Hangeul Day video with Claude Opus 5.5 — consonants and vowels assemble into your words, with gayageum sound

Make **a short Hangeul Day video with sound** (한글날, October 9) in which the Korean words I give fall apart into their consonants and vowels and then build themselves back up, syllable by syllable — showing how Hangeul letters are put together. 2026 is the 100th year since Hangeul Day began as 가갸날 in 1926.

**The words**
- use the words I write below. If I leave them blank, use 한글날
- split every syllable into its parts with the Unicode rule (syllable code − 0xAC00 → initial, vowel, final). Do this in code, never by guessing, and show the result in the plan as a table, for example 한 = ㅎ + ㅏ + ㄴ
- keep spaces and numbers as they are; numbers do not split
- copy my words exactly. Do not add, drop or swap any syllable

**Plan first — show me this before the code**
- a beat table: start–end time, what is on screen, what sound plays. Times add up to the total
- follow this arc: (1) a sheet of warm hanji paper, a drop of ink spreads, a low drum; (2) the loose letter parts drift in and float, each as a separate ink block; (3) for each syllable in order, its parts glide into place — the initial, then the vowel, then the final — and lock together with a soft stamp; show the small equation (ㅎ + ㅏ + ㄴ = 한) under the syllable while it forms; (4) the full words stand complete, a brush stroke sweeps under them; (5) small lines fade in: 한글날 100주년 and 1926 가갸날 · 2026 한글날, and a small red seal stamps down in the corner
- the last beat holds for at least 2 seconds

**Look**
- letters in the old woodblock print style of the Hunminjeongeum Haerye book (판본체): thick, even strokes, square shapes, ink a little uneven like a real print. Draw them with the system's Korean font (try "Nanum Myeongjo", "Noto Serif KR", "AppleMyungjo", "Batang", then serif) made bold with a thick stroke and slight ink texture
- warm off-white hanji with faint fibers, black ink, one deep red seal. Nothing else bright
- smooth, calm motion with gentle easing, nothing bouncy or cartoonish. Letter parts never overlap each other in a messy way and the finished words stay fully inside the frame with margins
- vertical 9:16 (1080×1920 drawn at a smaller size and scaled) for reels and shorts, unless I ask for horizontal

**Sound — made in code**
- through the Web Audio API only: a plucked string like a gayageum (Karplus–Strong), a soft low drum, a brush swish. An original calm melody in a Korean pentatonic scale, tempo (BPM) stated in the plan
- a pluck on every part that locks into place, a drum on every finished syllable, a swish on the brush stroke, a deeper drum on the seal
- browsers block sound until a tap: open on a simple screen that says 눌러서 시작; the picture and sound start together from 0 on the tap, both driven by the same clock so they never drift

**Build — it must work for someone who does not code**
- one self-contained HTML file, no external images, fonts or audio files; draw and synthesize everything in code. All motion is driven by one `render(t)` function of time in seconds (only seeded randomness)
- always print the whole HTML in one code block in your answer, even if you also saved a file — I may only see your answer. Never say you saved, ran or checked a file you did not
- 30 fps
- a **영상 저장 button** in a corner. Pressing it replays from 0 and records exactly one full run **with the sound** (the canvas stream plus the audio stream) using MediaRecorder, then downloads it. Prefer MP4 when `MediaRecorder.isTypeSupported` allows it, otherwise WebM. Show a progress bar while recording, and never include the button in the recording
- before handing over, walk through every beat boundary and fix letters leaving the frame, overlaps, and sounds that fire off the lock moment
- after the file, give me three short steps in plain words: how to open it, how to turn the sound on, and how to save the video