/* =====================================================================
   F7PBPZIT – Základy informačních technologií · design system
   Vanilla CSS, bez buildu. Barvy jako tokeny, světlý i tmavý režim.
   ===================================================================== */

:root {
  --font-sans: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-head: "Space Grotesk", "Inter", "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;

  --bg: #f4f6f9;
  --bg-elev: #ffffff;
  --bg-sunk: #e9edf3;
  --ink: #12203a;
  --ink-2: #4b5a72;
  --ink-3: #7b879a;
  --line: #d9dfe8;
  --line-strong: #b9c3d2;

  --brand: #16324f;
  --brand-ink: #ffffff;
  --accent: #f28c1e;
  --accent-ink: #1a1200;
  --accent-soft: #fff1e0;
  --ok: #1f9d68;
  --ok-soft: #e3f6ec;
  --warn: #d9a400;
  --warn-soft: #fff7d6;
  --danger: #d64545;
  --danger-soft: #fde6e6;
  --info: #2b7fd6;
  --info-soft: #e4f0fc;
  --violet: #7b5cd6;
  --violet-soft: #efe9fc;

  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(18, 32, 58, .06), 0 8px 24px -12px rgba(18, 32, 58, .18);
  --shadow-lg: 0 20px 50px -20px rgba(18, 32, 58, .35);
  --max: 1160px;
  --header-h: 64px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d131d;
    --bg-elev: #151d2a;
    --bg-sunk: #0a0f17;
    --ink: #e7ecf3;
    --ink-2: #aab5c6;
    --ink-3: #7c889b;
    --line: #26303f;
    --line-strong: #3b4757;
    --brand: #1f4a75;
    --accent-soft: #3a2a14;
    --ok-soft: #12301f;
    --warn-soft: #3a3110;
    --danger-soft: #3d1a1a;
    --info-soft: #14283d;
    --violet-soft: #26203d;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -12px rgba(0, 0, 0, .6);
    --shadow-lg: 0 20px 50px -20px rgba(0, 0, 0, .7);
  }
}
:root[data-theme="dark"] {
  --bg: #0d131d;
  --bg-elev: #151d2a;
  --bg-sunk: #0a0f17;
  --ink: #e7ecf3;
  --ink-2: #aab5c6;
  --ink-3: #7c889b;
  --line: #26303f;
  --line-strong: #3b4757;
  --brand: #1f4a75;
  --accent-soft: #3a2a14;
  --ok-soft: #12301f;
  --warn-soft: #3a3110;
  --danger-soft: #3d1a1a;
  --info-soft: #14283d;
  --violet-soft: #26203d;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -12px rgba(0, 0, 0, .6);
  --shadow-lg: 0 20px 50px -20px rgba(0, 0, 0, .7);
}

/* ---------- základ ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 80% -10%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 60%),
    radial-gradient(900px 500px at -10% 10%, color-mix(in srgb, var(--info) 8%, transparent), transparent 60%);
  background-attachment: fixed;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--info); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent); }
h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.2; margin: 0 0 .5em; letter-spacing: -.01em; }
h1 { font-size: clamp(1.9rem, 4vw, 2.8rem); font-weight: 700; }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.85rem); font-weight: 700; margin-top: 1.6em; }
h3 { font-size: 1.2rem; font-weight: 600; margin-top: 1.4em; }
h4 { font-size: 1rem; font-weight: 600; margin-top: 1.2em; }
p { margin: 0 0 1em; }
ul, ol { padding-left: 1.4em; margin: 0 0 1em; }
li { margin: .25em 0; }
code, kbd, pre { font-family: var(--font-mono); font-size: .92em; }
code { background: var(--bg-sunk); padding: .1em .4em; border-radius: 6px; }
pre {
  background: #0f172a; color: #e2e8f0; padding: 1rem 1.1rem; border-radius: var(--radius-sm);
  overflow: auto; line-height: 1.5; position: relative; margin: 0 0 1.2em;
}
pre code { background: none; padding: 0; color: inherit; }
kbd {
  background: var(--bg-elev); border: 1px solid var(--line-strong); border-bottom-width: 2px;
  padding: .05em .45em; border-radius: 6px; font-size: .85em;
}
table { border-collapse: collapse; width: 100%; margin: 0 0 1.2em; font-size: .95rem; }
th, td { text-align: left; padding: .55em .7em; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-weight: 600; color: var(--ink-2); font-size: .85rem; text-transform: uppercase; letter-spacing: .04em; }
tbody tr:hover { background: color-mix(in srgb, var(--bg-sunk) 60%, transparent); }
hr { border: 0; border-top: 1px solid var(--line); margin: 2rem 0; }
blockquote {
  margin: 0 0 1.2em; padding: .8em 1.1em; border-left: 4px solid var(--accent);
  background: var(--accent-soft); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 1.05rem; font-weight: 500;
}
blockquote p:last-child { margin-bottom: 0; }
.visually-hidden { position: absolute !important; clip: rect(0 0 0 0); width: 1px; height: 1px; overflow: hidden; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 70%, transparent); outline-offset: 2px; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }
.muted { color: var(--ink-2); }
.small { font-size: .88rem; }
.mono { font-family: var(--font-mono); }
.nowrap { white-space: nowrap; }
.center { text-align: center; }
.mt-0 { margin-top: 0 !important; }
.mb-0 { margin-bottom: 0 !important; }
.grid { display: grid; gap: 1rem; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
.flex { display: flex; gap: .6rem; flex-wrap: wrap; align-items: center; }
.between { justify-content: space-between; }

/* ---------- hlavička ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg-elev) 88%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; gap: 1rem; min-height: var(--header-h); }
.brand { display: flex; align-items: center; gap: .6rem; text-decoration: none; color: var(--ink); font-family: var(--font-head); font-weight: 700; }
.brand .logo {
  width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--brand), #2b5f8f); color: #fff; font-size: .8rem; letter-spacing: .02em;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.15);
}
.brand .logo::after { content: "ZIT"; }
.brand small { display: block; font-family: var(--font-sans); font-weight: 500; font-size: .72rem; color: var(--ink-3); line-height: 1.1; }
.site-nav { margin-left: auto; display: flex; gap: .15rem; align-items: center; }
.site-nav a {
  text-decoration: none; color: var(--ink-2); padding: .45rem .7rem; border-radius: 8px; font-weight: 500; font-size: .93rem;
}
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); background: var(--bg-sunk); }
.nav-toggle {
  display: none; margin-left: auto; background: none; border: 1px solid var(--line); border-radius: 8px;
  padding: .4rem .6rem; color: var(--ink); cursor: pointer; font-size: 1.1rem;
}
.icon-btn {
  background: none; border: 1px solid var(--line); border-radius: 8px; width: 36px; height: 36px;
  display: grid; place-items: center; cursor: pointer; color: var(--ink-2); font-size: 1rem;
}
.icon-btn:hover { color: var(--ink); background: var(--bg-sunk); }
@media (max-width: 860px) {
  .nav-toggle { display: inline-block; }
  .site-nav {
    display: none; position: absolute; left: 0; right: 0; top: var(--header-h);
    background: var(--bg-elev); border-bottom: 1px solid var(--line); flex-direction: column; align-items: stretch;
    padding: .6rem 16px 1rem; gap: .2rem;
  }
  .site-nav.open { display: flex; }
  .site-nav a { padding: .7rem .8rem; }
}

/* ---------- lišta pokroku v lekci ---------- */
.lecture-progress { height: 3px; background: var(--line); position: relative; }
.lecture-progress > span { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--accent), var(--ok)); transition: width .4s ease; }

/* ---------- patička ---------- */
.site-footer { margin-top: 4rem; border-top: 1px solid var(--line); padding: 2rem 0 3rem; color: var(--ink-2); font-size: .9rem; }
.site-footer .wrap { display: grid; gap: 1.2rem; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.site-footer h4 { margin: 0 0 .4em; color: var(--ink); }
.site-footer a { color: inherit; }

/* ---------- tlačítka ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .5rem; padding: .62rem 1.05rem; border-radius: 10px;
  border: 1px solid var(--line-strong); background: var(--bg-elev); color: var(--ink); font-weight: 600;
  text-decoration: none; cursor: pointer; font-size: .95rem; line-height: 1.2; transition: transform .08s, box-shadow .15s, background .15s;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); color: var(--ink); }
.btn:active { transform: translateY(0); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { color: var(--accent-ink); background: color-mix(in srgb, var(--accent) 88%, #000); }
.btn-brand { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn-brand:hover { color: #fff; }
.btn-ghost { background: transparent; }
.btn-sm { padding: .4rem .75rem; font-size: .85rem; border-radius: 8px; }
.btn[disabled], .btn.is-disabled { opacity: .55; pointer-events: none; }
.btn .ico { font-size: 1.05em; }

/* ---------- odznaky ---------- */
.badge {
  display: inline-flex; align-items: center; gap: .35em; padding: .18em .6em; border-radius: 999px;
  font-size: .76rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase;
  background: var(--bg-sunk); color: var(--ink-2); border: 1px solid transparent;
}
.badge-accent { background: var(--accent-soft); color: color-mix(in srgb, var(--accent) 70%, var(--ink)); }
.badge-ok { background: var(--ok-soft); color: var(--ok); }
.badge-warn { background: var(--warn-soft); color: color-mix(in srgb, var(--warn) 60%, var(--ink)); }
.badge-danger { background: var(--danger-soft); color: var(--danger); }
.badge-info { background: var(--info-soft); color: var(--info); }
.badge-violet { background: var(--violet-soft); color: var(--violet); }
.badge-live::before { content: ""; width: .5em; height: .5em; border-radius: 50%; background: currentColor; animation: pulse 1.6s infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: .4; transform: scale(.7); } }

.tag { display: inline-block; font-size: .8rem; padding: .15em .55em; border-radius: 6px; background: var(--bg-sunk); color: var(--ink-2); font-family: var(--font-mono); }

/* ---------- karty ---------- */
.card {
  background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.2rem 1.3rem; box-shadow: var(--shadow);
}
.card h3:first-child, .card h2:first-child { margin-top: 0; }
.card-link { text-decoration: none; color: inherit; display: block; transition: transform .12s, box-shadow .2s, border-color .2s; }
.card-link:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--line-strong); color: inherit; }
.card-soft { background: var(--bg-sunk); border-color: transparent; box-shadow: none; }

/* ---------- výstražné boxy ---------- */
.callout {
  border-radius: var(--radius); padding: 1rem 1.15rem 1rem 1.15rem; margin: 0 0 1.2em;
  border: 1px solid var(--line); background: var(--bg-elev); display: grid; grid-template-columns: auto 1fr; gap: .8rem;
}
.callout .ico { font-size: 1.4rem; line-height: 1.2; }
.callout .body > :last-child { margin-bottom: 0; }
.callout .title { font-weight: 700; font-family: var(--font-head); margin-bottom: .2em; display: block; }
.callout-info { background: var(--info-soft); border-color: color-mix(in srgb, var(--info) 30%, transparent); }
.callout-warn { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 40%, transparent); }
.callout-danger { background: var(--danger-soft); border-color: color-mix(in srgb, var(--danger) 35%, transparent); }
.callout-ok { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 35%, transparent); }
.callout-task { background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 45%, transparent); }
.callout-task .title::before { content: "Úkol · "; color: var(--accent); }

/* ---------- hero ---------- */
.hero { padding: 3.2rem 0 2rem; }
.hero .eyebrow { display: flex; gap: .5rem; flex-wrap: wrap; align-items: center; margin-bottom: 1rem; }
.hero h1 { max-width: 18ch; }
.hero .lead { font-size: 1.15rem; color: var(--ink-2); max-width: 60ch; }
.hero-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 2rem; align-items: center; }
@media (max-width: 860px) { .hero-grid { grid-template-columns: 1fr; } }
.hero-art {
  position: relative; aspect-ratio: 4 / 3; border-radius: 20px; overflow: hidden;
  background: linear-gradient(145deg, var(--brand), #2b5f8f 60%, #3f7fb5);
  box-shadow: var(--shadow-lg); color: #fff; display: grid; place-items: center;
}
.hero-art .flow { list-style: none; padding: 0; margin: 0; display: grid; gap: .45rem; width: 78%; font-family: var(--font-head); font-weight: 600; }
.hero-art .flow li {
  background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.22); border-radius: 10px; padding: .5rem .8rem; font-size: .95rem;
  backdrop-filter: blur(4px); display: flex; align-items: center; gap: .6rem; animation: rise .6s both;
}
.hero-art .flow li span.n { width: 1.6rem; height: 1.6rem; border-radius: 50%; display: grid; place-items: center; background: var(--accent); color: var(--accent-ink); font-size: .8rem; }
.hero-art .flow li:nth-child(2) { animation-delay: .1s; } .hero-art .flow li:nth-child(3) { animation-delay: .2s; }
.hero-art .flow li:nth-child(4) { animation-delay: .3s; } .hero-art .flow li:nth-child(5) { animation-delay: .4s; }
@keyframes rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.hero-art::before {
  content: ""; position: absolute; inset: 0; background-image:
    linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 28px 28px; mask-image: radial-gradient(circle at 50% 50%, #000 30%, transparent 75%);
}

/* ---------- paralelka ---------- */
.group-picker { display: inline-flex; border: 1px solid var(--line-strong); border-radius: 999px; padding: 3px; background: var(--bg-elev); gap: 2px; }
.group-picker button {
  border: 0; background: none; padding: .35rem .8rem; border-radius: 999px; cursor: pointer; font-weight: 600; color: var(--ink-2); font-size: .88rem;
}
.group-picker button[aria-pressed="true"] { background: var(--brand); color: #fff; }

/* ---------- časová osa / seznam cvičení ---------- */
.timeline { list-style: none; padding: 0; margin: 0; display: grid; gap: .7rem; }
.timeline li { display: grid; grid-template-columns: 56px 1fr; gap: 1rem; align-items: stretch; }
.timeline .num {
  font-family: var(--font-head); font-weight: 700; font-size: 1.3rem; color: var(--ink-3);
  display: grid; place-items: center; border-radius: 12px; background: var(--bg-sunk);
}
.timeline li.is-current .num { background: var(--accent); color: var(--accent-ink); }
.timeline li.is-done .num { background: var(--ok-soft); color: var(--ok); }
.timeline .card { padding: .9rem 1.1rem; display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; }
.timeline .card .t { flex: 1 1 260px; }
.timeline .card .t strong { display: block; font-family: var(--font-head); font-size: 1.05rem; }
.timeline .card .t span { color: var(--ink-2); font-size: .9rem; }
.timeline .card .d { font-size: .88rem; color: var(--ink-2); text-align: right; min-width: 150px; }
.timeline li.is-locked .card { opacity: .72; }

/* ---------- stránka lekce ---------- */
.lecture-head { padding: 2.2rem 0 1.2rem; border-bottom: 1px solid var(--line); margin-bottom: 1.5rem; }
.lecture-head .kicker { display: flex; gap: .5rem; align-items: center; flex-wrap: wrap; margin-bottom: .6rem; }
.lecture-head h1 { margin-bottom: .3em; }
.lecture-head .sub { color: var(--ink-2); font-size: 1.1rem; max-width: 65ch; }
.lecture-meta { display: flex; gap: .6rem; flex-wrap: wrap; margin: 1rem 0 1.2rem; }
.lecture-meta .chip {
  display: inline-flex; gap: .45rem; align-items: center; padding: .4rem .75rem; border-radius: 10px;
  background: var(--bg-elev); border: 1px solid var(--line); font-size: .88rem;
}
.lecture-meta .chip b { font-weight: 700; }
.lecture-meta .chip.is-mine { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }
.lecture-actions { display: flex; gap: .6rem; flex-wrap: wrap; }

.lecture-layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 2.4rem; align-items: start; }
@media (max-width: 960px) { .lecture-layout { grid-template-columns: 1fr; } .lecture-toc { position: static !important; } }
.lecture-toc { position: sticky; top: calc(var(--header-h) + 12px); font-size: .9rem; }
.lecture-toc h4 { margin: 0 0 .5rem; text-transform: uppercase; font-size: .72rem; letter-spacing: .08em; color: var(--ink-3); }
.lecture-toc ol { list-style: none; padding: 0; margin: 0 0 1rem; border-left: 2px solid var(--line); }
.lecture-toc li a {
  display: flex; gap: .5rem; align-items: baseline; padding: .32rem .7rem; color: var(--ink-2); text-decoration: none; border-left: 2px solid transparent; margin-left: -2px;
}
.lecture-toc li a:hover { color: var(--ink); }
.lecture-toc li a.is-active { color: var(--ink); border-left-color: var(--accent); font-weight: 600; }
.lecture-toc li.is-done a::after { content: "✓"; margin-left: auto; color: var(--ok); font-weight: 700; }
.lecture-toc .toc-num { color: var(--ink-3); font-family: var(--font-mono); font-size: .78rem; min-width: 1.4em; }
.lecture-toc .toc-progress { font-size: .82rem; color: var(--ink-2); }

.block { margin: 0 0 2.6rem; scroll-margin-top: calc(var(--header-h) + 16px); }
.block-head { display: flex; align-items: center; gap: .8rem; margin-bottom: .6rem; }
.block-head .bn {
  width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; flex: none;
  background: var(--brand); color: #fff; font-family: var(--font-head); font-weight: 700;
}
.block-head h2 { margin: 0; }
.block-head .bt { color: var(--ink-3); font-size: .82rem; margin-left: auto; white-space: nowrap; }
.block-goal { color: var(--ink-2); font-style: italic; margin-bottom: 1rem; }
.block-foot { display: flex; align-items: center; gap: 1rem; margin-top: 1rem; padding-top: .8rem; border-top: 1px dashed var(--line); }

/* ---------- soubory (chaotická složka) ---------- */
.file-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(118px, 1fr)); gap: .6rem; margin: 0 0 1.2em; }
.file {
  display: grid; justify-items: center; gap: .35rem; padding: .7rem .4rem .6rem; border-radius: 10px; background: var(--bg-elev);
  border: 1px solid var(--line); text-align: center; font-size: .78rem; font-family: var(--font-mono); word-break: break-all;
}
.file .fi {
  width: 42px; height: 52px; border-radius: 6px; position: relative; display: grid; place-items: end center; padding-bottom: 5px;
  font: 700 .62rem var(--font-sans); color: #fff; text-transform: uppercase; letter-spacing: .04em;
  background: var(--ink-3);
}
.file .fi::before { content: ""; position: absolute; top: 0; right: 0; border: 7px solid; border-color: var(--bg-elev) var(--bg-elev) rgba(0,0,0,.18) rgba(0,0,0,.18); }
.fi-docx { background: #2b5797; } .fi-xlsx { background: #1e7145; } .fi-pdf { background: #c62828; } .fi-csv { background: #2e7d32; }
.fi-txt { background: #616161; } .fi-jpg { background: #8e24aa; } .fi-png { background: #6a1b9a; } .fi-zip { background: #ef6c00; }
.folder-tree { font-family: var(--font-mono); font-size: .9rem; background: var(--bg-sunk); padding: 1rem 1.2rem; border-radius: var(--radius-sm); white-space: pre; overflow: auto; margin: 0 0 1.2em; line-height: 1.55; }

/* ---------- kroky ---------- */
.steps { counter-reset: step; list-style: none; padding: 0; margin: 0 0 1.2em; display: grid; gap: .6rem; }
.steps li { counter-increment: step; display: grid; grid-template-columns: 34px 1fr; gap: .8rem; align-items: start; }
.steps li::before {
  content: counter(step); width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  background: var(--accent); color: var(--accent-ink); font-weight: 700; font-size: .9rem; margin-top: .1em;
}
.steps li > :last-child { margin-bottom: 0; }

/* ---------- porovnání verzí ---------- */
.diff-table td.changed { background: var(--warn-soft); }
.diff-table td.added { background: var(--ok-soft); }
.diff-table td.removed { background: var(--danger-soft); text-decoration: line-through; color: var(--ink-3); }

/* ---------- sdílení – žebřík ---------- */
.ladder { list-style: none; padding: 0; margin: 0 0 1.2em; display: grid; gap: .4rem; }
.ladder li { display: grid; grid-template-columns: 1fr auto; gap: 1rem; padding: .6rem .9rem; border-radius: 10px; border: 1px solid var(--line); background: var(--bg-elev); align-items: center; }
.ladder li:nth-child(1) { border-left: 5px solid var(--ok); } .ladder li:nth-child(2) { border-left: 5px solid var(--info); }
.ladder li:nth-child(3) { border-left: 5px solid var(--warn); } .ladder li:nth-child(4) { border-left: 5px solid var(--danger); }

/* ---------- pravidla / tahák ---------- */
.rules { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin: 0 0 1.2em; }
.rule { background: var(--brand); color: #fff; border-radius: var(--radius); padding: 1.2rem 1.2rem 1.1rem; position: relative; overflow: hidden; }
.rule .n { font-family: var(--font-head); font-size: 2.6rem; font-weight: 700; opacity: .25; position: absolute; right: .8rem; top: .2rem; }
.rule strong { display: block; font-family: var(--font-head); font-size: 1.25rem; margin-bottom: .3rem; }
.rule span { opacity: .9; font-size: .93rem; }

.cheat { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; }
.cheat .card h4 { margin-top: 0; text-transform: uppercase; letter-spacing: .06em; font-size: .78rem; color: var(--accent); }
.cheat ul { margin: 0; padding-left: 1.1em; }

/* ---------- copy ---------- */
.copy-btn {
  position: absolute; top: .5rem; right: .5rem; font: 600 .75rem var(--font-sans); background: rgba(255,255,255,.12); color: #fff;
  border: 1px solid rgba(255,255,255,.25); border-radius: 6px; padding: .25rem .55rem; cursor: pointer;
}
.copy-btn:hover { background: rgba(255,255,255,.22); }
.copy-btn.done { background: var(--ok); border-color: var(--ok); }

/* ---------- 404 & drobnosti ---------- */
.empty { text-align: center; padding: 4rem 1rem; color: var(--ink-2); }
details.faq { border: 1px solid var(--line); border-radius: var(--radius-sm); padding: .6rem .9rem; margin-bottom: .6rem; background: var(--bg-elev); }
details.faq summary { cursor: pointer; font-weight: 600; }
details.faq[open] summary { margin-bottom: .5rem; }

/* =====================================================================
   INTERAKTIVNÍ PRVKY (custom elements) – stylizace
   ===================================================================== */
.zit { display: block; margin: 0 0 1.4em; border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg-elev); box-shadow: var(--shadow); overflow: hidden; }
.zit-head { display: flex; align-items: center; gap: .6rem; padding: .7rem 1rem; background: var(--bg-sunk); border-bottom: 1px solid var(--line); font-weight: 600; font-family: var(--font-head); }
.zit-head .ico { font-size: 1.1rem; }
.zit-head .kind { margin-left: auto; font: 600 .7rem var(--font-sans); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-3); }
.zit-body { padding: 1rem; }
.zit-foot { display: flex; gap: .6rem; align-items: center; flex-wrap: wrap; padding: .7rem 1rem; border-top: 1px solid var(--line); background: color-mix(in srgb, var(--bg-sunk) 50%, transparent); }
.zit-result { font-weight: 600; margin-left: auto; }
.zit-result.ok { color: var(--ok); } .zit-result.bad { color: var(--danger); } .zit-result.mid { color: color-mix(in srgb, var(--warn) 60%, var(--ink)); }

/* kvíz */
.q { margin-bottom: 1.2rem; }
.q:last-child { margin-bottom: 0; }
.q .q-text { font-weight: 600; margin-bottom: .5rem; }
.q .q-hint { color: var(--ink-3); font-size: .82rem; font-weight: 400; }
.q .opts { display: grid; gap: .4rem; }
.q .opt {
  display: flex; gap: .6rem; align-items: flex-start; padding: .55rem .8rem; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; background: var(--bg-elev);
  transition: border-color .15s, background .15s;
}
.q .opt:hover { border-color: var(--line-strong); background: var(--bg-sunk); }
.q .opt input { margin-top: .25rem; accent-color: var(--accent); }
.q.checked .opt.correct { border-color: var(--ok); background: var(--ok-soft); }
.q.checked .opt.wrong { border-color: var(--danger); background: var(--danger-soft); }
.q.checked .opt.missed { border-color: var(--ok); border-style: dashed; }
.q .explain { margin-top: .6rem; padding: .6rem .8rem; border-radius: 8px; background: var(--info-soft); font-size: .92rem; display: none; }
.q.checked .explain { display: block; }

/* třídění (drag & drop / klik) */
.sort-wrap { display: grid; gap: 1rem; grid-template-columns: minmax(200px, 1fr) 2fr; }
@media (max-width: 760px) { .sort-wrap { grid-template-columns: 1fr; } }
.sort-pool, .sort-cat { border: 1.5px dashed var(--line-strong); border-radius: 12px; padding: .6rem; min-height: 96px; background: var(--bg-sunk); transition: background .15s, border-color .15s; }
.sort-pool { display: flex; flex-wrap: wrap; gap: .4rem; align-content: flex-start; }
.sort-cats { display: grid; gap: .6rem; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); }
.sort-cat.over, .sort-pool.over { border-color: var(--accent); background: var(--accent-soft); }
.sort-cat.armed { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.sort-cat h5 { margin: 0 0 .45rem; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); display: flex; gap: .4rem; align-items: center; }
.sort-cat .items { display: flex; flex-wrap: wrap; gap: .4rem; min-height: 40px; }
.sort-item {
  display: inline-flex; align-items: center; gap: .4rem; padding: .35rem .65rem; border-radius: 8px; background: var(--bg-elev); border: 1px solid var(--line);
  font-size: .86rem; cursor: grab; user-select: none; box-shadow: var(--shadow); max-width: 100%; transition: transform .1s;
}
.sort-item:hover { transform: translateY(-1px); border-color: var(--line-strong); }
.sort-item.selected { outline: 2px solid var(--accent); outline-offset: 1px; }
.sort-item.dragging { opacity: .5; }
.sort-item.right { border-color: var(--ok); background: var(--ok-soft); }
.sort-item.wrong { border-color: var(--danger); background: var(--danger-soft); }
.sort-item .fi { width: 18px; height: 22px; border-radius: 3px; font-size: .45rem; padding-bottom: 2px; }
.sort-help { font-size: .84rem; color: var(--ink-3); margin: 0 0 .6rem; }
.sort-explain { margin-top: .8rem; display: grid; gap: .3rem; font-size: .88rem; }
.sort-explain div { padding: .4rem .6rem; border-radius: 8px; background: var(--bg-sunk); }
.sort-explain div.wrong { background: var(--danger-soft); }

/* flip karty */
.flip-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: .7rem; margin: 0 0 1.2em; }
zit-flip { display: block; perspective: 900px; min-height: 130px; cursor: pointer; }
zit-flip .inner { position: relative; width: 100%; height: 100%; min-height: 130px; transition: transform .45s; transform-style: preserve-3d; }
zit-flip.flipped .inner { transform: rotateY(180deg); }
zit-flip .face {
  position: absolute; inset: 0; backface-visibility: hidden; border-radius: 12px; padding: .8rem .9rem; border: 1px solid var(--line);
  background: var(--bg-elev); display: grid; place-content: center; text-align: center; box-shadow: var(--shadow);
}
zit-flip .face.front { font-family: var(--font-mono); font-weight: 700; font-size: 1.1rem; }
zit-flip .face.front small { display: block; font: 500 .72rem var(--font-sans); color: var(--ink-3); margin-top: .3rem; }
zit-flip .face.back { transform: rotateY(180deg); font-size: .84rem; background: var(--brand); color: #fff; border-color: transparent; }

/* pojmenování souboru – laboratoř */
.fnlab input {
  width: 100%; font-family: var(--font-mono); font-size: 1rem; padding: .7rem .9rem; border-radius: 10px; border: 1.5px solid var(--line-strong);
  background: var(--bg-sunk); color: var(--ink);
}
.fnlab input:focus { border-color: var(--accent); outline: none; }
.fnlab .checks { list-style: none; padding: 0; margin: .8rem 0 0; display: grid; gap: .3rem; }
.fnlab .checks li { display: flex; gap: .5rem; align-items: baseline; font-size: .9rem; color: var(--ink-2); }
.fnlab .checks li::before { content: "○"; color: var(--ink-3); font-weight: 700; }
.fnlab .checks li.ok { color: var(--ink); } .fnlab .checks li.ok::before { content: "✓"; color: var(--ok); }
.fnlab .checks li.bad::before { content: "✕"; color: var(--danger); }
.fnlab .score { margin-top: .8rem; font-weight: 600; }
.fnlab .examples { display: flex; gap: .4rem; flex-wrap: wrap; margin-top: .6rem; }
.fnlab .examples button { font: .8rem var(--font-mono); background: var(--bg-elev); border: 1px solid var(--line); border-radius: 6px; padding: .25rem .5rem; cursor: pointer; color: var(--ink-2); }

/* tvůrce promptu */
.pb-grid { display: grid; gap: .7rem; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.pb-field label { display: block; font-weight: 700; font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; color: var(--accent); margin-bottom: .25rem; }
.pb-field label small { text-transform: none; letter-spacing: 0; font-weight: 500; color: var(--ink-3); margin-left: .4rem; }
.pb-field textarea {
  width: 100%; min-height: 84px; resize: vertical; padding: .6rem .7rem; border-radius: 8px; border: 1.5px solid var(--line); background: var(--bg-sunk);
  color: var(--ink); font: .9rem var(--font-sans); line-height: 1.45;
}
.pb-field textarea:focus { border-color: var(--accent); outline: none; }
.pb-out { margin-top: 1rem; }
.pb-out pre { max-height: 320px; }

/* audit AI – označování vět */
.audit-text { line-height: 1.9; font-size: 1.02rem; }
.audit-s { padding: .1em .25em; border-radius: 6px; cursor: pointer; border-bottom: 2px dotted var(--line-strong); transition: background .15s; }
.audit-s:hover { background: var(--bg-sunk); }
.audit-s.flag { background: var(--warn-soft); border-bottom-color: var(--warn); }
.audit-s.reveal-bad { background: var(--danger-soft); border-bottom-color: var(--danger); }
.audit-s.reveal-ok { background: var(--ok-soft); border-bottom-color: var(--ok); }
.audit-legend { display: flex; gap: 1rem; flex-wrap: wrap; font-size: .84rem; color: var(--ink-2); margin-top: .6rem; }
.audit-legend span::before { content: ""; display: inline-block; width: .9em; height: .9em; border-radius: 3px; margin-right: .35em; vertical-align: -.1em; }
.audit-legend .l-flag::before { background: var(--warn-soft); border: 1px solid var(--warn); }
.audit-legend .l-bad::before { background: var(--danger-soft); border: 1px solid var(--danger); }
.audit-legend .l-ok::before { background: var(--ok-soft); border: 1px solid var(--ok); }
.audit-reasons { margin-top: .8rem; display: grid; gap: .4rem; }
.audit-reasons div { padding: .5rem .7rem; border-radius: 8px; background: var(--danger-soft); font-size: .9rem; }
.audit-reasons div b { color: var(--danger); }

/* simulátor synchronizace */
.sync-sim .devices { display: grid; grid-template-columns: repeat(3, 1fr); gap: .8rem; margin-bottom: .8rem; }
@media (max-width: 640px) { .sync-sim .devices { grid-template-columns: 1fr; } }
.sync-sim .dev { border: 1px solid var(--line); border-radius: 12px; padding: .8rem; background: var(--bg-sunk); text-align: center; min-height: 120px; }
.sync-sim .dev h5 { margin: 0 0 .5rem; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); }
.sync-sim .dev .doc { display: inline-block; font-family: var(--font-mono); font-size: .82rem; padding: .35rem .6rem; border-radius: 8px; background: var(--bg-elev); border: 1px solid var(--line); transition: all .3s; }
.sync-sim .dev .doc.v2 { border-color: var(--info); background: var(--info-soft); }
.sync-sim .dev .doc.gone { opacity: .35; text-decoration: line-through; }
.sync-sim .dev .doc.none { opacity: .35; border-style: dashed; }
.sync-sim .dev .doc.old { border-color: var(--warn); background: var(--warn-soft); }
.sync-sim .actions { display: flex; gap: .5rem; flex-wrap: wrap; }
.sync-sim .log { margin-top: .8rem; font-size: .9rem; padding: .6rem .8rem; border-radius: 8px; background: var(--info-soft); min-height: 2.6em; }

/* exit ticket */
.exit .field { margin-bottom: .9rem; }
.exit label { display: block; font-weight: 600; margin-bottom: .3rem; }
.exit textarea { width: 100%; min-height: 70px; padding: .6rem .7rem; border-radius: 8px; border: 1.5px solid var(--line); background: var(--bg-sunk); color: var(--ink); font: .95rem var(--font-sans); resize: vertical; }
.exit textarea:focus { border-color: var(--accent); outline: none; }

/* hotovo */
zit-done { display: inline-flex; }
zit-done label { display: inline-flex; gap: .5rem; align-items: center; cursor: pointer; font-weight: 600; padding: .45rem .8rem; border-radius: 10px; border: 1px solid var(--line-strong); background: var(--bg-elev); user-select: none; }
zit-done label:has(input:checked) { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
zit-done input { accent-color: var(--ok); width: 1.1em; height: 1.1em; }

/* reveal */
zit-reveal { display: block; margin: 0 0 1.2em; }
zit-reveal > summary, zit-reveal .rv-btn { display: inline-flex; }
zit-reveal .rv-body { margin-top: .7rem; padding: .9rem 1rem; border-radius: 10px; background: var(--bg-sunk); border: 1px solid var(--line); animation: rise .25s both; }
zit-reveal .rv-body > :last-child { margin-bottom: 0; }

/* ---------- objevení při scrollu ---------- */
html.js .block:not(.in), html.js .reveal:not(.in) { opacity: 0; transform: translateY(14px); }
.block, .reveal { transition: opacity .5s ease, transform .5s ease; }

/* ---------- GIF ---------- */
figure.gif { margin: 0 0 1.2em; }
.gif-frame { position: relative; width: 100%; aspect-ratio: 4 / 3; border-radius: 12px; overflow: hidden; background: var(--bg-sunk); box-shadow: var(--shadow); }
.gif-frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
figure.gif figcaption { font-size: .84rem; color: var(--ink-2); margin-top: .4rem; }
figure.gif .gif-src { color: var(--ink-3); font-size: .74rem; text-decoration: none; margin-left: .3em; }
.side-by-side { display: grid; grid-template-columns: 1fr 260px; gap: 1.2rem; align-items: start; }
@media (max-width: 720px) { .side-by-side { grid-template-columns: 1fr; } }

/* ---------- chaos → pořádek ---------- */
.fs-stage { position: relative; min-height: 180px; }
.fs-chaos { display: flex; flex-wrap: wrap; gap: .5rem; justify-content: center; padding: .4rem; }
.fs-file { transform: rotate(var(--r)); animation: jitter 3s ease-in-out infinite; animation-delay: var(--d); width: 108px; }
.fs-chaos.fs-gone { display: contents; }
@keyframes jitter { 0%, 100% { translate: 0 0; } 30% { translate: 1px -2px; } 60% { translate: -1px 1px; } }
.fs-folders { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: .6rem; }
.fs-folder { border: 1px solid var(--line); border-radius: 12px; padding: .6rem; background: var(--bg-sunk); min-height: 70px; }
.fs-folder-name { font: 600 .82rem var(--font-mono); color: var(--ink-2); margin-bottom: .4rem; }
.fs-folder-items { display: flex; flex-wrap: wrap; gap: .4rem; }
.fs-folder-items .fs-file { animation: none; width: auto; display: inline-flex; align-items: center; gap: .35rem; padding: .3rem .5rem; font-size: .74rem; }
.fs-folder-items .fs-file .fi { width: 18px; height: 22px; font-size: .45rem; padding-bottom: 2px; }
.fs-caption { margin: .9rem 0 0; color: var(--ink-2); }
.fs-caption:empty { display: none; }

/* ---------- psací stroj ---------- */
.tw { display: grid; gap: .5rem; padding: 1rem 1.1rem; border-radius: var(--radius); background: #0f172a; color: #e2e8f0; margin: 0 0 1.2em; }
.tw-row { display: grid; grid-template-columns: 92px 1fr; gap: .8rem; align-items: center; min-height: 1.8em; }
.tw-tag { font: 700 .68rem var(--font-sans); text-transform: uppercase; letter-spacing: .06em; padding: .2em .5em; border-radius: 6px; text-align: center; }
.tw-tag.bad { background: var(--danger); color: #fff; } .tw-tag.ok { background: var(--ok); color: #fff; }
.tw-text { background: none; padding: 0; font-size: 1rem; word-break: break-all; }
.tw-text.typing::after { content: "▍"; animation: blink 1s steps(1) infinite; }
.tw-bad { color: #fca5a5; } .tw-good { color: #86efac; }
@keyframes blink { 50% { opacity: 0; } }

/* ---------- chat s AI ---------- */
.chat { display: grid; gap: .8rem; }
.chat-user, .chat-ai { display: grid; grid-template-columns: 34px 1fr; gap: .6rem; align-items: start; }
.chat-who { width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; font: 700 .72rem var(--font-sans); background: var(--bg-sunk); color: var(--ink-2); }
.chat-ai .chat-who { background: var(--violet-soft); color: var(--violet); }
.chat-bubble { padding: .7rem .9rem; border-radius: 12px; background: var(--bg-sunk); line-height: 1.75; }
.chat-user .chat-bubble { background: var(--info-soft); }
.ai-s { padding: .05em .15em; border-radius: 5px; position: relative; }
.ai-s.reveal-bad { background: var(--danger-soft); box-shadow: inset 0 -2px 0 var(--danger); }
.ai-s.reveal-ok { background: var(--ok-soft); }
.stamp { display: inline-grid; place-items: center; width: 1.3em; height: 1.3em; border-radius: 50%; background: var(--danger); color: #fff; font: 700 .7rem var(--font-sans); margin-left: .25em; vertical-align: .15em; animation: pop .35s both; }
@keyframes pop { from { transform: scale(0); } 70% { transform: scale(1.25); } to { transform: scale(1); } }
.cursor::after { content: "▍"; animation: blink 1s steps(1) infinite; color: var(--ink-3); }

/* ---------- příběh povodně ---------- */
.story-line { list-style: none; padding: 0; margin: 0 0 1.2em; display: grid; gap: .35rem; }
.story-line li { display: grid; grid-template-columns: 110px 1fr; gap: .8rem; padding: .5rem .7rem; border-radius: 10px; background: var(--bg-elev); border: 1px solid var(--line); font-size: .93rem; }
.story-line li time { font-family: var(--font-mono); font-size: .8rem; color: var(--ink-2); }
.story-line li.is-open { border-color: var(--danger); }

/* tisk */
@media print {
  .site-header, .site-footer, .lecture-toc, .lecture-actions, .zit-foot, .copy-btn, .nav-toggle, zit-done { display: none !important; }
  body { background: #fff; color: #000; }
  .lecture-layout { grid-template-columns: 1fr; }
  .card, .zit, .callout { box-shadow: none; break-inside: avoid; }
  a { color: inherit; text-decoration: none; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } html { scroll-behavior: auto; } }