/* v07: mode portals, code atlas, guided practice, and a complete light/dark theme. */
:root{--page-glow:rgba(184,143,94,.10);--page-cool:rgba(94,130,143,.075);--page-lines:rgba(111,95,73,.055);--coach-mask:rgba(24,25,27,.33);--focus-ring:#b34029;--shadow:rgba(44,34,20,.13);--exam-bg:#24231f;--exam-fg:#fcfbf7;--serif:"Noto Serif SC","Noto Serif CJK SC","Songti SC","STSong","SimSun","Iowan Old Style",serif}
:root[data-theme=dark]{--paper:#191c20;--white:#23272d;--ink:#eee8dc;--muted:#aaa69d;--line:#42464b;--soft:#30353b;--accent:#efad92;--tint:#413128;--danger:#ffb1a2;--positive:#b4d3bc;--page-glow:rgba(143,103,76,.13);--page-cool:rgba(51,100,130,.17);--page-lines:rgba(201,212,224,.036);--coach-mask:rgba(0,0,0,.5);--focus-ring:#efad92;--shadow:rgba(0,0,0,.4);--exam-bg:#101419;--exam-fg:#f2ece3}
html{background:var(--paper)}body{min-height:100dvh;background:radial-gradient(ellipse at 12% 20%,var(--page-glow),transparent 52%),radial-gradient(ellipse at 91% 78%,var(--page-cool),transparent 58%),repeating-linear-gradient(116deg,transparent 0,transparent 63px,var(--page-lines) 64px,transparent 65px),linear-gradient(180deg,transparent,var(--page-cool));background-attachment:fixed}
body:after{content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;background:radial-gradient(ellipse at 50% 50%,transparent 45%,var(--page-glow));opacity:.8}.topbar{isolation:isolate}.topbar .top-actions,#account-bar{display:flex;align-items:center;justify-content:flex-end;height:44px;min-height:44px;gap:4px;flex-wrap:nowrap}.topbar .top-actions>.icon-button,#account-bar>.icon-button,.account-menu,.account-menu>summary{height:44px;min-height:44px;width:44px;flex:0 0 44px;line-height:1;display:flex;align-items:center;justify-content:center;margin:0;vertical-align:middle}.account-menu{display:block;position:relative}.account-menu>summary{padding:0}.topbar [hidden]{display:none!important}.brand-word{font-family:"Iowan Old Style","Baskerville","Palatino Linotype",Georgia,serif}.theme-host{height:44px;display:flex;align-items:center}.topbar [data-theme-toggle] .icon{width:20px;height:20px}.demo-label{align-self:center;line-height:1.4;white-space:nowrap}
body[data-view=home] #app{max-width:1220px;padding-top:clamp(48px,10vh,110px)}.mode-home{display:grid;grid-template-columns:1fr 1fr;gap:0;min-height:440px;position:relative;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.mode-home:before{content:"";position:absolute;left:50%;top:32px;bottom:32px;border-left:1px solid var(--line)}.mode-door{display:flex;align-items:flex-end;justify-content:space-between;min-width:0;position:relative;min-height:440px;padding:44px 42px;border:0;border-radius:0;text-align:left;overflow:hidden;background:transparent;isolation:isolate}.mode-door:before{content:"";position:absolute;inset:18px;background:var(--white);opacity:0;transition:opacity 250ms;z-index:-1}.mode-door:hover:before,.mode-door:focus-visible:before{opacity:.45}.mode-name{font-family:var(--serif);font-size:clamp(32px,3.5vw,46px);font-weight:500;letter-spacing:.08em;line-height:1.4;position:relative}.mode-door>.icon{margin-bottom:15px;width:25px;height:25px;color:var(--accent);transition:transform 250ms}.mode-door:hover>.icon{transform:translateX(5px)}.mode-art{position:absolute;width:330px;height:330px;top:-6px;right:15px;pointer-events:none;opacity:.83;transition:transform 900ms cubic-bezier(.2,.8,.2,1),opacity 250ms}.mode-art img{display:block;width:100%;height:100%;object-fit:contain}.mode-door:hover .mode-art{transform:translateY(-4px) rotate(5deg);opacity:1}.mode-soup .mode-art{transform:rotate(-7deg)}.mode-soup:hover .mode-art{transform:rotate(-2deg) translateY(-4px)}[data-theme=dark] .mode-art img,[data-theme=dark] .auth-art img{filter:brightness(1.65) contrast(.95);opacity:.84}
.level-heading{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:36px;padding-bottom:18px;border-bottom:1px solid var(--line)}.level-heading h1{font-size:32px;letter-spacing:.05em}.level-atlas{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(250px,.8fr);gap:64px;align-items:start;min-height:400px}.level-boxes{display:grid;grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:14px;max-width:600px;align-items:start}.level-box{position:relative;aspect-ratio:1;min-height:100px;border:1px solid var(--line);background:color-mix(in srgb,var(--white) 28%,transparent);padding:13px;align-items:center;justify-content:center;border-radius:0;min-width:0;overflow-wrap:anywhere;text-align:center;font-family:var(--serif);font-size:27px;line-height:1.35;letter-spacing:.025em}.level-box.long-code{font-size:17px;letter-spacing:0;aspect-ratio:auto;min-height:110px}.level-box.selected{border-color:var(--accent);background:color-mix(in srgb,var(--tint) 54%,transparent);color:var(--accent)}.level-box.selected:before{content:"";position:absolute;top:-1px;left:-1px;right:-1px;height:3px;background:var(--accent)}.level-done{position:absolute;right:6px;bottom:6px;width:17px;height:17px;color:var(--positive);display:grid;place-items:center}.level-done .icon{width:15px;height:15px}.level-detail{position:sticky;top:80px;padding:32px 0 0 28px;border-left:1px solid var(--line);display:flex;flex-direction:column;align-items:flex-start;gap:32px;min-width:0;min-height:210px}.level-detail h2{font-family:var(--serif);font-size:33px;line-height:1.65;letter-spacing:.045em;font-weight:500;overflow-wrap:anywhere}.level-detail .primary{min-width:158px;justify-content:space-between;gap:28px;padding:12px 16px}.level-detail .primary .icon{width:19px;height:19px}.admin-level-code{display:inline-block;font-family:var(--mono);font-size:14px;color:var(--accent);margin-right:12px;max-width:180px;vertical-align:baseline;overflow-wrap:anywhere}
.tutorial-label{font-size:14px;font-family:inherit;color:var(--muted);white-space:nowrap;letter-spacing:0;margin-left:5px}.guiding{scroll-padding-block:22px 260px}.guide-layer{position:fixed;inset:0;z-index:75;pointer-events:none}.guide-mask{position:fixed;background:var(--coach-mask);backdrop-filter:blur(5px);-webkit-backdrop-filter:blur(5px);pointer-events:auto;z-index:0}.guide-outline{position:fixed;border:1px solid var(--focus-ring);box-shadow:0 0 0 4px color-mix(in srgb,var(--focus-ring) 12%,transparent);pointer-events:none;z-index:1}.guide-target{scroll-margin-block:22px 260px}.coach{position:fixed;z-index:2;background:var(--white);color:var(--ink);border:1px solid var(--line);border-top:3px solid var(--accent);padding:19px 20px 18px;box-shadow:0 16px 50px var(--shadow);pointer-events:auto;overflow:auto;line-height:1.75}.coach-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:8px}.coach-title{font-family:var(--serif);font-size:21px;font-weight:500;line-height:1.5;outline:none;letter-spacing:.02em}.coach-head .icon-button{margin:-10px -10px -6px 0}.coach>p{font-size:15px;line-height:1.8}.coach .coach-sample{padding:10px 12px;margin-top:10px;background:var(--paper);border-left:2px solid var(--line);font-size:15px}.coach-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:14px}.coach-actions:empty{display:none}.coach-actions button{font-size:15px;padding:8px 12px;min-height:44px}.coach-actions .icon{width:17px;height:17px}.coach-head .icon{width:18px;height:18px}
/* Apply contrast deliberately, not a color inversion, to every workflow. */
[data-theme=dark] .exam-panel{background:var(--exam-bg);color:var(--exam-fg);--line:#53535b;--soft:#2c3239}[data-theme=dark] .exam-panel .choice{background:transparent;color:#ede7dc;border-color:#595e65}[data-theme=dark] .exam-panel .choice:hover{background:#303741}[data-theme=dark] .exam-panel .choice.selected{background:#d8c8b5;border-color:#d8c8b5;color:#211e1a}[data-theme=dark] .exam-panel .choice.selected>.icon{color:#853c27}[data-theme=dark] .exam-panel .form-bottom>.primary{background:#dfd8cb;color:#222;border-color:#dfd8cb}[data-theme=dark] .exam-panel .anon-value{color:#bcb6ac}[data-theme=dark] .exam-panel .anon-value.max{color:#ffd5c2}[data-theme=dark] .exam-step{color:#bcb8b0}[data-theme=dark] .exam-step.current{color:#fff}[data-theme=dark] .exam-step.correct{color:#bddbc4}[data-theme=dark] .exam-step.incorrect{color:#ffbda4}
[data-theme=dark] button.primary:hover:not(:disabled){background:var(--accent);color:#221d19}[data-theme=dark] .composer button[type=submit]{color:#211b17}[data-theme=dark] .composer button[type=submit]:hover:not(:disabled){background:#ffceb8;border-color:#ffceb8}[data-theme=dark] .auth-panel button[type=submit],[data-theme=dark] .login-wrap button[type=submit]{color:#251c17}[data-theme=dark] .auth-panel input,[data-theme=dark] .login-wrap input{border-bottom-color:#756f67;color:var(--ink)}[data-theme=dark] textarea::placeholder,[data-theme=dark] input::placeholder{color:#9f9a90}[data-theme=dark] .hint-slots span,[data-theme=dark] .milestone.locked{color:#aaa59b}[data-theme=dark] .card-art.art-unavailable:after,[data-theme=dark] .auth-art.art-unavailable:after{border-color:var(--accent)}[data-theme=dark] .table-card tbody tr:hover{background:var(--white)}[data-theme=dark] .ui-dialog{box-shadow:10px 10px 0 #0003;border-color:var(--line)}[data-theme=dark] .ui-dialog::backdrop{background:#05080bbc}[data-theme=dark] .activity-dates>div{box-shadow:5px 5px 0 #0003}[data-theme=dark] .account-menu .menu{box-shadow:6px 6px 0 #0004}[data-theme=dark] #ui-toast{background:#323941;color:#fff;border-color:var(--accent)}[data-theme=dark] #ui-toast .icon-button:hover{background:#45505c}[data-theme=dark] .surface,[data-theme=dark] .readable-text{color:var(--ink)}
@supports not(backdrop-filter:blur(1px)){.guide-mask{background:rgba(12,15,19,.7)}}
@media(max-width:1000px){.mode-door{min-height:380px;padding:32px}.mode-home{min-height:380px}.mode-art{width:275px;height:275px;right:2px;top:6px}.level-atlas{gap:34px;grid-template-columns:minmax(0,1fr) minmax(220px,.8fr)}.level-boxes{grid-template-columns:repeat(auto-fill,minmax(88px,1fr))}.level-box{min-height:90px}.level-detail{padding-left:22px}.level-detail h2{font-size:29px}}
@media(max-width:760px){.topbar .top-actions,#account-bar{gap:0}.topbar .brand-word em{display:none}.topbar .brand{gap:9px}.topbar .brand-word{font-size:26px}body[data-view=home] #app{padding:28px 20px 46px}.mode-home{grid-template-columns:1fr;min-height:0}.mode-home:before{display:none}.mode-door{min-height:240px;padding:29px 22px;border-bottom:1px solid var(--line)}.mode-door:last-child{border-bottom:0}.mode-name{font-size:33px}.mode-art{width:230px;height:230px;right:5px;top:-16px;opacity:.76}.mode-door>.icon{margin-bottom:11px;width:23px;height:23px}.mode-door:before{inset:12px}.level-heading{margin-bottom:24px;padding-bottom:14px}.level-heading h1{font-size:28px}.level-atlas{display:flex;flex-direction:column;gap:28px;min-height:0}.level-boxes{width:100%;max-width:none;grid-template-columns:repeat(auto-fill,minmax(80px,1fr));gap:10px}.level-box{font-size:25px;min-height:84px;padding:10px}.level-box.long-code{font-size:16px;min-height:100px}.level-detail{width:100%;position:static;min-height:0;border-left:0;border-top:1px solid var(--line);padding:24px 0 0;gap:24px}.level-detail h2{font-size:28px;line-height:1.6}.level-detail .primary{width:100%;min-width:0}.play-heading{flex-wrap:wrap}.tutorial-label{font-size:14px;margin-left:4px}.guiding .play-nav .actions{display:none}.guiding .play-heading h1{font-size:23px}.coach{padding:15px 17px 14px}.coach-title{font-size:20px}.coach>p,.coach .coach-sample{font-size:15px}.coach-actions{margin-top:11px}.coach .coach-sample{padding:8px 10px}.admin-level-code{display:block;margin-right:0;max-width:150px;font-size:14px}.mode-home .mode-door>.icon{color:var(--accent)}}
@media(max-width:360px){body[data-view=home] #app{padding-inline:16px}.mode-door{min-height:215px;padding:24px 17px}.mode-art{width:202px;height:202px;right:0;top:-8px}.mode-name{font-size:30px}.level-boxes{grid-template-columns:repeat(auto-fill,minmax(72px,1fr))}.topbar{padding-inline:16px}.topbar .brand-word{font-size:24px}.tutorial-label{margin-left:0}.guiding .play-heading h1{font-size:21px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Theme changes are instantaneous for readable contrast; ordinary interaction still animates. */
html.theme-switching *,html.theme-switching *:before,html.theme-switching *:after{transition:none!important}
.mode-name{font-family:"Ma Shan Zheng",var(--serif);font-weight:400;letter-spacing:.055em;font-size:clamp(38px,4vw,52px)}
@media(max-width:760px){.mode-name{font-size:39px}}
@media(max-width:360px){.mode-name{font-size:35px}}