/* Chemistry AI and Physics AI — shared tool styles, on top of /styles.css (09.10.2026).
   Blocks (source card, drop, status, how it works, FAQ) follow /copy-text-from-image/app.css. */

[hidden] { display: none !important; }

.tool-hero { padding-block: 3.5rem 1.75rem; }
.tool-hero h1 { margin-bottom: .3em; }
.tool-hero .lead { max-width: 62ch; margin: 0; }
.tool { padding-bottom: 4.5rem; }
.tool .container { display: grid; gap: 1.25rem; }
.tool .container > * { max-width: 980px; width: 100%; }

.hint { font-family: var(--font-mono); font-size: .76rem; color: var(--ink-3); margin: 0; }
.link-btn { background: none; border: 0; padding: 0; cursor: pointer; font: inherit; color: var(--accent); text-decoration: underline; text-underline-offset: .18em; }
.link-btn:hover { color: var(--accent-ink); }

/* ---------- question card ---------- */
.source {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 1.25rem; box-shadow: var(--shadow); display: grid; gap: 1rem;
}
.field-label { display: block; font-weight: 600; margin-bottom: .45rem; }
.q-input {
  width: 100%; min-height: 140px; resize: vertical; font: inherit; font-size: 1.02rem; line-height: 1.55; color: var(--ink);
  background: var(--paper); border: 1px solid var(--line-2); border-radius: var(--radius); padding: .85rem 1rem;
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.q-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-tint); }
.q-input.small { min-height: 72px; }

.attach-row { display: flex; flex-wrap: wrap; align-items: center; gap: .8rem; }
.drop {
  display: inline-flex; align-items: center; gap: .6rem; cursor: pointer;
  padding: .7rem 1rem; border: 1.5px dashed var(--line-2); border-radius: var(--radius); background: var(--paper);
  color: var(--ink-2); font-size: .95rem; transition: border-color .18s var(--ease), background-color .18s var(--ease);
}
.drop:hover, .drop.is-over { border-color: var(--accent); background: var(--accent-tint-2); color: var(--ink); }
.drop:focus-within { outline: 2px solid var(--accent); outline-offset: 3px; }
.drop .icon { width: 20px; height: 20px; color: var(--accent); }
.thumb { position: relative; display: inline-flex; align-items: center; gap: .6rem; padding: .35rem .5rem .35rem .35rem; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper); }
.thumb img { width: 64px; height: 48px; object-fit: cover; border-radius: 8px; border: 1px solid var(--line); }
.thumb span { font-size: .85rem; color: var(--ink-2); }
.thumb button { border: 0; background: none; cursor: pointer; color: var(--ink-3); font-size: 1.2rem; line-height: 1; padding: .2rem .4rem; border-radius: 6px; }
.thumb button:hover { color: var(--danger); background: var(--surface-2); }

.examples { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; }
.examples .ex-label { font-family: var(--font-mono); font-size: .76rem; color: var(--ink-3); margin-right: .2rem; }
.chip-btn {
  font: inherit; font-size: .88rem; color: var(--ink-2); background: var(--paper); cursor: pointer; text-align: left;
  border: 1px solid var(--line); border-radius: 999px; padding: .38rem .8rem; transition: border-color .18s, color .18s, background-color .18s;
}
.chip-btn:hover { border-color: var(--accent); color: var(--accent-ink); background: var(--accent-tint-2); }

.actions { display: flex; flex-wrap: wrap; align-items: center; gap: .8rem 1rem; }
.btn[disabled] { opacity: .55; pointer-events: none; }

.status { margin: 0; font-size: .92rem; color: var(--ink-2); }
.status:empty { display: none; }
.status.err { color: var(--danger); }
.status.busy::before {
  content: ""; display: inline-block; width: .85em; height: .85em; margin-right: .55em; vertical-align: -.1em;
  border: 2px solid var(--accent-tint); border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- conversation ---------- */
.thread { display: grid; gap: 1rem; }
.turn-q { justify-self: end; max-width: 82%; background: var(--accent-tint-2); border: 1px solid var(--accent-tint); border-radius: var(--radius-lg) var(--radius-lg) 6px var(--radius-lg); padding: .8rem 1rem; white-space: pre-wrap; word-break: break-word; }
.turn-q img { display: block; max-width: 240px; max-height: 180px; border-radius: 8px; border: 1px solid var(--line); margin-bottom: .5rem; }
.turn-a { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 1.3rem 1.4rem; box-shadow: var(--shadow); }
.turn-a-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: .6rem; }
.turn-a-head .who { font-family: var(--font-mono); font-size: .76rem; color: var(--accent-ink); background: var(--accent-tint); padding: .18rem .5rem; border-radius: 6px; }
.answer { line-height: 1.65; color: var(--ink); overflow-wrap: anywhere; }
.answer > :first-child { margin-top: 0; }
.answer > :last-child { margin-bottom: 0; }
.answer p { margin: 0 0 .8em; }
.answer ol, .answer ul { padding-left: 1.4rem; margin: 0 0 .9em; }
.answer li { margin-bottom: .45em; }
.answer h1, .answer h2, .answer h3, .answer h4 { font-size: 1.05rem; margin: 1.1em 0 .5em; letter-spacing: 0; }
.answer strong { font-weight: 600; }
.answer code { font-family: var(--font-mono); font-size: .9em; background: var(--surface-2); padding: .1em .35em; border-radius: 5px; }
.answer table { border-collapse: collapse; margin: 0 0 1em; font-size: .95rem; display: block; overflow-x: auto; }
.answer th, .answer td { border: 1px solid var(--line); padding: .4rem .65rem; text-align: left; }
.answer .katex-display { overflow-x: auto; overflow-y: hidden; padding: .3rem 0; margin: .6em 0; }
.answer .katex { font-size: 1.06em; }
.answer > p:last-child:has(> strong:first-child) { background: var(--accent-tint-2); border-left: 3px solid var(--accent); padding: .7rem .9rem; border-radius: 0 10px 10px 0; }

.follow { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 1rem 1.1rem; display: grid; gap: .75rem; }

/* ---------- how it works & FAQ ---------- */
.how { padding-block: 4.5rem 4rem; border-top: 1px solid var(--line); }
.how-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.how-list li { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.35rem 1.4rem; }
.how-num { display: block; color: var(--accent); font-size: .85rem; margin-bottom: .9rem; }
.how-list h3 { margin-bottom: .45rem; }
.how-list p { margin: 0; color: var(--ink-2); font-size: .95rem; }
.faq-wrap { padding-block: 1rem 5rem; }
.faq { max-width: 46rem; display: grid; gap: .7rem; }
.faq details { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0 1.2rem; }
.faq summary { cursor: pointer; list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1rem 0; font-weight: 600; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--font-mono); color: var(--ink-3); font-size: 1.1rem; transition: transform .2s var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin: 0 0 1.1rem; color: var(--ink-2); }

@media (max-width: 760px) {
  .how-list { grid-template-columns: 1fr; }
  .turn-q { max-width: 100%; }
  .turn-a { padding: 1.1rem 1rem; }
}