/* ============================================================
   CSS Grid Visualizer — Styles
   Theme: Light+Dark — Clean white canvas + bold indigo grid
   ============================================================ */

:root {
  --c-bg: #f8fafc;
  --c-surface: #ffffff;
  --c-surface-2: #f1f5f9;
  --c-border: #e2e8f0;
  --c-border-focus: #6366f1;
  --c-primary: #6366f1;
  --c-primary-dim: rgba(99, 102, 241, 0.1);
  --c-primary-bold: #4f46e5;
  --c-grid-line: #6366f1;
  --c-grid-cell: rgba(99, 102, 241, 0.08);
  --c-text: #1e293b;
  --c-text-dim: #475569;
  --c-text-muted: #94a3b8;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --transition: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);
}

[data-theme="dark"] {
  --c-bg: #0f1219;
  --c-surface: #161b26;
  --c-surface-2: #1c2333;
  --c-border: #252d3d;
  --c-text: #e2e8f0;
  --c-text-dim: #94a3b8;
  --c-text-muted: #64748b;
  --c-grid-cell: rgba(99, 102, 241, 0.12);
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--c-border); border-radius: 3px; }
::selection { background: var(--c-primary-dim); color: var(--c-primary); }
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 2px; }

/* ---------- Header ---------- */
#app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  box-shadow: var(--shadow);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo-group { display: flex; align-items: center; gap: 0.75rem; }

.logo-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--c-primary-dim);
  color: var(--c-primary);
}

h1 {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-bold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  font-size: 0.8125rem;
  font-weight: 500;
  font-family: var(--font-sans);
  border: none;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-bold));
  color: #fff;
  font-weight: 600;
}
.btn-primary:hover { filter: brightness(1.1); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3); }

.btn-outline {
  background: transparent;
  color: var(--c-text-dim);
  border: 1px solid var(--c-border);
}
.btn-outline:hover { border-color: var(--c-primary); color: var(--c-primary); background: var(--c-primary-dim); }

.btn-ghost { background: transparent; color: var(--c-text-dim); }
.btn-ghost:hover { color: var(--c-text); background: var(--c-primary-dim); }

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
  background: transparent;
  color: var(--c-text-dim);
  border: 1px solid var(--c-border);
  cursor: pointer;
  transition: all var(--transition);
}
.btn-icon:hover { border-color: var(--c-primary); color: var(--c-primary); }

.btn-sm { padding: 0.3rem 0.6rem; font-size: 0.75rem; }

/* ---------- Main ---------- */
#app-main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ---------- Controls Bar ---------- */
.controls-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  padding: 1rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: background var(--transition), border-color var(--transition);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.control-group label {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--c-text-muted);
}

.num-input, .select-input {
  padding: 0.4rem 0.6rem;
  font-size: 0.8125rem;
  font-family: var(--font-sans);
  color: var(--c-text);
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xs);
  transition: border-color var(--transition);
  min-width: 70px;
}
.num-input:focus, .select-input:focus { border-color: var(--c-primary); outline: none; }

.input-with-unit { display: flex; align-items: center; gap: 0.25rem; }
.unit-label { font-size: 0.75rem; color: var(--c-text-muted); font-weight: 500; }

/* ---------- Template Bar ---------- */
.template-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.template-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--c-text-muted);
}

.template-btn.active {
  background: var(--c-primary-dim);
  color: var(--c-primary);
  border: 1px solid rgba(99, 102, 241, 0.3);
}

/* ---------- Main Grid ---------- */
.main-grid {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 1.25rem;
}

/* ---------- Panels ---------- */
.panel-card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  transition: background var(--transition), border-color var(--transition);
}

.panel-card h2 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--c-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.panel-title-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

/* ---------- Grid Preview ---------- */
.preview-container {
  width: 100%;
  overflow: hidden;
  border: 2px dashed var(--c-border);
  border-radius: var(--radius-sm);
  padding: 1rem;
  min-height: 300px;
  transition: width var(--transition);
}

.grid-preview {
  display: grid;
  min-height: 280px;
  transition: all var(--transition);
}

.grid-cell {
  background: var(--c-grid-cell);
  border: 2px solid var(--c-grid-line);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--c-primary);
  min-height: 60px;
  transition: all var(--transition);
  cursor: default;
  position: relative;
}

.grid-cell:hover {
  background: rgba(99, 102, 241, 0.18);
  transform: scale(1.02);
}

.grid-cell .area-name {
  font-size: 0.6875rem;
  color: var(--c-text-dim);
  margin-top: 0.2rem;
}

/* Cell colors for visual distinction */
.grid-cell:nth-child(6n+1) { border-color: #6366f1; }
.grid-cell:nth-child(6n+2) { border-color: #8b5cf6; }
.grid-cell:nth-child(6n+3) { border-color: #06b6d4; }
.grid-cell:nth-child(6n+4) { border-color: #f59e0b; }
.grid-cell:nth-child(6n+5) { border-color: #22c55e; }
.grid-cell:nth-child(6n+6) { border-color: #ef4444; }

/* ---------- Breakpoint Bar ---------- */
.breakpoint-bar { display: flex; gap: 0.35rem; }

.bp-btn {
  padding: 0.25rem 0.5rem;
  font-size: 0.6875rem;
  font-weight: 500;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-xs);
  background: transparent;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--transition);
}
.bp-btn:hover { border-color: var(--c-primary); color: var(--c-primary); }
.bp-btn.active {
  background: var(--c-primary-dim);
  color: var(--c-primary);
  border-color: rgba(99, 102, 241, 0.3);
}

/* ---------- CSS Output ---------- */
.css-output {
  padding: 1rem;
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--c-text);
  overflow-x: auto;
  white-space: pre;
  max-height: 500px;
  overflow-y: auto;
}

/* CSS syntax highlight */
.css-prop { color: #06b6d4; }
.css-val { color: #6366f1; }
.css-selector { color: #f59e0b; font-weight: 600; }
.css-comment { color: var(--c-text-muted); font-style: italic; }

/* ---------- Named Areas ---------- */
.areas-textarea {
  width: 100%;
  min-height: 80px;
  padding: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  resize: vertical;
  transition: border-color var(--transition);
}
.areas-textarea::placeholder { color: var(--c-text-muted); }
.areas-textarea:focus { border-color: var(--c-primary); outline: none; }

/* ---------- Toast ---------- */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 1000;
}

.toast {
  padding: 0.6rem 1rem;
  font-size: 0.8125rem;
  border-radius: var(--radius-sm);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  color: var(--c-text);
  box-shadow: var(--shadow-lg);
  animation: toastIn 300ms ease;
  max-width: 320px;
}
.toast.success { border-color: rgba(34, 197, 94, 0.4); }
.toast.error { border-color: rgba(239, 68, 68, 0.4); }

@keyframes toastIn {
  from { opacity: 0; transform: translateY(12px) scale(0.95); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toastOut {
  to { opacity: 0; transform: translateY(12px) scale(0.95); }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .main-grid { grid-template-columns: 1fr; }
  .controls-bar { gap: 0.75rem; }
}

@media (max-width: 600px) {
  .header-inner { flex-direction: column; align-items: flex-start; }
  .control-group { flex: 1; min-width: 80px; }
}