The builder previously exposed only chapters. Now each chapter expands to show
its subtopics as individual checkboxes: selecting a chapter checks all of its
subtopics, selecting the subject-level box checks everything, and selecting
individual subtopics sets the chapter to indeterminate. The exam query filters
by subtopic_id when any are given; the SQL path deduplicates so a question
matching two subtopics only appears once.
JEE mode sets duration to 60 × unique-subject-count (180 min for a full paper).
On the exam screen this renders per-subject countdown strips: Physics 60:00,
Maths 60:00, Chemistry 60:00. Each strip counts down independently; when one
hits zero the screen auto-jumps to the first unanswered question of the next
subject. The last strip exhausting time submits the form.
Single-subject papers keep the flat timer and show no strips.
Also: all audit targets now genuinely 44px (the .opt labels were 42px).
The screen had no mobile state at all: the clock scrolled away mid-paper, the
only navigation was save-and-next so a candidate could not go back, the palette
sat below the question where it pushed submit off-screen, and the nav row lost
three of its four links under 700px.
Sticky header carries the clock and a progress bar; previous/next are real
buttons; the palette is a drawer below 1024px opened by a floating button that
sits above the tab bar. Primary destinations move to a bottom tab bar on
phones, data tables scroll inside their own card, and every control meets the
44px touch minimum.
Verified with a headless browser across five viewports rather than by reading
the stylesheet: scripts/audit_mobile.py fails on horizontal overflow, tap
targets under 44px, and content hidden behind a fixed bar; scripts/shots.py
captures each page at both widths. Both caught bugs I would otherwise have
shipped, including a palette toggle that lived inside the drawer it opened and
so could never be pressed on a phone.
fmt_dur drops a leading zero hour, so a 24 minute paper reads 24m 00s.
The subscriber was pinned to DEBUG, so RUST_LOG=warn was ignored and sqlx
logged every statement to stderr in production. Now an EnvFilter defaults to
info with sqlx at warn; RUST_LOG=debug restores the query log.
Three benchmarks, so the hosting numbers come from measurement rather than
guesswork: scripts/bench.py for latency and throughput, bench_write.py for the
autosave and submit path under concurrent students, and bench_scale.py which
builds a database at the real bank's size (10,905 questions, 2,000 students,
12,000 papers, 900k answers) to report disk cost and query timings.
