chore: import upstream snapshot with attribution

2026-07-13 12:58:35 +08:00
commit 85453da49f
4031 changed files with 710987 additions and 0 deletions
@@ -0,0 +1,779 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=1920, height=1080" />
+    <title>Scene 07 — HyperFrames Video Kinetic Text Pivot</title>
+
+    <!--
+      HyperFrames composition.tsx.
+
+      Choreography (4 phases, 6.5 seconds total):
+        0.17 – 0.87s   "HyperFrames" badge fades in (top)
+        0.17 – 0.87s   Demo screen card enters centered (scale 0.6 → 1)
+        2.20 – 3.00s   Video slides left to 32% W (scale → 0.85); MP4 pops in on right
+                       with 5-layer green depth stack and bouncy back.out(1.6)
+        3.00 – 3.86s   MP4 breathes (±2% scale at ~1.9 Hz)
+        3.86 – 4.46s   Video and MP4 slide off left + fade; typing stage fades in center
+        4.36 – 5.13s   "HTML pages become video" types char-by-char (23 chars at 30 ch/s)
+                       Accent words "pages" and "video" in brand green
+        4.83 – 5.43s   Gradient pill (purple → green) scales in behind line 2 with glow halo
+        5.13 – 5.63s   "frame by frame." types char-by-char inside the pill
+        0 – 6.50s      Continuous: video float, cursor blink, stat breath
+                       (each gated by time window)
+          so entry, continuous motion, and static tilt never overwrite each other
+        - Conditional rendering ({frame > X && ...}) replaced by permanent DOM +
+          opacity 0 + gates inside the scene-ticker onUpdate
+        - Cursor blink derived from tl.time() via Math.floor(t * 2) % 2
+        - Demo screen is a self-contained CSS scene (.video-scene); to showcase real
+          footage, drop a local mp4 back in as a muted &lt;video class="clip"&gt; (see
+          the note at the .video-content markup)
+        - 3D depth layers built once at composition setup with document.createElement
+    -->
+
+    <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
+
+    <style>
+      :root {
+        --bg-dark: #0a0a18;
+        --text-primary: #ffffff;
+        --text-secondary: rgba(255, 255, 255, 0.65);
+        --brand-purple: #7c3aed;
+        --brand-purple-soft: #a78bfa;
+        --brand-green: #22c55e;
+        --brand-purple-glow: rgba(124, 58, 237, 1);
+        --brand-green-glow: rgba(34, 197, 94, 1);
+      }
+      * {
+        margin: 0;
+        padding: 0;
+        box-sizing: border-box;
+      }
+      html,
+      body {
+        margin: 0;
+        width: 1920px;
+        height: 1080px;
+        overflow: hidden;
+        background: var(--bg-dark);
+        font-family:
+          "Inter",
+          system-ui,
+          -apple-system,
+          sans-serif;
+        color: var(--text-primary);
+      }
+
+      .stage {
+        position: absolute;
+        inset: 0;
+        overflow: hidden;
+      }
+
+      /* ============================================================
+         BACKGROUND + AMBIENT GLOW
+         ============================================================ */
+      .bg {
+        position: absolute;
+        inset: 0;
+        background:
+          radial-gradient(ellipse at 50% 50%, rgba(40, 30, 80, 0.5), transparent 65%),
+          linear-gradient(135deg, #0a0a18 0%, #160a1f 100%);
+      }
+      .ambient-glow {
+        position: absolute;
+        left: 50%;
+        top: 50%;
+        transform: translate(-50%, -50%);
+        width: 1536px;
+        height: 864px;
+        background: radial-gradient(
+          ellipse at center,
+          rgba(147, 51, 234, 0.13) 0%,
+          rgba(34, 197, 94, 0.08) 30%,
+          transparent 70%
+        );
+        filter: blur(80px);
+        pointer-events: none;
+      }
+
+      /* ============================================================
+         BADGE
+         ============================================================ */
+      .badge {
+        position: absolute;
+        top: 42px;
+        left: 50%;
+        transform: translateX(-50%);
+        padding: 12px 32px;
+        font-size: 112px;
+        font-weight: 800;
+        color: var(--text-primary);
+        line-height: 1;
+        white-space: nowrap;
+        text-shadow:
+          0 0 32px rgba(248, 250, 252, 0.12),
+          0 0 72px rgba(24, 217, 232, 0.1);
+        will-change: transform, opacity;
+        /* initial opacity 0 + scale 0.9 via gsap.set */
+      }
+      .badge .accent {
+        color: var(--brand-purple-soft);
+        background: linear-gradient(135deg, var(--brand-purple-soft) 0%, var(--brand-purple) 72%);
+        -webkit-background-clip: text;
+        background-clip: text;
+        -webkit-text-fill-color: transparent;
+        filter: drop-shadow(0 0 28px rgba(124, 58, 237, 0.34));
+      }
+
+      /* ============================================================
+         VIDEO CARD — three nested wrappers
+         ============================================================ */
+      .video-pos {
+        position: absolute;
+        left: 0;
+        top: 0;
+        width: 1040px;
+        height: 585px; /* 16:9 ratio, intentionally large for the pivot beat */
+        margin-left: -520px; /* so x: W/2 centers it */
+        margin-top: -292.5px;
+        will-change: transform, opacity;
+      }
+      .video-float {
+        width: 100%;
+        height: 100%;
+        will-change: transform;
+      }
+      .video-tilt {
+        width: 100%;
+        height: 100%;
+        transform-style: preserve-3d;
+        transform: rotateX(5deg) rotateY(15deg);
+      }
+      .video-content {
+        width: 100%;
+        height: 100%;
+        border-radius: 16px;
+        overflow: hidden;
+        border: 2px solid rgba(255, 255, 255, 0.1);
+        box-shadow:
+          0 30px 60px rgba(0, 0, 0, 0.5),
+          0 0 80px rgba(147, 51, 234, 0.2),
+          0 0 120px rgba(34, 197, 94, 0.15);
+        position: relative;
+      }
+      .video-scene {
+        position: absolute;
+        inset: 0;
+        background:
+          radial-gradient(circle at 30% 30%, rgba(255, 200, 100, 0.4), transparent 50%),
+          linear-gradient(135deg, #1a3a5f 0%, #2a4570 50%, #3a2a5a 100%);
+      }
+      .video-scene::before {
+        content: "";
+        position: absolute;
+        top: 35%;
+        left: 40%;
+        width: 220px;
+        height: 220px;
+        border-radius: 50%;
+        background: linear-gradient(135deg, #fbbf24, #f97316);
+        opacity: 0.6;
+        filter: blur(8px);
+      }
+      .video-caption {
+        position: absolute;
+        bottom: 60px;
+        left: 50%;
+        transform: translateX(-50%);
+        padding: 12px 24px;
+        background: rgba(0, 0, 0, 0.7);
+        border-radius: 8px;
+        color: var(--text-primary);
+        font-size: 34px;
+        font-weight: 600;
+        white-space: nowrap;
+      }
+      .video-caption .accent {
+        color: var(--brand-green);
+      }
+      .video-reflection {
+        position: absolute;
+        top: 0;
+        left: 0;
+        right: 0;
+        height: 40%;
+        background: linear-gradient(180deg, rgba(255, 255, 255, 0.08) 0%, transparent 100%);
+        pointer-events: none;
+      }
+
+      /* ============================================================
+         MP4 STAT — three nested wrappers + depth stack
+         ============================================================ */
+      .stat-pos {
+        position: absolute;
+        left: 0;
+        top: 0;
+        will-change: transform, opacity;
+      }
+      .stat-breath {
+        will-change: transform;
+      }
+      .stat-tilt {
+        transform-style: preserve-3d;
+        transform: rotateX(5deg) rotateY(-15deg);
+      }
+      .depth-stack {
+        position: relative;
+        display: inline-block;
+        font-size: 340px;
+        font-weight: 900;
+        letter-spacing: -0.03em;
+        line-height: 1;
+      }
+      .depth-stack .depth-layer.front {
+        position: relative;
+        color: var(--brand-green);
+      }
+      .depth-stack .depth-layer.back {
+        position: absolute;
+        top: var(--top);
+        left: var(--left);
+        color: rgba(34, 197, 94, var(--alpha));
+      }
+
+      /* ============================================================
+         TYPING STAGE — center, fades in during pivot
+         ============================================================ */
+      .typing-stage {
+        position: absolute;
+        left: 50%;
+        top: 50%;
+        transform: translate(-50%, -50%);
+        will-change: transform, opacity;
+      }
+      .typing-tilt {
+        perspective: 1200px;
+        transform-style: preserve-3d;
+        transform: rotateY(-15deg) rotateX(5deg);
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        justify-content: center;
+        gap: 30px;
+      }
+      .line1 {
+        display: flex;
+        align-items: center;
+        white-space: pre;
+      }
+      .seg {
+        font-size: 124px;
+        font-weight: 700;
+        color: var(--text-primary);
+        white-space: pre;
+        line-height: 1;
+      }
+      .seg.accent,
+      .seg.accent2 {
+        color: var(--brand-green);
+      }
+
+      .cursor {
+        display: inline-block;
+        width: 10px;
+        height: 124px;
+        background-color: var(--text-primary);
+        margin-left: 8px;
+        vertical-align: middle;
+        transform: translateY(4px);
+        opacity: 0;
+        will-change: opacity;
+      }
+      .cursor.green {
+        background-color: var(--brand-green);
+      }
+
+      .line2-wrap {
+        position: relative;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        padding: 24px 64px;
+      }
+      .pill-bg {
+        position: absolute;
+        top: 50%;
+        left: 50%;
+        transform: translate(-50%, -50%) scale(0);
+        width: calc(100% + 80px);
+        height: calc(100% + 40px);
+        border-radius: 80px;
+        background: linear-gradient(90deg, var(--brand-purple) 0%, var(--brand-green) 100%);
+        opacity: 0;
+        z-index: -1;
+        will-change: transform, opacity;
+      }
+      .pill-glow {
+        position: absolute;
+        top: 50%;
+        left: 50%;
+        transform: translate(-50%, -50%);
+        width: calc(100% + 100px);
+        height: calc(100% + 60px);
+        border-radius: 80px;
+        background: radial-gradient(
+          ellipse at center,
+          var(--brand-purple-glow) 0%,
+          transparent 70%
+        );
+        opacity: 0;
+        filter: blur(30px);
+        z-index: -2;
+        will-change: opacity;
+      }
+      .line2-content {
+        display: flex;
+        align-items: center;
+        position: relative;
+        z-index: 1;
+        opacity: 0;
+        will-change: opacity;
+      }
+      .seg.line2 {
+        color: var(--text-primary);
+      }
+
+      /* ============================================================
+         VIGNETTE
+         ============================================================ */
+      .vignette {
+        position: absolute;
+        inset: 0;
+        background: radial-gradient(ellipse at center, transparent 50%, rgba(0, 0, 0, 0.5) 100%);
+        pointer-events: none;
+        z-index: 400;
+      }
+    </style>
+  </head>
+  <body>
+    <div
+      id="root"
+      data-composition-id="main"
+      data-start="0"
+      data-duration="6.5"
+      data-width="1920"
+      data-height="1080"
+    >
+      <div
+        class="stage clip"
+        data-start="0"
+        data-duration="6.5"
+        data-track-index="1"
+        id="scene-stage"
+      >
+        <div class="bg"></div>
+        <div class="ambient-glow"></div>
+
+        <div class="badge" id="badge">Hyper<span class="accent">Frames</span></div>
+
+        <!-- Video card -->
+        <div class="video-pos" id="video-pos" data-layout-allow-overflow>
+          <div class="video-float" id="video-float">
+            <div class="video-tilt">
+              <div class="video-content">
+                <div class="video-scene"></div>
+                <!-- To showcase real footage, add a local mp4 on top of .video-scene:
+                     &lt;video id="demo-video" class="clip" src="assets/demo.mp4"
+                       style="position:absolute;inset:0;width:100%;height:100%;object-fit:cover"
+                       data-start="0.17" data-duration="3.69" data-track-index="2"
+                       data-media-start="0" muted playsinline&gt;&lt;/video&gt; -->
+                <div class="video-caption">
+                  HTML, CSS and JS become <span class="accent">video</span>
+                </div>
+                <div class="video-reflection"></div>
+              </div>
+            </div>
+          </div>
+        </div>
+
+        <!-- MP4 stat -->
+        <div class="stat-pos" id="stat-pos" data-layout-allow-overflow>
+          <div class="stat-breath" id="stat-breath">
+            <div class="stat-tilt">
+              <div class="depth-stack" id="depth-stack-97" data-text="MP4"></div>
+            </div>
+          </div>
+        </div>
+
+        <!-- Typing -->
+        <div class="typing-stage" id="typing-stage">
+          <div class="typing-tilt">
+            <div class="line1">
+              <span class="seg main">HTML </span><span class="seg accent">pages</span
+              ><span class="seg suffix"> become </span><span class="seg accent2">video</span
+              ><span class="cursor cursor1" id="cursor1"></span>
+            </div>
+            <div class="line2-wrap">
+              <div class="pill-bg" id="pill-bg"></div>
+              <div class="pill-glow" id="pill-glow"></div>
+              <div class="line2-content">
+                <span class="seg line2">frame by frame.</span
+                ><span class="cursor cursor2" id="cursor2"></span>
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+
+      <div class="vignette"></div>
+    </div>
+
+    <script>
+      /* ================================================================
+         CONSTANTS
+         ================================================================ */
+      const W = 1920,
+        H = 1080;
+      const TOTAL_DUR = 6.5;
+
+      /* ASR-anchored timing (the source source frame counts converted to seconds at 30fps). */
+      const TIMING = {
+        // Phase 1: video + badge enter
+        badgeAt: 0.17,
+        badgeDur: 0.7,
+        videoEntryAt: 0.17,
+        videoEntryDur: 0.7,
+
+        // Phase 2: video slides, MP4 appears
+        slideAt: 2.2,
+        videoSlideDur: 0.8,
+        videoSlideX: W * 0.29,
+        videoSlideScale: 0.92,
+
+        statEntryDur: 0.6,
+        statEntryX: W * 0.6,
+        statBreathAt: 3.0, // entry settles by here, breath begins
+        statBreathDur: 0.86, // until exit at 3.86
+
+        // Phase 3: pivot — both exit, typing begins
+        pivotAt: 3.86,
+        exitDur: 0.6,
+        videoExitX: -W * 0.5,
+        statExitX: -W * 0.7,
+        typingStageDur: 0.5,
+
+        // Phase 3 typing
+        typingStartAt: 4.36, // pivotAt + 0.5 s stage settle
+        typeRate: 30, // chars/sec
+
+        // Phase 4: pill
+        pillAt: 4.83, // typing reaches line2 at this time
+        pillDur: 0.6,
+        pillGlowDur: 0.8,
+      };
+
+      /* Text segments and boundaries */
+      const SEG = {
+        main: "HTML ",
+        accent: "pages",
+        suffix: " become ",
+        accent2: "video",
+        line2: "frame by frame.",
+      };
+      const BOUNDS = {
+        mainEnd: SEG.main.length, // 5
+        accentEnd: SEG.main.length + SEG.accent.length, // 10
+        suffixEnd: SEG.main.length + SEG.accent.length + SEG.suffix.length, // 18
+        accent2End: SEG.main.length + SEG.accent.length + SEG.suffix.length + SEG.accent2.length, // 23
+        line2End:
+          SEG.main.length +
+          SEG.accent.length +
+          SEG.suffix.length +
+          SEG.accent2.length +
+          SEG.line2.length, // 38
+      };
+      const TYPING_DUR = (BOUNDS.line2End - 0) / TIMING.typeRate; // ≈ 1.3 s
+
+      /* ================================================================
+         BUILD DOM — 5-layer depth stack for "MP4"
+         ================================================================ */
+      const LAYER_COUNT = 5;
+      const OFFSET_X = 1;
+      const OFFSET_Y = 2;
+      const depthStack = document.getElementById("depth-stack-97");
+      const depthText = depthStack.dataset.text;
+      for (let i = 0; i < LAYER_COUNT; i++) {
+        const layer = document.createElement("div");
+        layer.className = "depth-layer " + (i === LAYER_COUNT - 1 ? "front" : "back");
+        layer.textContent = depthText;
+        if (i < LAYER_COUNT - 1) {
+          layer.setAttribute("aria-hidden", "true");
+          const alpha = 0.62 + 0.08 * (LAYER_COUNT - 2 - i);
+          layer.style.setProperty("--alpha", alpha);
+          layer.style.setProperty("--top", i * OFFSET_Y + "px");
+          layer.style.setProperty("--left", -i * OFFSET_X + "px");
+        }
+        depthStack.appendChild(layer);
+      }
+
+      /* ================================================================
+         INITIAL STATES (via gsap.set, before the timeline runs)
+         ================================================================ */
+      gsap.set("#badge", { opacity: 0, scale: 0.9 });
+
+      // Video starts centered (x = W/2, y = H/2 via the .video-pos margin trick)
+      gsap.set("#video-pos", { x: W / 2, y: H / 2, scale: 0.6, opacity: 0 });
+
+      // Stat starts off-right + below + small + invisible
+      gsap.set("#stat-pos", { x: TIMING.statEntryX, y: H * 0.42 + 60, scale: 0.3, opacity: 0 });
+
+      gsap.set("#typing-stage", { scale: 0.9, opacity: 0 });
+
+      /* ================================================================
+         TIMELINE
+         ================================================================ */
+      window.__timelines = window.__timelines || {};
+      const tl = gsap.timeline({ paused: true });
+      window.__timelines["main"] = tl;
+
+      /* ----------------------------------------------------------------
+         PHASE 1: Badge + Video entry
+         ---------------------------------------------------------------- */
+      tl.to(
+        "#badge",
+        {
+          opacity: 1,
+          scale: 1,
+          duration: TIMING.badgeDur,
+          ease: "power3.out",
+        },
+        TIMING.badgeAt,
+      );
+
+      tl.to(
+        "#video-pos",
+        {
+          scale: 1,
+          opacity: 1,
+          duration: TIMING.videoEntryDur,
+          ease: "power3.out", // spring(stiffness:80, damping:15)
+        },
+        TIMING.videoEntryAt,
+      );
+
+      /* ----------------------------------------------------------------
+         PHASE 2: Video slides left, MP4 appears on right
+         ---------------------------------------------------------------- */
+      tl.to(
+        "#video-pos",
+        {
+          x: TIMING.videoSlideX,
+          scale: TIMING.videoSlideScale,
+          duration: TIMING.videoSlideDur,
+          ease: "power3.out", // spring(stiffness:100, damping:18)
+        },
+        TIMING.slideAt,
+      );
+
+      tl.to(
+        "#stat-pos",
+        {
+          y: H * 0.42, // rises to final y
+          scale: 1,
+          opacity: 1,
+          duration: TIMING.statEntryDur,
+          ease: "back.out(1.6)", // spring(stiffness:150, damping:12)
+        },
+        TIMING.slideAt,
+      );
+
+      /* ----------------------------------------------------------------
+         PHASE 3: Pivot — video + stat exit; typing fades in
+         ---------------------------------------------------------------- */
+      tl.to(
+        "#video-pos",
+        {
+          x: TIMING.videoExitX,
+          scale: 0.8,
+          opacity: 0,
+          duration: TIMING.exitDur,
+          ease: "power3.out", // spring(stiffness:120, damping:20)
+        },
+        TIMING.pivotAt,
+      );
+
+      tl.to(
+        "#stat-pos",
+        {
+          x: TIMING.statExitX,
+          scale: 0.8,
+          opacity: 0,
+          duration: TIMING.exitDur,
+          ease: "power3.out",
+        },
+        TIMING.pivotAt,
+      );
+
+      tl.to(
+        "#typing-stage",
+        {
+          scale: 1,
+          opacity: 1,
+          duration: TIMING.typingStageDur,
+          ease: "power3.out", // spring(stiffness:100, damping:15)
+        },
+        TIMING.pivotAt,
+      );
+
+      /* ----------------------------------------------------------------
+         PHASE 3 (continued): Character-by-character typing
+         ---------------------------------------------------------------- */
+      const segMain = document.querySelector(".seg.main");
+      const segAccent = document.querySelector(".seg.accent");
+      const segSuffix = document.querySelector(".seg.suffix");
+      const segAccent2 = document.querySelector(".seg.accent2");
+      const segLine2 = document.querySelector(".seg.line2");
+
+      const typeProxy = { idx: 0 };
+      function typedIndexAt(t) {
+        if (t < TIMING.typingStartAt) return 0;
+        return Math.min(BOUNDS.line2End, Math.floor((t - TIMING.typingStartAt) * TIMING.typeRate));
+      }
+
+      function renderTypedText(i) {
+        const m = SEG.main.slice(0, Math.min(i, BOUNDS.mainEnd));
+        const a = SEG.accent.slice(0, Math.max(0, Math.min(i - BOUNDS.mainEnd, SEG.accent.length)));
+        const s = SEG.suffix.slice(
+          0,
+          Math.max(0, Math.min(i - BOUNDS.accentEnd, SEG.suffix.length)),
+        );
+        const a2 = SEG.accent2.slice(
+          0,
+          Math.max(0, Math.min(i - BOUNDS.suffixEnd, SEG.accent2.length)),
+        );
+        const l2 = SEG.line2.slice(
+          0,
+          Math.max(0, Math.min(i - BOUNDS.accent2End, SEG.line2.length)),
+        );
+        if (segMain.textContent !== m) segMain.textContent = m;
+        if (segAccent.textContent !== a) segAccent.textContent = a;
+        if (segSuffix.textContent !== s) segSuffix.textContent = s;
+        if (segAccent2.textContent !== a2) segAccent2.textContent = a2;
+        if (segLine2.textContent !== l2) segLine2.textContent = l2;
+      }
+
+      tl.to(
+        typeProxy,
+        {
+          idx: BOUNDS.line2End,
+          duration: TYPING_DUR,
+          ease: "none",
+          onUpdate: function () {
+            renderTypedText(Math.floor(typeProxy.idx));
+          },
+        },
+        TIMING.typingStartAt,
+      );
+
+      /* ----------------------------------------------------------------
+         PHASE 4: Gradient pill behind line 2
+         ---------------------------------------------------------------- */
+      gsap.set("#pill-bg", { scaleX: 0, scaleY: 0.5, opacity: 0 });
+      gsap.set("#pill-glow", { opacity: 0 });
+
+      tl.to(
+        "#pill-bg",
+        {
+          scaleX: 1,
+          scaleY: 1,
+          opacity: 0.9,
+          duration: TIMING.pillDur,
+          ease: "power3.out", // spring(stiffness:80, damping:15)
+        },
+        TIMING.pillAt,
+      );
+
+      tl.to(
+        "#pill-glow",
+        {
+          opacity: 0.5,
+          duration: TIMING.pillGlowDur,
+          ease: "power2.out",
+        },
+        TIMING.pillAt,
+      );
+
+      tl.to(
+        ".line2-content",
+        {
+          opacity: 1,
+          duration: 0.18,
+          ease: "power2.out",
+        },
+        TIMING.pillAt + 0.3,
+      );
+
+      /* ----------------------------------------------------------------
+         CONTINUOUS SCENE-TICKER — float, breath, cursor blink
+         All gated by time windows so they only fire when visible.
+         ---------------------------------------------------------------- */
+      const videoFloat = document.getElementById("video-float");
+      const statBreathEl = document.getElementById("stat-breath");
+      const cursor1El = document.getElementById("cursor1");
+      const cursor2El = document.getElementById("cursor2");
+
+      tl.to(
+        { tick: 0 },
+        {
+          tick: 1,
+          duration: TOTAL_DUR,
+          ease: "none",
+          onUpdate: function () {
+            const t = tl.time();
+            const idx = typedIndexAt(t);
+            renderTypedText(idx);
+
+            // Video float — only while video is visible (Phase 1 + 2)
+            if (t < TIMING.pivotAt) {
+              const floatY = Math.sin(t * 0.9) * 6;
+              gsap.set(videoFloat, { y: floatY });
+            }
+
+            // Stat breath — only while MP4 is settled and not yet exiting
+            if (t > TIMING.statBreathAt && t < TIMING.pivotAt) {
+              const breath = 1 + Math.sin((t - TIMING.statBreathAt) * 1.2) * 0.02;
+              gsap.set(statBreathEl, { scale: breath });
+            }
+
+            // Cursor blink — 1 Hz (Math.floor(t * 2) % 2 === 0 → on for 0.5s, off for 0.5s)
+            const blink = Math.floor(t * 2) % 2 === 0 ? 1 : 0;
+
+            // Cursor 1: visible while typing line 1 (idx < accent2End)
+            // Determine cursor color: green when typing accent segments, white otherwise.
+            if (t >= TIMING.typingStartAt && idx < BOUNDS.accent2End) {
+              const inAccent = idx >= BOUNDS.mainEnd && idx < BOUNDS.accentEnd;
+              const inAccent2 = idx >= BOUNDS.suffixEnd && idx < BOUNDS.accent2End;
+              const isGreen = inAccent || inAccent2;
+              cursor1El.style.opacity = blink;
+              if (cursor1El._lastGreen !== isGreen) {
+                cursor1El.classList.toggle("green", isGreen);
+                cursor1El._lastGreen = isGreen;
+              }
+            } else {
+              cursor1El.style.opacity = 0;
+            }
+
+            // Cursor 2: visible while typing line 2 (idx ≥ accent2End && idx < line2End)
+            if (idx >= BOUNDS.accent2End && idx < BOUNDS.line2End) {
+              cursor2El.style.opacity = blink;
+            } else {
+              cursor2El.style.opacity = 0;
+            }
+          },
+        },
+        0,
+      );
+    </script>
+  </body>
+</html>