:root {
  color-scheme: light;
  --bg: #f3efe7;
  --panel: rgba(255, 252, 247, 0.92);
  --panel-strong: #fffdf8;
  --line: #d8cdbd;
  --text: #1f1d1a;
  --muted: #6a6258;
  --accent: #a84b2a;
  --accent-strong: #84341a;
  --accent-soft: rgba(168, 75, 42, 0.14);
  --shadow: 0 18px 45px rgba(63, 43, 25, 0.12);
  --thumb-columns: 4;
  --thumb-preview-min-height: 210px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Yu Gothic UI", "Hiragino Sans", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(224, 163, 76, 0.18), transparent 28%),
    radial-gradient(circle at top right, rgba(122, 81, 191, 0.08), transparent 24%),
    linear-gradient(180deg, #f8f4ec 0%, var(--bg) 100%);
}

.app-shell {
  width: calc(100% - 32px);
  margin: 32px auto 48px;
}

.hero,
.controls,
.grid-header,
.bottom-actions {
  background: var(--panel);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.hero {
  padding: 28px;
}

.hero-topbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.8rem;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-family: Georgia, "Yu Mincho", serif;
  font-size: clamp(2rem, 3vw, 3.2rem);
  line-height: 1.08;
}

.hero-copy {
  margin-top: 14px;
  max-width: 720px;
  color: var(--muted);
  line-height: 1.7;
}

.language-control {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.66);
  border: 1px solid rgba(216, 205, 189, 0.8);
  font-weight: 700;
}

.language-control select {
  border: none;
  background: transparent;
  font: inherit;
  color: var(--text);
}

.controls {
  margin-top: 20px;
  padding: 20px;
  display: grid;
  gap: 18px;
}

.file-picker {
  width: fit-content;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 999px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  font-weight: 700;
  cursor: pointer;
}

.file-picker input {
  max-width: 220px;
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.thumbnail-size-control {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(216, 205, 189, 0.8);
}

.thumbnail-size-control label {
  font-weight: 700;
}

.thumbnail-size-control input[type="range"] {
  flex: 1 1 220px;
  accent-color: var(--accent);
}

.thumbnail-size-control span {
  min-width: 48px;
  color: var(--muted);
  font-weight: 700;
  text-align: right;
}

button {
  appearance: none;
  border: none;
  border-radius: 999px;
  padding: 12px 18px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 140ms ease, background-color 140ms ease, opacity 140ms ease;
}

.blank-selected-button {
  color: #fff;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
}

.action-row button:last-child {
  color: var(--text);
  background: #ece2d4;
}

button:hover:enabled {
  transform: translateY(-1px);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.status-panel {
  display: grid;
  gap: 8px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.6);
  border: 1px dashed var(--line);
  border-radius: 18px;
  color: var(--muted);
}

.grid-header {
  margin-top: 20px;
  padding: 18px 20px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: end;
}

.grid-header p {
  color: var(--muted);
}

.thumbnail-grid {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(var(--thumb-columns), minmax(0, 1fr));
  gap: 16px;
}

.bottom-actions {
  margin-top: 20px;
  padding: 18px 20px;
  display: flex;
  justify-content: center;
}

.thumbnail-card {
  min-width: 0;
  align-self: start;
}

.thumbnail-button {
  width: 100%;
  display: grid;
  gap: 12px;
  padding: 14px;
  text-align: left;
  color: inherit;
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.thumbnail-button.selected {
  background: linear-gradient(180deg, rgba(255, 247, 241, 0.98), rgba(255, 236, 228, 0.92));
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.thumbnail-canvas-wrap {
  min-height: var(--thumb-preview-min-height);
  display: grid;
  place-items: center;
  padding: 10px;
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(248, 244, 236, 0.9), rgba(240, 231, 219, 0.9));
  border: 1px solid rgba(216, 205, 189, 0.7);
}

canvas {
  display: block;
  max-width: 100%;
  height: auto;
  box-shadow: 0 10px 20px rgba(34, 28, 23, 0.15);
}

.thumbnail-meta {
  display: grid;
  gap: 4px;
}

.page-label {
  font-size: 0.98rem;
}

.page-size {
  color: var(--muted);
  font-size: 0.88rem;
}

@media (max-width: 640px) {
  .app-shell {
    width: calc(100% - 20px);
    margin: 20px auto 32px;
  }

  .hero,
  .controls,
  .grid-header,
  .bottom-actions {
    border-radius: 20px;
  }

  .grid-header {
    align-items: start;
    flex-direction: column;
  }

  .hero-topbar {
    flex-direction: column;
  }

  .thumbnail-grid {
    grid-template-columns: repeat(var(--thumb-columns), minmax(0, 1fr));
  }
}