/* ChciHry.cz — Hra 2048. Standalone styl (bez styles.css/normalize.css).
 * Tokeny převzaty z vizuální identity webu. Animace pouze transform/opacity.
 * V klidu 0 % CPU: žádná trvalá smyčka, jen událostní transition/animation. */

/* reset, @font-face fallback a sdilene tokeny: viz css/tokens.css (nacist PRED timto souborem) */
:root {

    /* deska */
    --n: 4;
    --board: min(100vw - 1rem, 58svh);
    --gap: clamp(5px, calc(var(--board) * 0.025), 16px);
    --pad: var(--gap);
    --cell: calc((var(--board) - 2 * var(--pad) - (var(--n) - 1) * var(--gap)) / var(--n));
    --step: calc(var(--cell) + var(--gap));

    /* dlaždice — teplá cream→gold progrese, tmavý inkoust kvůli kontrastu ≥4.5:1 */
    --tile-ink: #2A2010;
    --slide: 110ms;
}

html { height: 100%; }

body {
    font-family: 'Montserrat', 'Montserrat-fallback', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--surface-dark);
    color: var(--text-primary);
    min-height: 100svh;
    overflow-x: hidden;
    background-image:
        radial-gradient(circle at 18% 12%, rgba(212, 175, 55, 0.07) 0%, transparent 45%),
        radial-gradient(circle at 85% 85%, rgba(212, 175, 55, 0.05) 0%, transparent 50%);
}

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
svg { display: block; }

.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---------- layout (shell = container) ---------- */
.shell {
    container-type: inline-size;
    container-name: app;
    padding: max(0.5rem, env(safe-area-inset-top)) max(0.5rem, env(safe-area-inset-right))
             0.5rem max(0.5rem, env(safe-area-inset-left));
}
.app {
    display: grid;
    grid-template-areas: "head" "board" "panel";
    justify-items: center;
    gap: clamp(0.4rem, 1.2dvh, 1rem);
    max-width: 1400px;
    margin: 0 auto;
}
.hd { grid-area: head; text-align: center; min-width: 0; width: 100%; }
.hd h1 {
    font-size: clamp(1.15rem, 4.4vw, 2rem);
    font-weight: 900;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--primary) 0%, #F5E6D3 55%, var(--primary-dark) 100%);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent; color: transparent;
}
.hd .h1-sub { font-weight: 600; font-size: 0.72em; white-space: nowrap; }
.status {
    margin-top: 0.2rem;
    font-size: clamp(0.82rem, 2.6vw, 1.02rem);
    font-weight: 600;
    color: var(--text-secondary);
    min-height: 1.4em;
}
.status.is-win { color: var(--primary); }
.status.is-over { color: var(--danger); }

/* ---------- HUD: skóre ---------- */
.hud {
    display: flex; gap: 0.5rem; justify-content: center; flex-wrap: wrap;
    margin-top: 0.4rem;
}
.score-box {
    position: relative;
    min-width: 5.2rem;
    padding: 0.35rem 0.9rem 0.45rem;
    background: linear-gradient(135deg, rgba(212, 175, 55, 0.12), rgba(212, 175, 55, 0.04));
    border: 1px solid var(--gold-border);
    border-radius: var(--radius-lg);
    text-align: center;
    line-height: 1.1;
}
.score-box .label {
    display: block;
    font-size: 0.62rem; font-weight: 700; letter-spacing: 0.08em;
    text-transform: uppercase; color: var(--text-muted);
}
.score-box .val {
    display: block;
    font-size: clamp(1.05rem, 3.4vw, 1.45rem); font-weight: 800;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}
.score-box.is-best .val { color: var(--primary); }
/* plovoucí +N nad skórem */
.gain {
    position: absolute; left: 50%; top: 0.2rem;
    transform: translateX(-50%);
    font-weight: 800; font-size: 0.95rem; color: var(--success);
    pointer-events: none;
    animation: gainFloat 700ms ease-out forwards;
}
@keyframes gainFloat {
    0% { opacity: 0; transform: translate(-50%, 0); }
    18% { opacity: 1; }
    100% { opacity: 0; transform: translate(-50%, -1.5rem); }
}

/* ---------- deska ---------- */
.board-zone { grid-area: board; min-width: 0; }
.board-wrap {
    position: relative;
    width: var(--board); height: var(--board);
    box-sizing: border-box;
    border-radius: var(--radius-lg);
    background: linear-gradient(150deg, rgba(15, 23, 42, 0.92), rgba(2, 6, 23, 0.92));
    outline: 3px solid var(--primary-dark);
    outline-offset: -3px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.55), 0 0 60px rgba(212, 175, 55, 0.08),
                inset 0 0 0 1px rgba(212, 175, 55, 0.18);
    /* none: řeší dvojklik-zoom A umožní swipe bez scrollu stránky */
    touch-action: none;
    -webkit-user-select: none; user-select: none;
}
.board-wrap:focus { outline-color: var(--primary); }
.board-wrap:focus-visible { outline: 3px solid var(--primary); outline-offset: -3px; }

.grid-bg, .tiles { position: absolute; inset: var(--pad); }
.grid-bg {
    display: grid;
    grid-template-columns: repeat(var(--n), 1fr);
    grid-template-rows: repeat(var(--n), 1fr);
    gap: var(--gap);
}
.cell {
    border-radius: calc(var(--radius-sm) + 1px);
    background: rgba(248, 250, 252, 0.045);
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.25);
}

/* ---------- dlaždice ---------- */
.tiles { pointer-events: none; }
.tile {
    position: absolute; left: 0; top: 0;
    width: var(--cell); height: var(--cell);
    transform: translate(calc(var(--c) * var(--step)), calc(var(--r) * var(--step)));
    transition: transform var(--slide) ease-out;
    will-change: transform;
}
.tv {
    width: 100%; height: 100%;
    display: flex; align-items: center; justify-content: center;
    border-radius: calc(var(--radius-sm) + 1px);
    font-weight: 800;
    color: var(--tile-ink);
    font-variant-numeric: tabular-nums;
    line-height: 1;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.28);
}
.tile.pop .tv { animation: pop 150ms ease; }
.tile.appear .tv { animation: appear 160ms ease; }
@keyframes pop {
    0% { transform: scale(1); }
    55% { transform: scale(1.14); }
    100% { transform: scale(1); }
}
@keyframes appear {
    0% { transform: scale(0); opacity: 0; }
    70% { opacity: 1; }
    100% { transform: scale(1); }
}

/* paleta dlaždic (cream → gold), tmavý inkoust — klíčováno na .tv (data-v),
 * aby ji sdílela hra i názorná ukázka v obsahu (.demo) — DRY, jeden zdroj barev */
.tv[data-v="2"]    { background: linear-gradient(150deg, #EFE7D6, #E5DBC4); }
.tv[data-v="4"]    { background: linear-gradient(150deg, #F0E1C0, #E7D2A6); }
.tv[data-v="8"]    { background: linear-gradient(150deg, #F6D69E, #F1C57E); }
.tv[data-v="16"]   { background: linear-gradient(150deg, #F8C77C, #F4B45E); }
.tv[data-v="32"]   { background: linear-gradient(150deg, #FBBA5E, #F7A53F); }
.tv[data-v="64"]   { background: linear-gradient(150deg, #FBAC44, #F59928); }
.tv[data-v="128"]  { background: linear-gradient(150deg, #F7CB4C, #F0BB1F); }
.tv[data-v="256"]  { background: linear-gradient(150deg, #F5CE3C, #EEBE12); }
.tv[data-v="512"]  { background: linear-gradient(150deg, #F3D224, #ECC40A); }
.tv[data-v="1024"] { background: linear-gradient(150deg, #F1D40D, #E9C800); }
.tv[data-v="2048"] {
    background: linear-gradient(150deg, #FFE16A, var(--primary));
    box-shadow: 0 0 18px rgba(212, 175, 55, 0.75), 0 2px 8px rgba(0, 0, 0, 0.35);
}
.tv[data-v="4096"] { background: linear-gradient(150deg, #7FE3DA, #43C6BA); }
.tv[data-v="8192"] { background: linear-gradient(150deg, #C2ABFF, #9D7CFF); }
.tv.super {
    background: linear-gradient(150deg, #FF9FBD, #F86A98);
    box-shadow: 0 0 16px rgba(248, 106, 152, 0.6), 0 2px 8px rgba(0, 0, 0, 0.35);
}

/* ---------- panel / tlačítka ---------- */
.panel {
    grid-area: panel;
    display: flex; flex-direction: column; align-items: center;
    gap: 0.6rem;
    width: 100%;
    max-width: calc(var(--board) + 0.5rem);
}
.btns {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.45rem;
    width: 100%;
}
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    min-height: 44px; min-width: 44px;
    padding: 0.5rem 0.7rem;
    background: linear-gradient(135deg, rgba(212, 175, 55, 0.12), rgba(212, 175, 55, 0.05));
    border: 1px solid var(--gold-border);
    border-radius: 9999px;
    color: var(--text-primary);
    font-size: 0.8rem; font-weight: 600; letter-spacing: 0.02em;
    transition: border-color 0.15s ease, transform 0.15s ease;
    text-align: center;
}
.btn:hover { border-color: var(--primary); transform: translateY(-1px); }
.btn:focus-visible { outline: 3px solid var(--primary); outline-offset: 2px; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--surface-dark); border-color: var(--primary);
}
.btn-primary:hover { border-color: #F5E6D3; }
.btn[hidden] { display: none; }
.hint-line {
    font-size: 0.74rem; color: var(--text-muted); text-align: center;
    line-height: 1.5; max-width: 22rem;
}
.hint-line kbd {
    font: inherit; font-weight: 700; color: var(--text-secondary);
    background: rgba(248, 250, 252, 0.08);
    border: 1px solid var(--gold-border);
    border-radius: 0.3rem; padding: 0 0.32rem;
}

/* ---------- dialogy ---------- */
dialog.dlg {
    margin: auto;
    max-width: min(92vw, 26rem); width: 100%;
    background: linear-gradient(160deg, rgba(15, 23, 42, 0.97), rgba(2, 6, 23, 0.97));
    color: var(--text-primary);
    border: 1px solid rgba(212, 175, 55, 0.35);
    border-radius: var(--radius-xl);
    padding: 1.3rem;
    box-shadow: 0 25px 70px rgba(0, 0, 0, 0.7), 0 0 90px rgba(212, 175, 55, 0.12);
}
dialog.dlg::backdrop { background: rgba(2, 6, 23, 0.72); backdrop-filter: blur(4px); }
.dlg h2 { font-size: 1.25rem; font-weight: 800; margin-bottom: 0.9rem; color: var(--primary); text-align: center; }
.dlg .dlg-text { color: var(--text-secondary); font-size: 0.95rem; line-height: 1.5; text-align: center; }
.dlg fieldset { border: 0; margin-bottom: 0.9rem; }
.dlg legend { font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); margin-bottom: 0.4rem; }
.seg { display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; gap: 0.4rem; }
.seg label {
    display: flex; align-items: center; justify-content: center;
    min-height: 44px; padding: 0.45rem 0.5rem;
    border: 1px solid var(--gold-border); border-radius: var(--radius-lg);
    background: rgba(30, 41, 59, 0.6);
    font-size: 0.85rem; font-weight: 600; text-align: center; cursor: pointer;
    transition: border-color 0.15s ease, background 0.15s ease;
}
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg input:checked + span { color: var(--primary); }
.seg label:has(input:checked) {
    border-color: var(--primary);
    background: rgba(212, 175, 55, 0.14);
    box-shadow: 0 0 12px rgba(212, 175, 55, 0.25);
}
.seg label:has(input:focus-visible) { outline: 2px solid var(--primary); outline-offset: 2px; }
.dlg-actions { display: flex; gap: 0.5rem; justify-content: center; margin-top: 1.1rem; flex-wrap: wrap; }
.dlg-actions .btn { flex: 1 1 auto; }
.dlg .stats-line { text-align: center; margin-top: 0.7rem; color: var(--text-secondary); font-size: 0.9rem; }
.dlg .result-emoji { display: block; text-align: center; font-size: 2.6rem; margin-bottom: 0.4rem; }

/* ---------- toast ---------- */
.toast {
    position: fixed; left: 50%; bottom: max(1rem, env(safe-area-inset-bottom));
    transform: translateX(-50%);
    display: flex; gap: 0.6rem; align-items: center;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.97), rgba(2, 6, 23, 0.97));
    border: 1px solid rgba(212, 175, 55, 0.4);
    border-radius: 9999px;
    padding: 0.55rem 0.6rem 0.55rem 1rem;
    font-size: 0.85rem; font-weight: 600;
    box-shadow: 0 10px 35px rgba(0, 0, 0, 0.6);
    z-index: 90; opacity: 1;
    transition: opacity 0.3s ease, transform 0.3s ease;
}
.toast[hidden] { display: none; }
.toast.hiding { opacity: 0; transform: translateX(-50%) translateY(10px); }
.toast .btn { min-height: 36px; padding: 0.3rem 0.8rem; font-size: 0.78rem; }

/* ---------- konfety ---------- */
.confetti { position: fixed; inset: 0; pointer-events: none; z-index: 80; }

/* ---------- obsahová sekce (SEO/GEO) ---------- */
.content {
    max-width: 820px; margin: 2.5rem auto 0;
    padding: 0 max(1rem, env(safe-area-inset-right)) 2.5rem max(1rem, env(safe-area-inset-left));
    line-height: 1.65; color: var(--text-secondary);
}
.content .answer-first {
    font-size: 1.02rem; color: var(--text-primary);
    background: rgba(15, 23, 42, 0.85);
    border: 1px solid var(--gold-border);
    border-left: 4px solid var(--primary);
    border-radius: var(--radius-lg);
    padding: 1rem 1.2rem;
}
.content h2 { font-size: clamp(1.25rem, 3.4vw, 1.6rem); font-weight: 800; color: var(--text-primary); margin: 2.2rem 0 0.8rem; }
.content h3 { font-size: 1.05rem; font-weight: 700; color: var(--primary); margin: 1.3rem 0 0.45rem; }
.content p { margin-bottom: 0.8rem; }
.content ul, .content ol { margin: 0 0 0.9rem 1.4rem; }
.content li { margin-bottom: 0.35rem; }
.content strong { color: var(--text-primary); }
.faq-item {
    background: rgba(15, 23, 42, 0.85);
    border: 1px solid var(--gold-border);
    border-radius: var(--radius-lg);
    padding: 0.9rem 1.1rem; margin-bottom: 0.7rem;
}
.faq-item h3 { margin: 0 0 0.4rem; }
.faq-item p { margin: 0; font-size: 0.95rem; }
.more-games { display: flex; flex-wrap: wrap; gap: 0.6rem; margin: 0.8rem 0; }
.more-games a {
    padding: 0.45rem 1rem;
    background: rgba(212, 175, 55, 0.1);
    border: 1px solid var(--gold-border);
    border-radius: 9999px; font-size: 0.875rem; font-weight: 600;
    transition: border-color 0.15s ease, transform 0.15s ease;
}
.more-games a:hover { border-color: var(--primary); transform: translateY(-2px); color: var(--primary); }
.more-games .all { flex-basis: 100%; display: flex; justify-content: center; margin-top: 0.6rem; }
.updated { margin-top: 2rem; font-size: 0.8rem; color: var(--text-muted); }

/* ---------- názorná ukázka v obsahu (statická, bez animace) ---------- */
.demo {
    margin: 1.1rem 0 1.3rem;
    padding: 1rem 1.1rem;
    background: linear-gradient(150deg, rgba(15, 23, 42, 0.92), rgba(2, 6, 23, 0.92));
    border: 1px solid var(--gold-border);
    border-radius: var(--radius-lg);
}
.demo-row { display: flex; align-items: center; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.7rem; }
.demo-ladder { gap: 0.4rem; }
.demo-lbl { flex: 0 0 auto; min-width: 5rem; font-size: 0.78rem; font-weight: 700; color: var(--text-muted); }
.demo-cell { display: inline-flex; width: var(--cell); height: var(--cell); flex: 0 0 auto; }
.demo-op { font-size: 1.1rem; font-weight: 800; color: var(--text-muted); }
.demo-goal { font-size: 0.68rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; color: var(--primary); align-self: center; }
.demo figcaption { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.5; margin-top: 0.2rem; }

/* ---------- responzivita ---------- */
/* tablet a výš: větší deska */
@media (min-width: 768px) {
    :root { --board: min(80svh, 720px); }
}
/* desktop: panel vpravo od desky (container query na shellu) */
@container app (min-width: 1024px) {
    .app {
        grid-template-areas: "head head" "board panel";
        grid-template-columns: auto minmax(220px, 280px);
        align-items: start; justify-content: center;
        justify-items: stretch; column-gap: 1.5rem;
    }
    .hd { justify-self: center; }
    .panel { max-width: none; position: sticky; top: 1rem; align-items: stretch; }
    .btns { grid-template-columns: 1fr; }
}
@media (min-width: 1024px) {
    :root { --board: min(80svh, calc(100vw - 360px), 720px); }
}
/* mobil landscape: deska vlevo, hlavička + ovládání vpravo, bez scrollu */
@media (max-height: 500px) and (orientation: landscape) {
    :root { --board: min(92svh - 1rem, calc(100vw - 250px)); }
    .app {
        grid-template-areas: "board head" "board panel";
        grid-template-columns: auto 1fr;
        grid-template-rows: auto 1fr;
        column-gap: 1rem; align-items: start;
    }
    .hd h1 { font-size: 1rem; }
    .hd .h1-sub { display: block; font-size: 0.7rem; }
    .panel { max-width: 320px; justify-self: center; }
    .btns { grid-template-columns: repeat(3, 1fr); gap: 0.35rem; }
    .btn { min-height: 40px; font-size: 0.72rem; }
    .hint-line { display: none; }
}
/* widescreen / 4K */
@media (min-width: 2560px) {
    :root { --board: min(80svh, 1000px); }
    .content { max-width: 1000px; font-size: 1.1rem; }
}

/* číslo na dlaždici škáluje podle --cell (font-size dopočítává JS přes --fs) */
.tv { font-size: calc(var(--cell) * var(--fs, 0.46)); }

/* ---------- omezený pohyb ---------- */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}