/* TRAS — ateliér architektury a interiérů
   Single-page site. Aesthetic kept: near-black ground, muted grey type,
   architectural restraint, generous emptiness — modernised and responsive. */

:root {
  --bg: #080c0a;
  --panel: #0c110f;
  --fg: #8b8e8c;
  --fg-dim: #55605c;   /* dark-grey secondary — a touch cooler */
  --fg-bright: #c6c8c7;
  --line: #1b201e;
  --accent: #b7b9b8;
  --maxw: 1180px;
  --gap: clamp(30px, 5vw, 60px);
  --gap-top: 16px;     /* opaque breathing room inside the sticky header, below the banner */
  --topbar-h: 190px;   /* sticky header height          — kept current by JS */
  --head-h: 90px;      /* sticky section heading height — kept current by JS */
  --sticky-top: 280px; /* topbar + heading + realizace nav — kept current by JS */
  --font: "Trebuchet MS", "Segoe UI", Tahoma, Verdana, "DejaVu Sans", sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 1rem;          /* 16px base */
  line-height: 1.65;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--fg); text-decoration: none; transition: color .18s ease; }
a:hover, a:focus-visible { color: var(--fg-bright); }
img { display: block; max-width: 100%; height: auto; }
strong { color: var(--fg-bright); font-weight: 700; }

:focus-visible { outline: 1px solid var(--accent); outline-offset: 3px; }

.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;
}

.skip {
  position: fixed; top: 0; left: 0; z-index: 300;
  padding: 12px 18px; background: var(--panel); color: var(--fg-bright);
  transform: translateY(-120%); transition: transform .2s ease;
}
.skip:focus { transform: translateY(0); }

/* ---------- splash ---------- */

#splash {
  position: fixed; inset: 0; z-index: 200;
  background: var(--bg);
  display: grid; place-items: center;
  transition: opacity 3s ease;
}
#splash.is-fading { opacity: 0; }
.splash__inner {
  position: relative; display: block;
  width: min(736px, 88vw);
  animation: fade .8s ease both;
}
.splash__skip {
  position: absolute; right: 6%; bottom: 8%;
  letter-spacing: .3em; font-size: 1.15rem; color: var(--fg-dim);
}
.splash__skip b { color: var(--fg); font-weight: 400; animation: pulse 1.4s ease-in-out infinite; }

/* ---------- sticky header: banner (+ mobile bar) ---------- */

.topbar {
  position: sticky; top: 0; z-index: 40;
  background: var(--bg);
}
.topbar__inner {
  max-width: var(--maxw); margin: 0 auto;
  padding: clamp(14px, 3.5vw, 34px) clamp(18px, 5vw, 60px) var(--gap-top);
}

.banner {
  position: relative;
  height: clamp(88px, 13vw, 144px);
  overflow: hidden;
  background: #050806;
}
.banner__img {
  position: absolute; inset: 0;
  background: url(../img/banner.webp) center 44% / cover no-repeat;
  filter: brightness(.6) contrast(1.05);
}
.banner__spot {
  position: absolute; left: 30%; top: -10%;
  width: clamp(260px, 44vw, 600px); aspect-ratio: 1;
  border-radius: 50%;
  background: hsl(210 90% 60%);
  filter: blur(65px);
  opacity: .82;
  mix-blend-mode: screen;
  pointer-events: none;
  transition: left 5s ease-in-out, top 5s ease-in-out, background-color 5s linear;
}
.banner__veil {
  position: absolute; inset: 0;
  background: linear-gradient(var(--bg), transparent 42%, transparent 58%, var(--bg)),
              rgba(8, 12, 10, .34);
}

.topbar__bar { display: none; }   /* only shown on narrow screens */

/* ---------- shell ---------- */

.page {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 clamp(18px, 5vw, 60px) 72px;
}

.layout {
  display: grid;
  grid-template-columns: 208px minmax(0, 1fr);
  gap: var(--gap);
  align-items: start;
}

/* ---------- navigation ---------- */

.nav {
  position: sticky;
  top: calc(var(--topbar-h) - 1px);
}
.nav__brand { display: none; }

.menu, .menu ul { list-style: none; margin: 0; padding: 0; }
.menu > li { margin: 0 0 .55em; }
.menu a { display: inline-block; padding: 2px 0; }
.menu a.is-active { color: var(--fg-bright); font-weight: 700; }

.menu__section { margin-top: 1.3em !important; }
.menu__label {
  display: block; color: var(--fg-dim);
  font-size: .82rem; letter-spacing: .16em; text-transform: uppercase;
  margin-bottom: .5em;
}
.menu__section ul { margin-left: .1em; }
.menu__section li { margin: .4em 0; }
.menu__section a { font-size: .94rem; }

/* ---------- content ---------- */

.content { min-height: 62vh; scroll-margin-top: calc(var(--topbar-h) + 4px); }
.content:focus { outline: none; }

.view { animation: fade .32s ease both; }

.view__head {
  position: sticky;
  top: calc(var(--topbar-h) - 1px);
  z-index: 15;
  background: var(--bg);
  padding: 0 0 1.1em;
}
.view__title {
  font-size: 1rem; font-weight: 700; color: var(--fg-bright);
  letter-spacing: .07em; margin: 0;
}
.view__head .lede { margin: .35em 0 0; }

.view--text { max-width: 42ch; }
.view[data-view="home"] .lede { max-width: 44ch; }
.view[data-view="obchod"] { max-width: 680px; }
.lede { margin: 0 0 1.4em; }

.contact { font-style: normal; }
.contact p { margin: 0 0 1.15em; }
.contact__meta { color: var(--fg-dim); }

/* ---------- realizace ---------- */

.realizace-body {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 44px);
  align-items: start;
}
.rnav {
  display: flex; flex-direction: column;
  text-align: right;
  min-width: 3em;
  position: sticky;
  top: calc(var(--topbar-h) + var(--head-h, 90px) - 3px);
  z-index: 16;
  background: var(--bg);
}
.rnav a { padding: 1px 0; color: var(--fg-dim); }
.rnav a:hover { color: var(--fg-bright); }
.rnav a.is-active { color: var(--fg-bright); font-weight: 700; }

.rgroups { min-width: 0; }
.rgroup { scroll-margin-top: calc(var(--sticky-top, 240px) - 8px); }
.rgroup + .rgroup { margin-top: clamp(40px, 7vw, 76px); }

/* ---------- gallery grid ---------- */

.grid { columns: 3 230px; column-gap: 12px; }
.grid figure { margin: 0 0 12px; break-inside: avoid; }
.grid button {
  display: block; width: 100%; padding: 0; border: 0; background: none;
  cursor: zoom-in; line-height: 0;
  transition: opacity .18s ease;
}
.grid img { width: 100%; }
.grid button:hover, .grid button:focus-visible { opacity: .8; }

/* ---------- obchod ---------- */

.brands {
  list-style: none; margin: 1.6em 0 0; padding: 0;
  display: grid; gap: 34px 40px;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  max-width: 640px;
}
.brand { display: block; }
.brand__logo {
  height: 26px; width: auto; object-fit: contain; object-position: left center;
  opacity: .5; transition: opacity .18s ease;
}
.brand:hover .brand__logo, .brand:focus-visible .brand__logo { opacity: .95; }
.brand__url {
  display: block; margin-top: 9px;
  font-size: .8rem; color: var(--fg-dim); letter-spacing: .04em;
}
.brand:hover .brand__url { color: var(--fg); }

/* ---------- footer ---------- */

.foot {
  display: flex; justify-content: space-between;
  margin-top: 80px; padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: .8rem; color: var(--fg-dim);
}

/* ---------- modal / lightbox ---------- */

.modal {
  position: fixed; inset: 0; z-index: 150;
  display: flex; align-items: center; justify-content: center;
  padding: clamp(12px, 4vw, 52px);
}
.modal__backdrop { position: absolute; inset: 0; background: rgba(4, 6, 5, .96); }
.modal__stage { position: relative; margin: 0; max-width: 100%; max-height: 100%; }
.modal__img {
  max-width: 92vw; max-height: 84vh; width: auto; height: auto;
  transform-origin: center;
  animation: zoom-in .28s cubic-bezier(.2, .7, .3, 1) both;
}
.modal.is-closing .modal__img { animation: zoom-out .18s ease both; }
.modal__count {
  position: absolute; left: 0; bottom: -1.9em;
  font-size: .78rem; color: var(--fg-dim); letter-spacing: .12em;
}
.modal__close, .modal__nav {
  position: absolute; z-index: 2;
  background: none; border: 0; color: var(--fg);
  cursor: pointer; line-height: 1; transition: color .18s ease;
}
.modal__close:hover, .modal__nav:hover { color: var(--fg-bright); }
.modal__close { top: clamp(10px, 3vw, 30px); right: clamp(10px, 3vw, 30px); font-size: 2rem; }
.modal__nav { top: 50%; transform: translateY(-50%); font-size: 2.8rem; padding: 14px; }
.modal__nav--prev { left: clamp(2px, 2vw, 22px); }
.modal__nav--next { right: clamp(2px, 2vw, 22px); }
body.is-locked { overflow: hidden; }

/* ---------- keyframes ---------- */

@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes pulse { 0%, 100% { opacity: .35; } 50% { opacity: 1; } }
@keyframes zoom-in { from { opacity: 0; transform: scale(.72); } to { opacity: 1; transform: scale(1); } }
@keyframes zoom-out { to { opacity: 0; transform: scale(.82); } }

/* ---------- responsive ---------- */

@media (max-width: 860px) {
  .topbar__inner { padding-top: clamp(12px, 4vw, 20px); }
  .banner { height: clamp(76px, 20vw, 116px); }

  .topbar__bar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 9px 0;
  }
  .nav__brand {
    display: block; font-size: 1.05rem; color: var(--fg-bright); letter-spacing: .2em;
  }
  .nav__toggle {
    display: inline-flex; flex-direction: column; align-items: flex-end; justify-content: center;
    width: 40px; height: 30px; padding: 0;
    background: none; border: 0; color: var(--fg); cursor: pointer;
  }
  .nav__toggle span, .nav__toggle span::before, .nav__toggle span::after {
    content: ""; display: block; width: 22px; height: 1px; background: currentColor; position: relative;
    transition: transform .2s ease, top .2s ease, background-color .2s ease;
  }
  .nav__toggle span::before { position: absolute; top: -7px; }
  .nav__toggle span::after  { position: absolute; top: 7px; }
  .nav__toggle[aria-expanded="true"] span { background: transparent; }
  .nav__toggle[aria-expanded="true"] span::before { top: 0; transform: rotate(45deg); }
  .nav__toggle[aria-expanded="true"] span::after  { top: 0; transform: rotate(-45deg); }

  .layout { grid-template-columns: 1fr; gap: 24px; }

  .nav { position: static; }
  .nav.is-open::before {
    content: ""; position: fixed; inset: var(--topbar-h) 0 0 0;
    background: rgba(8, 12, 10, .66); z-index: 38;
  }
  .menu {
    position: fixed; top: var(--topbar-h); left: 0; right: 0; z-index: 39;
    background: var(--bg); border-bottom: 1px solid var(--line);
    padding: 0 clamp(18px, 5vw, 60px);
    max-height: 0; overflow: hidden;
    transition: max-height .28s ease;
  }
  .nav.is-open .menu {
    max-height: calc(100dvh - var(--topbar-h));
    overflow-y: auto; padding-top: 14px; padding-bottom: 22px;
  }
  .menu > li { margin: .15em 0; }
  .menu a { padding: 9px 0; font-size: 1.05rem; }
  .menu__section a { font-size: 1rem; }

  .view__head { padding-bottom: .9em; }

  .realizace-body { grid-template-columns: 1fr; gap: 0; }
  .rnav {
    position: sticky; top: calc(var(--topbar-h) + var(--head-h, 84px) - 3px); z-index: 16;
    flex-flow: row wrap; text-align: left;
    gap: .1em 1.1em; min-width: 0;
    background: var(--bg); border-bottom: 1px solid var(--line);
    padding: 8px 0 16px; margin: 0;
  }
  .rnav a { padding: 4px 0; }
}

@media (max-width: 460px) {
  .grid { columns: 2 150px; }
}

@media (prefers-reduced-motion: reduce) {
  #splash { transition: opacity .4s ease; }
  .banner__spot { transition: none; left: 34%; top: -10%; }
  .view, .splash__inner, .splash__skip b, .modal__img { animation: none; }
  a, .brand__logo { transition: none; }
}