/* ─────────────────────────────────────────
   CSS Custom Properties — Dark Theme
   ───────────────────────────────────────── */
:root {
  --bg-base:       #0f0f0f;
  --bg-surface:    #1a1a1a;
  --bg-raised:     #242424;
  --bg-hover:      #2c2c2c;
  --border:        #2e2e2e;
  --border-focus:  #f97316;
  --accent:        #f97316;
  --accent-dim:    #7c3a12;
  --accent-hover:  #ea6c0a;
  --text-primary:  #e8e8e8;
  --text-secondary:#999999;
  --text-muted:    #555555;
  --danger:        #ef4444;
  --success:       #22c55e;

  --radius-sm: 4px;
  --radius-md: 8px;
  --shadow:    0 4px 20px rgba(0,0,0,0.6);
  --font: system-ui, -apple-system, 'Segoe UI', sans-serif;
}

/* ─────────────────────────────────────────
   Reset & Base
   ───────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 15px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }
h1 { font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 700; margin-bottom: 1.2rem; }
h2 { font-size: clamp(0.95rem, 2vw, 1.15rem); font-weight: 600; }
ul { padding-left: 1.4rem; }
ul li { margin-bottom: 0.4rem; color: var(--text-secondary); }

/* ─────────────────────────────────────────
   Navbar
   ───────────────────────────────────────── */
.navbar {
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
  height: 52px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 200;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-primary);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  margin-right: auto; /* pushes nav-right to the far right */
}
.logo:hover { color: var(--accent); text-decoration: none; }

/* Groups nav links + lang button on the right */
.nav-right {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}
.nav-links a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a.active { color: var(--accent); }

/* Single cycling language button */
.lang-cycle {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  letter-spacing: 0.05em;
  transition: color 0.12s, border-color 0.12s;
  flex-shrink: 0;
}
.lang-cycle:hover { color: var(--accent); border-color: var(--accent); }

/* Hamburger — hidden on desktop */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
  margin-left: 0.75rem;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.22s ease, opacity 0.22s ease;
  transform-origin: center;
}
.navbar.nav-open .hamburger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.navbar.nav-open .hamburger span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.navbar.nav-open .hamburger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ─────────────────────────────────────────
   App Layout
   ───────────────────────────────────────── */
.app-layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  align-self: stretch;
}

/* ─────────────────────────────────────────
   Panels
   ───────────────────────────────────────── */
.panel { background: var(--bg-base); padding: 1.5rem; }
.panel-title {
  margin-bottom: 0.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.panel-hint { font-size: 0.8rem; color: var(--text-muted); margin: 0.4rem 0 1rem; }

/* ─────────────────────────────────────────
   Upload Panel — Dropzones
   ───────────────────────────────────────── */
.upload-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
  margin-top: 0.5rem;
  max-width: calc(5 * 120px + 4 * 10px); /* cap each slot at 120px */
}

/*
 * DROPZONE STRUCTURE:
 *
 *  <div.dropzone>            ← outer div: drag target, border styling
 *    <label.dz-click>        ← absolute fill: click opens file dialog (via `for`)
 *      <canvas.dz-bg>        ← faint background image (35% opacity)
 *      <span.dz-name>        ← slot name (top center, always visible)
 *      <div.dz-empty>        ← placeholder icon (hidden when has-image)
 *    </label>
 *    <div.dz-controls>       ← transform buttons (z-index above label)
 *    <input[type=file]>      ← hidden, linked via label `for`
 *  </div>
 *
 * WHY div (not label) as outer:
 *   Drag events on a <label> containing <input[type=file]> can behave
 *   inconsistently across browsers. A plain <div> as the drop target is
 *   fully reliable. The label handles click→file-dialog natively.
 */
.dropzone {
  position: relative;
  background: var(--bg-raised);
  border: 1.5px dashed var(--border);
  border-radius: var(--radius-md);
  aspect-ratio: 1 / 1;
  overflow: hidden;
  transition: border-color 0.15s, background 0.15s;
  user-select: none;
}
.dropzone:hover { border-color: var(--accent-dim); }
.dropzone.drag-over {
  border-color: var(--accent);
  border-style: solid;
  background: rgba(249, 115, 22, 0.09);
}

/* Label fills entire zone — click anywhere opens file dialog */
.dz-click {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 1;
  /* reset label default inline display */
  font: inherit;
  color: inherit;
}

/* Background: uploaded image shown faintly.
 * Visibility is controlled by opacity (not the `hidden` attribute) so that
 * author CSS `display:block` cannot fight the UA `[hidden]{display:none}` rule.
 * JS adds `.has-image` to the outer .dropzone to reveal it. */
.dz-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  opacity: 0;
  transition: opacity 0.2s;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}
.dropzone.has-image .dz-bg { opacity: 0.38; }

/* Slot name — always at top center */
.dz-name {
  position: absolute;
  top: 5px;
  left: 0; right: 0;
  text-align: center;
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-secondary);
  pointer-events: none; /* let clicks pass to label */
  z-index: 2;
  transition: color 0.15s, text-shadow 0.15s;
}
.dropzone.has-image .dz-name {
  color: rgba(255, 255, 255, 0.92);
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.9);
}

/* Placeholder icon (hidden when image loaded) */
.dz-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem 0.5rem 2rem; /* extra bottom padding to avoid overlap with name */
}
.dropzone.has-image .dz-empty { display: none; }

.dz-icon-char {
  font-size: 1.6rem;
  color: var(--text-muted);
  line-height: 1;
}

/* Transform controls bar — at bottom, above label */
.dz-controls {
  position: absolute;
  bottom: 0;
  left: 0; right: 0;
  display: none;
  background: rgba(0, 0, 0, 0.72);
  padding: 3px 4px;
  gap: 3px;
  justify-content: center;
  align-items: center;
  z-index: 5; /* above .dz-click (z-index:1) */
}
.dropzone.has-image .dz-controls { display: flex; }

/* Transform buttons */
.tf-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.75);
  width: 22px;
  height: 22px;
  border-radius: 3px;
  cursor: pointer;
  font-size: 13px;
  padding: 0;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font);
  transition: background 0.1s, color 0.1s, border-color 0.1s;
}
.tf-btn:hover { background: rgba(249, 115, 22, 0.5); color: #fff; border-color: var(--accent); }
.tf-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ─────────────────────────────────────────
   Settings Panel
   ───────────────────────────────────────── */
.settings-panel { display: flex; flex-direction: column; gap: 1.2rem; }

.field-group { display: flex; flex-direction: column; gap: 6px; }
.field-group > label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

select, input[type="number"] {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  font-size: 0.9rem;
  font-family: var(--font);
  width: 100%;
  outline: none;
  transition: border-color 0.15s;
}
select:focus, input[type="number"]:focus { border-color: var(--border-focus); }

/* ─────────────────────────────────────────
   Buttons
   ───────────────────────────────────────── */
.btn-secondary {
  background: var(--bg-raised);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 0.85rem;
  font-weight: 500;
  font-family: var(--font);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
.btn-secondary:hover { border-color: var(--accent); background: var(--bg-hover); }

/* ─────────────────────────────────────────
   Status
   ───────────────────────────────────────── */
.status-msg {
  font-size: 0.8rem;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}
.status-msg.success { border-color: var(--success); color: var(--success); }
.status-msg.error   { border-color: var(--danger);  color: var(--danger);  }

/* ─────────────────────────────────────────
   Preview & Export Panels
   ───────────────────────────────────────── */
.canvas-wrap {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow: auto;
  /* Fixed height — zoom scales content inside; layout stays stable.
     Height = PREVIEW_PAD*2 + PREVIEW_LABEL_H + GRID_ROWS*DISPLAY_TS + 2*padding
            = 8+8 + 14 + 4*32 + 2*16 = 206px → round up to 210px */
  height: 210px;
  display: flex;
  align-items: flex-start;
  margin-top: 0.5rem;
}
#preview-canvas {
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  display: block;
}

.export-buttons { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 1rem; }

/* ─────────────────────────────────────────
   Zoom Bar
   ───────────────────────────────────────── */
.zoom-bar {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-top: 0.75rem;
}

.zoom-btn {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  width: 26px;
  height: 26px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.9rem;
  font-family: var(--font);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  transition: border-color 0.12s, color 0.12s;
  flex-shrink: 0;
}
.zoom-btn:hover { border-color: var(--accent); color: var(--accent); }

.zoom-label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  min-width: 2.4rem;
  text-align: center;
}

.zoom-reset {
  width: auto;
  padding: 0 6px;
  font-size: 0.75rem;
  letter-spacing: 0.02em;
}

/* ─────────────────────────────────────────
   Footer
   ───────────────────────────────────────── */
.footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: 1rem 1.5rem;
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.footer a { color: var(--text-secondary); }
.footer a:hover { color: var(--accent); }

/* ─────────────────────────────────────────
   Static Pages
   ───────────────────────────────────────── */
.static-page { flex: 1; display: flex; justify-content: center; padding: 3rem 1.5rem; }
.static-content { max-width: 680px; width: 100%; }
.static-content section { margin-bottom: 2.5rem; }
.static-content h2 {
  margin-bottom: 0.7rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.static-content p { color: var(--text-secondary); line-height: 1.75; }

.about-dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 6px 1.5rem;
  font-size: 0.9rem;
}
.about-dl dt { color: var(--text-muted); font-size: 0.8rem; align-self: center; }
.about-dl dd { color: var(--text-primary); }

.contact-links { display: flex; flex-direction: column; gap: 12px; margin: 1.5rem 0; }
.contact-card {
  display: flex; align-items: center; gap: 1rem;
  background: var(--bg-surface); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: 1rem 1.25rem;
  color: var(--text-primary); text-decoration: none;
  transition: border-color 0.15s;
}
.contact-card:hover { border-color: var(--accent); text-decoration: none; color: var(--text-primary); }
.contact-card strong { display: block; font-size: 0.9rem; }
.contact-card span span { font-size: 0.85rem; color: var(--text-secondary); }
.contact-icon { font-size: 1.4rem; color: var(--accent); width: 32px; text-align: center; flex-shrink: 0; }
.contact-note {
  font-size: 0.8rem; color: var(--text-muted); margin-top: 1.5rem;
  padding: 0.75rem 1rem;
  background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
}

/* ─────────────────────────────────────────
   Export Panel
   ───────────────────────────────────────── */
.export-panel { grid-column: span 2; }

.tilemap-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin: 0.5rem 0;
}

.tilemap-canvas-wrap {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow: auto;
  margin-top: 0.5rem;
  display: flex;
  align-items: flex-start;
}

#tilemap-canvas {
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  cursor: crosshair;
  display: block;
}

/* ─────────────────────────────────────────
   Tile Tooltip (spritesheet hover)
   ───────────────────────────────────────── */
.tile-tooltip {
  position: fixed;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 8px 10px;
  pointer-events: none;
  z-index: 1000;
  min-width: 76px;
}

.tt-grid {
  display: grid;
  grid-template-columns: repeat(3, 20px);
  grid-template-rows: repeat(3, 20px);
  gap: 2px;
  margin-bottom: 6px;
}

.tt-cell {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 2px;
}
.tt-cell.filled      { background: var(--accent); border-color: var(--accent); }
.tt-cell.tt-self     { background: var(--bg-hover); border-color: var(--border-focus); }
.tt-cell.tt-dc       { opacity: 0.25; }   /* don't-care diagonal in 16-tile mode */

.tt-label {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-align: center;
  white-space: nowrap;
}

/* ─────────────────────────────────────────
   Responsive — Tablet (≤900px)
   ───────────────────────────────────────── */
@media (max-width: 900px) {
  .app-layout { grid-template-columns: 1fr; }
  .upload-grid { grid-template-columns: repeat(3, 1fr); max-width: calc(3 * 120px + 2 * 10px); }
}

/* ─────────────────────────────────────────
   Responsive — Mobile (≤680px) + Hamburger
   ───────────────────────────────────────── */
@media (max-width: 680px) {
  .hamburger { display: flex; }

  .nav-right {
    display: none;
    position: absolute;
    top: 52px;
    left: 0; right: 0;
    flex-direction: column;
    align-items: center;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.25rem 1.5rem;
    gap: 1.25rem;
    box-shadow: var(--shadow);
    z-index: 199;
  }
  .navbar.nav-open .nav-right { display: flex; }
  .nav-links { flex-direction: column; gap: 0.9rem; width: 100%; align-items: center; }
  .nav-links a { font-size: 1rem; }

  .upload-grid { grid-template-columns: repeat(2, 1fr); max-width: calc(2 * 120px + 1 * 10px); }
  .panel { padding: 1rem; }
  .export-buttons { flex-direction: column; }
  .export-buttons .btn-secondary { width: 100%; }
}