/* Sdílené styly pro /lyceum/. Vizuální jazyk z /kombinatorika/ (tam je všechno inline,
   globální CSS web nemá), základ převzatý z /nerovnice/style.css.
   Modrá je o dva odstíny tmavší než v kombinatorice kvůli kontrastu bílého textu (5,3 : 1). */
:root {
    --blue: #2471a3;
    --blue-dark: #1f6391;
    --blue-light: #e8f4f8;
    --orange: #e67e22;
    --ink: #2c3e50;
    --text: #333;
    --muted: #595959;
    --line: #ddd;
    --good: #1e8449;
    --good-bg: #eafaf1;
    --bad: #b03a2e;
    --bad-bg: #fdedec;
    --warn-bg: #fef9e7;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 1rem;
    background-color: #f9f9f9;
    color: var(--text);
    line-height: 1.5;
}
h1 { color: var(--ink); margin: 0; font-size: 1.9rem; line-height: 1.2; }
h2 { font-size: 1.25rem; margin-top: 0; color: var(--ink); border-bottom: 2px solid #eee; padding-bottom: 0.5rem; }
h3 { font-size: 1.05rem; color: var(--ink); margin: 1.4rem 0 0.4rem; }
a { color: var(--blue); }
.header { display: flex; justify-content: space-between; align-items: center; gap: 1rem; margin-bottom: 0.5rem; }
.intro { color: #444; margin-top: 0.4rem; }
.tocline { font-size: 0.9rem; color: var(--muted); margin: -0.25rem 0 1.25rem; }
.crumbs { font-size: 0.85rem; color: var(--muted); margin-bottom: 0.6rem; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--blue); text-decoration: underline; }

/* ---- tlačítka ---- */
button {
    background-color: var(--blue); color: #fff; border: none; padding: 0.55rem 1rem;
    border-radius: 4px; cursor: pointer; font-weight: bold; transition: background 0.15s;
    font-size: 0.95rem; font-family: inherit; min-height: 44px;
}
button:hover { background-color: var(--blue-dark); }
button:disabled { opacity: 0.45; cursor: default; }
button:focus-visible, input:focus-visible, select:focus-visible, a:focus-visible { outline: 3px solid #f1c40f; outline-offset: 2px; }
button.secondary { background: #fff; color: var(--blue); border: 2px solid var(--blue); }
button.secondary:hover { background: var(--blue-light); }
button.reset-btn { background-color: #c0392b; padding: 0.5rem 0.9rem; font-size: 0.9rem; white-space: nowrap; }
button.reset-btn:hover { background-color: #a93226; }
.btn-row { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }

.card {
    background: #fff; border: 1px solid var(--line); border-radius: 8px;
    padding: 1.5rem; margin-bottom: 1.5rem; box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.desc { font-size: 0.9rem; color: #666; margin-bottom: 1rem; }
.ctl-label { display: block; font-size: 0.95rem; margin-bottom: 0.35rem; color: var(--ink); }

/* ---- formuláře ---- */
.input-row { display: flex; gap: 1rem; align-items: flex-end; margin-bottom: 1rem; flex-wrap: wrap; }
.field { display: flex; flex-direction: column; min-width: 0; }
.field > label, label.field-label { font-weight: 600; font-size: 0.9rem; margin-bottom: 0.3rem; color: var(--ink); }
input[type="text"], select {
    padding: 0.5rem 0.65rem; border: 2px solid #bbb; border-radius: 6px;
    font-size: 1.1rem; font-family: inherit; min-height: 46px; background: #fff; color: var(--text);
    transition: background-color 1.5s ease-out, border-color 1.5s ease-out;
}
input[type="text"]:focus, select:focus { border-color: var(--blue); }
input.num { width: 7.5rem; }
input.expr { width: 100%; max-width: 22rem; }
input.flash { background-color: #fff3b0 !important; border-color: #f1c40f !important; transition: none; }
input.ok, select.ok { border-color: var(--good); background: var(--good-bg); }
input.bad, select.bad { border-color: var(--bad); background: var(--bad-bg); }
.unit-pair { display: flex; gap: 0.35rem; }
.unit-pair select { font-size: 1rem; padding-right: 0.3rem; }
.preview { font-size: 0.88rem; color: var(--muted); min-height: 1.3em; margin-top: 0.25rem; }
.preview .warn { color: var(--bad); }
.radios { display: flex; flex-wrap: wrap; gap: 0.4rem 1rem; }
.radios label { display: inline-flex; align-items: center; gap: 0.4rem; min-height: 44px; cursor: pointer; font-weight: 500; }
.radios input { width: 1.2rem; height: 1.2rem; accent-color: var(--blue); }

/* ---- výsledek a rozpis (jako kombinatorika) ---- */
.result {
    margin-top: 1rem; padding: 0.9rem 1rem; background-color: var(--blue-light);
    border-left: 4px solid var(--blue); border-radius: 4px; font-size: 1.05rem;
}
.result strong { color: var(--orange); font-size: 1.2rem; }
.error { color: var(--bad); font-size: 0.9rem; margin-top: 0.5rem; }
.hint { font-size: 0.9rem; color: var(--muted); margin: 0.4rem 0 0.9rem; }
.breakdown {
    margin-top: 0.75rem; padding: 1rem 1.25rem; background: #fdf6e3;
    border-left: 4px solid var(--orange); border-radius: 4px; color: #5d4037; overflow-x: auto;
}
.breakdown-label {
    font-weight: 600; font-size: 0.8rem; color: #b35900; text-transform: uppercase;
    letter-spacing: 0.5px; margin-bottom: 0.6rem; display: block;
}
.breakdown-section-label { font-size: 0.8rem; color: #8a6d55; margin: 0.6rem 0 0.2rem; font-style: italic; }
.tex-line { margin: 0.35rem 0; overflow-x: auto; overflow-y: hidden; }
.tex-line .katex-display { margin: 0.3em 0; }

/* ---- kroky (řešený příklad i rozpis v procvičování) ---- */
ol.steps { margin: 0; padding-left: 1.4rem; line-height: 1.6; }
ol.steps > li { margin-bottom: 0.7rem; padding-left: 0.2rem; }
ol.steps > li.current { animation: stepin 0.35s ease-out; }
ol.steps .step-text { line-height: 1.6; }
@keyframes stepin { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
.step-bar { margin-top: 0.9rem; }
.step-count { margin-left: 0.3rem; }

/* ---- výklad ---- */
.vyklad { margin-top: 2.5rem; }
.vyklad > h2 { font-size: 1.35rem; border-bottom: 2px solid #ddd; margin: 2.2rem 0 0.9rem; }
.vyklad p, .vyklad li { line-height: 1.65; }
.vyklad ul, .vyklad ol { padding-left: 1.3rem; }
.vyklad li { margin-bottom: 0.35rem; }
.rule {
    background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--blue);
    border-radius: 4px; padding: 0.9rem 1.1rem; margin: 1rem 0;
}
.rule p:first-child { margin-top: 0; } .rule p:last-child { margin-bottom: 0; }
.rule ul, .rule ol { margin: 0.3rem 0; }
.rule strong { color: var(--ink); }
.rule.pozor { border-left-color: var(--bad); }
.priklad {
    background: #fff; border: 1px solid var(--line); border-radius: 8px;
    padding: 1.25rem 1.5rem; margin: 1.25rem 0; box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.priklad .zadani { font-style: italic; color: #444; margin-top: 0; }
.tex-block { margin: 0.6rem 0; overflow-x: auto; overflow-y: hidden; }
.pozor-txt { color: #c0392b; font-weight: 600; }
table.tab { border-collapse: collapse; width: 100%; margin: 0.5rem 0 1rem; font-size: 0.95rem; }
table.tab th, table.tab td { border-bottom: 1px solid #eee; padding: 0.45rem 0.5rem; text-align: left; vertical-align: top; }
table.tab th { font-size: 0.85rem; color: var(--muted); font-weight: 600; }
.figure { margin: 1rem 0; text-align: center; }
.figure svg { max-width: 100%; height: auto; }
.figure figcaption, .figcap { font-size: 0.88rem; color: var(--muted); margin-top: 0.3rem; }
.figs { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin: 1rem 0; }
.figs figure { margin: 0; text-align: center; }

/* ---- procvičování ---- */
.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 1rem; }
.chips button { background: #fff; color: var(--ink); border: 2px solid #ccc; font-weight: 600; font-size: 0.95rem; padding: 0.35rem 0.75rem; }
.chips button:hover { background: #f2f7fb; border-color: var(--blue); }
.chips button[aria-pressed="true"] { background: var(--blue); color: #fff; border-color: var(--blue); }
.chips-label { font-size: 0.9rem; color: var(--muted); margin: 0 0 0.5rem; }
.score { font-size: 0.95rem; color: var(--muted); margin-bottom: 0.75rem; }
.score strong { color: var(--ink); }
.task { font-size: 1.05rem; margin: 0.5rem 0 1rem; padding: 0.9rem 1rem; background: #f7f9fb; border-radius: 6px; border: 1px solid #e6ebef; }
.task .tex-line { font-size: 1.1rem; }
.qs { display: grid; gap: 1rem; margin-bottom: 1rem; }
.q { border-left: 3px solid #e3e8ec; padding-left: 0.8rem; }
.q.ok { border-left-color: var(--good); }
.q.bad { border-left-color: var(--bad); }
.q-label { font-weight: 600; color: var(--ink); margin-bottom: 0.35rem; font-size: 0.95rem; }
.q-msg { font-size: 0.9rem; margin-top: 0.3rem; }
.q-msg.ok { color: var(--good); }
.q-msg.bad { color: var(--bad); }
.inline-row { display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem 0.5rem; }
.feedback:not(:empty) { margin-top: 1rem; padding: 0.8rem 1rem; border-radius: 4px; border-left: 4px solid #999; background: #f4f4f4; }
.feedback.good { border-left-color: var(--good); background: var(--good-bg); }
.feedback.bad { border-left-color: var(--bad); background: var(--bad-bg); }
.feedback p { margin: 0.2rem 0; }
.muted { color: var(--muted); font-size: 0.92rem; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ---- rozcestníky (karty jako v /dg/) ---- */
.about {
    background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--blue);
    border-radius: 8px; padding: 1rem 1.3rem; margin: 1.4rem 0 1.8rem;
}
.about h2 { font-size: 1.05rem; margin: 0 0 0.5rem; border: none; padding: 0; }
.about p, .about li { color: #555; font-size: 0.94rem; line-height: 1.55; }
.about ul { margin: 0; padding-left: 1.2rem; }
h2.secth { font-size: 1.15rem; margin: 1.8rem 0 0.8rem; border: none; padding: 0; }
a.tool { display: block; text-decoration: none; color: inherit; }
.kcard {
    background: #fff; border: 1px solid var(--line); border-radius: 8px;
    padding: 1rem 1.3rem; margin-bottom: 0.9rem; box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    transition: box-shadow 0.15s, transform 0.15s;
}
.kcard:hover { box-shadow: 0 4px 10px rgba(0,0,0,0.10); transform: translateY(-1px); }
.kcard h3 { font-size: 1.1rem; margin: 0 0 0.3rem; font-weight: 700; display: flex; align-items: center; gap: 0.6rem; }
.kcard p { margin: 0; color: #666; font-size: 0.92rem; line-height: 1.5; }
.kcard .meta { margin-top: 0.4rem; font-size: 0.82rem; color: var(--muted); }
.ikona {
    display: inline-flex; align-items: center; justify-content: center; flex: none;
    width: 2rem; height: 2rem; border-radius: 50%; background: var(--blue); color: #fff;
    font-size: 0.95rem; font-weight: 700; font-style: italic; font-family: Georgia, "Times New Roman", serif;
}

footer { margin-top: 3rem; padding-top: 1.25rem; border-top: 1px solid var(--line); font-size: 0.9rem; color: var(--muted); }
footer ul { margin: 0.4rem 0 0.8rem; padding-left: 1.2rem; }

@media (max-width: 480px) {
    body { margin-top: 1rem; }
    h1 { font-size: 1.5rem; }
    .card { padding: 1rem; }
    .priklad { padding: 1rem; }
    .header { align-items: flex-start; }
    input.num { width: 6.5rem; }
    .breakdown { padding: 0.8rem 0.75rem; }
    .breakdown ol.steps, .priklad ol.steps { padding-left: 1.15rem; }
    .breakdown .katex-display, .priklad .katex-display { font-size: 0.9em; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }
.suffix { font-weight: 600; color: var(--ink); }

/* ---- záložky (jako sekce 2 v kombinatorice) ---- */
.tabs { display: flex; gap: 0; margin: 0 0 1rem; border-bottom: 2px solid #eee; overflow-x: auto; }
button.tab {
    background: none; color: var(--muted); border: none; padding: 0.6rem 1rem;
    border-bottom: 3px solid transparent; font-weight: 600; margin-bottom: -2px;
    font-size: 0.95rem; border-radius: 0; white-space: nowrap; transition: color 0.15s, border-color 0.15s;
}
button.tab:hover { background: none; color: var(--text); }
button.tab[aria-selected="true"] { color: var(--blue); border-bottom-color: var(--blue); }