:root{--navy:#172d36;--navy-2:#243942;--cream:#f4f3ee;--paper:#fffefa;--ink:#24353e;--dim:#70838b;--line:#e2e8e6;--accent:#d2ee8b;--gold:#e6c68b;--red:#bf554d;--shadow:0 12px 38px rgba(22,43,52,.06);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","PingFang TC","Noto Sans TC","Segoe UI",sans-serif;color:var(--ink);background:var(--cream)}
*{box-sizing:border-box}html,body{min-height:100%;margin:0}body{-webkit-font-smoothing:antialiased}button,input{font:inherit}button{cursor:pointer}button:disabled{cursor:default;opacity:.37}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #88b5e4;outline-offset:3px}svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}.app-shell{margin:0 auto;max-width:1740px;padding:0 clamp(14px,3.2vw,46px)}.masthead{display:flex;justify-content:space-between;align-items:center;gap:16px;min-height:108px;border-bottom:1px solid #dce3df}.identity{display:flex;align-items:center;gap:14px}.brand-icon{width:48px;height:48px;border-radius:15px;background:var(--navy);color:var(--accent);display:grid;place-items:center;font-size:32px;font-family:Georgia,serif;line-height:1}.identity h1{margin:0;font-size:28px;font-weight:750;letter-spacing:-.9px}.identity p{margin:5px 0 0;color:#798982;font-size:12px;letter-spacing:.5px}.version{font-size:10px;font-weight:700;letter-spacing:.5px;color:#889997;margin-left:4px;vertical-align:middle}.status-group{display:flex;gap:12px;align-items:center}.status-chip{display:inline-flex;align-items:center;gap:8px;background:#e9efeb;border:1px solid #dce8df;border-radius:30px;color:#576a62;font-size:12px;padding:9px 13px;font-weight:600}.status-dot,.tiny-circle{width:7px;height:7px;background:#57a17c;border-radius:99px;display:inline-block;flex:0 0 auto}.layout{display:grid;grid-template-columns:minmax(0,1fr) 315px;gap:25px;padding-top:28px;align-items:start}.workspace{min-width:0}.workspace-head,.history-top{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:14px}.eyebrow{font-size:10px;letter-spacing:1.9px;font-weight:700;color:#a4aaa0}.section-title h2,.history-top h2{margin:4px 0 0;font-size:20px;letter-spacing:-.5px}.autosave{font-size:12px;color:#7e8d85;display:flex;align-items:center;gap:8px}.toolbar{display:flex;align-items:center;gap:13px;padding:10px 14px;margin-bottom:13px;border:1px solid var(--line);background:#fff;border-radius:15px;min-height:64px;box-shadow:0 1px 5px rgba(23,45,54,.02);flex-wrap:wrap}.tool-set{display:flex;gap:4px}.tool-button{display:flex;gap:6px;align-items:center;justify-content:center;background:transparent;border:none;border-radius:9px;color:#7d8a8b;font-size:12px;font-weight:700;padding:10px}.tool-button.active{background:#eaf1e5;color:#1f3f37}.tool-button svg{width:19px;height:19px}.toolbar-divider{height:28px;width:1px;background:#e3e8e4}.color-options{display:flex;align-items:center;gap:10px}.color-dot{background:var(--ink);border:2px solid white;width:19px;height:19px;border-radius:50%;padding:0;box-shadow:inset 0 0 0 20px var(--ink);position:relative}.color-dot.selected:after{position:absolute;content:"";inset:-6px;border:1.5px solid var(--ink);border-radius:50%}.pen-width{display:flex;gap:8px;align-items:center;color:#74837f;white-space:nowrap;font-size:11px;font-weight:700}.pen-width input{width:83px;accent-color:#54756d}.toolbar-spacer{flex:1}.toolbar-actions{display:flex;gap:3px}.icon-button{background:transparent;color:#667b7c;border:0;width:37px;height:36px;border-radius:9px;display:grid;place-items:center}.icon-button:not(:disabled):hover{background:#f1f5f2}.danger-hover:not(:disabled):hover{color:var(--red);background:#fff1f0}.paper-frame{border:1px solid #e3e6df;border-radius:16px;background:var(--paper);overflow:hidden;box-shadow:var(--shadow)}.paper-header,.paper-bottom{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:14px 22px;background:#fffefa;color:#8e9b97;font-size:11px}.paper-header{border-bottom:1px solid #f0f2eb;letter-spacing:.4px}.paper-kicker{font-weight:800;color:#899a92;letter-spacing:1px}.paper{height:clamp(350px,53vh,670px);position:relative;overflow:hidden;touch-action:none;background-color:var(--paper);background-image:radial-gradient(#d4ded9 0.7px,transparent 0.7px);background-size:23px 23px;background-position:11px 10px;cursor:crosshair}.paper canvas{width:100%;height:100%;display:block;position:relative;z-index:2;touch-action:none}.paper-watermark{position:absolute;inset:0;z-index:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;pointer-events:none;color:#b9c4be}.watermark-mark{font:italic 68px Georgia,serif;color:#cbd8d0;line-height:1.15}.paper-watermark strong{font-size:16px;letter-spacing:.4px;font-weight:600}.paper-watermark span{font-size:12px}.paper-watermark.hidden{display:none}.paper-bottom{padding:11px 18px;border-top:1px solid #f0f2eb}.pencil-switch{display:flex;align-items:center;gap:10px;font-size:12px;font-weight:650;color:#7e8b86;cursor:pointer;user-select:none}.pencil-switch input{position:absolute;opacity:0;width:1px;height:1px}.toggle-track{display:inline-block;width:31px;height:18px;border-radius:99px;background:#cbd6d0;position:relative;transition:background .18s}.toggle-track:after{content:"";position:absolute;width:12px;height:12px;top:3px;left:3px;background:#fff;box-shadow:0 1px 3px #778; border-radius:50%;transition:transform .18s}.pencil-switch input:checked+.toggle-track{background:#4e7568}.pencil-switch input:checked+.toggle-track:after{transform:translateX(13px)}.pencil-switch input:focus-visible+.toggle-track{outline:3px solid #88b5e4;outline-offset:3px}.subtle-hint{color:#a1aca7;font-size:11px}.action-row{display:flex;align-items:stretch;gap:10px;margin-top:16px}.action-row button{border-radius:12px;min-height:60px;display:flex;align-items:center;justify-content:center;gap:10px;font-weight:750;font-size:14px;padding:12px 16px}.btn-primary{background:var(--navy);color:white;border:1px solid var(--navy);flex:1.25;box-shadow:0 4px 12px #172d361d}.btn-primary svg{color:var(--accent)}.btn-primary:hover{background:#274754}.btn-primary small{font-weight:500;font-size:10px;letter-spacing:.5px;color:#b6c9ca;margin-left:2px}.btn-secondary{background:#e3ebd7;color:var(--navy);border:1px solid #d8e2d1;flex:1}.btn-secondary:hover{background:#d5e4bf}.btn-outline{background:white;color:#5a6e6d;border:1px solid #dce4df}.btn-outline:hover{background:#f5f7f4}.copy-tip{font-size:11px;color:#869790;margin-top:13px;text-align:center;line-height:1.65}.copy-tip kbd{border:1px solid #dce3dd;border-bottom-width:2px;background:#fff;padding:1px 5px;border-radius:4px;color:#56645e}.history-panel{height:min(790px,calc(100dvh - 160px));min-height:580px;border:1px solid #e1e7e2;border-radius:16px;background:#fff;display:flex;flex-direction:column;box-shadow:0 4px 20px #122a3010;overflow:hidden}.history-top{padding:24px 20px 0;margin-bottom:10px}.history-top h2{font-size:18px}.history-count{font-size:11px;background:#e5ebdd;color:#547267;border-radius:50px;padding:3px 8px;margin-left:4px}.history-description{font-size:11px;line-height:1.7;color:#9aa6a0;padding:0 20px 14px;border-bottom:1px solid #edf0e9}.history-list{min-height:0;flex:1;overflow-y:auto;padding:14px;scrollbar-width:thin}.history-empty{text-align:center;color:#a3b0aa;font-size:12px;line-height:2.2;padding:70px 10px}.history-item{display:flex;align-items:center;gap:12px;padding:9px;border:1px solid #edf1eb;border-radius:11px;margin-bottom:10px;background:#fdfefb}.history-thumb{width:83px;height:82px;object-fit:contain;background:#fff;border:1px solid #f0f0ec;border-radius:8px;padding:5px;flex:0 0 auto}.history-meta{min-width:0;flex:1}.history-name{font-weight:800;font-size:12px;color:#3c4f4b;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history-date{font-size:10px;color:#a4b0ac;margin-top:5px}.history-item-actions{margin-top:8px;display:flex;gap:9px;flex-wrap:wrap}.mini-action{font-size:11px;font-weight:700;color:#4f8071;border:0;background:transparent;padding:1px 0}.mini-action:hover{text-decoration:underline}.mini-action.delete{color:#bc6b64}.history-bottom{padding:17px 18px 19px;background:#f8faf6;border-top:1px solid #edf0e8}.history-tools{display:grid;grid-template-columns:1fr 1fr;gap:8px}.history-button{background:#fff;border:1px solid #dde6dc;color:#526d63;border-radius:9px;padding:11px 7px;font-weight:700;font-size:12px;display:flex;align-items:center;justify-content:center;gap:6px}.history-button:hover{background:#eef5eb}.history-button svg{width:16px;height:16px}.history-bottom p{font-size:10px;line-height:1.75;color:#91a09a;margin:13px 2px 0}.site-footer{border-top:1px solid #dce4dc;margin-top:26px;padding:18px 0 25px;display:flex;justify-content:space-between;gap:20px;color:#9da9a1;font-size:10px;letter-spacing:.3px}.site-footer a{color:#779589;text-decoration:underline;text-underline-offset:3px}.toast{position:fixed;z-index:50;left:50%;bottom:calc(30px + env(safe-area-inset-bottom,0px));transform:translate(-50%,20px);opacity:0;pointer-events:none;color:white;background:#233b43;box-shadow:0 14px 42px #102b3552;border:1px solid #3d5959;padding:12px 20px;border-radius:12px;max-width:min(92vw,560px);font-size:13px;line-height:1.6;text-align:center;transition:opacity .15s,transform .15s}.toast.visible{opacity:1;transform:translate(-50%,0)}.toast.error{background:#653934;border-color:#94584f}.mobile-history-toggle,.history-close{display:none}
@media(max-width:1050px){.layout{grid-template-columns:minmax(0,1fr) 270px;gap:15px}.paper{height:clamp(350px,53vh,610px)}.toolbar{gap:9px;padding:8px}.tool-button span{display:none}.tool-button{width:40px}.history-panel{min-height:560px}.history-thumb{width:64px;height:68px}.history-item{gap:7px}}
@media(max-width:900px){.app-shell{padding:0 15px}.masthead{min-height:78px}.identity h1{font-size:23px}.identity p{font-size:10px}.brand-icon{height:41px;width:41px;font-size:27px}.status-chip{display:none}.mobile-history-toggle{display:inline-block;background:#e7ede8;border:1px solid #d8e4d9;border-radius:9px;padding:9px 12px;color:#426a5a;font-weight:750;font-size:12px}.layout{display:block;padding-top:18px}.workspace-head{margin-bottom:12px}.toolbar{flex-wrap:wrap}.toolbar-spacer{flex:1}.toolbar-divider{height:25px}.paper{height:min(58dvh,670px);min-height:350px}.history-panel{display:none;position:fixed;z-index:30;inset:9px 9px 9px auto;width:min(390px,calc(100vw - 22px));height:calc(100dvh - 18px);min-height:0;box-shadow:-20px 0 60px #203b385c}.history-panel.mobile-open{display:flex}.history-close{display:block;background:transparent;border:0;font-size:19px;color:#879b91}.site-footer{margin-top:22px}.action-row button{font-size:12px;padding:10px 8px;gap:6px}.btn-primary small{display:none}.action-row svg{width:18px;height:18px}}
@media(max-width:500px){.app-shell{padding:0 10px}.identity p{display:none}.masthead{min-height:68px}.toolbar{gap:9px}.color-options{gap:8px}.pen-width input{width:55px}.toolbar-divider{display:none}.toolbar-actions{margin-left:auto}.icon-button{width:32px}.paper-header{padding:12px}.paper{height:54dvh;min-height:310px}.paper-bottom{padding:11px}.subtle-hint{font-size:10px}.action-row{flex-wrap:wrap}.btn-primary{flex:1 1 56%}.btn-secondary{flex:1 1 35%}.btn-outline{flex:1 1 100%;min-height:46px!important}.site-footer{flex-wrap:wrap;line-height:1.8}.autosave{font-size:10px}}
@media (prefers-reduced-motion: reduce){*{transition:none!important}}