/* ==========================================================================
   Oliver Zeman — Engineering Portfolio
   Design system: graphite + safety orange, graph-paper motif,
   dark/light themes, motion-safe animations.
   ========================================================================== */

:root {
  --font-display: "Space Grotesk", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", Consolas, "Liberation Mono", monospace;

  --radius-s: 8px;
  --radius-m: 14px;
  --radius-l: 22px;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2.5rem;
  --space-6: 4rem;
  --space-7: 6.5rem;

  --w-content: 1120px;
  --w-prose: 46rem;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);

  /* Light theme (default) — elegant green palette:
     #192231 navy · #404a42 green · #c0b283 gold · #eddbcd cream · #f4f4f4 off-white */
  --c-bg: #f4f4f4;
  --c-bg-raise: #ffffff;
  --c-bg-sunk: #eddbcd;
  --c-ink: #192231;
  --c-ink-soft: #404a42;
  --c-ink-faint: #6b7280;
  --c-line: #ddd8cd;
  --c-grid: rgba(25, 34, 49, 0.06);
  --c-accent: #c0b283;
  --c-accent-ink: #6e6238;
  --c-accent-soft: rgba(192, 178, 131, 0.22);
  --c-focus: #192231;
  --shadow-s: 0 1px 2px rgba(25, 34, 49, 0.06), 0 2px 8px rgba(25, 34, 49, 0.06);
  --shadow-m: 0 2px 6px rgba(25, 34, 49, 0.07), 0 12px 32px rgba(25, 34, 49, 0.10);
}

:root[data-theme="dark"] {
  --c-bg: #192231;
  --c-bg-raise: #202b3d;
  --c-bg-sunk: #121a27;
  --c-ink: #f4f4f4;
  --c-ink-soft: #c3c9d2;
  --c-ink-faint: #8b94a3;
  --c-line: #2e3a4f;
  --c-grid: rgba(244, 244, 244, 0.05);
  --c-accent: #c0b283;
  --c-accent-ink: #d3c79f;
  --c-accent-soft: rgba(192, 178, 131, 0.16);
  --c-focus: #c0b283;
  --shadow-s: 0 1px 2px rgba(0, 0, 0, 0.4), 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-m: 0 2px 6px rgba(0, 0, 0, 0.45), 0 14px 36px rgba(0, 0, 0, 0.5);
  color-scheme: dark;
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--c-ink);
  background-color: var(--c-bg);
  -webkit-tap-highlight-color: transparent;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.15;
  letter-spacing: -0.015em;
  text-wrap: balance;
  margin: 0 0 var(--space-3);
}

h1 { font-size: clamp(2.3rem, 5.5vw, 3.9rem); font-weight: 700; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.3rem); font-weight: 700; }
h3 { font-size: clamp(1.2rem, 2.2vw, 1.45rem); font-weight: 600; }

p { margin: 0 0 var(--space-3); }

a {
  color: var(--c-accent-ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 160ms var(--ease-out);
}
a:hover { color: var(--c-accent); }

img { max-width: 100%; height: auto; display: block; }

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
  touch-action: manipulation;
}

:focus-visible {
  outline: 2px solid var(--c-focus);
  outline-offset: 2px;
}

a, button { touch-action: manipulation; }

::selection { background: var(--c-accent-soft); }

[id] { scroll-margin-top: 5.5rem; }

.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -100%;
  z-index: 100;
  padding: var(--space-2) var(--space-3);
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-s);
  box-shadow: var(--shadow-m);
}
.skip-link:focus { top: var(--space-3); }

.container {
  width: min(100% - 2.5rem, var(--w-content));
  margin-inline: auto;
}

.prose { max-width: var(--w-prose); }

.section { padding-block: var(--space-7); }
.section + .section { padding-top: 0; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-accent-ink);
  margin-bottom: var(--space-3);
}
.eyebrow::before,
.eyebrow::after {
  content: "";
  width: 1.6rem;
  height: 2px;
  background: var(--c-accent);
  border-radius: 1px;
}

.muted { color: var(--c-ink-soft); }

/* --------------------------------------------------------------------------
   Header / nav
   -------------------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--c-bg) 82%, transparent);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-line);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 4rem;
}

.brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--c-ink);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  white-space: nowrap;
}
.brand:hover { color: var(--c-ink); }
.brand-mark {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--c-accent);
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.site-nav a {
  position: relative;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--c-ink-soft);
  text-decoration: none;
  padding-block: 0.35rem;
}
.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  border-radius: 1px;
  background: var(--c-accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 220ms var(--ease-out);
}
.site-nav a:hover,
.site-nav a[aria-current="page"] { color: var(--c-ink); }
.site-nav a:hover::after,
.site-nav a[aria-current="page"]::after { transform: scaleX(1); }

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  border: 1px solid var(--c-line);
  border-radius: 50%;
  background: var(--c-bg-raise);
  transition: border-color 160ms var(--ease-out), transform 160ms var(--ease-out);
}
.theme-toggle:hover { border-color: var(--c-accent); transform: rotate(15deg); }
.theme-toggle svg { width: 1.1rem; height: 1.1rem; }
.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

.nav-toggle {
  display: none;
  width: 2.4rem;
  height: 2.4rem;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-s);
  background: var(--c-bg-raise);
  align-items: center;
  justify-content: center;
}
.nav-toggle svg { width: 1.2rem; height: 1.2rem; }

@media (max-width: 720px) {
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-2) var(--space-3) var(--space-3);
    background: var(--c-bg);
    border-bottom: 1px solid var(--c-line);
    box-shadow: var(--shadow-m);
    display: none;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 0.7rem 0.25rem; border-bottom: 1px solid var(--c-line); }
  .site-nav a:last-of-type { border-bottom: 0; }
  .site-nav a::after { content: none; }
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */

.hero {
  position: relative;
  padding-block: var(--space-6) var(--space-7);
  background-image:
    linear-gradient(var(--c-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--c-grid) 1px, transparent 1px);
  background-size: 32px 32px;
  border-bottom: 1px solid var(--c-line);
  overflow: hidden;
}

.hero .container {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: var(--space-5);
  align-items: center;
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--c-ink-soft);
  margin-bottom: var(--space-3);
}

.hero p.lede {
  font-size: 1.2rem;
  color: var(--c-ink-soft);
  max-width: 34rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.hero-figure { position: relative; min-width: 0; }

#linkage-canvas {
  width: 100%;
  aspect-ratio: 1 / 0.9;
  display: block;
}

.hero-figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-ink-faint);
  text-align: right;
  margin-top: var(--space-2);
}

@media (max-width: 860px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero-figure { max-width: 26rem; margin-inline: auto; width: 100%; }
  .hero-figure figcaption { text-align: center; }
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.35rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.98rem;
  text-decoration: none;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: transform 160ms var(--ease-out), box-shadow 160ms var(--ease-out),
    background-color 160ms var(--ease-out), border-color 160ms var(--ease-out);
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-s); }
.btn:active { transform: translateY(0); }

.btn-primary { background: var(--c-accent); color: #192231; }
.btn-primary:hover { background: color-mix(in srgb, var(--c-accent) 85%, #fff); color: #192231; }

.btn-ghost { border-color: var(--c-line); color: var(--c-ink); background: var(--c-bg-raise); }
.btn-ghost:hover { border-color: var(--c-accent); color: var(--c-ink); }

.btn svg { width: 1em; height: 1em; }

/* --------------------------------------------------------------------------
   Project cards
   -------------------------------------------------------------------------- */

.section-head {
  max-width: 44rem;
  margin-inline: auto;
  margin-bottom: var(--space-5);
  text-align: center;
}
.section-head p { max-width: 38rem; color: var(--c-ink-soft); margin: 0 auto; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(20rem, 100%), 1fr));
  gap: var(--space-4);
}

.project-card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
  overflow: hidden;
  transition: transform 220ms var(--ease-out), box-shadow 220ms var(--ease-out),
    border-color 220ms var(--ease-out);
}
.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-m);
  border-color: color-mix(in srgb, var(--c-accent) 45%, var(--c-line));
}

.project-card .thumb {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--c-bg-sunk);
  border-bottom: 1px solid var(--c-line);
}
.project-card .thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 400ms var(--ease-out);
}
.project-card:hover .thumb img { transform: scale(1.04); }

.project-card .body {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
  flex-grow: 1;
}

.project-card .tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.project-card .tags li {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  background: var(--c-accent-soft);
  color: var(--c-accent-ink);
}

.project-card h3 { margin: 0; }
.project-card h3 a {
  color: var(--c-ink);
  text-decoration: none;
}
/* stretch the whole card into the link's hit area */
.project-card h3 a::after { content: ""; position: absolute; inset: 0; }
.project-card:focus-within {
  outline: 2px solid var(--c-focus);
  outline-offset: 2px;
}
.project-card h3 a:focus-visible { outline: none; }

.project-card p { color: var(--c-ink-soft); font-size: 0.97rem; margin: 0; flex-grow: 1; }

.project-card .meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-ink-faint);
}

.project-card .cta {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--c-accent-ink);
  margin-top: var(--space-2);
}
.project-card .cta svg { width: 0.95em; height: 0.95em; transition: transform 220ms var(--ease-out); }
.project-card:hover .cta svg { transform: translateX(4px); }

/* --------------------------------------------------------------------------
   Skills
   -------------------------------------------------------------------------- */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(16rem, 100%), 1fr));
  gap: var(--space-4);
}

.skill-block {
  padding: var(--space-4);
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
}
.skill-block h3 {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.05rem;
  margin-bottom: var(--space-3);
}
.skill-block h3 svg { width: 1.15rem; height: 1.15rem; color: var(--c-accent); flex-shrink: 0; }
.skill-block ul { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 0.45rem; }
.skill-block li {
  font-size: 0.95rem;
  color: var(--c-ink-soft);
  padding-left: 1.1rem;
  position: relative;
}
.skill-block li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 0.45rem;
  height: 2px;
  background: var(--c-accent);
}

/* --------------------------------------------------------------------------
   Process timeline
   -------------------------------------------------------------------------- */

.timeline {
  list-style: none;
  margin: 0 auto;
  padding: 0;
  display: grid;
  gap: var(--space-4);
  counter-reset: step;
  max-width: 54rem;
}

.timeline li {
  position: relative;
  padding: var(--space-4) var(--space-4) var(--space-4) 4.4rem;
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
  counter-increment: step;
}
.timeline li::before {
  content: "0" counter(step);
  position: absolute;
  left: var(--space-4);
  top: var(--space-4);
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--c-accent);
}
.timeline h3 { font-size: 1.1rem; margin-bottom: var(--space-2); }
.timeline p { margin: 0; color: var(--c-ink-soft); font-size: 0.97rem; }

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

.contact-panel {
  text-align: center;
  padding: var(--space-6) var(--space-4);
  background:
    linear-gradient(var(--c-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--c-grid) 1px, transparent 1px),
    var(--c-bg-raise);
  background-size: 32px 32px, 32px 32px, auto;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-l);
}
.contact-panel p { max-width: 32rem; margin-inline: auto; color: var(--c-ink-soft); }

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.site-footer {
  border-top: 1px solid var(--c-line);
  padding-block: var(--space-4);
  margin-top: var(--space-7);
}
.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2);
  font-size: 0.88rem;
  color: var(--c-ink-faint);
}

/* --------------------------------------------------------------------------
   Case study pages
   -------------------------------------------------------------------------- */

.case-hero {
  padding-block: var(--space-6);
  border-bottom: 1px solid var(--c-line);
  background-image:
    linear-gradient(var(--c-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--c-grid) 1px, transparent 1px);
  background-size: 32px 32px;
  text-align: center;
}
.case-hero h1, .case-hero .lede { margin-inline: auto; }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.92rem;
  font-weight: 500;
  text-decoration: none;
  margin-bottom: var(--space-4);
}
.back-link svg { width: 0.9em; height: 0.9em; }

.case-hero .lede {
  font-size: 1.15rem;
  color: var(--c-ink-soft);
  max-width: var(--w-prose);
}

.meta-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
  gap: var(--space-3);
  margin-top: var(--space-5);
  padding: var(--space-4);
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
}
.meta-grid dt {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-ink-faint);
  margin-bottom: 0.25rem;
}
.meta-grid dd { margin: 0; font-size: 0.95rem; font-weight: 500; }
.meta-grid > div { min-width: 0; text-align: center; }

.case-body { padding-block: var(--space-6); }
.case-body > * + h2 { margin-top: var(--space-6); }
.case-body h2 { max-width: var(--w-prose); }
.case-body p, .case-body ul { max-width: var(--w-prose); }
.case-body > ul { padding-left: 1.2rem; color: var(--c-ink-soft); }
.case-body li { margin-bottom: 0.4rem; }

/* Alternating text/media rows */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--space-5);
  align-items: center;
  margin-block: var(--space-6);
}
.split .split-text h2 { margin-top: 0; }
.split figure { margin: 0; }
.split.flip .split-media { order: -1; }

@media (max-width: 860px) {
  .split { grid-template-columns: 1fr; gap: var(--space-4); }
  .split.flip .split-media { order: 0; }
}

/* Centered narrow sections */
.centered {
  max-width: var(--w-prose);
  margin-inline: auto;
  text-align: center;
}
.centered h2 { margin-inline: auto; }
.centered p { margin-inline: auto; }
.centered ul {
  text-align: left;
  display: inline-block;
  margin-inline: auto;
  padding-left: 1.2rem;
  color: var(--c-ink-soft);
}
.centered .stat-row { margin-inline: auto; }

/* Video embed */
.video-frame { max-width: 54rem; margin-inline: auto; }
.video-frame video {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
  background: #000;
}
.video-frame figcaption { text-align: center; margin-inline: auto; }

figure { margin: var(--space-5) 0; }
figcaption {
  font-size: 0.88rem;
  color: var(--c-ink-faint);
  margin-top: var(--space-2);
  max-width: var(--w-prose);
}

.figure-frame img {
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
  background: #fff;
}
:root[data-theme="dark"] .figure-frame img { background: #f4f4f2; }

.figure-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(15rem, 100%), 1fr));
  gap: var(--space-3);
  align-items: start;
}
.figure-row figure { margin: 0; }

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(13rem, 100%), 1fr));
  gap: var(--space-3);
}
.gallery button {
  padding: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-s);
  overflow: hidden;
  background: var(--c-bg-sunk);
  transition: transform 200ms var(--ease-out), box-shadow 200ms var(--ease-out);
}
.gallery button:hover { transform: translateY(-3px); box-shadow: var(--shadow-s); }
.gallery img { width: 100%; height: 100%; object-fit: cover; aspect-ratio: 4 / 3; }

.callout {
  max-width: var(--w-prose);
  margin: var(--space-4) 0;
  padding: var(--space-4);
  border-left: 3px solid var(--c-accent);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
  background: var(--c-accent-soft);
}
.callout p { margin: 0; }
.callout p + p { margin-top: var(--space-2); }

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
  gap: var(--space-3);
  margin: var(--space-4) 0;
  max-width: var(--w-prose);
}
.stat {
  padding: var(--space-3);
  background: var(--c-bg-raise);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-m);
  text-align: center;
}
.stat .num {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--c-accent-ink);
  display: block;
  line-height: 1.2;
}
.stat .label { font-size: 0.82rem; color: var(--c-ink-soft); }

.next-project {
  margin-top: var(--space-6);
  padding-top: var(--space-5);
  border-top: 1px solid var(--c-line);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  justify-content: center;
  align-items: center;
  text-align: center;
}

/* --------------------------------------------------------------------------
   Lightbox
   -------------------------------------------------------------------------- */

.lightbox {
  border: none;
  padding: 0;
  background: transparent;
  max-width: min(92vw, 70rem);
  max-height: 90vh;
  overscroll-behavior: contain;
}
.lightbox::backdrop { background: rgba(8, 10, 13, 0.82); -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px); }
.lightbox img {
  max-width: 100%;
  max-height: 80vh;
  width: auto;
  height: auto;
  margin-inline: auto;
  border-radius: var(--radius-s);
  background: #fff;
}
.lightbox figcaption { color: #cdd3da; text-align: center; }
.lightbox-close {
  position: absolute;
  top: -0.5rem;
  right: -0.5rem;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  border: none;
  background: var(--c-bg-raise);
  box-shadow: var(--shadow-m);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}
.lightbox figure { position: relative; margin: 0; }

/* --------------------------------------------------------------------------
   Interactive extras: scroll progress, back-to-top, draggable linkage
   -------------------------------------------------------------------------- */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 60;
  background: var(--c-accent);
  transform: scaleX(0);
  transform-origin: left center;
  pointer-events: none;
}

.to-top {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: 55;
  width: 2.9rem;
  height: 2.9rem;
  border-radius: 50%;
  border: 1px solid var(--c-line);
  background: var(--c-bg-raise);
  color: var(--c-ink);
  box-shadow: var(--shadow-m);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 220ms var(--ease-out), transform 220ms var(--ease-out),
    border-color 160ms var(--ease-out);
}
.to-top.is-shown { opacity: 1; transform: none; pointer-events: auto; }
.to-top:hover { border-color: var(--c-accent); }
.to-top svg { width: 1.1rem; height: 1.1rem; }

#linkage-canvas { cursor: grab; touch-action: pan-y; }
#linkage-canvas.is-dragging { cursor: grabbing; }

/* --------------------------------------------------------------------------
   Scroll reveal
   -------------------------------------------------------------------------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 600ms var(--ease-out), transform 600ms var(--ease-out);
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .project-card, .theme-toggle, .gallery button { transition: none; }
  .project-card .thumb img { transition: none; }
}