/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #f5f5f0;
  --surface: #ffffff;
  --border: #ddd;
  --text: #333;
  --text-muted: #888;
  --accent: #cc0000;
  --accent-hover: #aa0000;
  --radius: 6px;
  --shadow: 0 1px 4px rgba(0,0,0,.12);
}

body {
  font-family: 'Noto Serif JP', serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* ===== Header ===== */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px;
  box-shadow: var(--shadow);
}
header h1 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .05em;
}

/* ===== Layout ===== */
.app-layout {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 0;
  min-height: calc(100vh - 53px);
}

/* ===== Controls Panel ===== */
.controls-panel {
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 16px;
  overflow-y: auto;
  max-height: calc(100vh - 53px);
}

.section-label {
  font-size: .75rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin: 16px 0 8px;
}
.controls-panel .section-label:first-child { margin-top: 0; }

/* Type tabs */
.type-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
}
.tab-btn {
  padding: 7px 4px;
  font-size: .8rem;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  cursor: pointer;
  transition: background .15s, border-color .15s, color .15s;
  color: var(--text);
}
.tab-btn:hover { background: #eee; }
.tab-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 700;
}

/* Color palette */
.color-palette {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.color-btn {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform .1s, border-color .1s;
  flex-shrink: 0;
}
.color-btn:hover { transform: scale(1.15); }
.color-btn.active { border-color: var(--text); box-shadow: 0 0 0 2px var(--surface); }

.color-custom-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #f00, #ff0, #0f0, #0ff, #00f, #f0f);
  cursor: pointer;
  font-size: .75rem;
  color: #fff;
  font-weight: 700;
  text-shadow: 0 0 2px #000;
}
.color-custom-wrap input[type=color] {
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
  pointer-events: none;
}

/* Fields */
.fields-container { margin-top: 4px; }

.field-group {
  margin-bottom: 12px;
}
.field-group.hidden { display: none; }

.field-group label {
  display: block;
  font-size: .8rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.field-group input[type=text],
.field-group input[type=date],
.field-group select {
  width: 100%;
  padding: 7px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: .9rem;
  background: var(--bg);
  color: var(--text);
  outline: none;
  transition: border-color .15s;
}
.field-group input:focus,
.field-group select:focus { border-color: var(--accent); }

.field-group input[type=range] {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
}

/* Thickness buttons */
.thickness-btns {
  display: flex;
  gap: 6px;
}
.thickness-btn {
  flex: 1;
  padding: 6px;
  font-size: .85rem;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  cursor: pointer;
  transition: background .15s, border-color .15s, color .15s;
  color: var(--text);
}
.thickness-btn:hover { background: #eee; }
.thickness-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 700;
}

/* Save/Load row */
.save-load-row {
  display: flex;
  gap: 6px;
  margin-bottom: 8px;
}
.save-load-row input {
  flex: 1;
  padding: 7px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: .85rem;
  background: var(--bg);
  color: var(--text);
  outline: none;
}
.save-load-row input:focus { border-color: var(--accent); }

/* inline row for load/delete */
.field-group select + button { margin-top: 6px; }
.field-group { position: relative; }

.field-group > select + .btn-secondary + .btn-secondary {
  margin-left: 4px;
}

/* Button styles */
.btn-primary {
  padding: 10px 18px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-family: inherit;
  font-size: .9rem;
  font-weight: 700;
  cursor: pointer;
  transition: background .15s;
}
.btn-primary:hover { background: var(--accent-hover); }
.btn-primary:active { transform: scale(.98); }

.btn-secondary {
  padding: 7px 12px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: .82rem;
  cursor: pointer;
  transition: background .15s;
}
.btn-secondary:hover { background: #e8e8e8; }

.btn-danger { color: var(--accent); }

/* ===== Preview Panel ===== */
.preview-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 24px;
  gap: 24px;
}

.canvas-wrap {
  position: relative;
  display: inline-block;
  box-shadow: 0 2px 16px rgba(0,0,0,.15);
  border-radius: 4px;
  /* Checkerboard pattern to show transparency */
  background-image:
    linear-gradient(45deg, #ccc 25%, transparent 25%),
    linear-gradient(-45deg, #ccc 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ccc 75%),
    linear-gradient(-45deg, transparent 75%, #ccc 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0px;
  background-color: #f0f0f0;
}

#sealCanvas {
  display: block;
  width: 300px;
  height: 300px;
  border-radius: 4px;
}

.loading-overlay {
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,.85);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .9rem;
  color: var(--text-muted);
  border-radius: 4px;
  pointer-events: none;
}
.loading-overlay.hidden { display: none; }

.export-btns {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(16px);
  background: #333;
  color: #fff;
  padding: 10px 20px;
  border-radius: 20px;
  font-size: .9rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  z-index: 1000;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== Responsive: Mobile ===== */
@media (max-width: 767px) {
  .app-layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .controls-panel {
    border-right: none;
    border-bottom: 1px solid var(--border);
    max-height: none;
    order: 2;
  }

  .preview-panel {
    order: 1;
    position: sticky;
    top: 53px;
    background: var(--bg);
    z-index: 10;
    padding: 16px;
    gap: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,.1);
  }

  #sealCanvas {
    width: 200px;
    height: 200px;
  }

  .export-btns { gap: 8px; }
  .btn-primary { padding: 8px 14px; font-size: .85rem; }
}