/* ============================================
   Roman Zohrabyan — Portfolio
   Design system: Swiss editorial × Apple UX
   One size, weight-only hierarchy. Sentence case.
   ============================================ */

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; text-rendering: optimizeLegibility; }
body { line-height: 1.5; }
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { background: none; border: none; cursor: pointer; font: inherit; color: inherit; }
ul, ol { list-style: none; }

/* ---------- Tokens ---------- */
:root {
  --bg-main: #FFFFFF;
  --bg-sidebar: #F2F2F2;
  --divider: #E5E5E5;
  --text-primary: #0A0A0A;
  --text-secondary: #8A8A8A;
  --text-tertiary: #B5B5B5;

  --font-stack: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Helvetica, "Inter", Arial, sans-serif;
  --font-size: 13px;
  --w-regular: 400;
  --w-medium: 500;
  --w-semibold: 600;

  --sidebar-w: 280px;
  --gutter: 32px;
  --gutter-lg: 48px;

  --ease-standard: cubic-bezier(0.32, 0.72, 0, 1);
  --dur-fast: 180ms;
  --dur-med:  360ms;
}

/* ---------- Base ---------- */
html, body {
  font-family: var(--font-stack);
  font-size: var(--font-size);
  font-weight: var(--w-regular);
  color: var(--text-primary);
  background: var(--bg-main);
  letter-spacing: -0.005em;
}

/* ---------- Layout ---------- */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  min-height: 100vh;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  padding: var(--gutter-lg) var(--gutter);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--divider);
  display: flex;
  flex-direction: column;
  gap: var(--gutter-lg);
  overflow-y: auto;
  z-index: 10;
}

.main {
  grid-column: 2;
  padding: var(--gutter-lg) var(--gutter-lg) 96px;
  max-width: 1200px;
}

/* ---------- Sidebar structure ---------- */
.sidebar__top { display: flex; align-items: flex-start; justify-content: space-between; }

.sidebar__logo { width: 140px; display: block; }
.sidebar__logo svg { width: 100%; height: auto; display: block; }

.sidebar__sections { display: flex; flex-direction: column; gap: var(--gutter-lg); }
.sidebar section { display: flex; flex-direction: column; gap: 10px; }

.sidebar__label { color: var(--text-tertiary); letter-spacing: 0.02em; }

.sidebar__list { display: flex; flex-direction: column; gap: 6px; }
.sidebar__list a {
  display: inline-flex;
  align-items: baseline;
  color: var(--text-primary);
  transition: transform var(--dur-med) var(--ease-standard),
              color var(--dur-fast) var(--ease-standard);
}
.sidebar__list a:hover { transform: translateX(4px); }
.sidebar__list a.is-active { font-weight: var(--w-medium); }

.sidebar__list a .num {
  display: inline-block;
  width: 22px;
  color: var(--text-tertiary);
  font-variant-numeric: tabular-nums;
  transition: color var(--dur-fast) var(--ease-standard);
}
.sidebar__list a:hover .num { color: var(--text-primary); }

.sidebar__link {
  display: inline-block;
  color: var(--text-primary);
  font-weight: var(--w-regular);
  transition: transform var(--dur-med) var(--ease-standard);
}
.sidebar__link:hover { transform: translateX(4px); }
.sidebar__link.is-active { font-weight: var(--w-medium); }

.sidebar__footer { margin-top: auto; color: var(--text-tertiary); }

/* ---------- Mobile menu toggle (hidden on desktop) ---------- */
.menu-toggle {
  display: none;
  align-items: center;
  gap: 6px;
  padding: 4px 0;
  background: none;
  border: 0;
  color: var(--text-primary);
}
.menu-toggle svg { transition: transform var(--dur-med) var(--ease-standard); }
.sidebar.is-open .menu-toggle svg { transform: rotate(180deg); }

/* ---------- Playground: 3-column grid of hero-image tiles ---------- */
.playground {
  padding: 24px 0 48px;
}
.playground-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.playground-tile {
  position: relative;
  display: block;
  aspect-ratio: 1 / 1;
  background: var(--bg-sidebar);
  overflow: hidden;
  transition: transform var(--dur-med) var(--ease-standard);
}
.playground-tile:hover { transform: translateY(-4px); }
.playground-tile img { width: 100%; height: 100%; object-fit: cover; display: block; }
.playground-tile[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-tertiary);
}

/* Playground detail page: hero + short description */
.playground-detail {
  padding: 24px 0 48px;
  max-width: 960px;
}
.playground-detail__hero {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--bg-sidebar);
  overflow: hidden;
  margin-bottom: 48px;
}
.playground-detail__hero img { width: 100%; height: 100%; object-fit: cover; display: block; }
.playground-detail__hero[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-tertiary);
}
.playground-detail__body { max-width: 560px; }
.playground-detail__title { font-weight: var(--w-semibold); margin-bottom: 16px; }
.playground-detail__description { color: var(--text-primary); }
.playground-detail__description p + p { margin-top: 1em; }

/* ---------- About page ---------- */
.about {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--gutter-lg);
  padding: 24px 0 48px;
  max-width: 960px;
}
.about__media {
  position: relative;
  width: 100%;
  aspect-ratio: 3 / 4;
  background: var(--bg-sidebar);
  overflow: hidden;
}
.about__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.about__media[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-tertiary);
}
.about__epigraph { margin-bottom: 32px; max-width: 420px; }
.about__epigraph p { color: var(--text-primary); margin-bottom: 8px; }
.about__epigraph cite { color: var(--text-secondary); font-style: normal; display: block; }
.about__statement { color: var(--text-primary); max-width: 420px; }
.about__statement p + p { margin-top: 1em; }
.about__action { margin-top: 32px; }
.about__download {
  display: inline-block;
  color: var(--text-primary);
  font-weight: var(--w-medium);
  transition: transform var(--dur-med) var(--ease-standard);
}
.about__download:hover { transform: translateX(4px); }
.about__meta {
  margin-top: 32px;
  padding-top: 32px;
  border-top: 1px solid var(--divider);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px 32px;
  max-width: 420px;
}
.about__meta .meta__label { color: var(--text-tertiary); margin-bottom: 4px; }
.about__meta .meta__value { color: var(--text-primary); }

/* ---------- Homepage: project tiles with hero images ---------- */
.projects { border-top: none; }

.project-tile {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: var(--gutter-lg);
  padding: 32px 0 40px;
  border-bottom: 1px solid var(--divider);
  color: var(--text-primary);
  transition: transform var(--dur-med) var(--ease-standard);
  will-change: transform;
}
.project-tile:first-child { padding-top: 0; }
.project-tile:hover { transform: translateX(8px); }
.project-tile__media { grid-column: 1 / -1; }

.project-tile__media {
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--bg-sidebar);
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}
.project-tile__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.project-tile__media[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-tertiary);
}

.project-tile__meta {
  grid-column: 1;
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 4px 16px;
  align-items: baseline;
}
.project-tile__num { grid-row: 1 / span 3; }
.project-tile__title { grid-column: 2; }
.project-tile__discipline { grid-column: 2; }
.project-tile__year { grid-column: 2; text-align: left; }
.project-tile__num { color: var(--text-tertiary); font-variant-numeric: tabular-nums; transition: color var(--dur-fast) var(--ease-standard); }
.project-tile:hover .project-tile__num { color: var(--text-primary); }
.project-tile__title { font-weight: var(--w-medium); }
.project-tile__discipline { color: var(--text-secondary); }
.project-tile__year { color: var(--text-secondary); font-variant-numeric: tabular-nums; }
.project-tile__description {
  grid-column: 2;
  color: var(--text-primary);
  max-width: 100%;
  margin: 0;
}

/* ---------- Project page: hero ---------- */
.hero {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--bg-sidebar);
  margin-bottom: 48px;
  overflow: hidden;
}
.hero img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* ---------- Project page: masthead ---------- */
.masthead {
  padding-bottom: 48px;
  margin-bottom: 48px;
  border-bottom: 1px solid var(--divider);
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-areas:
    "title title"
    "meta  intro";
  column-gap: var(--gutter-lg);
  row-gap: 40px;
  max-width: 960px;
}
.masthead__title { grid-area: title; font-weight: var(--w-semibold); }
.masthead__intro { grid-area: intro; color: var(--text-primary); }
.masthead__intro p + p { margin-top: 1em; }

.meta {
  grid-area: meta;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px 32px;
  max-width: 480px;
}
.meta__label { color: var(--text-tertiary); margin-bottom: 4px; }
.meta__value { color: var(--text-primary); }

/* ---------- Project page: image gallery (2-col desktop) ---------- */
.gallery {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px 24px;
  margin-bottom: 96px;
}

.gallery__item {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.gallery__item--full { grid-column: 1 / -1; }

.gallery__frame {
  position: relative;
  width: 100%;
  background: var(--bg-sidebar);
  overflow: hidden;
}
.gallery__frame img { width: 100%; height: 100%; display: block; object-fit: cover; }

/* Letterbox image on black: image centered via contain, matching black background */
.gallery__frame--letterbox {
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
}
.gallery__frame--letterbox img {
  width: auto;
  height: auto;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.gallery__caption { color: var(--text-secondary); max-width: 560px; }
.gallery__caption .caption-num {
  color: var(--text-tertiary);
  margin-right: 10px;
  font-variant-numeric: tabular-nums;
}

.frame--16x10 { aspect-ratio: 16 / 10; }
.frame--16x9  { aspect-ratio: 16 / 9; }
.frame--4x3   { aspect-ratio: 4 / 3; }
.frame--3x2   { aspect-ratio: 3 / 2; }
.frame--1x1   { aspect-ratio: 1 / 1; }
.frame--3x4   { aspect-ratio: 3 / 4; }
.frame--4x5   { aspect-ratio: 4 / 5; }
.frame--21x9  { aspect-ratio: 21 / 9; }
.frame--banner { aspect-ratio: 2564 / 740; }

/* Video frame: black background, centered video, scaled down inside the frame */
.gallery__frame--video {
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
}
.gallery__frame--video video {
  width: 63%;
  height: 63%;
  object-fit: contain;
  display: block;
}
/* Larger video size (used for the app video and story cycle) */
.gallery__frame--video-lg video {
  width: 76%;
  height: 76%;
}
/* Video cycle: multiple videos stacked, wiping between on 'ended' */
.gallery__frame--video-cycle {
  display: block;
  position: relative;
}
.gallery__frame--video-cycle video {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 76%;
  height: 76%;
  object-fit: contain;
  display: block;
  clip-path: inset(0 100% 0 0);
  transition: clip-path 0.9s cubic-bezier(0.76, 0, 0.24, 1);
}

/* Gerbert Sans — Roman's own typeface, used in the type specimen slot */
@font-face {
  font-family: 'Gerbert Sans';
  src: url('assets/gerbert/gerbert-sans.otf') format('opentype');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* Typing specimen: white frame, black Gerbert Sans text, blinking cursor */
.type-specimen {
  background: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  overflow: hidden;
}
.type-specimen__inner {
  font-family: 'Gerbert Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-weight: 400;
  font-size: clamp(28px, 7cqw, 72px);
  color: #000;
  letter-spacing: -0.01em;
  line-height: 1.15;
  text-align: center;
  display: inline-flex;
  align-items: baseline;
  min-height: 1.15em;
  white-space: nowrap;
}
.type-specimen { container-type: inline-size; }
.type-specimen--large .type-specimen__inner {
  font-size: clamp(56px, 14cqw, 144px);
}
.type-specimen--large { padding: 40px; }
.type-specimen--dark { background: #000; }
.type-specimen--dark .type-specimen__inner { color: #FFFFFF; }
.type-specimen--dark .type-specimen__cursor { background: #FFFFFF; }

/* Wrapping variant: for longer sentences, let text wrap across multiple lines */
.type-specimen--wrap { padding: 48px; }
.type-specimen--wrap .type-specimen__inner {
  display: block;
  white-space: normal;
  text-align: center;
  width: 100%;
  min-height: 0;
  font-size: clamp(24px, 4.8cqw, 56px);
  line-height: 1.25;
}
.type-specimen--wrap .type-specimen__text { display: inline; }
.type-specimen--wrap .type-specimen__cursor { display: inline-block; vertical-align: baseline; }
.type-specimen__cursor {
  display: inline-block;
  width: 2px;
  height: 0.9em;
  background: #000;
  margin-left: 4px;
  vertical-align: baseline;
  transform: translateY(0.1em);
  animation: cursor-blink 1s steps(2, start) infinite;
}
@keyframes cursor-blink {
  50% { opacity: 0; }
}

/* Wipe-swap: two layered images, left-to-right wipe on loop */
.wipe-swap { position: relative; overflow: hidden; }
.wipe-swap img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.wipe-swap__after {
  clip-path: inset(0 100% 0 0);
  animation: wipe-loop 5s infinite;
}
/* Per-keyframe timing: linear through holds, warm ease on the wipe segments.
   cubic-bezier(0.76, 0, 0.24, 1) is a soft S-curve (easeInOutQuart). */
@keyframes wipe-loop {
  0%   { clip-path: inset(0 100% 0 0); animation-timing-function: linear; }
  20%  { clip-path: inset(0 100% 0 0); animation-timing-function: cubic-bezier(0.76, 0, 0.24, 1); }
  40%  { clip-path: inset(0 0 0 0);    animation-timing-function: linear; }
  60%  { clip-path: inset(0 0 0 0);    animation-timing-function: cubic-bezier(0.76, 0, 0.24, 1); }
  80%  { clip-path: inset(0 0 0 100%); animation-timing-function: linear; }
  100% { clip-path: inset(0 0 0 100%); }
}

/* Grey-box placeholders */
.gallery__frame[data-placeholder]::after,
.hero[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-tertiary);
}

/* ---------- Next project ---------- */
.next-project {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 32px 0;
  border-top: 1px solid var(--divider);
  color: var(--text-primary);
  transition: transform var(--dur-med) var(--ease-standard);
  will-change: transform;
}
.next-project:hover { transform: translateX(8px); }
.next-project__label { color: var(--text-tertiary); }
.next-project__title { font-weight: var(--w-medium); margin-top: 6px; }

/* ---------- Visually hidden ---------- */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ============================================
   MOBILE  (< 900px)
   ============================================ */
@media (max-width: 900px) {
  :root { --font-size: 14px; }

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

  .sidebar {
    position: sticky;
    top: 0;
    width: 100%;
    height: auto;
    padding: 16px 24px;
    border-right: none;
    border-bottom: 1px solid var(--divider);
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }
  .sidebar__top { align-items: center; }
  .sidebar__logo { width: 110px; }
  .menu-toggle { display: inline-flex; }

  .sidebar__sections {
    max-height: 0;
    overflow: hidden;
    gap: 0;
    transition: max-height var(--dur-med) var(--ease-standard);
  }
  .sidebar.is-open .sidebar__sections {
    max-height: 720px;
    padding-top: 24px;
    gap: 28px;
  }
  .sidebar__footer { display: none; }
  .sidebar.is-open .sidebar__footer {
    display: block;
    padding: 24px 0 8px;
    color: var(--text-tertiary);
  }

  .main {
    grid-column: 1;
    padding: 24px 24px 72px;
    max-width: 100%;
  }

  /* About page on mobile */
  .about { grid-template-columns: 1fr; gap: 24px; padding: 16px 0 48px; }
  .about__media { aspect-ratio: 4 / 5; }

  /* Playground on mobile: 2-column grid */
  .playground-grid { grid-template-columns: 1fr 1fr; gap: 16px; }
  .playground-detail__hero { aspect-ratio: 4 / 3; margin-bottom: 32px; }

  /* Homepage tiles on mobile */
  .project-tile {
    grid-template-columns: 1fr;
    padding: 20px 0 28px;
  }
  .project-tile__media { aspect-ratio: 4 / 3; margin-bottom: 14px; }
  .project-tile__meta { grid-column: 1; gap: 6px 12px; }
  .project-tile__description { display: none; }

  .hero { aspect-ratio: 4 / 3; margin-bottom: 32px; }

  .masthead {
    grid-template-columns: 1fr;
    grid-template-areas: "title" "meta" "intro";
    row-gap: 24px;
    padding-bottom: 36px;
    margin-bottom: 36px;
  }
  .meta { grid-template-columns: 1fr 1fr; gap: 20px; }

  /* Gallery collapses to one column */
  .gallery { grid-template-columns: 1fr; gap: 40px; margin-bottom: 72px; }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .sidebar__sections { max-height: none !important; }
  .wipe-swap__after { clip-path: inset(0 0 0 0); }
}