/* ═══════════════════════════════════════════════════════════════════
   Article Drill (D88 / D89 / D92)

   ONE widget, three articles. /Articles/RomanizedChineseExplained,
   /Articles/AllPinyinSyllables and /Articles/PinyinOrCharactersFirst each
   embed a four-level drill, and the only thing that differs between them is
   the question bank their PageModel builds and the two hero colours the page
   sets. A second stylesheet per article is three copies of the same grid
   drifting apart, which is the thing this file exists to prevent.

   D87's tonemark-trainer.css is deliberately NOT merged into it: that widget
   shipped first, it is pinned by twelve tests, and rewriting a live page's
   markup to share a class prefix buys nothing a reader can see.

   The prefix is "drl", never "ad" — a class or id containing "ad" is what
   content blockers match on, and a blocked drill looks like a broken page.

   Everything colour-neutral uses Bootstrap's own CSS variables so the widget
   follows the site's dark mode without a second palette to keep in step.
   ═══════════════════════════════════════════════════════════════════ */

.drl {
    /* Overridden per page; these are the fallbacks. */
    --drl-a: #4338ca;
    --drl-b: #7c3aed;
    --drl-c: #c026d3;
    border-radius: 0.75rem;
    overflow: hidden;
}

.drl-hero {
    background: linear-gradient(135deg, var(--drl-a) 0%, var(--drl-b) 55%, var(--drl-c) 100%);
    color: #fff;
}

/* ── Level picker ────────────────────────────────────────────────── */
.drl-levels {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 0.6rem;
}

.drl-level {
    border: 2px solid var(--bs-border-color);
    background: var(--bs-body-bg);
    color: var(--bs-body-color);
    border-radius: 0.6rem;
    padding: 0.7rem 0.75rem;
    text-align: left;
    transition: transform .12s ease, border-color .12s ease, box-shadow .12s ease;
}

.drl-level:hover,
.drl-level:focus-visible {
    transform: translateY(-2px);
    border-color: var(--drl-b);
    box-shadow: 0 6px 18px rgba(124, 58, 237, .25);
}

.drl-level-name { font-weight: 700; display: block; }
.drl-level-sub { font-size: .78rem; opacity: .75; display: block; }
.drl-best { font-size: .72rem; font-weight: 700; color: var(--drl-b); }

.drl-level[data-tier="1"] { border-left: 6px solid #10b981; }
.drl-level[data-tier="2"] { border-left: 6px solid #0ea5e9; }
.drl-level[data-tier="3"] { border-left: 6px solid #f59e0b; }
.drl-level[data-tier="4"] { border-left: 6px solid #e11d48; }

/* ── HUD ─────────────────────────────────────────────────────────── */
.drl-hud {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: .35rem .9rem;
    font-weight: 700;
}

.drl-hud small {
    display: block;
    font-weight: 400;
    font-size: .7rem;
    opacity: .7;
    text-transform: uppercase;
    letter-spacing: .04em;
}

.drl-combo {
    font-weight: 800;
    color: #f59e0b;
    transition: transform .15s ease;
}

.drl-combo.drl-combo-hot {
    color: #e11d48;
    transform: scale(1.15);
}

.drl-timerbar {
    height: 6px;
    border-radius: 3px;
    background: var(--bs-secondary-bg);
    overflow: hidden;
}

.drl-timerbar > span {
    display: block;
    height: 100%;
    width: 100%;
    background: linear-gradient(90deg, #10b981, #f59e0b, #e11d48);
    transform-origin: left center;
}

/* ── Prompt ──────────────────────────────────────────────────────── */
.drl-stage { position: relative; }

.drl-prompt {
    font-size: clamp(1.9rem, 8vw, 3.2rem);
    font-weight: 800;
    line-height: 1.2;
    text-align: center;
    margin: .35rem 0 .1rem;
    /* Tone marks sit above the x-height; a tight line box clips ǚ on Android. */
    padding-top: .15rem;
    word-break: break-word;
}

/* Hanzi needs a taller box than Latin at the same font-size, and the ceiling
   levels on /Articles/PinyinOrCharactersFirst are nothing but hanzi. */
.drl-prompt.drl-han { font-size: clamp(2.6rem, 12vw, 4.2rem); line-height: 1.35; }

.drl-ask {
    text-align: center;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: .2rem;
}

.drl-prompt-hint {
    text-align: center;
    font-size: .85rem;
    opacity: .75;
    margin-bottom: .35rem;
}

.drl-build {
    text-align: center;
    font-size: clamp(1.6rem, 7vw, 2.4rem);
    font-weight: 700;
    min-height: 2.6rem;
    letter-spacing: .04em;
}

.drl-build .drl-slot {
    display: inline-block;
    min-width: 1.4ch;
    border-bottom: 3px solid var(--drl-b);
    color: var(--drl-c);
}

/* ── Options ─────────────────────────────────────────────────────── */
.drl-options {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: .55rem;
}

.drl-options.drl-options-short { grid-template-columns: repeat(2, 1fr); }

.drl-option {
    border: 2px solid var(--bs-border-color);
    background: var(--bs-body-bg);
    color: var(--bs-body-color);
    border-radius: .6rem;
    padding: .7rem .6rem;
    font-size: 1.15rem;
    font-weight: 700;
    transition: transform .1s ease, background-color .15s ease, border-color .15s ease;
}

.drl-options-short .drl-option { font-size: 1.6rem; }

.drl-option:hover:not(:disabled) {
    transform: translateY(-2px);
    border-color: var(--drl-b);
}

.drl-option .drl-key {
    display: block;
    font-size: .68rem;
    font-weight: 600;
    opacity: .55;
}

.drl-option.drl-right {
    background: #10b981;
    border-color: #10b981;
    color: #fff;
    animation: drl-pop .32s ease;
}

.drl-option.drl-wrong {
    background: #e11d48;
    border-color: #e11d48;
    color: #fff;
    animation: drl-shake .34s ease;
}

/* ── Two-part build (pick A, then pick B) ────────────────────────── */
.drl-parts { margin: 0 auto; max-width: 34rem; }

.drl-part-label {
    font-size: .7rem;
    text-transform: uppercase;
    letter-spacing: .06em;
    opacity: .65;
    margin-bottom: .2rem;
}

.drl-chips {
    display: flex;
    flex-wrap: wrap;
    gap: .3rem;
    justify-content: center;
    margin-bottom: .5rem;
}

.drl-chip {
    border: 1px solid var(--bs-border-color);
    background: var(--bs-body-bg);
    color: var(--bs-body-color);
    border-radius: .45rem;
    padding: .3rem .6rem;
    font-size: 1.05rem;
    font-weight: 700;
    transition: transform .1s ease, background-color .15s ease;
}

.drl-chip:hover:not(:disabled) { transform: translateY(-2px); background: var(--bs-secondary-bg); }
.drl-chip.drl-picked { background: var(--drl-b); border-color: var(--drl-b); color: #fff; }
.drl-chip.drl-right { background: #10b981; border-color: #10b981; color: #fff; animation: drl-pop .32s ease; }
.drl-chip.drl-wrong { background: #e11d48; border-color: #e11d48; color: #fff; animation: drl-shake .34s ease; }

/* ── Typed answer ────────────────────────────────────────────────── */
.drl-typebox {
    max-width: 20rem;
    margin: 0 auto;
    font-size: 1.35rem;
    font-weight: 700;
    text-align: center;
    letter-spacing: .06em;
}

/* ── Feedback and effects ────────────────────────────────────────── */
.drl-feedback {
    min-height: 2.6rem;
    text-align: center;
    font-weight: 600;
}

.drl-float {
    position: absolute;
    left: 50%;
    top: 40%;
    transform: translateX(-50%);
    font-size: 1.6rem;
    font-weight: 800;
    color: #10b981;
    pointer-events: none;
    animation: drl-float 900ms ease-out forwards;
    text-shadow: 0 2px 10px rgba(0, 0, 0, .25);
}

/* A burst of eight sparks, CSS only — no library, no images, nothing to load. */
.drl-spark {
    position: absolute;
    left: 50%;
    top: 45%;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    pointer-events: none;
    animation: drl-spark 700ms ease-out forwards;
}

.drl-levelup { animation: drl-pop .5s ease; }

.drl-dots { display: flex; gap: .25rem; justify-content: center; }

.drl-dot {
    width: .55rem;
    height: .55rem;
    border-radius: 50%;
    background: var(--bs-secondary-bg);
    border: 1px solid var(--bs-border-color);
}

.drl-dot-hit { background: #10b981; border-color: #10b981; }
.drl-dot-miss { background: #e11d48; border-color: #e11d48; }
.drl-dot-now { background: var(--drl-b); border-color: var(--drl-b); }

@keyframes drl-pop {
    0% { transform: scale(.85); }
    60% { transform: scale(1.08); }
    100% { transform: scale(1); }
}

@keyframes drl-shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-7px); }
    40% { transform: translateX(7px); }
    60% { transform: translateX(-4px); }
    80% { transform: translateX(4px); }
}

@keyframes drl-float {
    0% { opacity: 1; transform: translate(-50%, 0) scale(1); }
    100% { opacity: 0; transform: translate(-50%, -70px) scale(1.25); }
}

@keyframes drl-spark {
    0% { opacity: 1; transform: translate(0, 0) scale(1); }
    100% { opacity: 0; transform: translate(var(--dx), var(--dy)) scale(.35); }
}

/* Respect the visitor's own setting — every effect here is decorative. */
@media (prefers-reduced-motion: reduce) {
    .drl-option,
    .drl-chip,
    .drl-level,
    .drl-combo,
    .drl-float,
    .drl-spark,
    .drl-levelup {
        animation: none !important;
        transition: none !important;
    }

    .drl-float { opacity: 1; }
}

@media (min-width: 576px) {
    .drl-options { grid-template-columns: repeat(2, 1fr); }
    .drl-options.drl-options-short { grid-template-columns: repeat(4, 1fr); }
}