:root{--bg:#f7f7f3;--paper:#fff;--ink:#202a30;--muted:#7a8285;--line:#e5e8e5;--green:#416c54;--pale:#ecf4ed;--orange:#f7d8b7;--lav:#eae7f7;--blue:#e5f0f5;--shadow:0 10px 32px rgba(25,45,35,.05)}*{box-sizing:border-box}html,body{min-height:100%;margin:0}body{background:var(--bg);font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Inter,Arial,sans-serif;color:var(--ink);font-size:15px;-webkit-font-smoothing:antialiased}button,input,textarea,select{font:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #a7c5ad;outline-offset:2px}.shell{min-height:100vh;display:grid;grid-template-columns:260px minmax(0,1fr)}.sidebar{background:#fff;border-right:1px solid var(--line);display:flex;flex-direction:column;padding:30px 20px;position:sticky;top:0;height:100vh}.brand{display:flex;align-items:center;gap:12px;padding:0 8px}.brand strong{display:block;font-size:17px;letter-spacing:-.5px}.brand small{display:block;font-size:11px;color:var(--muted);margin-top:5px}.brandmark{width:40px;height:40px;background:var(--green);color:white;border-radius:14px;display:grid;place-items:center;font-size:24px}.sidebar-meta{display:flex;gap:6px;margin:30px 0 19px}.language-chip,.level-chip{font-size:11px;background:var(--pale);border-radius:100px;padding:7px 10px;font-weight:650}.level-chip{background:#f2effb;color:#7460a0}.nav{display:flex;flex-direction:column;gap:6px}.nav-item{width:100%;text-align:left;display:flex;align-items:center;gap:12px;padding:13px 14px;background:transparent;border:none;color:#586260;border-radius:11px;font-weight:600}.nav-item>span:first-child{width:22px;font-size:21px;text-align:center;font-weight:400}.nav-item:hover{background:#f3f6f3}.nav-item.active{color:#27613c;background:var(--pale)}.nav-count{margin-left:auto;background:#dbe9dd;border-radius:20px;font-size:11px;padding:2px 7px}.sidebar-footer{margin-top:auto;padding:20px 8px 0;border-top:1px solid var(--line)}.sidebar-footer p{font-size:12px;line-height:1.6;color:#777f7e}.text-button{display:block;border:none;background:transparent;color:var(--green);padding:8px 0;font-size:12px;font-weight:700;text-align:left}.version{display:block;font-size:10px;color:#a3a9a3;margin-top:15px}.main{max-width:1500px;width:100%;margin:auto;padding:35px 4vw 80px}.topbar{display:flex;justify-content:space-between;align-items:center;gap:16px;margin:0 0 27px}.eyebrow{font-weight:800;font-size:11px;letter-spacing:2px;color:#7a9984}.topbar h1{font-size:30px;margin:8px 0 0;letter-spacing:-1.1px}.top-right{display:flex;align-items:center;gap:12px}.saved{font-size:11px;color:#8c9890}.icon-button{width:38px;height:38px;background:var(--paper);border:1px solid var(--line);border-radius:11px;color:#305b43;font-size:24px}.view{display:none;max-width:1130px}.view.active{display:block}.hero{border-radius:19px;padding:31px;background:#dfece0;display:grid;grid-template-columns:1fr 180px;gap:20px;align-items:center;overflow:hidden}.hero h2{font-size:31px;line-height:1.16;letter-spacing:-1.2px;margin:9px 0 11px;max-width:550px}.hero p{color:#586e61;font-size:14px;max-width:500px;line-height:1.6;margin:0 0 20px}.hero-illustration{width:165px;height:185px;background:#fff;border-radius:12px;transform:rotate(8deg);box-shadow:16px 18px 0 rgba(65,108,84,.13);padding:23px 15px;color:#809e88;position:relative}.hero-illustration:before{content:'';display:block;border-top:3px solid #92b9a0;position:absolute;top:60px;left:20px;width:100px;box-shadow:0 30px #ccdecf,0 60px #ccdecf,0 90px #ccdecf}.hero-illustration strong{font-family:Georgia,serif;font-style:italic;color:#40694c;font-size:18px}.btn{display:inline-flex;gap:9px;align-items:center;justify-content:center;border-radius:11px;padding:11px 17px;border:1px solid var(--line);background:white;font-size:13px;font-weight:700;color:#33453a;transition:transform .08s}.btn:active{transform:scale(.98)}.btn-primary{background:var(--green);color:#fff;border-color:var(--green)}.btn-ghost{background:transparent}.btn-small{padding:8px 11px;font-size:12px}.stats,.tiles{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:18px 0 28px}.stats .stat{background:#fff;border:1px solid var(--line);border-radius:14px;padding:20px 22px}.stat .value{font-size:30px;letter-spacing:-1px;font-weight:750;display:block}.stat .caption{font-size:12px;color:var(--muted)}.heading-row{display:flex;align-items:center;justify-content:space-between;gap:15px;margin:26px 0 13px}.heading-row h2{font-size:18px;letter-spacing:-.35px;margin:0}.heading-row small{color:var(--muted)}.tiles{grid-template-columns:repeat(3,1fr);margin:0}.tile{border:1px solid var(--line);padding:22px;border-radius:15px;background:white;text-align:left;min-height:160px}.tile:nth-child(1){background:#f1f5f0}.tile:nth-child(2){background:#f5f1fa}.tile:nth-child(3){background:#f9f4ef}.tile-icon{display:inline-flex;font-size:23px;margin-bottom:20px}.tile strong{display:block;font-size:16px}.tile p{color:#79827a;line-height:1.5;font-size:12px;margin:8px 0 0}.notebook-layout{display:grid;grid-template-columns:225px minmax(0,1fr);gap:16px}.pages-sidebar,.paper,.panel,.word-item,.grammar-item,.question-item,.study-card,.empty-panel{background:white;border-radius:15px;border:1px solid var(--line);box-shadow:var(--shadow)}.pages-sidebar{padding:14px;align-self:start}.pages-sidebar h3{font-size:13px;margin:7px 8px 15px}.page-list{display:flex;flex-direction:column;gap:6px}.page-entry{background:transparent;border:none;border-radius:9px;padding:13px 11px;text-align:left;display:flex;flex-direction:column;gap:4px}.page-entry strong{font-size:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.page-entry small{font-size:10px;color:var(--muted)}.page-entry.selected{background:#eaf2eb;color:#376448}.paper{padding:22px 25px;min-height:650px}.paper-header{display:flex;align-items:center;justify-content:space-between;gap:8px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:14px}.paper-title{background:transparent;border:none;min-width:50px;font-size:22px;font-weight:750;letter-spacing:-.5px;color:var(--ink);max-width:100%}.paper-title:focus{outline:none;border-bottom:1px dashed #76977c}.mode-switch{display:flex;gap:3px;background:#f0f3ef;border-radius:11px;padding:4px}.mode-switch button{border:0;background:transparent;padding:8px 12px;color:#6b7a6d;border-radius:8px;font-weight:650;font-size:12px}.mode-switch button.active{background:white;color:#2d6542;box-shadow:0 1px 4px #cdd6ce}.note-help{font-size:12px;color:#88968b;line-height:1.5;margin:12px 0}.lined-textarea,.ink-stage{border:1px solid #edf0ea;border-radius:10px;background-color:#fff;background-image:linear-gradient(to bottom, transparent 32px, #e6ede7 33px);background-size:100% 34px}.lined-textarea{width:100%;min-height:455px;resize:vertical;border:none;outline:none;font-size:16px;line-height:34px;padding:7px 14px;letter-spacing:.1px;color:#304239}.ink-stage{position:relative;overflow:hidden;min-height:450px;touch-action:none}.ink-stage canvas{display:block;width:100%;height:450px;cursor:crosshair;touch-action:none}.ink-tools{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin:11px 0}.color-dot{border-radius:50%;width:25px;height:25px;border:3px solid white;box-shadow:0 0 0 1px #cfdcd0}.color-dot.active{box-shadow:0 0 0 2px #678d70}.pen-label{font-size:11px;color:#88918a;margin-right:2px}.tiny-note{font-size:11px;color:#9a9f9b}.translation-panel{padding:16px;border:1px solid #dfe8dc;border-radius:12px;background:#f6faf5;margin:10px 0}.translation-panel .original{font-size:18px;font-weight:750}.translation-panel .translation{font-size:15px;color:#3b6b50;margin:5px 0 14px}.translation-panel small{color:#7a8a7b;font-size:11px}.toolbar{display:flex;gap:8px;flex-wrap:wrap}.toolbar .search{flex:1;min-width:190px}.search,.field,textarea.field{border:1px solid var(--line);background:white;color:var(--ink);padding:12px 14px;border-radius:10px;outline:none}.search:focus,.field:focus{border-color:#9cc2a5}.word-list,.grammar-list,.question-list{display:grid;gap:11px;margin-top:16px}.word-item{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:17px 19px}.word-item strong{font-size:17px}.word-item .meaning{color:#436c50;margin:5px 0}.word-item small{color:var(--muted);font-size:11px}.word-item .word-actions{display:flex;gap:6px;flex-shrink:0}.round{width:36px;height:36px;border-radius:10px;border:1px solid #e5eae5;background:#fafcf9;color:#4f6855}.panel{padding:20px}.panel-title{font-weight:750;margin-bottom:14px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.form-grid .full{grid-column:1/-1}.grammar-item,.question-item{padding:0;overflow:hidden}.grammar-item summary,.question-item summary{padding:18px 20px;cursor:pointer;font-weight:750;list-style:none;display:flex;justify-content:space-between}.grammar-item summary:after,.question-item summary:after{content:'⌄';color:#7f9d87}.grammar-item[open] summary:after,.question-item[open] summary:after{content:'⌃'}.grammar-body,.question-body{padding:2px 20px 20px;color:#4b5950;font-size:14px;line-height:1.6}.example{background:#f3f7f2;padding:12px 14px;border-radius:10px;margin:10px 0}.grammar-note{width:100%;resize:vertical;margin-top:10px;min-height:66px}.study-layout{display:grid;grid-template-columns:minmax(0,1fr) 240px;gap:16px}.study-card{min-height:335px;padding:32px;text-align:center;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px}.study-card .flash-label{font-size:10px;letter-spacing:2px;color:#899e89;font-weight:800}.study-card .term{font-size:40px;font-weight:750;letter-spacing:-1px;word-break:break-word}.study-card .definition{font-size:24px;color:#406c4e}.study-card .hint{color:#9aa49a;font-size:12px}.study-actions{display:flex;gap:10px;justify-content:center;margin-top:15px;flex-wrap:wrap}.study-side{padding:20px;border-radius:15px;background:#edf3eb}.study-side h3{font-size:15px;margin:0 0 12px}.study-side p{color:#667c6b;font-size:12px;line-height:1.7}.pill{display:inline-flex;border-radius:30px;font-size:11px;background:#f0f5f1;padding:7px 9px;color:#51745b}.empty-panel{padding:38px 20px;text-align:center;color:#718175}.empty-panel h3{color:#354a3a}.badge-pink{background:#f5e8e6;color:#9b5c5b}.mobile-nav{display:none}.toast{position:fixed;bottom:25px;left:50%;transform:translate(-50%,30px);opacity:0;pointer-events:none;background:#203c2e;color:#fff;padding:12px 16px;border-radius:10px;font-size:12px;transition:all .25s;box-shadow:0 5px 20px #29402e26;z-index:50}.toast.show{opacity:1;transform:translate(-50%,0)}@media(max-width:1000px){.shell{grid-template-columns:205px minmax(0,1fr)}.sidebar{padding:25px 12px}.main{padding:30px 24px 80px}.notebook-layout{grid-template-columns:170px minmax(0,1fr)}.hero{grid-template-columns:1fr 120px}.hero-illustration{width:120px;height:160px}.tiles{gap:10px}.tile{padding:16px}}@media(max-width:730px){.shell{display:block}.sidebar{display:none}.main{padding:20px 14px 100px}.topbar h1{font-size:25px}.saved{display:none}.hero{grid-template-columns:1fr;padding:25px 21px}.hero h2{font-size:26px}.hero-illustration{display:none}.stats{grid-template-columns:repeat(3,1fr);gap:7px}.stats .stat{padding:14px 10px}.stat .value{font-size:24px}.stats .caption{font-size:10px}.tiles{grid-template-columns:1fr}.tile{min-height:90px;padding:17px}.tile-icon{margin-bottom:8px}.notebook-layout{display:block}.pages-sidebar{margin-bottom:10px;padding:9px}.pages-sidebar h3{margin:8px 9px}.page-list{flex-direction:row;overflow-x:auto;padding:0 2px 6px}.page-entry{min-width:135px}.paper{padding:12px 12px;min-height:530px}.paper-title{font-size:18px;width:100%;padding:6px 0}.paper-header{display:block}.mode-switch{margin-top:10px}.mode-switch button{flex:1}.lined-textarea{min-height:360px;font-size:15px}.ink-stage,.ink-stage canvas{min-height:360px;height:360px}.mobile-nav{display:flex;position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid var(--line);padding:8px 4px max(8px,env(safe-area-inset-bottom));justify-content:space-around;z-index:30}.mobile-nav button{border:0;background:transparent;display:flex;flex-direction:column;align-items:center;color:#89928a;gap:4px;padding:4px 0;min-width:47px}.mobile-nav button.active{color:#2e6946}.mobile-nav button span{font-size:22px}.mobile-nav button small{font-size:9px}.toolbar{display:flex}.form-grid{grid-template-columns:1fr}.study-layout{grid-template-columns:1fr}.study-card{min-height:285px}.study-card .term{font-size:34px}.study-side{display:none}.word-item{padding:14px 11px}.word-item strong{font-size:15px}.word-item .word-actions{gap:2px}.round{width:32px;height:32px}.toast{bottom:85px;width:max-content;max-width:90vw}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}
/* v0.2: smart capture & handwriting OCR */
.paper-aside-hint{background:#f2f7f2;border-radius:12px;padding:14px 12px;margin-top:20px}.paper-aside-hint strong{font-size:12px;color:#456d4e}.paper-aside-hint p{font-size:11px;color:#7c917e;line-height:1.5;margin:7px 0 0}
.action-toolbar{flex-wrap:wrap;align-items:center;gap:8px;margin-top:12px}.smart-scan{background:#f8faf7;border:1px solid #e0e9de;padding:20px;margin:26px -3px 4px;border-radius:17px}.smart-scan-heading{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}.smart-scan h3{margin:4px 0 0;font-size:18px;letter-spacing:-.35px}.smart-scan .eyebrow{font-size:9px}.smart-scan>p.tiny-note{line-height:1.7;max-width:650px;color:#7a887b}.tiny-ai{display:inline-block;font-size:9px;background:#d5e8da;color:#457354;border-radius:20px;padding:4px 7px;vertical-align:3px;letter-spacing:0}.ocr-status{font-size:12px;color:#5a7865;line-height:1.6;min-height:16px;margin-top:8px}.ocr-status.working:before{content:'◌';display:inline-block;margin-right:8px;animation:ocrspin 1s linear infinite}@keyframes ocrspin{to{transform:rotate(360deg)}}.ocr-preview-wrap{max-height:190px;overflow:hidden;border:1px solid #e0e8e1;border-radius:10px;background:#fff;margin:10px 0}.ocr-preview-wrap img{max-width:100%;height:auto;max-height:190px;display:block;margin:auto;object-fit:contain}.scan-label{font-size:10px;letter-spacing:.6px;text-transform:uppercase;font-weight:750;color:#65836a;display:block;margin:13px 0 8px}#ocr-text{display:block;width:100%;line-height:1.6;padding:13px;resize:vertical;min-height:110px}.translation-panel{margin-top:14px}.translation-panel .original{word-wrap:break-word}.translation-panel .translation{white-space:pre-wrap;line-height:1.65;word-wrap:break-word}.context-hint{margin-top:12px;border-top:1px solid #e0e8dc;padding-top:12px;font-size:12px;line-height:1.6;color:#637868}.link-inline{margin-left:8px;border:0;background:transparent;color:#396c4d;font-size:12px;font-weight:750;cursor:pointer;text-decoration:underline}.written-answer{background:#eef5f0;color:#4d6651;font-size:13px;padding:12px;border-radius:10px;line-height:1.5}
@media(max-width:730px){.paper-aside-hint{display:none}.smart-scan{padding:16px 13px;margin:20px 0 0}.smart-scan h3{font-size:16px}.smart-scan-heading>.btn{max-width:100%;font-size:11px}.action-toolbar>.btn{flex:1 1 auto;min-width:120px}.ink-stage canvas{touch-action:none}}
.tiles-four{grid-template-columns:repeat(4,minmax(0,1fr))}.tiles-four .tile{padding:18px;min-height:175px}.tiles-four .tile-icon{margin-bottom:16px}
@media(max-width:1150px){.tiles-four{grid-template-columns:repeat(2,minmax(0,1fr))}.tiles-four .tile{min-height:125px}}
@media(max-width:730px){.tiles-four{grid-template-columns:1fr}.tiles-four .tile{min-height:80px}}
.auto-translate-setting{display:flex;align-items:center;gap:7px;font-size:11px;line-height:1.4;color:#819184;margin-top:10px}.auto-translate-setting input{accent-color:#416c54}
/* v0.3: compact selection toolbar, sync state and owner login */
.sync-btn{border:1px solid #dce4dd;border-radius:10px;background:#fff;color:#416c54;padding:9px 12px;font-size:12px;white-space:nowrap;cursor:pointer}
.sync-btn.sync-error{color:#a25d35;border-color:#eac8b3}
.ink-tool-active{background:#e4eee7!important;color:#315e41!important;border-color:#aac4b1!important}
.tool-divider{display:inline-flex;height:22px;width:1px;background:#d7dcd6;margin:0 3px}
.ink-stage{position:relative}.ink-stage canvas{touch-action:none;cursor:crosshair}
.auth-gate{position:fixed;inset:0;z-index:3000;align-items:center;justify-content:center;background:rgba(24,37,29,.72);backdrop-filter:blur(6px);padding:24px}
.auth-panel{width:min(100%,440px);background:#fff;border-radius:24px;padding:36px;box-shadow:0 30px 90px rgba(0,0,0,.18)}
.auth-panel .auth-mark{width:48px;height:48px;display:grid;place-items:center;background:#d9ebdc;color:#326c48;border-radius:14px;font-size:30px;margin-bottom:18px}
.auth-panel h2{font-size:27px;line-height:1.12;letter-spacing:-.8px;margin:12px 0}
.auth-panel p{color:#66766d;line-height:1.55}
.auth-panel label{display:block;font-weight:650;font-size:13px;margin:20px 0 9px}
.auth-panel input{width:100%;padding:15px 14px;background:#f8faf7;border:1px solid #d6dfd9;border-radius:11px}
.auth-panel button{width:100%;margin-top:13px;padding:14px}
.auth-error{margin:12px 0;color:#b94e42;font-size:13px;min-height:17px}
.auth-panel small{display:block;color:#88948d;line-height:1.5}
@media(max-width:750px){.top-right{gap:5px}.sync-btn{padding:7px 8px;font-size:10px}.auth-panel{padding:24px}.ink-tools{flex-wrap:wrap}.ink-stage canvas{min-height:240px}}