/* Digital Darkroom: one continuous sequence (Pick photo -> Enlarger -> Focus -> Expose -> Develop).
   Tokens, components and motion are lifted from the four interaction studies in /studies. */
:root {
  --bg: #0b0807;
  --ink: #e3d9cc;
  --dim: #7a6d63;
  --safe: #d0402e;
  --glow: #ffd9a8;
  --paper: #ece6da;
  --tray: #15100e;
  --mono: 'IBM Plex Mono', ui-monospace, Menlo, Consolas, monospace;
  color-scheme: dark;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
}
* { box-sizing: border-box; }
html { scroll-padding-top: env(safe-area-inset-top, 0px); }
[hidden]:not([hidden=until-found i]) { display: none !important; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 15px;
  line-height: 1.5;
  margin: 0;
  padding-block: 24px 56px;
  padding-inline: 16px;
}
#lamp {
  position: fixed; inset: 0; pointer-events: none; z-index: 0; opacity: 0;
  background: radial-gradient(ellipse at 50% 30%, rgba(255,160,110,.22), rgba(0,0,0,0) 65%);
  transition: opacity 1.4s ease;
}
#flood { position: fixed; inset: 0; pointer-events: none; z-index: 0; opacity: 0; background: #ffe9d6; }
#app { position: relative; z-index: 1; max-width: 760px; margin: 0 auto; overflow-x: clip; --ar: .8; }

.topbar { display: flex; flex-wrap: wrap; row-gap: 0; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 6px; min-height: 44px; }
.brand { font-size: 12px; letter-spacing: .16em; text-transform: uppercase; color: var(--dim); margin: 0; }
header { display: flex; flex-direction: column; gap: 14px; margin-bottom: 24px; }
#dots { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; }
#dots li {
  font-size: 12px; letter-spacing: .08em; text-transform: uppercase;
  border: 1px dashed var(--dim); color: var(--dim); padding: 4px 10px;
  transition: border-color .4s, color .4s, background .4s;
}
#dots li.current { border: 1px solid var(--safe); color: var(--ink); }
#dots li.done { border: 1px solid var(--dim); color: var(--ink); background: rgba(255,255,255,.05); }
h1 { font-size: clamp(22px, 5vw, 30px); font-weight: 500; margin: 0; text-wrap: balance; }
#stephint { margin: 0; color: var(--dim); min-height: 1.5em; }

/* Starting state: pick the photo to print */
#intro { display: flex; flex-direction: column; gap: 20px; align-items: flex-start; padding-top: 8px; }
#intro p { margin: 0; color: var(--dim); max-width: 52ch; }
.row { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.linkbtn { font: inherit; color: var(--dim); background: none; border: 0; padding: 12px 4px; text-decoration: underline; text-underline-offset: 4px; cursor: pointer; }
.linkbtn:hover { color: var(--ink); }
.linkbtn:focus-visible { outline: 2px solid var(--safe); outline-offset: 3px; }
#err { color: #f08a7a; min-height: 1.5em; }
#dropnote { font-size: 13px; }
body.dragging #intro { outline: 2px dashed var(--safe); outline-offset: 12px; }
#file { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }

#room.fadein { animation: fadein .9s ease both; }

.bench {
  display: flex; flex-wrap: wrap; gap: 24px; justify-content: center; align-items: flex-start;
  min-height: 300px; margin-bottom: 24px;
}
.bench > * { min-width: 0; }

/* The easel holds the one sheet of paper for the whole sequence.
   Width follows the photo's shape so tall photos never push the controls off a phone screen. */
.easel {
  width: min(360px, 100%, calc(46vh * var(--ar) + 28px)); border: 1px dashed var(--dim); padding: 14px; background: #050403;
  transition: border-color .6s ease, background .6s ease;
}
.bench.develop .easel { width: 190px; max-width: 100%; padding: 0; border-color: transparent; background: transparent; }

/* The paper. Under the enlarger it is lit only by the projected negative; under the safelight it reads as cream paper. */
.paper {
  width: 100%; background: #1a1714; padding: 10px 10px 30px;
  user-select: none; -webkit-user-select: none; -webkit-touch-callout: none; position: relative; z-index: 3;
  transition: background .9s ease;
}
.paper.lit { background: #4a443d; }
.paper.safelight { background: var(--paper); }
.paper.draggable { touch-action: none; cursor: grab; }
.paper.lifted { cursor: grabbing; transform-origin: center; }
.paper.in-tray { cursor: default; }
.paper:focus-visible { outline: 2px solid var(--safe); outline-offset: 4px; }
.surface { position: relative; overflow: hidden; }
.surface canvas { display: block; width: 100%; height: auto; aspect-ratio: var(--ar); }
/* The projected negative, laid over the paper */
#photo { position: absolute; inset: 0; height: 100%; transition: filter .9s ease, opacity .8s ease; filter: blur(16px) brightness(.16); }
/* The latent image on the paper: invisible until it is developed */
#print { opacity: 0; filter: invert(1) contrast(.5) brightness(1.2); }
/* In the developer the print appears as a negative, then flips to a positive */
@keyframes develop {
  0%   { opacity: 0; filter: invert(1) contrast(.5) brightness(1.2); }
  18%  { opacity: 1; filter: invert(1) contrast(.95) brightness(1); }
  100% { opacity: 1; filter: invert(0) contrast(1) brightness(1); }
}
.paper.developing #print { animation: develop 9s ease-in-out forwards; }
.paper.revealed { overflow: hidden; }
.paper::after {
  content: ''; position: absolute; inset: 0; pointer-events: none; opacity: 0; transform: translateX(-120%);
  background: linear-gradient(105deg, transparent 38%, rgba(255,255,255,.34) 50%, transparent 62%);
}
.paper.sheen::after { opacity: 1; animation: sheen 1.3s ease-out forwards; }
@keyframes sheen { from { transform: translateX(-120%); } to { transform: translateX(120%); } }
@keyframes fadein { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.paper .grab { position: absolute; left: 0; right: 0; bottom: 8px; text-align: center; font-size: 11px; letter-spacing: .1em; text-transform: uppercase; color: #8a8174; }

.tray {
  width: 240px; max-width: 100%; height: 280px; border: 2px dashed var(--dim); background: var(--tray);
  position: relative; transition: border-color .2s, background .6s;
}
.tray.arrive { animation: fadein .9s ease both; }
.tray.ready { border-color: var(--safe); }
.tray.active { background: #231713; border-style: solid; }
/* Tray and paper share one rocking motion (individual translate/rotate props, so the paper's drag transform is untouched) */
@keyframes agitate {
  0%   { translate: 0 0;      rotate: 0deg; }
  15%  { translate: -5px 2px; rotate: -1.4deg; }
  30%  { translate: 4px -2px; rotate: 1.2deg; }
  45%  { translate: -4px 1px; rotate: -1deg; }
  60%  { translate: 5px 2px;  rotate: 1.5deg; }
  80%  { translate: -3px -1px; rotate: -.8deg; }
  100% { translate: 0 0;      rotate: 0deg; }
}
.tray.agitating, .paper.agitating { animation: agitate 1.4s ease-in-out infinite; }
@media (prefers-reduced-motion: reduce) { .tray.agitating, .paper.agitating { animation-duration: 3s; } }
.tray span { position: absolute; top: 8px; left: 10px; font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--dim); }

.controls { min-height: 150px; display: flex; flex-direction: column; align-items: center; gap: 14px; text-align: center; }
.controls [hidden] { display: none !important; }
.group { display: flex; flex-direction: column; align-items: center; gap: 14px; width: 100%; }
.group.fadein { animation: fadein .9s ease both; }

.switch {
  font: inherit; color: var(--ink); background: transparent; cursor: pointer; -webkit-tap-highlight-color: transparent;
  display: flex; align-items: center; gap: 14px; border: 2px solid var(--ink); padding: 8px 16px 8px 8px;
}
.switch .track { width: 64px; height: 36px; border: 2px solid var(--ink); position: relative; }
.switch .knob { position: absolute; top: 2px; left: 2px; width: 28px; height: 28px; background: var(--ink); transition: left .2s, background .2s; }
.switch[aria-checked="true"] .knob { left: 30px; background: var(--safe); }
.switch .lbl { letter-spacing: .12em; font-size: 13px; width: 5.5ch; text-align: left; }
.switch:focus-visible, .btn:focus-visible, input[type=range]:focus-visible, .bulb:focus-visible { outline: 2px solid var(--safe); outline-offset: 4px; }

input[type=range] { width: min(420px, 100%); accent-color: var(--safe); height: 44px; cursor: pointer; }
input[type=range]:disabled { cursor: default; opacity: .6; }

/* Focus slider: 440px wide, 7px track, 21px center circle, darkroom red */
#focus {
  --sl-width: 440px; --sl-track: 7px; --sl-thumb: 21px; --sl-color: #d0402e; --sl-pct: 8%;
  -webkit-appearance: none; appearance: none; background: transparent;
  width: min(var(--sl-width), 100%); height: max(44px, calc(var(--sl-thumb) + 8px));
}
#focus::-webkit-slider-runnable-track {
  height: var(--sl-track); border-radius: 999px;
  background: linear-gradient(to right, var(--sl-color) 0 var(--sl-pct), #efe9e0 var(--sl-pct) 100%);
}
#focus::-moz-range-track { height: var(--sl-track); border-radius: 999px; background: #efe9e0; }
#focus::-moz-range-progress { height: var(--sl-track); border-radius: 999px; background: var(--sl-color); }
#focus::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; border: 0; border-radius: 50%;
  width: var(--sl-thumb); height: var(--sl-thumb); background: var(--sl-color);
  margin-top: calc((var(--sl-track) - var(--sl-thumb)) / 2);
}
#focus::-moz-range-thumb { border: 0; border-radius: 50%; width: var(--sl-thumb); height: var(--sl-thumb); background: var(--sl-color); }

.label { font-size: 12px; letter-spacing: .14em; text-transform: uppercase; color: var(--dim); }
#focus-state { min-height: 1.5em; }

.btn {
  font: inherit; font-size: 14px; letter-spacing: .14em; text-transform: uppercase; color: var(--ink);
  background: transparent; border: 2px solid var(--ink); padding: 14px 32px; cursor: pointer; -webkit-tap-highlight-color: transparent;
}
.btn:hover:not(:disabled) { background: rgba(255,255,255,.08); }
.btn:disabled { opacity: .5; cursor: default; }

/* Hold-to-expose light bulb */
.bulb {
  position: relative; width: 128px; height: 128px; padding: 0; border: 0; border-radius: 50%; background: transparent; color: var(--ink);
  cursor: pointer; touch-action: none; user-select: none; -webkit-user-select: none; -webkit-touch-callout: none; -webkit-tap-highlight-color: transparent;
}
.bulb:disabled { cursor: default; }
.bulb .ring { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.ring circle { fill: none; stroke-width: 3; }
.ring .track { stroke: var(--dim); stroke-dasharray: 3 5; opacity: .75; }
.ring .prog { stroke: var(--safe); stroke-linecap: round; stroke-dasharray: 1; stroke-dashoffset: 1; transform: rotate(-90deg); transform-origin: 60px 60px; }
.bulb .icon {
  position: absolute; left: 50%; top: 50%; width: 60px; height: 60px; translate: -50% -50%;
  fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round;
  transition: fill .12s ease, stroke .12s ease, filter .12s ease;
}
.bulb.on .icon { fill: var(--glow); stroke: var(--glow); filter: drop-shadow(0 0 16px rgba(255,190,120,.95)); }
.bulb.on .fil { stroke: #8f5f2e; }
.bulb.on { color: var(--glow); }
#exp-read { font-variant-numeric: tabular-nums; text-transform: none; font-size: 14px; }

#done-msg { font-size: clamp(24px, 6vw, 34px); font-weight: 500; margin: 0; }
#done { margin-top: 4px; }
#done-sub { margin: 0; color: var(--dim); max-width: 46ch; }
#save-note { margin: 0; color: var(--dim); min-height: 1.5em; }
#dev-bar-wrap { width: min(420px, 100%); height: 8px; border: 1px solid var(--dim); }
#dev-fill { display: block; height: 100%; width: 0; background: var(--safe); }

@media (max-width: 560px) {
  .bench { gap: 16px; min-height: 0; }
  .bench.develop { flex-wrap: nowrap; }
  .bench.develop .easel { width: min(190px, 34vw); }
  .paper.safelight { padding: 8px 8px 26px; }
  .tray { width: min(240px, 46vw); height: min(280px, 64vw); }
  .bulb { width: 144px; height: 144px; }
}