/* ========= Design Tokens ========= */
:root, [data-theme="light"] {
  --color-bg:         #f5f5f0;
  --color-surface:    #ffffff;
  --color-surface-2:  #fafaf7;
  --color-border:     #d4d1ca;
  --color-divider:    #e5e3de;
  --color-text:       #1a1a18;
  --color-text-muted: #6b6b66;
  --color-text-faint: #a3a39e;
  --color-primary:    #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-active: #1e40af;
  --color-primary-text: #ffffff;
  --color-cell-bg:    #ffffff;
  --color-cell-black: #1a1a18;
  --color-cell-number: #2563eb;
  --color-cell-letter: #1a1a18;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
  --color-bg:         #141413;
  --color-surface:    #1e1e1c;
  --color-surface-2:  #252523;
  --color-border:     #3a3a36;
  --color-divider:    #2e2e2a;
  --color-text:       #e5e5e0;
  --color-text-muted: #8a8a85;
  --color-text-faint: #5a5a56;
  --color-primary:    #60a5fa;
  --color-primary-hover: #93c5fd;
  --color-primary-active: #3b82f6;
  --color-primary-text: #141413;
  --color-cell-bg:    #2a2a28;
  --color-cell-black: #0a0a09;
  --color-cell-number: #60a5fa;
  --color-cell-letter: #e5e5e0;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.4);
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
}

/* ========= Layout ========= */
.app {
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-divider);
  backdrop-filter: blur(12px);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.logo-icon { color: var(--color-primary); flex-shrink: 0; }

.logo-text {
  font-size: clamp(1rem, 0.9rem + 0.5vw, 1.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.theme-toggle:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

.main {
  flex: 1;
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

/* ========= Input Section ========= */
.input-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.section-header h2 {
  font-size: clamp(1.125rem, 1rem + 0.5vw, 1.375rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.hint {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

.hint code {
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
}

.word-input {
  width: 100%;
  padding: 1rem;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.8125rem;
  line-height: 1.7;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  resize: vertical;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.word-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 15%, transparent);
}

.actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ========= Title & Solution Inputs ========= */
.input-row {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 1rem;
  align-items: start;
}

.input-field--narrow {
  width: 130px;
}

.input-row--api {
  grid-template-columns: 1fr;
  margin-top: -0.25rem;
}

.input-field--api .title-input {
  font-family: monospace;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

.input-field--narrow .title-input {
  text-align: center;
  font-size: 1.1rem;
  font-weight: 600;
}

.input-field {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.input-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text);
}

.hint-inline {
  font-weight: 400;
  color: var(--color-text-muted);
  font-size: 0.75rem;
}

.title-input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.title-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 15%, transparent);
}
.title-input::placeholder {
  color: var(--color-text-faint);
}

/* ========= Solution Word Cells ========= */
.cell.solution-cell {
  background: #fef3c7;
  border-color: #f59e0b;
}
[data-theme="dark"] .cell.solution-cell {
  background: #78350f;
  border-color: #f59e0b;
}

/* Pre-filled hint letters */
.cell.prefilled-cell {
  background: #f0f7ff;
  border-color: #93c5fd;
}
[data-theme="dark"] .cell.prefilled-cell {
  background: #1e3a5f;
  border-color: #3b82f6;
}
.prefilled-letter {
  color: #2563eb !important;
  font-weight: 600 !important;
  opacity: 0.75;
}
[data-theme="dark"] .prefilled-letter {
  color: #60a5fa !important;
}

.cell-solution-index {
  position: absolute;
  bottom: 1px;
  right: 2px;
  font-size: 7px;
  font-weight: 700;
  color: #d97706;
  line-height: 1;
  pointer-events: none;
}
[data-theme="dark"] .cell-solution-index {
  color: #fbbf24;
}

.solution-display {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: 0.5rem;
}

.solution-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.solution-boxes {
  display: flex;
  gap: 2px;
}

.solution-box {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fef3c7;
  border: 1.5px solid #f59e0b;
  border-radius: 3px;
  font-size: 13px;
  font-weight: 700;
  color: #92400e;
}
[data-theme="dark"] .solution-box {
  background: #78350f;
  border-color: #f59e0b;
  color: #fef3c7;
}

.solution-box-prefilled {
  background: #dbeafe;
  border-color: #60a5fa;
  color: #1d4ed8;
}
[data-theme="dark"] .solution-box-prefilled {
  background: #1e3a5f;
  border-color: #3b82f6;
  color: #bfdbfe;
}

.solution-arrow {
  color: var(--color-text-muted);
  font-size: 1.25rem;
  margin: 0 0.25rem;
}

.solution-word {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.05em;
}

/* ========= Buttons ========= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition), color var(--transition), transform 80ms ease;
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--color-primary);
  color: var(--color-primary-text);
}
.btn-primary:hover { background: var(--color-primary-hover); }
.btn-primary:active { background: var(--color-primary-active); }

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover {
  background: var(--color-surface-2);
  border-color: var(--color-text-muted);
}

.btn-sm {
  padding: 0.4375rem 0.875rem;
  font-size: 0.8125rem;
}

/* ========= Output Section ========= */
.output-section { display: flex; flex-direction: column; gap: 1.5rem; }
.output-section.hidden { display: none; }

.output-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.output-header h2 {
  font-size: clamp(1.125rem, 1rem + 0.5vw, 1.375rem);
  font-weight: 700;
}

.output-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* ========= Puzzle Grid ========= */
.puzzle-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding: 1rem 0;
}

.puzzle-grid {
  display: inline-grid;
  gap: 0;
  border: 2px solid var(--color-cell-black);
  background: var(--color-cell-black);
}

.cell {
  width: 34px;
  height: 34px;
  position: relative;
  background: var(--color-cell-bg);
  border: 0.5px solid var(--color-border);
}

.cell.black {
  background: var(--color-cell-black);
}

.cell-number {
  position: absolute;
  top: 1px;
  left: 2px;
  font-size: 9px;
  font-weight: 700;
  color: var(--color-cell-number);
  line-height: 1;
  pointer-events: none;
}

.cell-letter {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-cell-letter);
  line-height: 1;
  pointer-events: none;
  margin-top: 2px;
}

/* ========= Clues ========= */
.clues-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.clues-column h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-primary);
  color: var(--color-primary);
}

.clue-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.clue-item {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--color-text);
  padding: 0.25rem 0;
}

.clue-number {
  font-weight: 700;
  color: var(--color-primary);
  min-width: 1.5rem;
  display: inline-block;
}

/* ========= Footer ========= */
.footer {
  text-align: center;
  padding: 1.5rem;
  border-top: 1px solid var(--color-divider);
}
.footer a {
  color: var(--color-text-faint);
  text-decoration: none;
  font-size: 0.75rem;
  transition: color var(--transition);
}
.footer a:hover { color: var(--color-text-muted); }

/* ========= Print Styles ========= */
@media print {
  body {
    background: white !important;
    color: black !important;
    font-size: 11pt;
  }
  .header, .footer, .input-section, .output-actions, .theme-toggle, .btn { display: none !important; }
  .main { padding: 0; max-width: 100%; }
  .output-section { display: flex !important; }
  .output-section.hidden { display: flex !important; }
  .output-header { justify-content: center; }
  .output-header h2 { font-size: 18pt; text-align: center; }

  .puzzle-container { overflow: visible; padding: 0; }
  .puzzle-grid {
    border-color: black !important;
    background: black !important;
  }
  .cell {
    background: white !important;
    border-color: #ccc !important;
  }
  .cell.black { background: black !important; }
  .cell-number { color: black !important; font-size: 7pt; }
  .cell-letter { color: black !important; font-size: 12pt; }

  .cell-letter.print-hidden { display: none !important; }

  .clues-container {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    page-break-inside: avoid;
  }
  .clues-column h3 {
    color: black !important;
    border-color: black !important;
    font-size: 12pt;
  }
  .clue-item { font-size: 9pt; }
  .clue-number { color: black !important; }
}

/* ========= Responsive ========= */
@media (max-width: 640px) {
  .header-inner { padding: 0.625rem 1rem; }
  .main { padding: 1.25rem 1rem 2rem; }
  .input-row { grid-template-columns: 1fr; }
  .input-field--narrow { width: 100%; }
  .clues-container { grid-template-columns: 1fr; gap: 1.5rem; }
  .cell { width: 28px; height: 28px; }
  .cell-number { font-size: 7px; }
  .cell-letter { font-size: 12px; }
  .output-header { flex-direction: column; }
  .output-actions { width: 100%; }
  .output-actions .btn { flex: 1; justify-content: center; }
  .solution-boxes { flex-wrap: wrap; }
}

/* ── KI Content Panel ──────────────────────────────────────── */
.ai-content-panel {
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  margin-bottom: 0.75rem;
  overflow: hidden;
}
.ai-content-summary {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  cursor: pointer;
  font-size: 0.875rem;
  color: var(--color-text);
  list-style: none;
  user-select: none;
}
.ai-content-summary::-webkit-details-marker { display: none; }
.ai-content-summary:hover { background: var(--color-surface-2); }
.ai-content-summary svg { color: var(--color-primary); flex-shrink: 0; }
.ai-content-body {
  padding: 1rem;
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

/* Slider */
.slider-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.25rem;
}
.slider-label { font-size: 0.75rem; color: var(--color-text-muted); white-space: nowrap; }
.difficulty-slider {
  flex: 1;
  accent-color: var(--color-primary);
  height: 4px;
  cursor: pointer;
}
.difficulty-value {
  float: right;
  font-weight: 600;
  color: var(--color-primary);
  font-size: 0.8125rem;
}
.difficulty-desc {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-top: 0.375rem;
  font-style: italic;
}

/* Dropzone */
.dropzone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color 0.15s, background 0.15s;
}
.dropzone.drag-over {
  border-color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 6%, transparent);
}
.dropzone-label {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 1.25rem 1rem;
  cursor: pointer;
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  text-align: center;
}
.dropzone-label:hover { color: var(--color-primary); }
.dropzone-label svg { opacity: 0.6; }
.sr-only-file {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap;
}

/* Status */
.ai-status {
  font-size: 0.8125rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
  margin-top: 0.25rem;
}
.ai-status.loading { background: #fffbeb; color: #92400e; border: 1px solid #fde68a; }
.ai-status.success { background: #f0fdf4; color: #166534; border: 1px solid #bbf7d0; }
.ai-status.error   { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }

/* Divider */
.input-section-divider {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 0.25rem 0;
  font-size: 0.75rem;
  color: var(--color-text-faint);
}
.input-section-divider::before,
.input-section-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}