/* ==========================================================================
   Global Reset & Base Variables
   ========================================================================== */
:root {
  --bg-primary: #0f1117;
  --bg-secondary: #171a23;
  --bg-tertiary: #202433;
  --bg-elevated: #282e42;
  --bg-card: rgba(23, 26, 35, 0.85);

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --border-focus: #3b82f6;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent-primary: #3b82f6;
  --accent-hover: #2563eb;
  --accent-glow: rgba(59, 130, 246, 0.35);

  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', sans-serif;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;

  --canvas-aspect: calc(4.27 / 3);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ==========================================================================
   Layout
   ========================================================================== */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 1720px;
  margin: 0 auto;
  padding: 1rem 1.75rem;
  gap: 1rem;
}

/* ==========================================================================
   Header
   ========================================================================== */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.brand-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  color: white;
  box-shadow: 0 4px 12px var(--accent-glow);
}

.brand-title-row {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  background: linear-gradient(90deg, #38bdf8 0%, #a855f7 50%, #34d399 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-motto {
  font-size: 0.75rem;
  font-weight: 500;
  color: #38bdf8;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.brand-subtitle {
  font-size: 0.825rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Main Content Grid
   ========================================================================== */
.main-content {
  display: grid;
  grid-template-columns: 1fr 390px;
  gap: 1.25rem;
  flex: 1;
  min-height: 0;
}

@media (max-width: 1080px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   Canvas Section
   ========================================================================== */
.canvas-section {
  display: flex;
  flex-direction: column;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  min-height: 520px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.canvas-wrapper-outer {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  position: relative;
  /* 모눈종이 / 투명 격자 배경 */
  background-size: 20px 20px;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  border-radius: var(--radius-md);
  padding: 0.5rem;
}

.canvas-aspect-container {
  width: 100%;
  max-width: calc((85vh - 120px) * (2670 / 1878));
  aspect-ratio: 2670 / 1878;
  max-height: calc(85vh - 120px);
  position: relative;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.6);
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: #0b0d13;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: aspect-ratio 0.25s ease, max-width 0.25s ease;
}

#compositeCanvas {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
  cursor: grab;
  user-select: none;
}

#compositeCanvas.grabbing {
  cursor: grabbing;
}

/* 드롭존 (이미지 업로드 전 상태) */
.upload-dropzone {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 17, 23, 0.88);
  backdrop-filter: blur(8px);
  border: 2px dashed var(--border-strong);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
  z-index: 10;
}

.upload-dropzone.drag-over {
  border-color: var(--accent-primary);
  background: rgba(59, 130, 246, 0.15);
}

.dropzone-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 2rem;
  max-width: 480px;
  pointer-events: none;
}

.dropzone-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent-primary);
  margin-bottom: 1.25rem;
  transition: transform var(--transition-normal);
}

.upload-dropzone:hover .dropzone-icon {
  transform: translateY(-4px) scale(1.05);
}

.dropzone-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.dropzone-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.dropzone-desc strong {
  color: #93c5fd;
}

.dropzone-content .btn-upload {
  pointer-events: auto;
}

/* 캔버스 하단 플로팅 힌트 */
.canvas-hints {
  position: absolute;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 17, 23, 0.8);
  backdrop-filter: blur(6px);
  border: 1px solid var(--border-subtle);
  padding: 0.35rem 0.9rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  pointer-events: none;
  z-index: 5;
}

.canvas-hints .dot {
  color: var(--text-muted);
}

/* ==========================================================================
   Control Panel & Cards
   ========================================================================== */
.control-panel {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  /* 스크롤 없이 전체 내용이 한눈에 보이도록 처리 */
  overflow-y: visible;
}

.panel-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.highlight-card {
  border-color: rgba(59, 130, 246, 0.4);
  background: linear-gradient(180deg, rgba(30, 41, 59, 0.7) 0%, rgba(23, 26, 35, 0.9) 100%);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 0.95rem;
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(255, 255, 255, 0.02);
}

.card-title {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
}

.card-sub-hint {
  font-size: 0.725rem;
  color: var(--text-muted);
}

.card-body {
  padding: 0.75rem 0.95rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

/* ==========================================================================
   Effects Selection Chips
   ========================================================================== */
.effects-chip-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.45rem;
}

@media (max-width: 1200px) {
  .effects-chip-group {
    grid-template-columns: repeat(auto-fit, minmax(95px, 1fr));
  }
}

.btn-effect-chip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.55rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.775rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  white-space: nowrap;
  gap: 0.25rem;
}

.btn-effect-chip:hover {
  background: var(--bg-elevated);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn-effect-chip.active {
  background: rgba(59, 130, 246, 0.16);
  border-color: var(--accent-primary);
  color: #60a5fa;
  font-weight: 600;
  box-shadow: 0 0 10px rgba(59, 130, 246, 0.2);
}

.chip-icon {
  font-size: 0.9rem;
  flex-shrink: 0;
}

.chip-title {
  flex: 1;
  text-align: left;
  overflow: hidden;
  text-overflow: ellipsis;
}

.chip-status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-muted);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.btn-effect-chip.active .chip-status-dot {
  background: #38bdf8;
  box-shadow: 0 0 6px #38bdf8;
}

/* ==========================================================================
   Form Controls, Sliders & Buttons
   ========================================================================== */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.value-display {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--accent-primary);
  font-weight: 600;
}

.slider-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--bg-elevated);
  outline: none;
  cursor: pointer;
  transition: background var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-primary);
  box-shadow: 0 0 6px var(--accent-glow);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  background: #60a5fa;
}

.btn-icon-small {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.btn-icon-small:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.form-select {
  width: 100%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: 0.85rem;
  outline: none;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.form-select:focus {
  border-color: var(--border-focus);
}

/* Button Group */
.button-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.45rem;
}

.fit-buttons button {
  font-size: 0.8rem;
  padding: 0.55rem 0.4rem;
}

.transform-buttons button {
  font-size: 0.775rem;
  padding: 0.5rem 0.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.6rem 1rem;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  user-select: none;
}

.btn-primary {
  background: var(--accent-primary);
  color: white;
  box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 16px var(--accent-glow);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

.btn-secondary:hover {
  background: var(--bg-elevated);
  border-color: var(--border-strong);
}

.btn-secondary.active {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--accent-primary);
  color: #60a5fa;
  font-weight: 600;
}

.btn-outline {
  background: transparent;
  border: 1px dashed var(--border-strong);
  color: var(--text-secondary);
  width: 100%;
}

.btn-outline:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
  background: rgba(59, 130, 246, 0.05);
}

.btn-ghost-small {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.6rem;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 0.75rem;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.btn-ghost-small:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn-large {
  padding: 0.75rem 1.15rem;
  font-size: 0.925rem;
  font-weight: 600;
  width: 100%;
}

.export-actions {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 0.2rem;
}

/* ==========================================================================
   Toast Notification System
   ========================================================================== */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 1000;
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 1.1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.85rem;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  pointer-events: auto;
  animation: toastIn 0.25s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.toast.toast-success {
  border-color: rgba(16, 185, 129, 0.4);
}
.toast.toast-success svg {
  color: var(--success-color);
}

.toast.toast-error {
  border-color: rgba(239, 68, 68, 0.4);
}
.toast.toast-error svg {
  color: var(--danger-color);
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* 드롭존 하단 단축키 팁 */
.dropzone-shortcut-tip {
  margin-top: 1rem;
  font-size: 0.775rem;
  color: var(--text-muted);
}
.dropzone-shortcut-tip strong {
  color: #93c5fd;
}

/* ==========================================================================
   Philosophy & Story Essay Section
   ========================================================================== */
.philosophy-section {
  margin-top: 1rem;
  padding: 1.25rem 0 0.5rem;
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

@media (max-width: 900px) {
  .philosophy-grid {
    grid-template-columns: 1fr;
  }
}

.philosophy-card {
  position: relative;
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.45) 0%, rgba(15, 23, 42, 0.65) 100%);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}

.philosophy-card:hover {
  transform: translateY(-2px);
  border-color: rgba(56, 189, 248, 0.3);
}

.quote-symbol {
  font-family: Georgia, serif;
  font-size: 3.5rem;
  line-height: 0.8;
  color: #38bdf8;
  opacity: 0.4;
  user-select: none;
}

.philosophy-card-body {
  flex: 1;
}

.philosophy-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #f1f5f9;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
  background: linear-gradient(90deg, #f8fafc 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.philosophy-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.65;
  word-break: keep-all;
}

/* ==========================================================================
   Witty Footer & Disclaimers
   ========================================================================== */
.app-footer {
  margin-top: 1rem;
  padding: 1.5rem 0 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.footer-disclaimers {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.85rem;
}

@media (max-width: 980px) {
  .footer-disclaimers {
    grid-template-columns: 1fr;
  }
}

.disclaimer-chip {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  background: rgba(23, 26, 35, 0.6);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.75rem 0.95rem;
  font-size: 0.775rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.disclaimer-icon {
  font-size: 1rem;
  flex-shrink: 0;
}

.disclaimer-text {
  flex: 1;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.5rem;
  font-size: 0.775rem;
  color: var(--text-muted);
}

.footer-slogan {
  font-weight: 600;
  color: #38bdf8;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.footer-copy {
  color: var(--text-muted);
}