/* ============================================================
   VKThermo pages: shared stylesheet
   Matches the petrziegner.cz site system (see index.html / contact.html).
   ============================================================ */

:root {
    --bg:          #07090f;
    --bg-card:     #0f1421;
    --bg-card-alt: #111828;
    --cyan:        #00e5ff;
    --cyan-dim:    rgba(0,229,255,.08);
    --cyan-mid:    rgba(0,229,255,.18);
    --cyan-glow:   rgba(0,229,255,.35);
    --purple:      #a855f7;
    --purple-dim:  rgba(168,85,247,.12);
    --green:       #22d3a0;
    --gold:        #f5c542;
    --silver:      #cdd5df;
    --bronze:      #d38b5d;
    --white:       #f1f5f9;
    --muted:       #8695aa;
    --faint:       #3d4a5a;
    --border:      rgba(255,255,255,.07);
    --border-c:    rgba(0,229,255,.25);
    --nav-h:       68px;
    --max-w:       1200px;
    --radius:      12px;
    --mono:        'JetBrains Mono', 'Fira Code', monospace;
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--white);
    overflow-x: hidden;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}
::-webkit-scrollbar { width: 0; height: 0; }
* { scrollbar-width: none; }
#custom-scrollbar { position: fixed; top: 0; right: 0; width: 5px; height: 100%; z-index: 9999; pointer-events: none; }
#custom-scrollbar-thumb {
    position: absolute; right: 0; width: 5px; border-radius: 3px;
    background: rgba(0,229,255,.4); opacity: 0; transition: opacity .6s ease;
}
a { text-decoration: none; color: inherit; }
img { display: block; max-width: 100%; }
ul { list-style: none; }

/* ── Canvas ── */
#particles { position: fixed; inset: 0; z-index: 0; pointer-events: none; }

/* ── Nav ── */
#nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 900; height: var(--nav-h);
    display: flex; align-items: center; padding: 0 clamp(1.5rem,5%,3.5rem);
    background: rgba(7,9,15,.7);
    backdrop-filter: blur(20px) saturate(160%); -webkit-backdrop-filter: blur(20px) saturate(160%);
    border-bottom: 1px solid var(--border); transition: background .3s, box-shadow .3s;
}
#nav.solid { background: rgba(7,9,15,.95); box-shadow: 0 4px 40px rgba(0,0,0,.6); }
.nav-brand { display: flex; align-items: center; gap: 11px; }
.nav-brand img { height: 54px; width: auto; filter: drop-shadow(0 0 6px var(--cyan-glow)); }
.nav-name { font-family: 'Oxanium', sans-serif; font-size: 1rem; font-weight: 500; letter-spacing: .15em; color: var(--white); }
.nav-links { display: flex; gap: 2.2rem; margin-left: auto; }
.nav-links a { font-size: .85rem; font-weight: 500; color: var(--muted); letter-spacing: .03em; position: relative; transition: color .2s; }
.nav-links a::after { content: ''; position: absolute; bottom: -5px; left: 0; width: 0; height: 1px; background: var(--cyan); transition: width .3s; }
.nav-links a:hover, .nav-links a.active { color: var(--cyan); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-menu-btn { display: none; flex-direction: column; gap: 5px; margin-left: auto; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-menu-btn span { display: block; width: 22px; height: 2px; background: var(--white); border-radius: 2px; }

/* ── Main ── */
#main { position: relative; z-index: 1; min-height: 100vh; padding: calc(var(--nav-h) + 4rem) clamp(1.5rem,5%,3.5rem) 5rem; overflow: hidden; overflow-anchor: none; }
#main::before {
    content: ''; position: absolute; top: 8%; left: -8%; width: 560px; height: 560px; border-radius: 50%;
    background: radial-gradient(circle, rgba(0,229,255,.05) 0%, transparent 65%); pointer-events: none;
}
#main::after {
    content: ''; position: absolute; bottom: 10%; right: 5%; width: 460px; height: 460px; border-radius: 50%;
    background: radial-gradient(circle, rgba(168,85,247,.05) 0%, transparent 65%); pointer-events: none;
}
.main-inner { position: relative; z-index: 1; width: 100%; max-width: var(--max-w); margin: 0 auto; }

/* ── Page header ── */
.page-h1 { font-family: 'Science Gothic', sans-serif; font-size: clamp(2.4rem, 4.6vw, 3.8rem); font-weight: 400; line-height: 1.05; letter-spacing: .01em; color: var(--white); margin-bottom: .9rem; }
.page-desc { font-size: .96rem; color: var(--muted); line-height: 1.78; max-width: 640px; margin-bottom: 2rem; }
.page-updated { font-family: var(--mono); font-size: .72rem; color: var(--faint); letter-spacing: .05em; margin-bottom: 1.4rem; }

/* ── Hero (index page) ── */
.vk-hero-row { display: flex; align-items: center; gap: 1.6rem; margin-bottom: 1.2rem; }
.vk-hero-logo {
    width: 84px; height: 84px; border-radius: 20px; flex-shrink: 0;
    box-shadow: 0 8px 30px rgba(0,0,0,.45), 0 0 0 1px var(--border);
}
.vk-hero-row .page-h1 { margin-bottom: 0; }

/* ── App Store badge (placeholder) ── */
.vk-appstore-badge {
    display: inline-flex; align-items: center; gap: .65rem; background: #000; color: #fff;
    border: 1px solid rgba(255,255,255,.15); border-radius: 10px; padding: .55rem 1.2rem .55rem 1rem;
    opacity: .8; cursor: default; user-select: none; margin-bottom: 2rem;
}
.vk-appstore-badge-text { display: flex; flex-direction: column; line-height: 1.2; }
.vk-appstore-badge-top { font-size: .62rem; letter-spacing: .04em; color: #cfcfcf; }
.vk-appstore-badge-main { font-size: 1rem; font-weight: 600; font-family: -apple-system, 'Inter', sans-serif; }

/* ── Screenshots ── */
.vk-screens-row { display: flex; gap: 1rem; overflow-x: auto; padding: .2rem .2rem 1rem; }
.vk-screen {
    flex: 0 0 190px; aspect-ratio: 9 / 19.5; border-radius: 26px; border: 1px solid var(--border);
    background: var(--bg-card); position: relative; overflow: hidden; padding: 0; cursor: pointer;
    display: block; font: inherit; transition: border-color .2s, transform .2s;
}
.vk-screen:hover, .vk-screen:focus-visible { border-color: var(--border-c); transform: translateY(-3px); }
.vk-screen img { width: 100%; height: 100%; object-fit: cover; display: block; }
.vk-screen-expand {
    position: absolute; right: .6rem; bottom: .6rem; width: 28px; height: 28px; border-radius: 50%;
    background: rgba(7,9,15,.65); border: 1px solid var(--border); color: var(--white);
    display: flex; align-items: center; justify-content: center; opacity: .75;
    backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
    transition: opacity .2s, border-color .2s, color .2s;
}
.vk-screen:hover .vk-screen-expand, .vk-screen:focus-visible .vk-screen-expand { opacity: 1; border-color: var(--border-c); color: var(--cyan); }

/* ── Screenshot lightbox ── */
.vk-lightbox {
    position: fixed; inset: 0; z-index: 10000; display: none; align-items: center; justify-content: center;
    background: rgba(4,5,9,.92); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    padding: 4rem 1.5rem; opacity: 0; transition: opacity .25s ease;
}
.vk-lightbox.show { display: flex; opacity: 1; }
.vk-lightbox img {
    max-width: min(90vw, 520px); max-height: 86vh; width: auto; height: auto; border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,.6), 0 0 0 1px var(--border-c);
    transform: scale(.96); transition: transform .25s ease;
}
.vk-lightbox.show img { transform: scale(1); }
.vk-lightbox-close {
    position: absolute; top: 1.4rem; right: 1.4rem; width: 42px; height: 42px; border-radius: 50%;
    background: rgba(255,255,255,.06); border: 1px solid var(--border); color: var(--white);
    display: flex; align-items: center; justify-content: center; cursor: pointer;
    transition: border-color .2s, color .2s, background .2s;
}
.vk-lightbox-close:hover { border-color: var(--border-c); color: var(--cyan); background: rgba(0,229,255,.08); }

@media (max-width: 560px) {
    .vk-hero-row { gap: 1.1rem; }
    .vk-hero-logo { width: 62px; height: 62px; border-radius: 15px; }
}

/* ── Sub-nav (Privacy / Support / Donate) ── */
.vk-subnav { display: flex; gap: .6rem; flex-wrap: wrap; margin-bottom: 3.2rem; }
.vk-subnav a {
    font-size: .82rem; font-weight: 600; color: var(--muted); padding: .55rem 1.1rem;
    border: 1px solid var(--border); border-radius: 100px; transition: all .2s; background: var(--bg-card);
}
.vk-subnav a:hover { color: var(--cyan); border-color: var(--border-c); }
.vk-subnav a.active { color: var(--bg); background: var(--cyan); border-color: var(--cyan); }

/* ── Sliding sub-nav panels ── */
.vk-panels { position: relative; overflow-anchor: none; }
.vk-panels.vk-sliding { overflow: hidden; transition: height .5s cubic-bezier(.65,0,.35,1); }
.vk-panel { width: 100%; }
.vk-panel.vk-sliding { position: absolute; top: 0; left: 0; transition: transform .5s cubic-bezier(.65,0,.35,1); will-change: transform; }

/* ── Prose / content sections ── */
.vk-section { margin-bottom: 2.6rem; }
.vk-section h2 {
    font-family: 'Science Gothic', sans-serif; font-weight: 400; font-size: 1.5rem;
    color: var(--white); margin-bottom: .9rem; letter-spacing: .01em;
}
.vk-section p { font-size: .92rem; color: var(--muted); line-height: 1.8; margin-bottom: .9rem; max-width: 720px; }
.vk-section ul { margin: 0 0 .9rem 0; max-width: 720px; }
.vk-section li { font-size: .92rem; color: var(--muted); line-height: 1.8; padding-left: 1.4rem; position: relative; margin-bottom: .4rem; }
.vk-section li::before { content: ''; position: absolute; left: 0; top: .7rem; width: 6px; height: 6px; border-radius: 50%; background: var(--cyan); opacity: .6; }
.vk-section strong { color: var(--white); font-weight: 600; }
.vk-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 1.6rem 1.8rem; max-width: 760px;
}
.vk-callout {
    background: var(--cyan-dim); border: 1px solid var(--border-c); border-radius: var(--radius);
    padding: 1.2rem 1.5rem; max-width: 760px; font-size: .9rem; color: var(--white); line-height: 1.7;
}
.vk-callout strong { color: var(--cyan); }

/* ── Email / contact-form buttons (reused from /contact) ── */
.methods { display: flex; flex-direction: column; gap: .8rem; max-width: 420px; }
.c-method {
    display: flex; align-items: center; gap: 1.2rem; padding: 1rem 1.3rem;
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    cursor: pointer; width: 100%; max-width: 420px; text-align: left; font: inherit; color: inherit;
    transition: border-color .2s, background .2s, transform .2s;
}
.c-method:hover { border-color: var(--border-c); background: rgba(0,229,255,.04); transform: translateX(4px); }
.c-method-icon {
    width: 42px; height: 42px; border-radius: 10px; flex-shrink: 0;
    background: var(--cyan-dim); border: 1px solid var(--border-c);
    display: flex; align-items: center; justify-content: center; color: var(--cyan);
}
.c-method-body { flex: 1; min-width: 0; }
.c-method-lbl { font-family: var(--mono); font-size: .62rem; letter-spacing: .12em; text-transform: uppercase; color: var(--faint); margin-bottom: .15rem; }
.c-method-val { font-size: .92rem; font-weight: 600; color: var(--white); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.c-method-arrow { flex-shrink: 0; color: var(--faint); transition: color .2s; }
.c-method:hover .c-method-arrow { color: var(--cyan); }

/* ── FAQ ── */
.vk-faq-item { border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-card); margin-bottom: .8rem; max-width: 760px; overflow: hidden; }
.vk-faq-q {
    display: flex; align-items: center; justify-content: space-between; gap: 1rem;
    padding: 1.05rem 1.3rem; cursor: pointer; font-size: .92rem; font-weight: 600; color: var(--white);
    background: none; border: none; width: 100%; text-align: left; font-family: inherit;
}
.vk-faq-q svg { flex-shrink: 0; color: var(--cyan); transition: transform .25s; }
.vk-faq-item.open .vk-faq-q svg { transform: rotate(45deg); }
.vk-faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.vk-faq-a-inner { padding: 0 1.3rem 1.15rem; font-size: .88rem; color: var(--muted); line-height: 1.75; }
.vk-faq-a-inner code {
    font-family: var(--mono); font-size: .85em; color: var(--cyan);
    background: rgba(0,229,255,.08); padding: .1em .4em; border-radius: 4px;
}
.vk-faq-item.open .vk-faq-a { max-height: 900px; }

/* ── Form ── */
.vk-form { max-width: 620px; }
.vk-form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 1.1rem; }
.vk-field { margin-bottom: 1.1rem; }
.vk-field label { display: block; font-family: var(--mono); font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; color: var(--faint); margin-bottom: .5rem; }
.vk-field input[type="text"],
.vk-field input[type="email"],
.vk-field select,
.vk-field textarea {
    width: 100%; background: var(--bg-card); border: 1px solid var(--border); border-radius: 8px;
    padding: .75rem .95rem; color: var(--white); font-family: inherit; font-size: .9rem;
    transition: border-color .2s, background .2s;
}
.vk-field select { cursor: pointer; }
.vk-field textarea { resize: vertical; min-height: 140px; line-height: 1.6; }
.vk-field input:focus, .vk-field select:focus, .vk-field textarea:focus {
    outline: none; border-color: var(--border-c); background: rgba(0,229,255,.03);
}
.vk-field input::placeholder, .vk-field textarea::placeholder { color: var(--faint); }
.vk-hp { position: absolute; left: -9999px; top: -9999px; width: 1px; height: 1px; opacity: 0; overflow: hidden; }
.vk-submit-btn {
    display: inline-flex; align-items: center; gap: .6rem; padding: .85rem 1.8rem;
    background: var(--cyan); color: #041014; border: none; border-radius: 8px;
    font-family: inherit; font-size: .88rem; font-weight: 700; letter-spacing: .02em;
    cursor: pointer; transition: transform .15s, box-shadow .15s;
}
.vk-submit-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(0,229,255,.25); }
.vk-submit-btn:disabled { opacity: .55; cursor: default; transform: none; box-shadow: none; }
.vk-form-note { font-size: .78rem; color: var(--faint); margin-top: .8rem; }

/* ── Donation methods ── */
.vk-donate-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 1rem; max-width: 900px; margin-bottom: .5rem; }
.vk-donate-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.4rem 1.5rem; }
.vk-donate-card-lbl { font-family: var(--mono); font-size: .65rem; letter-spacing: .12em; text-transform: uppercase; color: var(--cyan); margin-bottom: .7rem; display: flex; align-items: center; gap: .5rem; }
.vk-donate-value {
    font-family: var(--mono); font-size: .84rem; color: var(--white); word-break: break-all;
    background: rgba(255,255,255,.03); border: 1px solid var(--border); border-radius: 6px;
    padding: .6rem .7rem; cursor: pointer; transition: border-color .2s;
}
.vk-donate-value:hover { border-color: var(--border-c); }
.vk-kofi-btn {
    display: inline-flex; align-items: center; gap: .5rem; background: var(--cyan); color: #041014;
    font-weight: 700; font-size: .85rem; padding: .65rem 1.2rem; border-radius: 8px; transition: transform .15s;
}
.vk-kofi-btn:hover { transform: translateY(-1px); }

/* ── Feature grid ── */
.vk-feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; max-width: 980px; }
.vk-feature-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.4rem 1.5rem; }
.vk-feature-card-icon {
    width: 40px; height: 40px; border-radius: 10px; background: var(--cyan-dim); border: 1px solid var(--border-c);
    display: flex; align-items: center; justify-content: center; color: var(--cyan); margin-bottom: 1rem;
}
.vk-feature-card h3 { font-size: 1rem; font-weight: 700; color: var(--white); margin-bottom: .5rem; }
.vk-feature-card p { font-size: .85rem; color: var(--muted); line-height: 1.7; margin: 0; }

/* ── Steps ── */
.vk-steps { counter-reset: vk-step; display: flex; flex-direction: column; gap: .9rem; max-width: 720px; }
.vk-step { display: flex; gap: 1.1rem; align-items: flex-start; }
.vk-step-num {
    counter-increment: vk-step; flex-shrink: 0; width: 30px; height: 30px; border-radius: 50%;
    background: var(--cyan-dim); border: 1px solid var(--border-c); color: var(--cyan);
    display: flex; align-items: center; justify-content: center; font-family: var(--mono); font-size: .8rem; font-weight: 700;
}
.vk-step-num::before { content: counter(vk-step); }
.vk-step-body { padding-top: .2rem; }
.vk-step-body strong { display: block; color: var(--white); font-size: .92rem; margin-bottom: .2rem; }
.vk-step-body span { font-size: .85rem; color: var(--muted); line-height: 1.65; }

/* ── Spec table ── */
.vk-spec-table { width: 100%; max-width: 720px; border-collapse: collapse; font-size: .87rem; }
.vk-spec-table td { padding: .65rem 0; border-bottom: 1px solid var(--border); color: var(--muted); vertical-align: top; line-height: 1.6; }
.vk-spec-table td:first-child { color: var(--white); font-weight: 600; width: 200px; padding-right: 1.5rem; }
.vk-spec-table tr:last-child td { border-bottom: none; }

/* ── Hall of Fame ── */
.vk-hof-list { display: flex; flex-direction: column; gap: .6rem; max-width: 620px; }
.vk-hof-row {
    display: flex; align-items: center; gap: 1rem; background: var(--bg-card); border: 1px solid var(--border);
    border-radius: 10px; padding: .8rem 1.1rem;
}
.vk-hof-rank {
    width: 34px; height: 34px; border-radius: 50%; display: flex; align-items: center; justify-content: center;
    font-family: var(--mono); font-size: .78rem; font-weight: 700; flex-shrink: 0;
    background: rgba(255,255,255,.04); color: var(--muted); border: 1px solid var(--border);
}
.vk-hof-row.gold .vk-hof-rank   { background: rgba(245,197,66,.15); color: var(--gold); border-color: rgba(245,197,66,.4); font-size: 1.1rem; }
.vk-hof-row.silver .vk-hof-rank { background: rgba(205,213,223,.15); color: var(--silver); border-color: rgba(205,213,223,.4); font-size: 1.1rem; }
.vk-hof-row.bronze .vk-hof-rank { background: rgba(211,139,93,.15); color: var(--bronze); border-color: rgba(211,139,93,.4); font-size: 1.1rem; }
.vk-hof-name { flex: 1; font-size: .92rem; font-weight: 600; color: var(--white); }
.vk-hof-amount { font-family: var(--mono); font-size: .88rem; color: var(--cyan); font-weight: 700; }
.vk-hof-empty { font-size: .88rem; color: var(--faint); padding: 1rem 0; }

/* ── Footer ── */
#footer { position: relative; z-index: 1; border-top: 1px solid var(--border); }
.footer-inner { max-width: var(--max-w); margin: 0 auto; padding: 3.5rem clamp(1.5rem,5%,3.5rem) 2.5rem; }
.footer-bottom { display: flex; align-items: center; justify-content: space-between; }
.footer-copy { font-size: .78rem; color: #637A8D; }

/* ── Toast ── */
#pz-toast {
    position: fixed; bottom: 2rem; left: 50%; transform: translateX(-50%) translateY(12px);
    background: rgba(7,9,15,.92); border: 1px solid rgba(0,229,255,.35); color: var(--cyan);
    font-family: var(--mono); font-size: .72rem; font-weight: 600; letter-spacing: .12em;
    text-transform: uppercase; padding: .55rem 1.3rem; border-radius: 6px;
    backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 4px 20px rgba(0,229,255,.1); opacity: 0; transition: opacity .25s, transform .25s;
    pointer-events: none; z-index: 9999; white-space: nowrap;
}
#pz-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
#pz-toast.error { border-color: rgba(248,81,73,.45); color: #f87171; }

/* ── Reveal ── */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .65s ease, transform .65s ease; }
.reveal.d1 { transition-delay: .1s; }
.reveal.d2 { transition-delay: .2s; }
.reveal.in { opacity: 1; transform: none; }

/* ── Responsive ── */
@media (max-width: 800px) {
    .nav-links { display: none; }
    .nav-menu-btn { display: flex; }
}
@media (max-width: 640px) {
    .page-h1 { font-size: 2.1rem; }
    .vk-subnav {
        flex-wrap: nowrap; overflow-x: auto; -webkit-overflow-scrolling: touch;
        gap: clamp(.4rem, .14rem + 1.14vw, .6rem); margin-bottom: 2.4rem; padding-bottom: .2rem;
    }
    .vk-subnav a {
        flex: 0 0 auto; white-space: nowrap;
        font-size: clamp(.76rem, .68rem + .34vw, .82rem);
        padding: clamp(.5rem, .44rem + .29vw, .55rem) clamp(.75rem, .3rem + 2vw, 1.1rem);
    }
    .vk-form-row { grid-template-columns: 1fr; gap: 0; }
    .footer-bottom { flex-direction: column; gap: 1rem; text-align: center; align-items: center; }
    .vk-donate-grid { grid-template-columns: 1fr; }
    .vk-spec-table, .vk-spec-table tbody, .vk-spec-table tr, .vk-spec-table td { display: block; width: auto; }
    .vk-spec-table tr { padding: .65rem 0; border-bottom: 1px solid var(--border); }
    .vk-spec-table td { border-bottom: none; padding: 0; }
    .vk-spec-table td:first-child { padding-bottom: .25rem; }
    .vk-spec-table tr:last-child { border-bottom: none; }
}