查看“︁MediaWiki:KuranokaPageTransition.js”︁的源代码

/* ============================================================
   Kuranoka / Kuronata — Page Transition V15
   V2-inspired REAL CANVAS FIRE: bright flames, smoke, fragments.
   Only this page-scoped JS/CSS; never modify Citizen or loader.js.
   Two living same-origin Wiki documents; no reload for toggles.
   ============================================================ */
(function () {
    'use strict';
    if (!window.mw || !mw.config) return;

    const pathMatch = location.pathname.match(/\/wiki\/(Kuranoka|Kuronata)\/?$/);
    const urlPage = pathMatch ? pathMatch[1]
        : new URLSearchParams(location.search).get('title');
    const basePage = ['Kuranoka','Kuronata'].includes(urlPage)
        ? urlPage : mw.config.get('wgPageName');
    const action = new URLSearchParams(location.search).get('action') || 'view';
    if (!['Kuranoka','Kuronata'].includes(basePage) || action !== 'view') return;

    // Snapshot the user's actual Citizen theme. An entering Kuronata
    // is dark only for this document; returning to Kuranoka restores
    // exactly the former Day / OS / Night preference classes.
    const root=document.documentElement;
    const themeNames=['skin-theme-clientpref-day','skin-theme-clientpref-os',
        'skin-theme-clientpref-night','skin-theme-clientpref-black',
        'skin-citizen-light'];
    let savedTheme=themeNames.filter(c=>root.classList.contains(c));
    let wantsNight=basePage==='Kuronata';
    let changingTheme=false;
    function syncTheme() {
        if (changingTheme) return;
        const expected=wantsNight
            ? ['skin-theme-clientpref-night','kkpt-kuronata-dark']
            : savedTheme;
        const forbidden=wantsNight
            ? themeNames.filter(c=>c!=='skin-theme-clientpref-night')
            : ['kkpt-kuronata-dark',...themeNames.filter(c=>!savedTheme.includes(c))];
        if(expected.every(c=>root.classList.contains(c)) &&
            forbidden.every(c=>!root.classList.contains(c))) return;
        changingTheme=true;
        root.classList.remove(...themeNames,'kkpt-kuronata-dark');
        root.classList.add(...expected);
        changingTheme=false;
    }
    function showTheme(dark) { wantsNight=dark;syncTheme(); }
    syncTheme();
    new MutationObserver(()=>{
        // Follow later preference changes while Kuranoka is visible.
        // Only Kuronata needs an enforced appearance.
        if(wantsNight)syncTheme();
        else savedTheme=themeNames.filter(c=>root.classList.contains(c));
    }).observe(root,{
        attributes:true,attributeFilter:['class']
    });

    // The nested preview only applies its own theme; no recursive iframe.
    if (window!==window.top || window.__kkptV12) return;
    window.__kkptV12=true;
    window.__kkptVersion='15.0';

    // Easter eggs + Infobox gear are the default. No floating pill.
    const SHOW_FLOATING_BUTTON=false;
    const otherPage=basePage==='Kuranoka'?'Kuronata':'Kuranoka';
    const baseUrl=location.href;
    const baseTitle=document.title;
    const otherUrl=new URL('/wiki/'+encodeURIComponent(otherPage),location.href);
    const clipSide=basePage==='Kuranoka'?'right':'left';
    const hideClip=clipSide==='right'?'inset(0 0 0 100%)':'inset(0 100% 0 0)';
    const sleep=ms=>new Promise(r=>setTimeout(r,ms));
    const smooth=t=>t*t*(3-2*t);
    const imagePool=new Map();

    const ENABLE_TRANSITION_AUDIO = true;
    const FIRE_VOLUME = .30;
    const DAWN_VOLUME = .20;
    let soundContext=null,fireBuffer=null,activeSound=null;
    function primeSound(){
        if(!ENABLE_TRANSITION_AUDIO)return;
        try{
            const AudioEngine=window.AudioContext||window.webkitAudioContext;
            if(!AudioEngine)return;
            if(!soundContext)soundContext=new AudioEngine();
            if(soundContext.state==='suspended')soundContext.resume().catch(()=>{});
        }catch(err){console.debug('[KKPT] Audio unavailable:',err);}
    }
    function createFireAudio(ctx){
        const length=Math.round(ctx.sampleRate*4.5);
        const buffer=ctx.createBuffer(1,length,ctx.sampleRate);
        const data=buffer.getChannelData(0);
        let low=0,middle=0;
        for(let i=0;i<length;i++){
            const random=Math.random()*2-1;
            low=low*.992+random*.008;
            middle=middle*.92+random*.08;
            data[i]=Math.max(-1,Math.min(1,
                low*3.9+middle*.33+random*.055));
        }
        // Micro-crackles: impulsive bursts with different decay times.
        for(let k=0;k<350;k++){
            const at=Math.floor(Math.random()*(length-1500));
            const decay=36+Math.random()*330;
            const duration=Math.min(1400,Math.ceil(decay*4));
            const power=.20+Math.pow(Math.random(),3)*.68;
            for(let j=0;j<duration;j++){
                const env=Math.exp(-j/decay);
                data[at+j]=Math.max(-1,Math.min(1,data[at+j]+
                    (Math.random()*2-1)*power*env));
            }
        }
        return buffer;
    }
    function transitionSound(dark,durationMs){
        const ctx=soundContext;
        if(!ctx||ctx.state!=='running')return;
        const start=ctx.currentTime+.018;
        const span=durationMs/1000;
        if(activeSound){
            const old=activeSound.gain;
            old.cancelScheduledValues(start);
            old.setTargetAtTime(.0001,start,.05);
        }
        const master=ctx.createGain();
        master.gain.setValueAtTime(.0001,start);
        master.gain.linearRampToValueAtTime(dark?FIRE_VOLUME:DAWN_VOLUME,
            start+(dark?.75:1.10));
        master.gain.setValueAtTime(dark?FIRE_VOLUME:DAWN_VOLUME,
            start+span-(dark?.88:1.0));
        master.gain.exponentialRampToValueAtTime(.0001,start+span);
        master.connect(ctx.destination);
        activeSound={gain:master};
        if(dark){
            if(!fireBuffer)fireBuffer=createFireAudio(ctx);
            const src=ctx.createBufferSource();
            src.buffer=fireBuffer;src.loop=true;
            const lowpass=ctx.createBiquadFilter();
            lowpass.type='lowpass';lowpass.frequency.value=2050;
            const bass=ctx.createBiquadFilter();
            bass.type='highpass';bass.frequency.value=55;
            src.connect(lowpass);lowpass.connect(bass);bass.connect(master);
            src.start(start);src.stop(start+span+.12);
        }else{
            // Return to blue: a rising E-major wind-chime motif and airy
            // breath, with no fire or electrical crackle artifacts.
            const notes=[329.63,415.30,493.88,659.25,830.61];
            notes.forEach((hz,i)=>{
                const at=start+.14+i*.36;
                const osc=ctx.createOscillator();
                osc.type=i%2?'triangle':'sine';
                osc.frequency.setValueAtTime(hz,at);
                const note=ctx.createGain();
                note.gain.setValueAtTime(.0001,at);
                note.gain.exponentialRampToValueAtTime(.20/(1+i*.16),at+.095);
                note.gain.exponentialRampToValueAtTime(.0001,
                    Math.min(start+span-.04,at+1.45));
                osc.connect(note);note.connect(master);
                osc.start(at);osc.stop(Math.min(start+span,at+1.52));
            });
            // A soft, swelling harmonic makes the return sound alive and
            // spacious without turning it into another impact blast.
            const air=ctx.createOscillator();
            air.type='sine';air.frequency.setValueAtTime(164.81,start);
            air.frequency.linearRampToValueAtTime(246.94,start+span*.82);
            const breath=ctx.createGain();
            breath.gain.setValueAtTime(.0001,start);
            breath.gain.linearRampToValueAtTime(.115,start+1.0);
            breath.gain.exponentialRampToValueAtTime(.0001,start+span);
            air.connect(breath);breath.connect(master);
            air.start(start);air.stop(start+span+.01);
        }
        setTimeout(()=>{
            if(activeSound&&activeSound.gain===master)activeSound=null;
            try{master.disconnect();}catch(_){}
        },durationMs+350);
    }

    let active = false; // false: original top-level doc; true: otherPage iframe
    let animating = false;
    let gearPending = false;
    let ready = false;
    let loading = null;
    let button, labelTitle, labelSub, labelIcon, frame;
    let otherTitle = otherPage + ' - Blockland Wiki';

    function whichPage() { return active ? otherPage : basePage; }
    function destination() { return active ? basePage : otherPage; }
    function isDark(page) { return page === 'Kuronata'; }
    function pathPage() {
        const url = new URL(location.href);
        if (url.pathname.startsWith('/wiki/')) {
            try { return decodeURIComponent(url.pathname.slice(6)).replace(/_/g, ' '); }
            catch (e) { return ''; }
        }
        return url.searchParams.get('title') || '';
    }

    function updateButton() {
        if (!button) return;
        const to = destination();
        button.href = to === basePage ? baseUrl : otherUrl.href;
        labelTitle.textContent = to.toUpperCase();
        labelSub.textContent = isDark(to) ? 'BURN THE SKY' : 'RECLAIM THE SKY';
        labelIcon.textContent = isDark(to) ? '✦' : '❄';
        button.classList.toggle('kkpt-dark', isDark(whichPage()));
        button.setAttribute('aria-label', isDark(to) ? '燃尽天空，进入 Kuronata' : '驱散黑暗，回到 Kuranoka');
    }

    // Accept the two standard MediaWiki link forms, while rejecting
    // edit/action links, external sites and similarly named articles.
    function wikiLinkPage(anchor, doc) {
        try {
            const url = new URL(anchor.href, doc.baseURI);
            if (url.origin !== location.origin) return null;
            const action = url.searchParams.get('action');
            if (action && action !== 'view') return null;
            let title = url.searchParams.get('title');
            if (!title) {
                const matched = url.pathname.match(/^\/wiki\/([^/?#]+)\/?$/);
                if (matched) title = decodeURIComponent(matched[1]);
            }
            title = (title || '').replace(/_/g, ' ');
            return title === 'Kuranoka' || title === 'Kuronata' ? title : null;
        } catch (_) {
            return null;
        }
    }

    function decoratePortalLinks(doc, targetPage) {
        // Use only the article: sidebar, edit tools and site-wide links
        // must retain their usual navigation behavior.
        const content = doc.querySelector('#mw-content-text,.mw-parser-output');
        if (!content) return;
        content.querySelectorAll('a[href]').forEach(anchor => {
            if(anchor.classList.contains('kkpt-fate-gear'))return;
            if (wikiLinkPage(anchor, doc) !== targetPage) return;
            anchor.classList.add('kkpt-portal-link');
            anchor.classList.toggle('kkpt-portal-red', targetPage === 'Kuronata');
            anchor.classList.toggle('kkpt-portal-blue', targetPage === 'Kuranoka');
            const caption = (anchor.textContent || '').trim();
            if (caption) anchor.dataset.kkptText = caption.slice(0, 120);
            anchor.setAttribute('aria-label', caption + '，切换至 ' + targetPage);
        });
    }

    function watchPortalLinks(doc, targetPage) {
        decoratePortalLinks(doc, targetPage);
        if (doc.__kkptPortalObserver) return;
        const root = doc.querySelector('#mw-content-text,.mw-parser-output');
        if (!root) return;
        let pending=false;
        const observer = new MutationObserver(() => {
            if(pending)return;
            pending=true;
            setTimeout(()=>{
                pending=false;
                decoratePortalLinks(doc,targetPage);
            },120);
        });
        observer.observe(root, {childList:true,subtree:true});
        doc.__kkptPortalObserver = observer;
    }

    function isPlainClick(event) {
        return !event.defaultPrevented && event.button === 0 &&
            !event.ctrlKey && !event.metaKey && !event.altKey && !event.shiftKey;
    }

    function findAnchor(event, doc) {
        const target = event.target;
        return target && target.nodeType === 1 &&
            typeof target.closest === 'function'
            ? target.closest('a[href]') : null;
    }

    function portalClick(event, doc, targetPage, nextActive) {
        if (!isPlainClick(event)) return false;
        const anchor = findAnchor(event, doc);
        if (!anchor || (anchor.target && anchor.target !== '_self') ||
            anchor.hasAttribute('download') ||
            wikiLinkPage(anchor, doc) !== targetPage) return false;
        event.preventDefault();
        primeSound(); // Synchronous click activation unlocks Web Audio.
        if(anchor.classList.contains('kkpt-fate-gear')) {
            beginFateSwap(anchor,nextActive);
        } else {
            requestSwap(nextActive);
        }
        return true;
    }

    // The Infobox gear begins to turn before the actual world changes.
    function beginFateSwap(anchor,nextActive) {
        if(animating||gearPending||nextActive===active)return;
        gearPending=true;
        anchor.classList.add('kkpt-fate-gear-turning');
        setTimeout(()=>{
            gearPending=false;
            requestSwap(nextActive);
        },570);
        setTimeout(()=>anchor.classList.remove('kkpt-fate-gear-turning'),4800);
    }

    function fateGearShape() {
        const parts=[];
        for(let i=0;i<48;i++) {
            const a=i/48*Math.PI*2-Math.PI/2;
            const r=(i%4===0||i%4===3)?21:16.8;
            parts.push((i?'L':'M')+(24+Math.cos(a)*r).toFixed(2)+' '+
                (24+Math.sin(a)*r).toFixed(2));
        }
        return parts.join(' ')+' Z';
    }

    function mountFateGear(doc,targetPage) {
        if(doc.querySelector('.kkpt-fate-gear'))return;
        const content=doc.querySelector('#mw-content-text,.mw-parser-output');
        if(!content)return;
        const selectors='table.infobox,.infobox-character,.portable-infobox,'+
            '.infobox,[class*="infobox"]';
        const box=[...content.querySelectorAll(selectors)].find(el=>{
            const r=el.getBoundingClientRect();
            return r.width>175&&r.width<720&&r.height>210;
        });
        if(!box)return;
        const header=box.querySelector('.infobox-title,.infobox-header,'+
            '.infobox-above,.infobox-heading,.infobox-head,'+
            '.pi-title,caption,th[colspan]');
        // Deliberately NEVER append to or restyle a native Infobox node.
        // A fixed-position overlay follows its visual rectangle instead.
        const host=header&&header.tagName!=='TR'?header:box;
        const anchor=doc.createElement('a');
        anchor.className='kkpt-fate-gear';
        anchor.hidden=true;
        anchor.href=new URL('/wiki/'+targetPage,doc.baseURI).href;
        anchor.title=targetPage==='Kuronata'
            ?'转动命运齿轮 · 唤醒 Kuronata':'转动命运齿轮 · 回到 Kuranoka';
        anchor.setAttribute('aria-label',anchor.title);
        anchor.innerHTML='<svg class="kkpt-fate-gear-svg" viewBox="0 0 48 48" '+
            'aria-hidden="true" focusable="false"><path d="'+fateGearShape()+
            '"/><circle cx="24" cy="24" r="8.5"/>'+
            '<circle cx="24" cy="24" r="3"/></svg>';
        doc.body.appendChild(anchor);
        let pendingPosition=false;
        function positionGear(){
            pendingPosition=false;
            if(!doc.body.contains(anchor)||!doc.body.contains(host)){
                anchor.hidden=true;return;
            }
            const rect=host.getBoundingClientRect();
            const view=doc.defaultView;
            const y=host===box?rect.top+23:rect.top+rect.height*.5;
            anchor.hidden=rect.width<120||rect.bottom<0||rect.top>view.innerHeight||
                y<0||y>view.innerHeight;
            if(anchor.hidden)return;
            anchor.style.left=Math.round(rect.right-49)+'px';
            anchor.style.top=Math.round(y-21)+'px';
        }
        function updateGear(){
            if(pendingPosition)return;
            pendingPosition=true;
            doc.defaultView.requestAnimationFrame(positionGear);
        }
        doc.defaultView.addEventListener('scroll',updateGear,{passive:true});
        doc.defaultView.addEventListener('resize',updateGear,{passive:true});
        updateGear();
    }

    // Read backgrounds after background-template code populates --bg-image.
    function backgroundUrls(doc) {
        const urls = new Set();
        const selector = [doc.documentElement, doc.body];
        try {
            doc.querySelectorAll('.background-theme,[class*="background"],[style*="background"],#mw-content-text,.citizen-page-container')
                .forEach((el, i) => { if (i < 18) selector.push(el); });
        } catch (e) { /* use html/body */ }
        function add(value) {
            if (!value) return;
            const pattern = /url\(\s*(['"]?)(.*?)\1\s*\)/gi;
            let match;
            while ((match = pattern.exec(value))) {
                try { urls.add(new URL(match[2], doc.baseURI).href); } catch (e) { /* ignore */ }
            }
            if (/^https?:\/\/\S+\.(?:jpg|jpeg|png|webp|avif)(?:\?\S*)?$/i.test(value)) {
                try { urls.add(new URL(value, doc.baseURI).href); } catch (e) { /* ignore */ }
            }
        }
        selector.forEach(el => {
            if (!el) return;
            try {
                [null, '::before', '::after'].forEach(pseudo => {
                    const style = doc.defaultView.getComputedStyle(el, pseudo);
                    if (!style) return;
                    add(style.backgroundImage);
                    add(style.getPropertyValue('--bg-image'));
                    add(style.getPropertyValue('--background-image'));
                });
                if (el.dataset) add(el.dataset.bgImage);
            } catch (e) { /* style not yet ready */ }
        });
        return [...urls];
    }

    function warmImage(url) {
        if (imagePool.has(url)) return imagePool.get(url).promise;
        const image = new Image();
        const promise = new Promise(resolve => {
            let finished = false;
            const timeout = setTimeout(() => done(false), 5000);
            function done(ok) {
                if (finished) return;
                finished = true;
                clearTimeout(timeout);
                resolve(ok);
            }
            image.onload = () => done(true);
            image.onerror = () => done(false);
            image.src = url;
            if (image.complete) done(image.naturalWidth > 0);
        }).then(ok => ok && image.decode
            ? Promise.race([image.decode().then(() => true).catch(() => true),sleep(900).then(() => true)])
            : ok);
        imagePool.set(url, { image, promise });
        return promise;
    }

    async function warmBackgrounds(doc) {
        const urls = backgroundUrls(doc);
        await Promise.allSettled(urls.map(warmImage));
    }

    function wireFrame() {
        try {
            const doc = frame.contentDocument;
            if (!doc) return;
            otherTitle = doc.title || otherTitle;
            watchPortalLinks(doc, basePage);
            mountFateGear(doc, basePage);
            if (doc.__kkptFrameBridge) return;
            doc.__kkptFrameBridge = true;

            // Non-anchor navigation should leave the iframe and open normally
            // in the top window, so the browser's URL doesn't become stale.
            doc.addEventListener('click', event => {
                if (!active || !isPlainClick(event)) return;
                if (portalClick(event, doc, basePage, false)) return;
                const el = findAnchor(event, doc);
                if (!el || (el.target && el.target !== '_self')) return;
                const href = el.href;
                if (!href || href.startsWith('javascript:')) return;
                const next = new URL(href, doc.baseURI);
                // Same-document fragments stay inside the iframe.
                const currentFrame = new URL(frame.contentWindow.location.href);
                if (next.origin === currentFrame.origin &&
                    next.pathname === currentFrame.pathname &&
                    next.search === currentFrame.search && next.hash) {
                    history.replaceState(history.state, '', next.href);
                    return;
                }
                event.preventDefault();
                window.location.assign(next.href);
            }, true);

            doc.addEventListener('submit', event => {
                if (active && event.target instanceof doc.defaultView.HTMLFormElement) {
                    event.target.target = '_top';
                }
            }, true);
        } catch (err) {
            console.warn('[KuranokaPageTransition] Frame link bridge unavailable:', err);
        }
    }

    function warmFrame() {
        if (loading) return loading;
        frame = document.createElement('iframe');
        frame.id = 'kkpt-preview';
        frame.src = otherUrl.href; // set BEFORE insertion, avoids extra initial history hop
        frame.title = otherPage + ' 预载页面';
        frame.tabIndex = -1;
        frame.setAttribute('aria-hidden', 'true');
        frame.setAttribute('loading', 'eager');
        frame.style.clipPath = hideClip;

        loading = new Promise(resolve => {
            let settled = false;
            let preparing = false;
            let poll = null;
            function finish(ok, reason) {
                if (settled) return;
                settled = true;
                clearInterval(poll);
                ready = ok;
                if (!ok) console.warn('[KuranokaPageTransition] Preview:', reason);
                resolve(ok);
            }
            async function inspect() {
                if (settled || preparing) return;
                try {
                    const doc = frame.contentDocument;
                    if (!doc || !doc.querySelector('#mw-content-text,.mw-parser-output')) return;
                    preparing = true;
                    clearInterval(poll);
                    await sleep(320); // Background.js / wiki style scripts
                    await Promise.race([warmBackgrounds(doc), sleep(3600)]);
                    await sleep(120);
                    await Promise.race([warmBackgrounds(doc), sleep(1300)]);
                    frame.contentWindow.scrollTo(0, 0);
                    wireFrame();
                    finish(true);
                } catch (err) { finish(false, String(err)); }
            }
            frame.addEventListener('load', () => {
                if (!settled && !preparing) inspect();
            });
            frame.addEventListener('error', () => finish(false,'iframe 网络加载错误'));
            document.body.append(frame);
            poll = setInterval(inspect, 130);
            setTimeout(() => { if (!settled && !preparing) finish(false,'18 秒仍未找到目标正文'); }, 18000);
        });

        warmBackgrounds(document).catch(() => {});
        setTimeout(() => warmBackgrounds(document).catch(() => {}), 700);
        return loading;
    }


    // Original V2's moving flame sprites and three bright contours, rebuilt
    // with bounded particle counts. No WebGL, no full-screen noise pass,
    // no 1,000-point polygon or per-frame image-texture upload.
    let sprites=null;
    function makeSprites() {
        if (sprites) return sprites;
        function radial(stops) {
            const el=document.createElement('canvas');
            el.width=el.height=96;
            const c=el.getContext('2d');
            const g=c.createRadialGradient(48,48,0,48,48,48);
            stops.forEach(pair=>g.addColorStop(pair[0],pair[1]));
            c.fillStyle=g;c.fillRect(0,0,96,96);
            return el;
        }
        sprites={
            flame:radial([[0,'#fffbed'],[.18,'#fff2a0'],
                [.43,'#ffb42b'],[.70,'#ff360088'],[1,'#8f050000']]),
            ember:radial([[0,'#ffffff'],[.15,'#fff6a8'],
                [.44,'#ff9900cc'],[1,'#ef280000']]),
            smoke:radial([[0,'#080608dd'],[.30,'#100b10bb'],
                [.62,'#160f1677'],[1,'#08050800']]),
            sky:radial([[0,'#ffffff'],[.16,'#e6ffff'],
                [.46,'#94deffe0'],[1,'#4ab5ff00']]),
            mist:radial([[0,'#f2fdffb0'],[.4,'#abdffff0'],
                [1,'#a9e7ff00']])
        };
        return sprites;
    }

    // V2's simple advancing boundary. The reader asked for the
    // vibrant fire curtain, not a mathematically fractal tearing wire.
    function makeEdge(t,seconds,dark,w) {
        const center=dark
            ? w+105-(w+210)*smooth(t)
            : -105+(w+210)*smooth(t);
        const wobble=Math.sin(Math.PI*t);
        return y=>center+wobble*(
            17*Math.sin(y*.023+seconds*5.5)+
             9*Math.sin(y*.063-seconds*8.4)+
             4*Math.sin(y*.13+seconds*12)
        );
    }

    // Clip the ACTUAL preloaded Wiki frame, precisely where the fire is.
    function clipFrame(edge) {
        const w=innerWidth,h=innerHeight;
        const rows=Math.max(32,Math.ceil(h/22));
        const pts=[];
        for(let i=rows;i>=0;i--) {
            const y=h*i/rows;
            pts.push(edge(y).toFixed(1)+'px '+y.toFixed(1)+'px');
        }
        frame.style.clipPath=clipSide==='right'
            ? 'polygon(100% 0,100% 100%,'+pts.join(',')+')'
            : 'polygon(0 0,0 100%,'+pts.join(',')+')';
    }

    function canvasFire(canvas,dark,duration,done) {
        const ctx=canvas.getContext('2d',{alpha:true,desynchronized:true});
        if(!ctx){done();return;}
        const art=makeSprites();
        const w=innerWidth,h=innerHeight;
        const scale=Math.min(window.devicePixelRatio||1,w<650?.88:1.0);
        canvas.width=Math.max(1,Math.round(w*scale));
        canvas.height=Math.max(1,Math.round(h*scale));
        ctx.setTransform(scale,0,0,scale,0,0);

        const rand=(a,b)=>a+Math.random()*(b-a);
        const mobile=w<650;
        const maxCount=mobile?175:340;
        const p=[];
        const accum={flame:0,ember:0,smoke:0,shard:0,sky:0,mist:0,pollen:0};
        const rates=dark
            ? {flame:mobile?85:120,ember:mobile?75:113,
               smoke:mobile?28:43,shard:mobile?30:50}
            : {sky:mobile?50:80,mist:mobile?13:20,pollen:mobile?27:50};
        const started=performance.now();
        let previous=started;
        let lastPaint=0;
        function spawn(kind,edge,seconds) {
            if(p.length>=maxCount)return;
            const y=rand(-25,h+25);
            const x=edge(y);
            const type=kind;
            const smoke=type==='smoke';
            const shard=type==='shard';
            const ember=type==='ember'||type==='pollen';
            const blue=type==='sky'||type==='mist'||type==='pollen';
            let radius,life,vx,vy;
            if(shard){
                radius=rand(4,18);life=rand(.6,1.65);
                vx=rand(-130,65);vy=rand(-125,30);
            }else if(smoke){
                radius=rand(32,85);life=rand(1.1,2.5);
                vx=rand(-20,65);vy=rand(-88,-22);
            }else if(type==='mist'){
                radius=rand(45,100);life=rand(.9,1.8);
                vx=rand(-35,45);vy=rand(-75,-15);
            }else if(type==='flame'){
                radius=rand(20,57);life=rand(.3,.82);
                vx=rand(-100,30);vy=rand(-180,-45);
            }else{
                radius=ember?rand(2.5,9):rand(18,47);
                life=ember?rand(.45,1.1):rand(.35,.85);
                vx=rand(-95,75);vy=rand(-150,-25);
            }
            p.push({
                type,life,left:life,
                x:x+rand(smoke?12:shard?-35:-27,smoke?140:shard?36:64),
                y:y+rand(-14,14),vx,vy,radius,
                angle:rand(-Math.PI,Math.PI),spin:rand(-5,5),
                drift:rand(-.65,.65),blue
            });
        }
        function spawnAtRate(dt,edge,seconds,strength){
            for(const type in rates){
                accum[type]+=rates[type]*dt*strength;
                const n=Math.min(11,Math.floor(accum[type]));
                accum[type]-=n;
                for(let i=0;i<n;i++)spawn(type,edge,seconds);
            }
        }
        function advance(dt){
            for(let i=p.length-1;i>=0;i--) {
                const q=p[i];
                q.left-=dt;
                if(q.left<=0){p[i]=p[p.length-1];p.pop();continue;}
                q.x+=q.vx*dt;
                q.y+=q.vy*dt;
                q.vx+=q.drift*dt*35;
                q.vy-=10*dt;
                q.angle+=q.spin*dt;
            }
        }
        function spriteDraw(image,x,y,sx,sy,alpha){
            ctx.globalAlpha=alpha;
            ctx.drawImage(image,x-sx,y-sy,sx*2,sy*2);
        }
        function drawSmoke(fade){
            ctx.globalCompositeOperation='source-over';
            for(const q of p){
                if(q.type!=='smoke'&&q.type!=='mist')continue;
                const age=1-q.left/q.life;
                const radius=q.radius*(1+age*.98);
                const alpha=(q.type==='smoke'?.76:.32)*
                    Math.min(1,age*5)*Math.min(1,q.left/.55)*fade;
                spriteDraw(q.type==='smoke'?art.smoke:art.mist,
                    q.x,q.y,radius*1.7,radius*1.3,alpha);
            }
            ctx.globalAlpha=1;
        }
        function drawShards(fade) {
            if(!dark)return;
            ctx.save();
            ctx.globalCompositeOperation='source-over';
            for(const q of p){
                if(q.type!=='shard')continue;
                const age=1-q.left/q.life;
                const a=Math.min(1,q.left/.38)*(.90-age*.28)*fade;
                ctx.save();
                ctx.translate(q.x,q.y);
                ctx.rotate(q.angle);
                ctx.globalAlpha=a;
                const r=q.radius;
                ctx.beginPath();
                ctx.moveTo(-r*.9,-r*.3);
                ctx.lineTo(r*.7,-r*.75);
                ctx.lineTo(r*.48,r*.42);
                ctx.lineTo(-r*.35,r*.8);
                ctx.closePath();
                ctx.fillStyle=age<.3?'#371d22':'#140d13';
                ctx.fill();
                ctx.strokeStyle=age<.42?'#f57d3c':'#5a2c2b';
                ctx.lineWidth=age<.42?1.6:.75;
                ctx.stroke();
                ctx.restore();
            }
            ctx.restore();
        }
        function drawCore(edge,seconds,t,fade){
            const waviness=Math.sin(Math.PI*t);
            ctx.save();
            ctx.beginPath();
            const count=Math.max(35,Math.ceil(h/19));
            for(let i=0;i<=count;i++){
                const y=h*i/count;
                if(i===0)ctx.moveTo(edge(y),y);
                else ctx.lineTo(edge(y),y);
            }
            ctx.lineCap='round';
            ctx.lineJoin='round';
            if(dark){
                ctx.globalCompositeOperation='lighter';
                ctx.globalAlpha=fade;
                ctx.shadowColor='#ff3903';
                ctx.shadowBlur=36;
                ctx.strokeStyle='rgba(255,55,5,.82)';
                ctx.lineWidth=43;
                ctx.stroke();
                ctx.shadowBlur=21;
                ctx.strokeStyle='#ff9b17';
                ctx.lineWidth=20;
                ctx.stroke();
                ctx.shadowBlur=9;
                ctx.strokeStyle='#ffe45e';
                ctx.lineWidth=9;
                ctx.stroke();
                ctx.shadowBlur=4;
                ctx.strokeStyle='#fffcde';
                ctx.lineWidth=3.8;
                ctx.stroke();
            }else{
                ctx.globalAlpha=fade*.64;
                ctx.shadowColor='#8ccfff';
                ctx.shadowBlur=29;
                ctx.strokeStyle='rgba(139,219,255,.68)';
                ctx.lineWidth=28;
                ctx.stroke();
                ctx.shadowBlur=10;
                ctx.strokeStyle='#e7f8ff';
                ctx.lineWidth=9;
                ctx.stroke();
                ctx.shadowBlur=0;
                ctx.strokeStyle='white';
                ctx.lineWidth=2;
                ctx.stroke();
            }
            ctx.restore();

            // Dense GOLD / WHITE rolling fire, including on both sides
            // of the border. These are the luminous shapes from V2.
            if(dark){
                ctx.save();
                ctx.globalCompositeOperation='lighter';
                for(let y=-70;y<h+80;y+=48){
                    const x=edge(y);
                    const pulse=.65+.35*Math.sin(seconds*8.5+y*.083);
                    spriteDraw(art.flame,x+rand(-8,30),y,77,70,
                        fade*(.26+.16*pulse));
                }
                for(let y=-20;y<h+52;y+=36){
                    const x=edge(y);
                    const flicker=Math.sin(seconds*13+y*.19);
                    const length=52+30*flicker+17*Math.sin(seconds*6-y*.11);
                    const lean=15+18*Math.sin(seconds*9+y*.069);
                    ctx.globalAlpha=.62*fade;
                    ctx.fillStyle='#ff5705';
                    ctx.beginPath();
                    ctx.moveTo(x+18,y+19);
                    ctx.bezierCurveTo(x-18,y+2,x-lean-24,y-length*.57,
                        x-lean,y-length);
                    ctx.bezierCurveTo(x+2,y-length*.57,x+13,y-12,x+18,y+19);
                    ctx.fill();
                    ctx.globalAlpha=.58*fade;
                    ctx.fillStyle='#ffdb58';
                    ctx.beginPath();
                    ctx.moveTo(x+7,y+8);
                    ctx.quadraticCurveTo(x-10,y-length*.33,
                        x-lean*.8,y-length*.72);
                    ctx.quadraticCurveTo(x+3,y-length*.30,x+8,y+8);
                    ctx.fill();
                    ctx.globalAlpha=.38*fade;
                    ctx.fillStyle='#fffced';
                    ctx.beginPath();
                    ctx.moveTo(x+3,y+5);
                    ctx.quadraticCurveTo(x-5,y-length*.2,
                        x-lean*.5,y-length*.48);
                    ctx.quadraticCurveTo(x+4,y-length*.19,x+5,y+5);
                    ctx.fill();
                }
                ctx.restore();
            }else{
                ctx.save();
                ctx.globalCompositeOperation='lighter';
                for(let y=-50;y<h+55;y+=88){
                    spriteDraw(art.sky,edge(y),y,89,109,.27*fade);
                }
                ctx.restore();
            }
        }
        function drawBrightParticles(fade) {
            ctx.save();
            ctx.globalCompositeOperation='lighter';
            for(const q of p){
                if(q.type==='smoke'||q.type==='mist'||q.type==='shard')continue;
                const age=1-q.left/q.life;
                const brightness=Math.min(1,q.left/.25)*(1-age*.25)*fade;
                let artName='flame',sx=q.radius,sy=q.radius;
                if(q.type==='ember'){artName='ember';sx*=1.2;sy*=1.2;}
                else if(q.type==='pollen'){artName='sky';sx*=1.15;sy*=1.15;}
                else if(q.type==='sky'){artName='sky';sx*=1.1;sy*=1.55;}
                else {sx*=.9;sy*=1.65;}
                spriteDraw(art[artName],q.x,q.y,sx,sy,
                    brightness*(q.type==='ember'?.93:.78));
            }
            ctx.restore();
            ctx.globalAlpha=1;
            ctx.globalCompositeOperation='source-over';
        }
        function paint(now) {
            if(now-lastPaint<(mobile?39:31)){
                requestAnimationFrame(paint);return;
            }
            const dt=Math.min(.05,(now-previous)/1000);
            previous=now;lastPaint=now;
            const t=Math.min(1,(now-started)/duration);
            const seconds=now/1000;
            const edge=makeEdge(t,seconds,dark,w);
            const fade=Math.min(1,t/.055,(1-t)/.045);
            clipFrame(edge);
            advance(dt);
            if(t<1)spawnAtRate(dt,edge,seconds,Math.max(0,fade));
            ctx.clearRect(0,0,w,h);
            drawSmoke(fade);
            drawShards(fade);
            drawCore(edge,seconds,t,fade);
            drawBrightParticles(fade);
            if(t<1)requestAnimationFrame(paint);
            else done();
        }
        requestAnimationFrame(paint);
    }

    function setDisplayed(nextActive) {
        active=nextActive;
        frame.classList.toggle('kkpt-active',active);
        frame.style.clipPath=active?'inset(0)':hideClip;
        frame.style.pointerEvents='';
        frame.tabIndex=active?0:-1;
        frame.setAttribute('aria-hidden',active?'false':'true');
        document.title=active?otherTitle:baseTitle;
        showTheme((active?otherPage:basePage)==='Kuronata');
        updateButton();
    }

    async function animateSwap(nextActive) {
        if(animating)return;
        animating=true;
        button.classList.add('kkpt-busy');
        labelSub.textContent='PREPARING THE OTHER SIDE...';
        if(!loading)warmFrame();
        const ok=await Promise.race([loading,sleep(11000).then(()=>false)]);
        if(!ok||!ready){
            window.location.assign(nextActive?otherUrl.href:baseUrl);return;
        }

        const dark=(nextActive?otherPage:basePage)==='Kuronata';
        labelSub.textContent=dark?'THE SKY IS BURNING':'DAWN IS BREAKING';
        frame.classList.remove('kkpt-active');
        frame.style.pointerEvents='none';
        frame.style.clipPath=active?'inset(0)':hideClip;

        const canvas=document.createElement('canvas');
        canvas.id='kkpt-vfx';
        canvas.setAttribute('aria-hidden','true');
        document.body.append(canvas);
        const duration=dark?3450:2950;
        transitionSound(dark,duration);
        await new Promise(resolve=>canvasFire(canvas,dark,duration,resolve));

        setDisplayed(nextActive);
        canvas.style.opacity='0';
        await sleep(160);
        canvas.remove();
        animating=false;
        button.classList.remove('kkpt-busy','kkpt-quiet');
        // The target remains visible in a live iframe. No reload.
        history.pushState({kkptV12:true,active},'',
            active?otherUrl.href:baseUrl);
    }

    function requestSwap(nextActive) {
        if (animating || nextActive === active) return;
        if (matchMedia('(prefers-reduced-motion: reduce)').matches && ready) {
            setDisplayed(nextActive);
            history.pushState({kkptV12:true,active},'',active?otherUrl.href:baseUrl);
            return;
        }
        animateSwap(nextActive).catch(err => {
            console.error('[KuranokaPageTransition] V12:',err);
            document.getElementById('kkpt-vfx')?.remove();
            if (frame) frame.style.filter = '';
            window.location.assign(nextActive ? otherUrl.href : baseUrl);
        });
    }

    function createButton() {
        if (!document.body || document.getElementById('kkpt-toggle')) return;
        button=document.createElement('a');
        button.id='kkpt-toggle';
        labelIcon=document.createElement('span');
        labelIcon.className='kkpt-icon';
        labelIcon.setAttribute('aria-hidden','true');
        const text=document.createElement('span');
        text.className='kkpt-text';
        labelTitle=document.createElement('span');
        labelSub=document.createElement('span');
        labelSub.className='kkpt-sub';
        text.append(labelTitle,labelSub);
        button.append(labelIcon,text);
        document.body.append(button);
        button.hidden=!SHOW_FLOATING_BUTTON;
        updateButton();
        watchPortalLinks(document, otherPage);
        mountFateGear(document,otherPage);
        warmFrame();

        button.addEventListener('click', event => {
            if (!isPlainClick(event)) return;
            event.preventDefault();
            primeSound();
            requestSwap(!active);
        });
    }

    // A plain [[Kuronata|your mysterious text]] now triggers everything.
    // The inverse [[Kuranoka|...]] works inside the already-loaded iframe.
    document.addEventListener('click', event => {
        if (active) return;
        portalClick(event, document, otherPage, true);
    }, true);
    mw.hook('wikipage.content').add(() => {
        if (document.readyState !== 'loading') watchPortalLinks(document, otherPage);
    });

    // Back and Forward restore the two already-loaded documents instantly.
    window.addEventListener('popstate', () => {
        if (!frame || !ready || animating) return;
        const route = pathPage();
        if (route === basePage || route === otherPage) {
            setDisplayed(route === otherPage);
        }
    });

    window.addEventListener('pageshow', event => {
        if (!event.persisted || !frame || !ready) return;
        animating=false;
        document.getElementById('kkpt-vfx')?.remove();
        frame.style.filter = '';
        setDisplayed(pathPage() === otherPage);
        button?.classList.remove('kkpt-busy','kkpt-quiet');
    });

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded',createButton,{once:true});
    } else {
        createButton();
    }
}());