:root {
  --paper: #ffffff;
  --paper-deep: #f2f2f2;
  --ink: #111111;
  --muted: #626262;
  --line: rgba(17, 17, 17, 0.17);
  --accent: #e53935;
  --white: #ffffff;
  --shadow: 0 30px 70px rgba(17, 17, 17, 0.1);
  --radius: 2px;
  --ease: cubic-bezier(0.2, 0.75, 0.25, 1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(17, 17, 17, 0.022) 1px, transparent 1px),
    var(--paper);
  background-size: 100% 8px;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", sans-serif;
  -webkit-font-smoothing: antialiased;
}

button,
input,
label {
  font: inherit;
}

button,
label {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
label:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(229, 57, 53, 0.42);
  outline-offset: 3px;
}

.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;
}

.site-header {
  min-height: 88px;
  padding: 0 clamp(24px, 5vw, 76px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.brand {
  color: inherit;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 13px;
  font: 700 17px/1 Arial, sans-serif;
  letter-spacing: 0.2em;
}

.brand-mark {
  width: 26px;
  height: 26px;
  display: flex;
  overflow: hidden;
  border: 1px solid var(--ink);
  border-radius: 50%;
  transform: rotate(-30deg);
}

.brand-mark i {
  flex: 1;
  background: var(--ink);
}

.brand-mark i:nth-child(2) {
  background: var(--accent);
}

.brand-mark i:nth-child(3) {
  background: var(--white);
}

.site-header > p,
footer span {
  margin: 0;
  color: var(--muted);
  font: 600 10px/1 Arial, sans-serif;
  letter-spacing: 0.25em;
}

main {
  width: min(1440px, 100%);
  margin-inline: auto;
  padding: 0 clamp(24px, 5vw, 76px) 90px;
}

.intro {
  padding: clamp(68px, 9vw, 130px) 0 clamp(44px, 6vw, 82px);
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(250px, 0.62fr);
  gap: 48px;
  align-items: end;
}

.eyebrow {
  margin: 0 0 25px;
  color: var(--muted);
  font: 700 10px/1.2 Arial, sans-serif;
  letter-spacing: 0.19em;
}

.eyebrow span {
  display: inline-block;
  padding-right: 34px;
  color: var(--accent);
}

.intro h1,
.control-heading h2,
.result h2 {
  margin: 0;
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-weight: 400;
}

.intro h1 {
  grid-column: 1;
  font-size: clamp(42px, 5.8vw, 86px);
  line-height: 1.23;
  letter-spacing: -0.055em;
}

.headline-phrase {
  display: inline-block;
  white-space: nowrap;
}

.intro h1 em {
  color: var(--accent);
  font-style: normal;
  border-bottom: 1px solid currentColor;
}

.lead {
  grid-column: 2;
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 2;
}

.intro .eyebrow {
  grid-column: 1 / -1;
  margin-bottom: -12px;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.8fr) minmax(300px, 0.78fr);
  min-height: 620px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.image-panel {
  min-width: 0;
  min-height: 620px;
  position: relative;
  background: var(--paper-deep);
}

.drop-zone {
  height: 100%;
  min-height: 620px;
  padding: 48px 24px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background:
    radial-gradient(circle at 50% 45%, rgba(255, 255, 255, 0.9) 0 7%, transparent 7.2%),
    linear-gradient(145deg, #ffffff 0%, #ededed 100%);
  transition: filter 220ms var(--ease);
}

.drop-zone::before {
  content: "";
  position: absolute;
  inset: 28px;
  border: 1px dashed rgba(17, 17, 17, 0.32);
  pointer-events: none;
}

.drop-zone:hover,
.drop-zone.is-dragging {
  filter: brightness(1.035);
}

.drop-zone.is-dragging::before {
  border-style: solid;
  border-color: var(--accent);
}

.upload-orbit {
  width: 116px;
  height: 116px;
  display: grid;
  place-items: center;
  margin-bottom: 28px;
  border: 1px solid rgba(17, 17, 17, 0.35);
  border-radius: 50%;
  transition: transform 280ms var(--ease), background 280ms var(--ease);
}

.upload-orbit span {
  display: grid;
  width: 52px;
  height: 52px;
  place-items: center;
  color: var(--white);
  background: var(--ink);
  border-radius: 50%;
  font: 300 27px/1 Arial, sans-serif;
}

.drop-zone:hover .upload-orbit {
  transform: scale(1.05) rotate(6deg);
  background: rgba(255, 255, 255, 0.6);
}

.drop-title {
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-size: clamp(22px, 2.5vw, 34px);
}

.drop-sub {
  margin-top: 9px;
  color: var(--muted);
  font-size: 12px;
}

.file-types {
  margin-top: 34px;
  color: var(--muted);
  font: 700 9px/1 Arial, sans-serif;
  letter-spacing: 0.17em;
}

.preview-wrap {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: #d8d8d8;
}

.preview-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.preview-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(17, 17, 17, 0.09), transparent 35%, transparent 65%, rgba(17, 17, 17, 0.45));
  pointer-events: none;
}

.change-image {
  position: absolute;
  top: 24px;
  right: 24px;
  padding: 11px 15px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.93);
  border: 0;
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .05em;
}

.change-image span {
  display: inline-block;
  margin-right: 5px;
  font-size: 15px;
}

.image-caption {
  position: absolute;
  left: 26px;
  right: 26px;
  bottom: 24px;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  color: white;
}

.image-caption span {
  font: 700 9px/1 Arial, sans-serif;
  letter-spacing: .18em;
}

.image-caption strong {
  max-width: 55%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 11px;
  font-weight: 500;
}

.control-panel {
  padding: clamp(36px, 5vw, 68px) clamp(28px, 4vw, 54px);
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--line);
}

.control-heading h2,
.result h2 {
  font-size: clamp(28px, 3vw, 42px);
  letter-spacing: -0.04em;
}

.control-block {
  padding: 0;
  margin: 45px 0 0;
  border: 0;
}

.control-block + .control-block {
  margin-top: 34px;
}

.control-block legend {
  margin-bottom: 16px;
  padding: 0;
  font-size: 12px;
  font-weight: 700;
}

.count-row {
  display: flex;
  align-items: center;
  gap: 20px;
}

input[type="range"] {
  min-width: 0;
  flex: 1;
  height: 2px;
  appearance: none;
  background: var(--line);
}

input[type="range"]::-webkit-slider-thumb {
  width: 20px;
  height: 20px;
  appearance: none;
  background: var(--ink);
  border: 5px solid var(--white);
  border-radius: 50%;
  box-shadow: 0 0 0 1px var(--ink);
}

.count-row output {
  min-width: 42px;
  font-family: "Yu Mincho", serif;
  font-size: 20px;
}

.segmented {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
}

.segmented label {
  cursor: pointer;
}

.segmented label + label {
  border-left: 1px solid var(--line);
}

.segmented input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.segmented span {
  min-height: 46px;
  padding: 8px 10px;
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--muted);
  font-size: 11px;
}

.segmented input:checked + span {
  color: var(--white);
  background: var(--ink);
}

.hint {
  min-height: 20px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 10px;
  line-height: 1.6;
}

.primary-button,
.secondary-button {
  border: 0;
  cursor: pointer;
  transition: transform 180ms var(--ease), background 180ms var(--ease);
}

.primary-button {
  min-height: 58px;
  padding: 0 20px;
  margin-top: auto;
  color: var(--white);
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  font-weight: 700;
}

.primary-button:hover:not(:disabled) {
  transform: translateY(-2px);
  background: var(--accent);
  box-shadow: 0 8px 22px rgba(229, 57, 53, 0.22);
}

.primary-button:disabled {
  cursor: not-allowed;
  opacity: .35;
}

.status {
  min-height: 38px;
  margin: 15px 0 0;
  color: var(--muted);
  font-size: 10px;
  line-height: 1.7;
}

.result {
  padding: clamp(80px, 10vw, 150px) 0 20px;
}

.result-title-row {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.result-title-row .eyebrow {
  margin-bottom: 18px;
}

.format-picker {
  display: flex;
}

.format-button {
  min-width: 62px;
  min-height: 38px;
  padding: 0 12px;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  cursor: pointer;
  font: 700 9px/1 Arial, sans-serif;
  letter-spacing: .12em;
}

.format-button + .format-button {
  border-left: 0;
}

.format-button.is-active {
  color: var(--white);
  background: var(--ink);
}

.result-grid {
  display: grid;
  grid-template-columns: minmax(320px, .78fr) minmax(0, 1.25fr);
  gap: clamp(40px, 8vw, 120px);
  padding: clamp(50px, 7vw, 96px) 0 55px;
}

.composition-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 30px;
}

.chart-wrap {
  position: relative;
  width: min(100%, 420px);
  aspect-ratio: 1;
}

#palette-chart {
  width: 100%;
  height: 100%;
  display: block;
}

.chart-center {
  position: absolute;
  inset: 29%;
  display: grid;
  place-content: center;
  text-align: center;
  background: var(--paper);
  border-radius: 50%;
}

.chart-center span,
.mini-label {
  color: var(--muted);
  font: 700 9px/1 Arial, sans-serif;
  letter-spacing: .18em;
}

.chart-center strong {
  margin-top: 8px;
  font: 400 clamp(14px, 2vw, 23px)/1 "Yu Mincho", serif;
  letter-spacing: .06em;
}

.mini-label {
  margin: 0 0 9px;
}

.chart-note {
  margin: 0;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.8;
}

.swatch-list {
  border-top: 1px solid var(--line);
}

.swatch {
  width: 100%;
  padding: 18px 4px;
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr) auto;
  gap: 20px;
  align-items: center;
  color: inherit;
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--line);
  text-align: left;
  cursor: pointer;
  transition: padding 180ms var(--ease), background 180ms var(--ease);
}

.swatch:hover {
  padding-left: 12px;
  padding-right: 12px;
  background: rgba(17, 17, 17, 0.035);
}

.swatch-color {
  height: 54px;
  background: var(--swatch);
}

.swatch-role {
  display: block;
  margin-bottom: 7px;
  color: var(--muted);
  font-size: 10px;
  letter-spacing: .08em;
}

.swatch-code {
  display: block;
  font: 400 clamp(16px, 2vw, 22px)/1.2 "SFMono-Regular", Consolas, monospace;
  letter-spacing: -.04em;
}

.swatch-ratio {
  color: var(--muted);
  font: 400 17px/1 "Yu Mincho", serif;
}

.result-actions {
  padding: 27px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  border-top: 1px solid var(--line);
}

.secondary-button {
  min-height: 48px;
  padding: 0 20px;
  color: var(--white);
  background: var(--ink);
  font-size: 11px;
  font-weight: 700;
}

.secondary-button:hover {
  transform: translateY(-2px);
  background: var(--ink);
  box-shadow: 0 8px 22px rgba(17, 17, 17, 0.16);
}

.result-actions p {
  margin: 0;
  color: var(--muted);
  font-size: 10px;
}

footer {
  min-height: 94px;
  padding: 0 clamp(24px, 5vw, 76px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 10px;
}

.toast {
  position: fixed;
  z-index: 10;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  padding: 12px 18px;
  color: var(--white);
  background: var(--ink);
  box-shadow: 0 12px 30px rgba(0,0,0,.2);
  font-size: 11px;
}

@media (max-width: 820px) {
  .site-header {
    min-height: 70px;
  }

  .site-header > p {
    display: none;
  }

  .intro {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .intro h1,
  .lead {
    grid-column: 1;
  }

  .intro .eyebrow {
    grid-column: 1;
  }

  .lead {
    max-width: 36em;
  }

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

  .image-panel,
  .drop-zone {
    min-height: min(76svh, 620px);
  }

  .control-panel {
    min-height: 520px;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

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

  .composition-card {
    align-items: center;
    text-align: center;
  }
}

@media (max-width: 520px) {
  .intro h1 {
    font-size: clamp(39px, 12.5vw, 58px);
  }

  .intro h1 br {
    display: none;
  }

  .image-panel,
  .drop-zone {
    min-height: 460px;
  }

  .drop-zone::before {
    inset: 18px;
  }

  .control-panel {
    min-height: 500px;
  }

  .result-title-row,
  .result-actions {
    align-items: flex-start;
    flex-direction: column;
  }

  .format-button {
    min-width: 58px;
  }

  .swatch {
    grid-template-columns: 55px minmax(0, 1fr) auto;
    gap: 14px;
  }

  .swatch-color {
    height: 48px;
  }

  .swatch-code {
    font-size: 14px;
  }

  footer {
    padding-block: 28px;
    align-items: flex-start;
    flex-direction: column;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}