/* ALVILA, minimalisticka prezentace studia.
   Paleta: papirova bila, inkoustova cern a jedna signalni barva (limetka),
   ktera je zaroven teckou v logu i sluncem v hero scene.
   Vlastni CSS je jen tam, kde bootstrap nema co nabidnout: typografie,
   hero scena, seznam praci a detail formulare. */

:root {
  --av-paper: #f6f5f1;
  --av-ink: #16150f;
  --av-ink-soft: rgba(22, 21, 15, .68);
  --av-line: rgba(22, 21, 15, .14);
  --av-signal: #c8ff2e;
  --av-dark: #16150f;
  --av-dark-soft: rgba(246, 245, 241, .72);
  --av-dark-line: rgba(246, 245, 241, .16);
  --av-err: #b3261e;
  --av-serif: 'Instrument Serif', 'Iowan Old Style', 'Times New Roman', Georgia, serif;
  --av-sans: 'Instrument Sans', 'Helvetica Neue', Arial, system-ui, sans-serif;
  --av-ease: cubic-bezier(.2, .7, .2, 1);
}

* { -webkit-tap-highlight-color: transparent; }

html { scroll-behavior: smooth; }

body {
  background: var(--av-paper);
  color: var(--av-ink);
  font-family: var(--av-sans);
  font-size: 1rem;
  line-height: 1.6;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: var(--av-signal); color: var(--av-ink); }

/* Fokus z klavesnice musi byt videt vsude; na tmave sekci prepneme barvu. */
:focus-visible {
  outline: 2px solid var(--av-ink);
  outline-offset: 4px;
  border-radius: 2px;
}
.av-section--dark :focus-visible { outline-color: var(--av-signal); }

.av-skip {
  position: absolute; top: .6rem; left: .6rem; z-index: 50;
  background: var(--av-ink); color: var(--av-paper);
  padding: .55rem 1rem; border-radius: 2px;
  font-size: .85rem; text-decoration: none;
}

/* ===== hlavicka ===== */

.av-top {
  position: sticky; top: 0; z-index: 20;
  padding: 1.2rem 0;
  background: rgba(246, 245, 241, .86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease, padding .3s ease;
}
.av-top.is-stuck { border-bottom-color: var(--av-line); padding: .9rem 0; }

.av-mark {
  display: inline-flex; align-items: baseline; gap: .32rem;
  text-decoration: none; color: var(--av-ink);
  font-weight: 600; letter-spacing: .18em; font-size: .82rem;
}
.av-mark-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--av-signal);
  transition: transform .4s var(--av-ease);
}
.av-mark:hover .av-mark-dot { transform: translateY(-4px); }
.av-mark-word { display: inline-block; }

.av-nav { display: flex; gap: 1.8rem; }
.av-nav a {
  color: var(--av-ink-soft); text-decoration: none;
  font-size: .82rem; letter-spacing: .05em; font-weight: 500;
  position: relative; padding-bottom: 2px;
  transition: color .25s ease;
}
.av-nav a::after {
  content: ''; position: absolute; left: 0; bottom: 0;
  width: 100%; height: 1px; background: var(--av-ink);
  transform: scaleX(0); transform-origin: right;
  transition: transform .35s var(--av-ease);
}
.av-nav a:hover { color: var(--av-ink); }
.av-nav a:hover::after { transform: scaleX(1); transform-origin: left; }

@media (max-width: 575.98px) {
  .av-nav { gap: 1.1rem; }
  .av-nav a { font-size: .74rem; }
  .av-mark { font-size: .76rem; }
}

/* ===== typografie ===== */

.av-eyebrow {
  display: flex; align-items: center; gap: .9rem;
  font-size: .72rem; letter-spacing: .22em; text-transform: uppercase;
  font-weight: 500;
  color: var(--av-ink-soft); margin: 0 0 1.5rem;
}
.av-num {
  font-family: var(--av-serif); font-style: italic; letter-spacing: 0;
  font-size: 1rem; text-transform: none;
  padding-right: .9rem; border-right: 1px solid var(--av-line);
}
.av-section--dark .av-eyebrow { color: var(--av-dark-soft); }
.av-section--dark .av-num { border-right-color: var(--av-dark-line); }

.av-h1 {
  font-family: var(--av-serif);
  font-weight: 400;
  font-size: clamp(3rem, 10.5vw, 7.6rem);
  line-height: .94;
  letter-spacing: -.025em;
  margin: 0;
  text-wrap: balance;
}
.av-h1 em {
  font-style: italic;
  position: relative;
  display: inline-block;
  z-index: 0;
}
.av-h1 em::after {
  content: ''; position: absolute;
  left: -.04em; right: -.04em; bottom: .08em; height: .14em;
  background: var(--av-signal); z-index: -1;
  transform: scaleX(0); transform-origin: left;
  animation: avUnderline 1s var(--av-ease) .5s forwards;
}
@keyframes avUnderline { to { transform: scaleX(1); } }

.av-h2 {
  font-family: var(--av-serif);
  font-weight: 400;
  font-size: clamp(2rem, 4.6vw, 3.4rem);
  line-height: 1.04;
  letter-spacing: -.015em;
  margin: 0 0 1.5rem;
  max-width: 18ch;
  text-wrap: balance;
}

.av-lead {
  font-size: clamp(1.05rem, 1.6vw, 1.22rem);
  line-height: 1.5;
  color: var(--av-ink-soft);
  max-width: 30ch;
  margin: 0;
  padding-bottom: .4rem;
}

.av-say {
  color: var(--av-ink-soft);
  font-size: 1.02rem;
  max-width: 48ch;
  margin: 0 0 2rem;
}

/* ===== hero + drobnohra "jeden den v jednom tahu" =====
   Vychozi hodnoty promennych odpovidaji poledni, aby scena davala smysl
   i bez skriptu. Skript je prepisuje podle polohy jezdce. */

.av-hero { padding: clamp(4.5rem, 13vh, 9rem) 0 clamp(3rem, 8vh, 5rem); }

.av-scene {
  --av-sky-top: #dee2dc;
  --av-sky-bot: #f6f5f1;
  --av-sky-glow: #f6f5f1;
  --av-ground: #dcd9cf;
  --av-sign-fg: #16150f;
  --av-fg: #16150f;
  --av-sun-x: 50%;
  --av-sun-e: 1;
  --av-moon-x: 50%;
  --av-moon-e: -1;
  --av-stars: 0;
  --av-sh-op: .14;
  --av-sh-len: .16;
  --av-sh-skew: 0deg;
  --av-horizon: 30%;
  --av-arc: 52%;
  position: relative;
  margin-top: clamp(3rem, 8vh, 5.5rem);
  height: clamp(250px, 44vw, 400px);
  border-radius: 6px;
  overflow: hidden;
  background: linear-gradient(var(--av-sky-top), var(--av-sky-bot) 58%, var(--av-sky-glow));
  color: var(--av-fg);
  touch-action: pan-y;
  isolation: isolate;
}

.av-sky { position: absolute; inset: 0; }

/* hvezdy: jedna vrstva radialnich prechodu, zadne extra prvky v DOM */
.av-stars {
  position: absolute; inset: 0;
  opacity: var(--av-stars);
  background-image:
    radial-gradient(circle at 8% 22%, var(--av-paper) 0 1px, transparent 1.8px),
    radial-gradient(circle at 19% 58%, var(--av-paper) 0 .8px, transparent 1.5px),
    radial-gradient(circle at 27% 14%, var(--av-paper) 0 1.2px, transparent 2px),
    radial-gradient(circle at 36% 41%, var(--av-paper) 0 .8px, transparent 1.5px),
    radial-gradient(circle at 44% 9%, var(--av-paper) 0 1px, transparent 1.8px),
    radial-gradient(circle at 57% 30%, var(--av-paper) 0 .9px, transparent 1.6px),
    radial-gradient(circle at 63% 55%, var(--av-paper) 0 1.3px, transparent 2.1px),
    radial-gradient(circle at 71% 12%, var(--av-paper) 0 .8px, transparent 1.5px),
    radial-gradient(circle at 78% 38%, var(--av-paper) 0 1px, transparent 1.8px),
    radial-gradient(circle at 86% 20%, var(--av-paper) 0 1.2px, transparent 2px),
    radial-gradient(circle at 92% 50%, var(--av-paper) 0 .8px, transparent 1.5px),
    radial-gradient(circle at 50% 62%, var(--av-paper) 0 .7px, transparent 1.4px);
  animation: avTwinkle 3.2s ease-in-out infinite;
}
@keyframes avTwinkle {
  0%, 100% { opacity: var(--av-stars); }
  50% { opacity: calc(var(--av-stars) * .45); }
}

.av-sun, .av-moon {
  position: absolute; z-index: 1;
  border-radius: 50%;
  transform: translate(-50%, 50%);
  transition: left .09s linear, bottom .09s linear, opacity .3s ease;
}
.av-sun {
  width: clamp(28px, 3.6vw, 44px); height: clamp(28px, 3.6vw, 44px);
  left: var(--av-sun-x);
  bottom: calc(var(--av-horizon) + var(--av-sun-e) * var(--av-arc));
  background: var(--av-signal);
  box-shadow: 0 0 36px 10px rgba(200, 255, 46, .32);
}
.av-moon {
  width: 26px; height: 26px;
  left: var(--av-moon-x);
  bottom: calc(var(--av-horizon) + var(--av-moon-e) * var(--av-arc));
  box-shadow: inset 7px -4px 0 0 var(--av-paper);
  opacity: var(--av-stars);
}

.av-ground {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 2;
  height: var(--av-horizon);
  background: var(--av-ground);
}

/* Napis stoji na obzoru; posun o vysku dotahu pisma ho posadi na caru.
   Stin je zrcadlena kopie napisu, zkosena podle polohy slunce. */
.av-sign {
  position: absolute; z-index: 3;
  left: 5%; bottom: var(--av-horizon);
  transform: translateY(.2em);
  font-family: var(--av-serif);
  font-size: clamp(3.2rem, 11.5vw, 8.8rem);
  line-height: 1; letter-spacing: -.02em;
  color: var(--av-sign-fg);
  transition: color .5s ease, text-shadow .6s ease;
  user-select: none;
}
.av-sign-word { position: relative; display: block; z-index: 1; }
.av-sign-shadow {
  position: absolute; left: 0; top: 0; z-index: 0;
  display: block;
  color: var(--av-ink);
  opacity: var(--av-sh-op);
  transform-origin: 50% calc(100% - .2em);
  transform: skewX(var(--av-sh-skew)) scaleY(calc(-1 * var(--av-sh-len)));
  transition: transform .09s linear, opacity .2s ease;
  filter: blur(.6px);
}
.av-scene.is-lit .av-sign {
  color: var(--av-signal);
  text-shadow: 0 0 14px rgba(200, 255, 46, .6), 0 0 56px rgba(200, 255, 46, .28);
}

.av-clock {
  position: absolute; z-index: 4;
  top: 1rem; right: 1.15rem;
  font-size: .78rem; letter-spacing: .12em; font-weight: 500;
  font-variant-numeric: tabular-nums;
  color: var(--av-fg);
  transition: color .3s ease;
}

.av-scene-hint, .av-scene-prize {
  position: absolute; z-index: 4;
  top: 1rem; left: 1.15rem; margin: 0;
  max-width: calc(100% - 6.5rem);
  font-size: .72rem; letter-spacing: .16em; text-transform: uppercase;
  font-weight: 500; line-height: 1.5;
  color: var(--av-fg);
  transition: opacity .45s ease, transform .45s var(--av-ease), color .3s ease;
}
.av-scene.is-touched .av-scene-hint { opacity: 0; transform: translateY(-4px); }
.av-scene-prize { opacity: 0; transform: translateY(6px); }
.av-scene.is-lit .av-scene-prize { opacity: 1; transform: none; }
.av-scene-prize mark { background: var(--av-signal); color: var(--av-ink); padding: .1em .4em; }

/* Jezdec je nativni range pres celou scenu: klavesnice, dotyk i ctecka
   zadarmo. Vizual nad nim je jen obraz, ovlada se cela plocha. */
.av-scene-range {
  position: absolute; inset: 0; z-index: 5;
  width: 100%; height: 100%; margin: 0;
  opacity: 0; cursor: grab;
  touch-action: pan-y;
}
.av-scene-range:active { cursor: grabbing; }
.av-scene-range:focus-visible { outline: none; }
.av-scene-focus {
  position: absolute; inset: 0; z-index: 6;
  border-radius: 6px; pointer-events: none;
  box-shadow: inset 0 0 0 2px var(--av-ink), inset 0 0 0 5px var(--av-signal);
  opacity: 0; transition: opacity .2s ease;
}
.av-scene-range:focus-visible + .av-scene-focus { opacity: 1; }

@media (max-width: 575.98px) {
  .av-scene { border-radius: 4px; }
  .av-scene-hint, .av-scene-prize { font-size: .64rem; letter-spacing: .12em; max-width: calc(100% - 5.5rem); }
  .av-clock { font-size: .7rem; }
}

/* Bez animaci: scena dal reaguje na jezdec, jen skokove; nic se nehybe samo. */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, ::before, ::after { transition: none !important; animation: none !important; }
  .av-h1 em::after { transform: scaleX(1); }
}

/* ===== sekce ===== */

.av-section { padding: clamp(4.5rem, 12vh, 8.5rem) 0; }
.av-section--dark { background: var(--av-dark); color: var(--av-paper); }
.av-section--dark .av-say { color: var(--av-dark-soft); }
.av-section--dark ::selection { background: var(--av-signal); color: var(--av-ink); }
.av-section--form { border-top: 1px solid var(--av-line); }

/* ===== prace ===== */

.av-work { margin: clamp(1.5rem, 4vh, 3rem) 0 0; border-top: 1px solid var(--av-line); }
.av-work-item { border-bottom: 1px solid var(--av-line); }
.av-work-item a {
  position: relative;
  display: grid;
  grid-template-columns: 3.2rem 1fr auto;
  align-items: center;
  gap: 1rem 1.5rem;
  padding: 1.8rem .6rem;
  text-decoration: none; color: var(--av-ink);
  transition: padding-left .4s var(--av-ease);
}
.av-work-item a::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px; background: var(--av-signal);
  transform: scaleY(0); transform-origin: bottom;
  transition: transform .4s var(--av-ease);
}
.av-work-item a:hover, .av-work-item a:focus-visible { padding-left: 1.2rem; }
.av-work-item a:hover::before, .av-work-item a:focus-visible::before { transform: scaleY(1); transform-origin: top; }
.av-work-item a:focus-visible { outline-offset: -2px; }

.av-work-idx {
  font-family: var(--av-serif); font-style: italic;
  font-size: 1.05rem; color: var(--av-ink-soft);
}
.av-work-body { display: grid; gap: .35rem; min-width: 0; }
.av-work-name {
  font-family: var(--av-serif);
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  line-height: 1.05; letter-spacing: -.01em;
  overflow-wrap: anywhere;
}
.av-work-note { color: var(--av-ink-soft); font-size: .95rem; max-width: 52ch; }
.av-work-tags { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: .35rem; }
.av-work-tags > span {
  font-size: .66rem; letter-spacing: .14em; text-transform: uppercase; font-weight: 500;
  color: var(--av-ink-soft);
  border: 1px solid var(--av-line); border-radius: 999px;
  padding: .2rem .6rem;
  transition: border-color .3s ease, color .3s ease;
}
.av-work-item a:hover .av-work-tags > span { border-color: var(--av-ink); color: var(--av-ink); }
.av-work-go {
  width: 2.6rem; height: 2.6rem; border-radius: 50%;
  display: grid; place-items: center;
  border: 1px solid var(--av-line);
  font-size: .85rem;
  transition: background-color .3s ease, border-color .3s ease;
}
.av-work-go i { transition: transform .4s var(--av-ease); }
.av-work-item a:hover .av-work-go, .av-work-item a:focus-visible .av-work-go {
  background: var(--av-signal); border-color: var(--av-signal);
}
.av-work-item a:hover .av-work-go i, .av-work-item a:focus-visible .av-work-go i { transform: rotate(-45deg); }

@media (max-width: 767.98px) {
  .av-work-item a { grid-template-columns: 1fr auto; gap: .5rem 1rem; padding: 1.4rem .4rem; }
  .av-work-item a:hover, .av-work-item a:focus-visible { padding-left: .9rem; }
  .av-work-idx { display: none; }
}

/* ===== karty ===== */

.av-cards { margin-top: clamp(2rem, 6vh, 4rem); }
.av-card {
  position: relative;
  height: 100%;
  padding: 1.8rem 0 .5rem;
  border-top: 1px solid var(--av-dark-line);
}
.av-card::before {
  content: ''; position: absolute; left: 0; top: -1px;
  width: 100%; height: 1px; background: var(--av-signal);
  transform: scaleX(0); transform-origin: left;
  transition: transform .5s var(--av-ease);
}
.av-card:hover::before { transform: scaleX(1); }
.av-card-num {
  display: block;
  font-family: var(--av-serif); font-style: italic;
  font-size: 1.05rem; color: var(--av-signal);
  margin-bottom: 1.6rem;
}
.av-card h3 {
  font-family: var(--av-serif); font-weight: 400;
  font-size: 1.7rem; line-height: 1.1; letter-spacing: -.01em;
  margin: 0 0 .6rem;
}
.av-card p { margin: 0; color: var(--av-dark-soft); font-size: .95rem; max-width: 30ch; }

/* ===== formular ===== */

.av-mail {
  font-family: var(--av-serif);
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  color: var(--av-ink); text-decoration: none;
  border-bottom: 1px solid var(--av-line);
  padding-bottom: .05rem;
  transition: border-color .3s ease;
}
.av-mail:hover { color: var(--av-ink); border-bottom-color: var(--av-ink); border-bottom-width: 2px; }

.av-form .form-label {
  font-size: .72rem; letter-spacing: .16em; text-transform: uppercase; font-weight: 500;
  color: var(--av-ink-soft); margin-bottom: .4rem;
  transition: color .25s ease;
}
.av-form .form-control {
  background: transparent;
  border: 0; border-bottom: 1px solid var(--av-line);
  border-radius: 0;
  padding: .6rem 0;
  color: var(--av-ink);
  font-size: 1.05rem;
  transition: border-color .3s ease, box-shadow .3s ease;
}
.av-form .form-control:focus {
  background: transparent;
  border-bottom-color: var(--av-ink);
  box-shadow: 0 1px 0 0 var(--av-ink);
  color: var(--av-ink);
  outline: none;
}
.av-form .col-sm-6:focus-within .form-label,
.av-form .col-12:focus-within .form-label { color: var(--av-ink); }
.av-form .form-control.is-invalid,
.av-form .form-control.is-invalid:focus {
  border-bottom-color: var(--av-err);
  box-shadow: 0 1px 0 0 var(--av-err);
  background-image: none;
  padding-right: 0;
}
.av-form .invalid-feedback { color: var(--av-err); font-size: .82rem; margin-top: .4rem; }
.av-form textarea.form-control { resize: vertical; min-height: 7rem; }

/* honeypot: skryty pred lidmi, vyplni ho jen robot */
.av-hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

.av-btn {
  display: inline-flex; align-items: center; gap: .8rem;
  margin-top: 1rem;
  padding: .85rem 1.8rem;
  border: 1px solid var(--av-ink);
  border-radius: 999px;
  background: transparent; color: var(--av-ink);
  font-size: .86rem; letter-spacing: .1em; font-weight: 500; text-transform: uppercase;
  position: relative; overflow: hidden; isolation: isolate;
  transition: color .3s ease;
}
.av-btn::before {
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: var(--av-signal);
  transform: scaleX(0); transform-origin: left;
  transition: transform .45s var(--av-ease);
}
.av-btn:hover::before, .av-btn:focus-visible::before { transform: scaleX(1); }
.av-btn i { transition: transform .4s var(--av-ease); }
.av-btn:hover i, .av-btn:focus-visible i { transform: translateX(5px); }
.av-btn[disabled] { opacity: .5; }

.av-form-msg { margin: 1.2rem 0 0; font-size: .9rem; min-height: 1.4em; }
.av-form-msg.is-ok { color: var(--av-ink); }
.av-form-msg.is-err { color: var(--av-err); }

/* ===== paticka ===== */

.av-foot {
  border-top: 1px solid var(--av-line);
  padding: 1.7rem 0;
  font-size: .78rem; letter-spacing: .03em;
  color: var(--av-ink-soft);
}

/* ===== nabeh sekci pri scrollu (tridu pridava skript) ===== */

.av-reveal { opacity: 0; transform: translateY(16px); }
.av-reveal.is-in {
  opacity: 1; transform: none;
  transition: opacity .8s ease, transform .8s var(--av-ease);
}
@media (prefers-reduced-motion: reduce) {
  .av-reveal { opacity: 1; transform: none; }
}