*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-bg: #0d1117;
  --color-surface: #161b22;
  --color-surface-alt: #1c2128;
  --color-surface-hover: #21262d;
  --color-text: #e6edf3;
  --color-text-muted: #8b949e;
  --color-text-heading: #f0f6fc;
  --color-border: #30363d;
  --color-accent: #58a6ff;
  --color-accent-hover: #79c0ff;
  --color-danger: #f85149;
  --color-danger-hover: #da3633;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial,
    sans-serif;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --transition-fast: 150ms ease;
}

html {
  color-scheme: dark;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  touch-action: manipulation;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: 56px;
  flex-shrink: 0;
}

.toolbar-brand {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
  text-transform: uppercase;
  white-space: nowrap;
}

.canvas-name-input {
  background: transparent;
  border: 1px solid transparent;
  color: var(--color-text-heading);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition-fast),
    background var(--transition-fast);
  min-width: 200px;
  flex: 1;
}

.canvas-name-input:hover {
  border-color: var(--color-border);
}

.canvas-name-input:focus {
  background: var(--color-surface-alt);
  border-color: var(--color-accent);
}

.canvas-controls {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-left: auto;
  flex-shrink: 0;
}

.canvas-controls select {
  appearance: none;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 0.85rem;
  padding: var(--space-xs) var(--space-lg) var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238b949e' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  min-width: 140px;
}

.canvas-controls select:focus {
  border-color: var(--color-accent);
}

.btn {
  appearance: none;
  border: 1px solid var(--color-border);
  background: var(--color-surface-alt);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 500;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition-fast),
    border-color var(--transition-fast);
  white-space: nowrap;
}

.btn:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-text-muted);
}

.btn-primary {
  background: rgba(88, 166, 255, 0.1);
  border-color: rgba(88, 166, 255, 0.3);
  color: var(--color-accent);
}

.btn-primary:hover {
  background: rgba(88, 166, 255, 0.2);
  border-color: var(--color-accent);
}

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

.btn-danger:hover {
  background: rgba(248, 81, 73, 0.1);
  border-color: var(--color-danger);
}

.btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.btn:disabled:hover {
  background: var(--color-surface-alt);
  border-color: var(--color-border);
}

.canvas-container {
  flex: 1;
  padding: var(--space-md);
  overflow: hidden;
}

.canvas-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  grid-template-rows: 1fr 1fr 0.6fr;
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  height: 100%;
}

.block {
  background: var(--color-surface);
  padding: var(--space-sm) var(--space-md);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.block h3 {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
  flex-shrink: 0;
  font-weight: 600;
}

.block-content {
  flex: 1;
  overflow-y: auto;
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--color-text);
  outline: none;
  cursor: text;
  white-space: pre-wrap;
  word-break: break-word;
  padding: var(--space-xs);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.block-content:empty::before {
  content: attr(data-placeholder);
  color: var(--color-text-muted);
  opacity: 0.4;
  pointer-events: none;
}

.block-content:focus {
  background: var(--color-surface-alt);
}

.block-content::-webkit-scrollbar {
  width: 4px;
}

.block-content::-webkit-scrollbar-track {
  background: transparent;
}

.block-content::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 2px;
}

.block[data-block="problem"] {
  grid-column: 1 / 3;
  grid-row: 1 / 3;
}

.block[data-block="solution"] {
  grid-column: 3 / 5;
  grid-row: 1 / 2;
}

.block[data-block="key-metrics"] {
  grid-column: 3 / 5;
  grid-row: 2 / 3;
}

.block[data-block="uvp"] {
  grid-column: 5 / 7;
  grid-row: 1 / 3;
}

.block[data-block="unfair-advantage"] {
  grid-column: 7 / 9;
  grid-row: 1 / 2;
}

.block[data-block="channels"] {
  grid-column: 7 / 9;
  grid-row: 2 / 3;
}

.block[data-block="customer-segments"] {
  grid-column: 9 / 11;
  grid-row: 1 / 3;
}

.block[data-block="cost-structure"] {
  grid-column: 1 / 6;
  grid-row: 3 / 4;
}

.block[data-block="revenue-streams"] {
  grid-column: 6 / 11;
  grid-row: 3 / 4;
}

@media (max-width: 1024px) {
  body {
    overflow: auto;
    height: auto;
    min-height: 100vh;
    min-height: 100dvh;
  }

  .toolbar {
    position: sticky;
    top: 0;
    z-index: 10;
  }

  .canvas-container {
    overflow: visible;
    padding: var(--space-sm);
  }

  .canvas-grid {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto;
    height: auto;
    gap: 1px;
  }

  .canvas-grid .block {
    grid-column: auto !important;
    grid-row: auto !important;
    min-height: 140px;
  }

  .block[data-block="problem"] { order: 1; }
  .block[data-block="customer-segments"] { order: 2; }
  .block[data-block="uvp"] { order: 3; }
  .block[data-block="solution"] { order: 4; }
  .block[data-block="unfair-advantage"] { order: 5; }
  .block[data-block="channels"] { order: 6; }
  .block[data-block="key-metrics"] { order: 7; }
  .block[data-block="revenue-streams"] { order: 8; }
  .block[data-block="cost-structure"] { order: 9; }
}

@media (max-width: 640px) {
  body {
    padding-bottom: env(safe-area-inset-bottom);
  }

  .toolbar {
    flex-wrap: wrap;
    height: auto;
    padding: var(--space-sm);
    gap: var(--space-sm);
  }

  .toolbar-brand {
    font-size: 0.75rem;
  }

  .canvas-name-input {
    order: 3;
    min-width: 0;
    width: 100%;
    font-size: 0.9rem;
  }

  .canvas-controls {
    margin-left: auto;
  }

  .canvas-controls select {
    min-width: 100px;
    font-size: 0.8rem;
    padding: var(--space-sm) var(--space-lg) var(--space-sm) var(--space-sm);
  }

  .btn {
    padding: var(--space-sm) var(--space-md);
    font-size: 0.8rem;
  }

  .canvas-container {
    padding: var(--space-xs);
  }

  .canvas-grid {
    grid-template-columns: 1fr;
    border-radius: var(--radius-md);
  }

  .canvas-grid .block {
    min-height: 120px;
    padding: var(--space-sm);
  }

  .block h3 {
    font-size: 0.6rem;
    margin-bottom: var(--space-xs);
  }

  .block-content {
    font-size: 0.85rem;
    line-height: 1.5;
    -webkit-overflow-scrolling: touch;
  }
}