/* ── Design tokens ──────────────────────────────────────────────────────────── */
:root {
  /* Dark theme (default) */
  --bg:       #0f1115;
  --panel:    #171a21;
  --panel-2:  #1e222b;
  --fg:       #e6e8ec;
  --muted:    #8a93a6;
  --accent:   #7cc4ff;
  --border:   #272b35;
  --radius-card: 10px;
}

[data-theme="light"] {
  --bg:       #f0f2f5;
  --panel:    #ffffff;
  --panel-2:  #f5f7fa;
  --fg:       #1a1d24;
  --muted:    #5a6378;
  --accent:   #1a7fd4;
  --border:   #dde1ea;
}

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

html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
  transition: background 0.2s, color 0.2s;
}

/* ── Header ─────────────────────────────────────────────────────────────────── */
header {
  padding: 20px 32px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.header-main h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.header-main p {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.theme-btn {
  padding: 5px 14px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--fg);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: border-color 0.15s;
}
.theme-btn:hover { border-color: var(--accent); }

.lang-switch {
  display: flex;
  align-items: center;
  gap: 6px;
}
.lang-switch label {
  color: var(--muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
}
select {
  padding: 6px 10px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--fg);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
}
select:focus { outline: none; border-color: var(--accent); }

/* ── Main layout ────────────────────────────────────────────────────────────── */
main {
  padding: 28px 32px 56px;
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.section { }

.section-title {
  margin: 0 0 12px;
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  font-weight: 600;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.section-header .section-title { margin: 0; }

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 20px 24px;
}

/* ── Preview ────────────────────────────────────────────────────────────────── */
.preview-canvas {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 220px;
  border-radius: 12px;
  border: 1px solid var(--border);
  margin-bottom: 14px;
  overflow: hidden;
  transition: background 0.2s;
}

.preview-box {
  transition: box-shadow 0.15s ease, width 0.15s, height 0.15s, border-radius 0.15s, background 0.15s;
}

/* ── Box controls ───────────────────────────────────────────────────────────── */
.box-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.box-controls .field {
  flex: 1;
  min-width: 120px;
}

/* ── Field base ─────────────────────────────────────────────────────────────── */
.field-label {
  display: block;
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
  margin-bottom: 5px;
}

/* ── Number + range combo ───────────────────────────────────────────────────── */
.num-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}
.num-wrap input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}
.num-input {
  width: 58px;
  padding: 5px 7px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--fg);
  font-size: 12px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  text-align: right;
}
.num-input:focus { outline: none; border-color: var(--accent); }

/* Standalone num-input (box controls) */
.box-controls .num-input {
  width: 100%;
  text-align: left;
}

.color-input {
  width: 100%;
  height: 32px;
  padding: 0 2px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 5px;
  cursor: pointer;
}

/* ── Add layer button ───────────────────────────────────────────────────────── */
.add-btn {
  padding: 5px 14px;
  background: var(--accent);
  color: #0b1320;
  border: none;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  transition: opacity 0.15s;
}
.add-btn:hover { opacity: 0.85; }

/* ── Layers list ────────────────────────────────────────────────────────────── */
.layers {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.layer-card {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
}

.layer-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.layer-title {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 12px;
  color: var(--accent);
  font-weight: 700;
  flex: 1;
}

.inset-label {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}
.inset-label input[type="checkbox"] {
  accent-color: var(--accent);
  width: 14px;
  height: 14px;
  cursor: pointer;
}

.remove-btn {
  padding: 4px 9px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
  font-family: inherit;
  transition: color 0.15s, border-color 0.15s;
}
.remove-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.remove-btn:hover:not(:disabled) { color: #ff6b6b; border-color: #ff6b6b; }

.layer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px 14px;
}

/* ── Output ─────────────────────────────────────────────────────────────────── */
.output-section {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  background: var(--panel-2);
  border-bottom: 1px solid var(--border);
}

.output-label-text {
  color: var(--muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
}

.copy-btn {
  padding: 4px 12px;
  background: var(--accent);
  color: #0b1320;
  border: none;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  text-transform: uppercase;
  transition: opacity 0.15s;
}
.copy-btn:hover { opacity: 0.85; }

.output {
  margin: 0;
  padding: 16px 20px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  color: var(--accent);
  white-space: pre-wrap;
  word-break: break-all;
  line-height: 1.7;
}

/* ── Presets ────────────────────────────────────────────────────────────────── */
.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.preset-btn {
  padding: 20px 28px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--fg);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.1s ease, border-color 0.15s;
  min-width: 110px;
  text-align: center;
}
.preset-btn:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

/* ── Footer ─────────────────────────────────────────────────────────────────── */
footer {
  padding: 20px 32px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

/* ── Responsive ─────────────────────────────────────────────────────────────── */
@media (max-width: 600px) {
  header { padding: 16px 16px 10px; }
  main { padding: 20px 16px 48px; }
  footer { padding: 16px; }

  .layer-grid {
    grid-template-columns: 1fr;
  }
  .box-controls .field {
    min-width: 100px;
  }
  .presets { gap: 8px; }
  .preset-btn { padding: 16px 18px; min-width: 90px; }
}