.study-page { width: min(1000px, 100%); margin-inline: auto; }
.study-page > .lead { max-width: none; margin-bottom: 2.3rem; text-wrap: pretty; }
.study-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.5rem; }
.study-panel { display: grid; align-content: start; gap: 1.1rem; margin: 0; }
.study-module { position: relative; }
.study-module[aria-busy="true"] { opacity: .64; pointer-events: none; }
.study-module-status { margin: 0; }
.study-form { display: grid; gap: 1.25rem; }
.study-form .button-quiet { justify-self: start; }
.study-trigram-group { min-width: 0; margin: 0; padding: 0; border: 0; }
.study-trigram-group legend { margin-bottom: .65rem; color: var(--blue); font-weight: 600; }
.study-trigram-choices { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .5rem; }
.study-trigram-input { position: absolute; inline-size: 1px; block-size: 1px; opacity: 0; pointer-events: none; }
.study-trigram-tile { display: grid; min-height: 92px; place-items: center; gap: .3rem; padding: .45rem .2rem; border: 1px solid var(--line); color: var(--blue); background: var(--input); cursor: pointer; transition: border-color 180ms ease, background 180ms ease, transform 180ms ease; }
.study-trigram-tile:hover { border-color: var(--jade); transform: translateY(-1px); }
.study-trigram-tile > span { font-size: 18px; font-weight: 700; line-height: 1; }
.study-trigram-tile small { color: var(--muted); font-size: 11px; }
.study-trigram-input:checked + .study-trigram-tile { border-color: var(--jade); background: var(--success-soft); box-shadow: inset 0 0 0 1px var(--jade); }
.study-trigram-input:focus-visible + .study-trigram-tile { outline: 2px solid var(--gold); outline-offset: 3px; }
.study-trigram-diagram, .study-hexagram-diagram { display: grid; width: 44px; gap: 4px; }
.study-diagram-line { display: block; height: 4px; background: var(--blue); }
.study-diagram-line.yin { background: linear-gradient(to right, var(--blue) 0 42%, transparent 42% 58%, var(--blue) 58% 100%); }
.study-quiz-diagram { display: grid; width: 132px; gap: 7px; justify-self: center; margin: .15rem 0 .45rem; }
.study-quiz-diagram .study-diagram-line { height: 8px; }
.study-options { display: grid; gap: .65rem; }
.study-option { display: flex; align-items: center; gap: .65rem; min-height: 48px; padding: .55rem .8rem; border: 1px solid var(--line); color: var(--reading); cursor: pointer; }
.study-option:has(input:checked):not(.incorrect) { border-color: var(--jade); background: var(--success-soft); }
.study-option input { width: auto; min-height: 1.1rem; margin: 0; accent-color: var(--jade); }
.study-option small { margin-left: auto; font-size: 12px; font-weight: 700; }
.study-option.correct { border-color: var(--success); color: var(--success); background: var(--success-soft); }
.study-option.incorrect { border-color: var(--danger); color: var(--danger); background: var(--danger-soft); }
.study-option.incorrect input { accent-color: var(--danger); }
.study-option:has(input:disabled) { cursor: default; }
.study-query-result { margin-top: 1.5rem; border-top: 2px solid var(--gold); color: var(--ink); background: var(--ivory); }
.study-query-result:focus { outline: 2px solid var(--jade); outline-offset: 5px; }
.study-query-result.is-revealed { animation: study-query-reveal 480ms ease-out; }
.study-query-result article { display: grid; justify-items: center; gap: .65rem; padding: 2.4rem 2rem 2rem; text-align: center; }
.study-query-result .eyebrow { margin-bottom: .1rem; }
.study-query-pair, .study-query-pinyin { margin: 0; color: var(--muted); }
.study-query-pair { font-size: 14px; }
.study-query-pinyin { font-family: system-ui, sans-serif; letter-spacing: .08em; }
.study-query-result h2 { color: var(--blue); font-size: clamp(31px, 7vw, 42px); letter-spacing: .08em; }
.study-query-classical-text { width: min(760px, 100%); margin-top: 1rem; padding-top: 1.35rem; border-top: 1px solid var(--line); color: var(--reading); text-align: left; }
.study-query-classical-text h3, .study-query-classical-text h4 { color: var(--blue); }
.study-query-classical-text h3 { margin: 0 0 .8rem; font-size: 22px; text-align: center; }
.study-query-classical-text h4 { margin: 1.15rem 0 .55rem; font-size: 16px; }
.study-query-classical-text p { margin: 0; line-height: 1.9; letter-spacing: .04em; }
.study-query-passage { padding: .75rem 1rem; border-left: 3px solid var(--gold); background: var(--warning-soft); }
.study-query-text-list { display: grid; gap: .55rem; margin: 0; padding-left: 1.45rem; line-height: 1.8; }
.study-query-classical-text .zhouyi-yizhu-inline-translation { margin: .35rem 0 1rem; padding: .45rem .75rem; border-left: 2px solid var(--gold); color: var(--reading); background: var(--warning-soft); line-height: 1.9; letter-spacing: .04em; }
.study-query-classical-text .zhouyi-yizhu-inline-translation > strong { color: var(--jade); }
.study-hexagram-diagram { width: 150px; gap: 8px; margin: .7rem 0; }
.study-hexagram-diagram .study-diagram-line { height: 9px; }
.study-answer { padding: 1rem; border-left: 3px solid var(--gold); color: var(--reading); background: var(--warning-soft); }
.study-answer.correct { border-left-color: var(--jade); color: var(--success); background: var(--success-soft); }
.study-answer p { margin: .35rem 0 0; }
.study-mistake-action { margin-top: .85rem; }

@keyframes study-query-reveal {
  from { opacity: .45; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .study-query-result.is-revealed { animation: none; }
}

@media (max-width: 720px) {
  .study-grid { grid-template-columns: 1fr; }
  .study-trigram-choices { gap: .4rem; }
  .study-trigram-tile { min-height: 82px; }
  .study-query-result article { padding: 1.7rem 1rem; }
  .study-query-classical-text { width: 100%; }
}