/* ============================================
   Layout
   Header, main grid, panels, responsive
   ============================================ */

/* ---- Header ---- */
.app-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-xl);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-light);
}

/* Candy stripe accent bar under header */
.app-header::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  right: 0;
  height: 3px;
  background: repeating-linear-gradient(
    90deg,
    var(--color-candy-pink) 0px,
    var(--color-candy-pink) 8px,
    var(--color-candy-lavender) 8px,
    var(--color-candy-lavender) 16px,
    var(--color-candy-mint) 16px,
    var(--color-candy-mint) 24px,
    var(--color-candy-peach) 24px,
    var(--color-candy-peach) 32px,
    var(--color-candy-sky) 32px,
    var(--color-candy-sky) 40px
  );
  opacity: 0.6;
}

.header-left,
.header-right {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.header-center {
  flex: 1;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.brand {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.3;
}

.brand-subtitle {
  font-size: 0.78rem;
  color: var(--color-text-tertiary);
  margin-top: 1px;
  letter-spacing: 0.04em;
}

.brand-subtitle-row {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
}

[data-ui-mode="pro"] .app-header {
  background: rgba(255, 249, 236, 0.92);
  border-bottom-color: var(--color-border);
  box-shadow: 0 1px 0 rgba(36, 36, 36, 0.08);
}

[data-ui-mode="pro"][data-theme="dark"] .app-header {
  background: rgba(36, 36, 36, 0.94);
}

[data-ui-mode="pro"] .app-header::after {
  background: var(--color-border);
  height: 1px;
  opacity: 1;
}

[data-ui-mode="pro"] .brand {
  background: none;
  -webkit-text-fill-color: var(--color-text-primary);
  color: var(--color-text-primary);
  letter-spacing: -0.01em;
}

/* ---- Main Content Grid (3 columns) ---- */
.app-main {
  display: grid;
  grid-template-columns: 300px 1fr 320px;
  gap: var(--space-lg);
  max-width: 1600px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-xl);
  position: relative;
  z-index: 1;
}

.panel-input,
.panel-canvas,
.panel-output {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.panel-input {
  min-width: 0;
}

.panel-canvas {
  min-width: 0;
}

.panel-output {
  min-width: 0;
}

/* ---- Poster Workspace Layout ---- */
body.poster-workspace-active {
  --poster-header-offset: 88px;
  --poster-viewport-height: calc(100dvh - var(--poster-header-offset));
  overflow: hidden;
}

body.poster-workspace-active .app-main {
  grid-template-columns: minmax(0, 1fr) clamp(360px, 24vw, 440px);
  max-width: 1920px;
  height: var(--poster-viewport-height);
  max-height: var(--poster-viewport-height);
  align-items: stretch;
  overflow: hidden;
}

body.poster-workspace-active .panel-input,
body.poster-workspace-active .panel-output {
  display: none !important;
}

body.poster-workspace-active .panel-canvas {
  grid-column: 1 / 2;
  grid-row: 1;
  order: 0;
  height: 100%;
  min-height: 0;
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
}

body.poster-workspace-active #poster-inspector {
  display: flex !important;
  grid-column: 2 / 3;
  grid-row: 1;
  order: 0;
}

body.poster-workspace-active #canvas-section {
  flex: 0 0 auto;
  min-height: calc(var(--poster-viewport-height) - 48px);
  height: auto;
  max-height: none;
  display: flex;
  flex-direction: column;
  overflow: visible;
}

body.poster-workspace-active #canvas-section .canvas-layout {
  flex: 0 0 auto;
  min-height: 0;
  overflow: visible;
  align-items: flex-start;
}

/* ---- Overlay (backdrop for side panels) ---- */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(45, 43, 61, 0.25);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
  z-index: var(--z-overlay);
}

.overlay.open {
  opacity: 1;
  visibility: visible;
}

/* ---- Side Panels (settings, history) ---- */
.side-panel {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  width: 380px;
  max-width: 90vw;
  background: var(--color-bg-card);
  transform: translateX(-100%);
  transition: transform var(--transition-slow);
  z-index: var(--z-panel);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
}

.side-panel.side-panel-right {
  left: auto;
  right: 0;
  transform: translateX(100%);
}

.side-panel.open {
  transform: translateX(0);
}

.side-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.side-panel-header h2 {
  font-size: 1.1rem;
  font-weight: 600;
}

.side-panel-body {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* ---- Responsive ---- */
@media (max-width: 1280px) {
  .app-main {
    grid-template-columns: 300px 1fr;
    /* Canvas and output stack in the right column */
  }

  .panel-canvas {
    grid-column: 1 / -1;
    order: 3;
  }

  body.poster-workspace-active .app-main {
    grid-template-columns: minmax(0, 1fr) clamp(340px, 28vw, 400px);
  }
}

@media (max-width: 768px) {
  body.poster-workspace-active {
    --poster-header-offset: 56px;
  }

  .app-header {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-xs) var(--space-sm);
    padding: var(--space-sm) var(--space-md);
  }

  .header-left,
  .header-center,
  .header-right {
    min-width: 0;
  }

  .header-center {
    align-items: flex-start;
    text-align: left;
  }

  .brand-subtitle-row {
    max-width: 100%;
    gap: var(--space-xs);
  }

  .brand-subtitle {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .header-right {
    grid-column: 1 / -1;
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--space-xs);
    padding-top: var(--space-xs);
  }

  .style-slider-track-wrap {
    width: min(112px, 32vw);
  }

  body.poster-workspace-active .app-header {
    display: flex;
    min-height: var(--poster-header-offset);
    gap: 5px;
    padding: 6px var(--space-sm);
  }

  body.poster-workspace-active .header-center {
    display: none;
  }

  body.poster-workspace-active .header-left {
    display: flex;
    flex: 0 0 30px;
  }

  body.poster-workspace-active .header-left .btn-icon {
    width: 30px;
    height: 30px;
  }

  body.poster-workspace-active .header-right {
    grid-column: auto;
    flex: 1 1 auto;
    width: 100%;
    justify-content: space-between;
    flex-wrap: nowrap;
    gap: 5px;
    padding-top: 0;
  }

  body.poster-workspace-active .ui-mode-switch {
    flex: 0 0 96px;
    padding: 2px;
  }

  body.poster-workspace-active .ui-mode-btn {
    min-height: 30px;
    flex: 1 1 0;
    padding: 0 5px;
    font-size: 0.72rem;
  }

  body.poster-workspace-active .style-slider-wrap {
    flex: 0 1 136px;
    min-width: 0;
    max-width: 136px;
    gap: 4px;
    margin-right: 4px;
  }

  body.poster-workspace-active .style-slider-label {
    display: none;
  }

  body.poster-workspace-active .style-slider-track-wrap {
    width: 100%;
    min-width: 0;
  }

  body.poster-workspace-active .header-right .btn-icon {
    width: 30px;
    height: 30px;
  }

  body.poster-workspace-active .header-right .btn-icon svg {
    width: 17px;
    height: 17px;
  }

  .app-main {
    grid-template-columns: 1fr;
    padding: var(--space-md);
    gap: var(--space-md);
  }

  .panel-canvas {
    order: 2;
  }

  .panel-output {
    order: 3;
  }

  body.poster-workspace-active .app-main {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
    height: var(--poster-viewport-height);
    max-height: var(--poster-viewport-height);
  }

  body.poster-workspace-active .panel-canvas {
    min-height: 0;
  }

  body.poster-workspace-active #canvas-section {
    min-height: calc(var(--poster-viewport-height) - 32px);
    height: auto;
    max-height: none;
  }
}

@media (max-width: 640px) {
  .app-header {
    padding: 10px var(--space-sm);
  }

  .brand {
    font-size: 1.2rem;
  }

  .brand-subtitle {
    font-size: 0.7rem;
  }

  .header-right .btn-icon {
    width: 36px;
    height: 36px;
  }

  .ui-mode-switch {
    order: -1;
  }

  .side-panel {
    width: 100%;
    max-width: 100vw;
  }
}