:root {
  --primary: #6366f1;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --border: rgba(0, 0, 0, 0.12);
  --text: #111;
  --muted: #555;
  --card-bg: rgba(255, 255, 255, 0.95);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: #fff;
  color: var(--text);
  min-height: 100vh;
  padding-top: 60px;
  background-image:
    radial-gradient(circle at 0% 0%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 100% 100%, rgba(168, 85, 247, 0.08) 0%, transparent 50%);
}

/* ── Back button ── */
.back-btn {
  position: fixed;
  top: 12px; left: 12px;
  z-index: 999;
  background: rgba(255, 255, 255, 0.92);
  padding: 7px 18px;
  border-radius: 30px;
  text-decoration: none;
  color: var(--primary);
  font-weight: 700;
  font-size: 13px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(0, 0, 0, 0.06);
  backdrop-filter: blur(6px);
  transition: transform 0.2s;
}
.back-btn:hover { transform: scale(1.04); }

/* ── Layout ── */
.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 1rem 1.25rem 5rem;
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

h1 {
  font-size: 2.2rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

header p {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 0.35rem;
}

/* ── Upload zone ── */
.upload-zone {
  position: relative;
  border: 2px dashed var(--border);
  border-radius: 18px;
  padding: 4rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: 0.25s;
  background: var(--card-bg);
}
.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--primary);
  background: rgba(99, 102, 241, 0.04);
}
.upload-zone .upload-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 0.9rem;
}
.upload-zone p { color: var(--muted); font-size: 0.95rem; }
#imageInput { display: none; }

/* ── Platform tabs ── */
.tab-scroll-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 4px;
  scrollbar-width: none;
  margin-bottom: 12px;
}
.tab-scroll-wrap::-webkit-scrollbar { display: none; }

.tab-bar {
  display: flex;
  gap: 6px;
  width: max-content;
  padding: 2px 0;
}

.tab-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 8px 14px;
  border: 1.5px solid var(--border);
  border-radius: 12px;
  background: var(--card-bg);
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  white-space: nowrap;
  transition: 0.2s;
  min-width: 62px;
}
.tab-btn .tab-emoji { font-size: 17px; }
.tab-btn:hover { border-color: var(--primary); color: var(--primary); }
.tab-btn.active {
  background: var(--accent-gradient);
  border-color: transparent;
  color: #fff;
}

/* ── Preset chips ── */
.preset-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.chip {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1.5px solid var(--border);
  border-radius: 30px;
  background: var(--card-bg);
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
  transition: 0.2s;
}
.chip:hover { border-color: var(--primary); color: var(--primary); }
.chip.active {
  background: var(--accent-gradient);
  border-color: transparent;
  color: #fff;
}
.chip-size {
  font-size: 10px;
  font-weight: 400;
  opacity: 0.7;
}
.chip.active .chip-size { opacity: 0.85; }

/* ── Free size ── */
.free-size-inner {
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 12px;
}

.free-mode-toggle {
  display: flex;
  gap: 6px;
}
.free-mode-toggle button {
  padding: 5px 16px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: none;
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
  transition: 0.2s;
}
.free-mode-toggle button.active {
  background: var(--accent-gradient);
  border-color: transparent;
  color: #fff;
}

.free-inputs {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.free-inputs input[type="number"] {
  width: 88px;
  padding: 7px 10px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  text-align: center;
  outline: none;
  background: #fff;
  color: var(--text);
  transition: border-color 0.2s;
}
.free-inputs input[type="number"]:focus { border-color: var(--primary); }
.free-inputs .sep { font-size: 18px; font-weight: 700; color: var(--muted); }

.btn-apply {
  padding: 7px 16px;
  background: var(--accent-gradient);
  color: #fff;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn-apply:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

/* ── Size badge ── */
.size-badge {
  text-align: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  margin: 6px 0 10px;
  letter-spacing: 0.5px;
}

/* ── Crop wrapper ── */
.crop-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 24px;
  background: rgba(99, 102, 241, 0.04);
  border-radius: 20px;
  border: 1.5px solid var(--border);
  min-height: 180px;
  margin-bottom: 12px;
}

.crop-frame {
  position: relative;
  overflow: hidden;
  cursor: grab;
  border-radius: 2px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25), 0 0 0 2px var(--primary);
  user-select: none;
  /* Checkerboard background for transparent images */
  background-color: #e5e5f7;
  background-image:
    repeating-linear-gradient(45deg, #c0c0cc 25%, transparent 25%, transparent 75%, #c0c0cc 75%),
    repeating-linear-gradient(45deg, #c0c0cc 25%, #e5e5f7 25%, #e5e5f7 75%, #c0c0cc 75%);
  background-position: 0 0, 10px 10px;
  background-size: 20px 20px;
}
.crop-frame:active { cursor: grabbing; }

.crop-frame img {
  position: absolute;
  pointer-events: none;
  user-select: none;
  display: block;
}

/* Corner markers */
.crop-corner {
  position: absolute;
  width: 20px;
  height: 20px;
  pointer-events: none;
  z-index: 10;
}
.crop-corner.tl { top: 0; left: 0; border-top: 3px solid rgba(255,255,255,0.9); border-left: 3px solid rgba(255,255,255,0.9); }
.crop-corner.tr { top: 0; right: 0; border-top: 3px solid rgba(255,255,255,0.9); border-right: 3px solid rgba(255,255,255,0.9); }
.crop-corner.bl { bottom: 0; left: 0; border-bottom: 3px solid rgba(255,255,255,0.9); border-left: 3px solid rgba(255,255,255,0.9); }
.crop-corner.br { bottom: 0; right: 0; border-bottom: 3px solid rgba(255,255,255,0.9); border-right: 3px solid rgba(255,255,255,0.9); }

/* ── Zoom controls ── */
.zoom-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: 50px;
  padding: 10px 16px;
  margin-bottom: 14px;
}
.zoom-icon {
  font-size: 16px;
  font-weight: 700;
  color: var(--muted);
  flex-shrink: 0;
  width: 16px;
  text-align: center;
}
input[type="range"] {
  flex: 1;
  accent-color: var(--primary);
  height: 4px;
}
.zoom-controls button {
  padding: 4px 14px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: none;
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  color: var(--muted);
  white-space: nowrap;
  transition: 0.15s;
}
.zoom-controls button:hover { border-color: var(--primary); color: var(--primary); }

/* ── Download area ── */
.download-area {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.format-toggle {
  display: flex;
  gap: 3px;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 9px;
  padding: 3px;
  flex-shrink: 0;
}
.format-toggle button {
  padding: 7px 16px;
  border: none;
  border-radius: 7px;
  background: none;
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
  transition: 0.2s;
}
.format-toggle button.active {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.btn-primary {
  flex: 1;
  padding: 13px 28px;
  background: var(--accent-gradient);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  min-width: 140px;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  display: block;
  width: 100%;
  margin-top: 10px;
  padding: 10px;
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: 0.2s;
}
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }

/* ── Utility ── */
.hidden { display: none !important; }

/* ── Responsive ── */
@media (max-width: 600px) {
  h1 { font-size: 1.8rem; }
  .container { padding: 0.75rem 0.75rem 5rem; }
  .upload-zone { padding: 3rem 1.5rem; }
  .crop-wrapper { padding: 14px; }
  .download-area { flex-direction: column; }
  .btn-primary { width: 100%; }
}