* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

:root {
  --primary: #e8a87c;
  --secondary: #c38d9e;
  --accent: #41b3a3;
  --dark: #242424;
  --light: #faf3e0;
  --card-bg: rgba(255, 255, 255, 0.95);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

html {
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
  min-height: 100vh;
  min-height: 100dvh;
  color: var(--dark);
  overflow-x: hidden;
}

.container {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px;
  padding-top: calc(16px + var(--safe-top));
  padding-bottom: calc(16px + var(--safe-bottom));
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

header {
  text-align: center;
  padding: 24px 0 16px;
}

header h1 {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--dark);
  text-shadow: 2px 2px 0 rgba(255, 255, 255, 0.5);
}

.tagline {
  font-size: 0.95rem;
  color: var(--secondary);
  margin-top: 6px;
  font-style: italic;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* Upload Area */
.upload-area {
  background: var(--card-bg);
  border: 3px dashed var(--secondary);
  border-radius: 20px;
  padding: 50px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  -webkit-touch-callout: none;
  user-select: none;
}

.upload-area:active {
  transform: scale(0.98);
  background: rgba(232, 168, 124, 0.15);
}

.upload-area.dragover {
  background: rgba(232, 168, 124, 0.2);
  border-color: var(--primary);
}

.upload-icon {
  font-size: 3.5rem;
  margin-bottom: 12px;
}

.upload-content p {
  color: #666;
  font-size: 1rem;
  line-height: 1.6;
}

.upload-sub {
  font-size: 0.8rem;
  color: #999;
}

.hidden {
  display: none !important;
}

/* Editor */
.editor {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 16px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.canvas-wrapper {
  position: relative;
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  background: #f0f0f0;
  margin-bottom: 16px;
}

#canvas {
  display: block;
  width: 100%;
  height: auto;
}

/* Filters */
.filters {
  margin-bottom: 16px;
}

.filters h3 {
  font-size: 0.85rem;
  color: #666;
  margin-bottom: 10px;
}

.filter-list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.filter-list::-webkit-scrollbar {
  display: none;
}

.filter-btn {
  flex-shrink: 0;
  padding: 10px 18px;
  border: 2px solid #ddd;
  border-radius: 20px;
  background: white;
  font-size: 0.85rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
  touch-action: manipulation;
}

.filter-btn:active {
  transform: scale(0.95);
}

.filter-btn.active {
  background: var(--secondary);
  border-color: var(--secondary);
  color: white;
}

/* Doodle Art Section */
.doodle-section {
  margin-bottom: 16px;
}

.doodle-toggle {
  width: 100%;
  padding: 12px;
  border: 2px solid #ddd;
  border-radius: 12px;
  background: white;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  color: #666;
  cursor: pointer;
  transition: all 0.2s ease;
  touch-action: manipulation;
}

.doodle-toggle:active {
  transform: scale(0.98);
}

.doodle-toggle.active {
  background: linear-gradient(135deg, #ff9a9e, #fad0c4);
  border-color: #ff9a9e;
  color: white;
}

.doodle-options {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* Controls */
.controls {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 16px;
}

.control-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.control-item span {
  font-size: 0.8rem;
  color: #666;
}

.control-item input[type="range"] {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: #ddd;
  outline: none;
  -webkit-appearance: none;
}

.control-item input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--secondary);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

.control-item input[type="range"]::-moz-range-thumb {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--secondary);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

/* Action Buttons */
.actions {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
}

.btn {
  padding: 14px 10px;
  border: none;
  border-radius: 12px;
  font-size: 0.9rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  touch-action: manipulation;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.95);
  opacity: 0.9;
}

.btn-secondary {
  background: #eee;
  color: #666;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-share {
  background: var(--accent);
  color: white;
}

/* QR Code Section */
.qr-section {
  text-align: center;
}

.qr-toggle {
  background: none;
  border: 2px solid rgba(195, 141, 158, 0.4);
  border-radius: 12px;
  padding: 12px 24px;
  font-family: inherit;
  font-size: 0.85rem;
  color: var(--secondary);
  cursor: pointer;
  width: 100%;
  transition: all 0.2s ease;
  touch-action: manipulation;
}

.qr-toggle:active {
  transform: scale(0.98);
}

.qr-content {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 24px;
  margin-top: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.qr-image {
  width: 180px;
  height: 180px;
  margin: 0 auto 12px;
  display: block;
}

.qr-url {
  font-size: 0.8rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 4px;
}

.qr-hint {
  font-size: 0.75rem;
  color: #999;
}

/* Footer */
footer {
  text-align: center;
  padding: 24px 0 16px;
  color: #aaa;
  font-size: 0.8rem;
}

/* Loading state */
.loading {
  pointer-events: none;
  opacity: 0.7;
}

.loading::after {
  content: '';
  position: fixed;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 40px;
  margin: -20px 0 0 -20px;
  border: 3px solid #ddd;
  border-top-color: var(--secondary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  z-index: 100;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ====== Responsive Breakpoints ====== */

/* Small phones (iPhone SE, Galaxy S series) */
@media (max-width: 375px) {
  header h1 {
    font-size: 1.8rem;
  }

  .tagline {
    font-size: 0.85rem;
  }

  .upload-area {
    padding: 40px 16px;
  }

  .upload-icon {
    font-size: 2.8rem;
  }

  .filter-btn {
    padding: 8px 14px;
    font-size: 0.8rem;
  }

  .btn {
    padding: 12px 8px;
    font-size: 0.82rem;
  }

  .editor {
    padding: 12px;
  }

  .qr-image {
    width: 150px;
    height: 150px;
  }
}

/* Medium phones (iPhone 12/13/14, Pixel) */
@media (min-width: 376px) and (max-width: 430px) {
  .container {
    padding: 16px;
  }
}

/* Large phones & small tablets */
@media (min-width: 431px) and (max-width: 768px) {
  .container {
    max-width: 500px;
    padding: 20px;
  }

  .actions {
    gap: 10px;
  }
}

/* Tablets & Desktop */
@media (min-width: 769px) {
  .container {
    max-width: 520px;
    padding: 24px;
  }

  header h1 {
    font-size: 2.5rem;
  }

  .upload-area {
    padding: 60px 20px;
  }

  .upload-area:hover {
    border-color: var(--primary);
    transform: scale(1.02);
  }

  .filter-btn:hover {
    border-color: var(--secondary);
  }

  .btn:hover {
    transform: translateY(-2px);
  }

  .qr-toggle:hover {
    border-color: var(--secondary);
    background: rgba(195, 141, 158, 0.08);
  }
}

/* Landscape orientation on phones */
@media (max-height: 500px) and (orientation: landscape) {
  header {
    padding: 8px 0;
  }

  header h1 {
    font-size: 1.6rem;
  }

  .tagline {
    display: none;
  }

  .upload-area {
    padding: 24px 16px;
  }

  .upload-icon {
    font-size: 2rem;
    margin-bottom: 4px;
  }

  .editor {
    padding: 10px;
  }

  .canvas-wrapper {
    margin-bottom: 10px;
  }

  .controls {
    flex-direction: row;
    gap: 12px;
    margin-bottom: 10px;
  }

  .control-item {
    flex: 1;
  }

  footer {
    padding: 8px 0;
  }
}