 16px calc(16px + env(safe-area-inset-bottom));background:#000;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px;display:grid}.thumbs{align-items:center;gap:4px;min-height:56px;display:flex;position:relative}.thumbs img{object-fit:cover;border:1px solid #555;border-radius:4px;width:40px;height:56px}.thumbs .count{background:var(--brand);border-radius:999px;padding:1px 7px;font-size:12px;font-weight:700;position:absolute;top:-8px;left:-6px}.shutter{background:#fff;border:5px solid #fff;border-radius:50%;width:76px;height:76px;box-shadow:inset 0 0 0 3px #000}.shutter:active{transform:scale(.94)}.send{color:#fff;background:var(--brand-gradient);border:0;border-radius:999px;justify-self:end;padding:12px 22px;font-weight:700}.phone-error{color:#fca5a5;text-align:center;background:#000;margin:0;padding:8px 16px 16px}.column.narrow{max-width:480px}.enter{flex-direction:column;gap:12px;display:flex}.enter label{font-weight:600}.enter input,input.wide{width:100%;padding:12px 14px;font-size:18px}.ask{text-align:center;padding:32px 20px}.ask h2{margin-bottom:20px;font-size:22px}.ask-buttons{justify-content:center;gap:16px;display:flex}.ask-buttons button{min-width:140px;font-size:18px}.week-grid{-webkit-user-select:none;user-select:none;touch-action:none;grid-template-columns:52px repeat(7,1fr);font-size:12px;display:grid}.wg-row{display:contents}.wg-corner,.wg-day{background:var(--surface);text-align:center;padding:4px 0 6px;font-size:13px;font-weight:600;position:sticky;top:0}.wg-time{color:var(--ink-secondary);text-align:right;padding-right:6px;transform:translateY(-7px)}.wg-cell{border-left:1px solid var(--separator);border-top:1px solid var(--separator);cursor:pointer;height:18px}.wg-cell.half{border-top-style:dotted}.wg-cell.on{background:var(--brand);border-color:var(--brand)}.week-notes{margin-top:16px}.week-notes label{font-weight:600}.week-notes textarea{margin-top:6px}.week-grid.two-clocks{grid-template-columns:max-content repeat(7,1fr)}.week-grid.two-clocks .wg-corner{padding-left:6px;padding-right:6px}.week-grid.two-clocks .wg-time{white-space:nowrap}.practice-start{text-align:center;padding:32px 20px}.practice-start h1{margin-bottom:8px}.topic-cells{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px;margin:24px 0 16px;display:grid}.topic-cell{border:1px solid var(--separator);background:var(--background);min-height:120px;color:var(--ink);text-align:center;border-radius:16px;flex-direction:column;justify-content:center;align-items:center;gap:6px;padding:20px;font-size:22px;font-weight:600;line-height:1.25;display:flex}.topic-cell:hover:enabled,.topic-cell.starting{border-color:var(--brand);background:var(--brand-surface);color:var(--brand)}.topic-cell.starting:disabled{opacity:1}.topic-cell-note{color:var(--ink-secondary);font-size:14px;font-weight:500}.topic-cell-note.carry-on{color:var(--brand)}.practice-head{justify-content:space-between;align-items:baseline;margin-bottom:8px;display:flex}.practice-head .link{font-size:18px}.practice-head .eyebrow{font-size:16px}.question-number{text-align:center;margin-bottom:24px;font-size:20px}.question-text{text-align:center;max-width:1000px;margin:0 auto;font-size:29px}.question-card{padding-bottom:72px}.under-question{margin-top:32px}.column.wide.waiting{flex-direction:column;min-height:100vh;padding-bottom:0;display:flex}.column.wide.waiting .question-card{margin-bottom:0}.column.wide.waiting .under-question{flex-direction:column;flex:1;justify-content:center;margin-top:0;display:flex}.photo-received{text-align:center;font-size:27px}.photo-received p{margin:0}.photo-received-title{font-weight:600}.photo-received-note{color:var(--ink-secondary);margin-top:8px}.shimmer{background:linear-gradient(90deg, var(--ink-secondary) 0 40%, var(--brand) 50%, var(--ink-secondary) 60% 100%) 100% 0 / 300% 100%;color:#0000;-webkit-background-clip:text;background-clip:text;animation:2s linear infinite shimmer}@keyframes shimmer{0%{background-position:100% 0}65%,to{background-position:0 0}}@media (prefers-reduced-motion:reduce){.shimmer{color:var(--ink-secondary);background:0 0;animation:none}}.question-text .graph svg{margin:0 auto}.question-text .graph-legend{justify-content:center}.graph{margin:12px 0 4px;font-size:14px;line-height:1.3}.graph svg{max-width:100%;display:block}.graph-legend{flex-wrap:wrap;gap:4px 16px;margin-top:6px;display:flex}.graph-legend span{align-items:center;gap:6px;display:inline-flex}.photo-code.compact{text-align:center}.photo-code.compact h2{font-size:16px}.photo-code.compact .qr img{width:220px}.practice-offer{text-align:center}.pen-verdict{margin:8px 0 4px;font-size:22px;font-weight:700}.pen-verdict.right{color:var(--right)}.pen-verdict.wrong,.pen-summary{color:var(--wrong)}.pen-photos{flex-wrap:wrap;gap:12px;margin:12px 0;display:flex}.pen-photo{max-width:100%;position:relative}.pen-photo img{border:1px solid var(--separator);border-radius:8px;max-width:100%;max-height:560px;display:block}.pen-mark{border:3px solid var(--wrong);border-radius:10px;position:absolute}.pen-mark.correct{border-style:dashed;border-color:var(--pen-right)}.pen-mark .pen-num{position:absolute;top:-12px;left:-12px}.pen-num{background:var(--wrong);color:#fff;border-radius:12px;place-items:center;min-width:24px;height:24px;padding:0 4px;font-size:14px;font-weight:700;display:inline-grid}.pen-notes{color:var(--wrong);margin:0;padding:0;font-size:17px;list-style:none}.pen-notes li{align-items:baseline;gap:8px;margin-bottom:6px;display:flex}.pen-notes li.correct{color:var(--pen-right)}.pen-mark.correct .pen-num,.pen-notes li.correct .pen-num{background:var(--pen-right)}.pen-mark{transition:opacity .35s}.pen-mark.hidden{opacity:0}.column.wide{max-width:none;padding-left:32px;padding-right:32px}.pen-pages{grid-template-columns:max-content minmax(0,760px);align-items:start;gap:32px;display:grid}.pen-paper{position:sticky;top:12px}.pen-paper .pen-photos{flex-direction:column;align-items:flex-start;margin:0}.pen-paper .pen-photo img,.right-paper .pen-photo img{max-width:calc(50vw - 56px);max-height:calc(100vh - 24px)}.pen-photo.cropped{width:min(var(--width), calc(50vw - 56px), calc((100vh - 24px) * var(--ratio)))}.pen-crop{border:1px solid var(--separator);border-radius:8px;position:absolute;inset:0;overflow:hidden}.pen-photo.cropped .pen-crop img{border:0;border-radius:0;max-width:none;max-height:none;position:absolute}.pen-steps>div+div>.pen-page{margin-top:18px}.right-answer{flex-direction:column;align-items:center;gap:24px;display:flex}.right-paper{position:relative}.right-paper .pen-photos{flex-direction:column;align-items:center;margin:0}.right-stamp{width:112px;height:112px;color:var(--pen-right);margin-top:-56px;animation:.3s cubic-bezier(.2,.8,.3,1.25) both stamp;position:absolute;top:50%;left:calc(100% + 24px);transform:rotate(-10deg)}@keyframes stamp{0%{opacity:0;transform:rotate(-10deg)scale(1.9)}to{opacity:1;transform:rotate(-10deg)scale(1)}}@media (prefers-reduced-motion:reduce){.right-stamp{animation:none}}.right-answer .pen-nav{justify-content:center;margin-top:0}@media (width<=640px){.column.wide{padding-left:16px;padding-right:16px}.pen-pages{grid-template-columns:minmax(0,1fr)}.pen-paper{position:static}.pen-paper .pen-photo img{max-width:100%}.pen-photo.cropped{width:min(var(--width), 100%)}.right-paper .pen-photo img{max-width:calc(100vw - 76px)}.right-paper .pen-photo.cropped{width:min(var(--width), calc(100vw - 76px))}.right-stamp{width:72px;height:72px;margin-top:0;top:-18px;left:auto;right:-10px}}.pen-page-title{margin:8px 0 12px;font-size:20px}.pen-page-formula{opacity:0;margin:0 0 12px;padding:.15em 0 .25em;font-size:23.6px;transition:opacity .35s;overflow:auto hidden}.pen-page-formula .katex-display{margin:0}.pen-page-formula .katex-display>.katex{text-align:left}.pen-page-formula.shown{opacity:1}.pen-page-body{margin:0;font-size:20px;line-height:1.5}.unseen{visibility:hidden}.math-text .nowrap{white-space:nowrap}.pen-nav{justify-content:flex-end;align-items:center;gap:12px;margin-top:20px;display:flex}.pen-pages-list{margin-top:12px}.pen-pages-list summary{cursor:pointer;color:var(--brand);font-weight:500}.pen-pages-list li{margin:6px 0}.pen-pages-list li>*+*{margin-left:8px}.topic{border-top:1px solid var(--separator);flex-direction:column;gap:8px;padding:12px 0;display:flex}.topic-head{gap:4px;display:flex}.topic-head input{flex:1;font-weight:600}label.check{align-items:flex-start;gap:10px;display:flex}label.check input{margin-top:4px}.point-progress{margin:-2px 0 0;padding-left:18px}.grading-points{padding-left:18px}.grading-points li+li{margin-top:6px}.calendar{grid-template-columns:repeat(7,minmax(0,1fr));gap:4px;display:grid}.calendar-head{color:var(--ink-secondary);text-align:center;font-size:12px}.calendar-day{background:var(--background);border-radius:8px;flex-direction:column;justify-content:space-between;min-height:52px;padding:6px;font-size:13px;display:flex}.calendar-day.today{outline:2px solid var(--brand)}.calendar-day.future{border:1px dashed var(--separator);background:0 0}.calendar-date{color:var(--ink-secondary);font-size:12px}.calendar-minutes{font-variant-numeric:tabular-nums;font-weight:600}.calendar-day.met{background:color-mix(in srgb, var(--right) 22%, var(--surface))}.calendar-day.extra{background:color-mix(in srgb, var(--right) 10%, var(--surface))}.calendar-day.partial{background:color-mix(in srgb, #f59e0b 25%, var(--surface))}.calendar-day.missed{background:color-mix(in srgb, var(--wrong) 15%, var(--surface))}.field-label{color:var(--ink-secondary);margin-bottom:-4px;font-size:12px;font-weight:600}.unknown-emails{margin:0;padding:0;list-style:none}.unknown-emails li{border-top:1px solid var(--separator);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;padding:10px 0;display:flex}.unknown-email-actions{align-items:center;gap:8px;display:flex}.practice-days{grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:8px;display:grid}.practice-day{border:1px solid var(--separator);background:var(--background);text-align:left;border-radius:10px;flex-direction:column;align-items:flex-start;gap:2px;padding:10px 12px;display:flex}.practice-day:hover{border-color:var(--brand)}.day-practice{margin:28px 0 12px;font-size:18px}.shown-screen{border:1px solid var(--separator);border-radius:10px;width:100%;height:auto;margin-top:12px;display:block}.unread{color:var(--wrong)}.vocab-chapters{margin:8px 0 0}.column.vocab{--u:clamp(1px, min((100vw - 32px) / 728, (100vh - 229px) / 450), 2px);max-width:calc(728 * var(--u) + 32px);min-height:100dvh;padding-bottom:calc(88px + env(safe-area-inset-bottom));flex-direction:column;display:flex}.vocab-main{margin:auto 0}.vocab-top{justify-content:space-between;align-items:center;min-height:40px;margin-bottom:8px;display:flex}.vocab-top .link{font-size:19px}.vocab-box{border:1px solid var(--separator);background:var(--surface);color:var(--ink);border-radius:12px;align-items:center;gap:6px;padding:7px 12px;font-weight:600;display:inline-flex}.vocab-box:hover:not(:disabled){border-color:var(--brand);background:var(--brand-surface);color:var(--brand)}.vocab-box-title{align-items:center;gap:10px;margin:4px 0 8px;font-size:24px;display:flex}.vocab-where{color:var(--ink-secondary);justify-content:space-between;gap:12px;margin:8px 0 10px;font-size:14px;display:flex}.vocab-stage{align-items:center;gap:calc(12 * var(--u));display:flex}.vocab-step{width:calc(44 * var(--u));height:calc(44 * var(--u));border:1px solid var(--separator);background:var(--surface);color:var(--ink);border-radius:50%;flex:none;place-items:center;padding:0;display:grid}.vocab-step:hover:not(:disabled){border-color:var(--brand);color:var(--brand)}.vocab-step svg{width:calc(24 * var(--u));height:calc(24 * var(--u))}.vocab-card{cursor:pointer;justify-content:center;align-items:center;gap:calc(12 * var(--u));min-width:0;min-height:calc(300 * var(--u));padding:calc(32 * var(--u)) calc(24 * var(--u));border:1px solid var(--separator);border-radius:calc(20 * var(--u));background:var(--surface);color:var(--ink);text-align:center;flex-direction:column;flex:1;display:flex}.vocab-card.turned{text-align:left;justify-content:flex-start;align-items:stretch}.vocab-kind{font-size:calc(13 * var(--u));color:var(--brand);font-weight:600}.vocab-term{font-size:calc(40 * var(--u));overflow-wrap:anywhere;font-weight:700;line-height:1.15}.vocab-card.turned .vocab-term{font-size:calc(24 * var(--u))}.vocab-meaning{font-size:calc(24 * var(--u));font-weight:600;line-height:1.35}.vocab-meaning.long{font-size:calc(18 * var(--u));font-weight:500}.vocab-line{font-size:calc(16 * var(--u))}.vocab-line b{margin-right:calc(8 * var(--u));color:var(--ink-secondary)}.vocab-example-button{padding:calc(6 * var(--u)) calc(18 * var(--u));border:1px solid var(--brand);background:var(--surface);color:var(--brand);font-size:calc(15 * var(--u));border-radius:999px;font-weight:600}.vocab-example-button[aria-expanded=true]{background:var(--brand-surface)}.vocab-example{padding:calc(12 * var(--u)) calc(16 * var(--u));border-radius:calc(12 * var(--u));background:var(--background);text-align:left;align-self:stretch}.vocab-example-title{margin-bottom:calc(4 * var(--u));font-size:calc(13 * var(--u));color:var(--ink-secondary);display:block}.vocab-example-text{font-size:calc(19 * var(--u));line-height:1.45}.vocab-hit{color:#ea580c;font-weight:700}.vocab-source{margin-top:calc(6 * var(--u));font-size:calc(13 * var(--u));color:var(--ink-secondary)}.vocab-answer{margin-top:calc(20 * var(--u));justify-content:center;display:flex}.vocab-answer button{min-width:calc(160 * var(--u));padding:calc(12 * var(--u)) calc(20 * var(--u));border-radius:calc(12 * var(--u));font-size:calc(18 * var(--u))}.vocab-keys,.vocab-tap{text-align:center;color:var(--ink-secondary);margin:12px 0 0;font-size:13px}.vocab-tap{display:none}@media (hover:none){.vocab-keys{display:none}.vocab-tap{display:block}}.vocab-done{text-align:center;padding:32px 20px}.vocab-done h2{margin-bottom:20px;font-size:22px}.vocab-bar{z-index:10;padding:12px 19px calc(12px + env(safe-area-inset-bottom));border-top:1px solid var(--separator);background:var(--surface);align-items:center;gap:14px;display:flex;position:fixed;bottom:0;left:0;right:0}.vocab-chapter{border-right:1px solid var(--separator);white-space:nowrap;flex:none;padding-right:14px;font-size:19px;font-weight:700}.vocab-lessons{scrollbar-width:thin;flex:1;gap:10px;min-width:0;display:flex;position:relative;overflow-x:auto}.vocab-lesson{border:1px solid var(--separator);background:var(--background);color:var(--ink);white-space:nowrap;border-radius:14px;flex:none;padding:10px 17px;font-size:19px;font-weight:600}.vocab-lesson:hover:not(:disabled){border-color:var(--brand);color:var(--brand)}.vocab-lesson.here{border-color:var(--brand);background:var(--brand-surface);color:var(--brand)}@media (width<=480px){.vocab-stage{gap:6px}.vocab-step{width:36px;height:36px}.vocab-card{min-height:260px;padding:24px 14px}.vocab-term{font-size:32px}.vocab-example-text{font-size:17px}}