:root {
  --primary-color: #4a90e2;
  --primary-dark: #357abd;
  --secondary-color: #50e3c2;
  --secondary-dark: #38a89d;
  --text-color: #333;
  --text-light: #555;
  --text-lighter: #777;
  --border-color: #e0e0e0;
  --border-darker: #c5c5c5;
  --input-bg: #ffffff;
  --control-bg: #ffffff;
  --preview-bg: #f7f9fc;
  --body-bg: #f0f2f5;
  --danger-color: #e94e77;
  --danger-dark: #c73860;
  --white: #ffffff;
  --shadow-color: rgba(0, 0, 0, 0.1);
  --shadow-light: rgba(0, 0, 0, 0.05);

  --font-primary: "Roboto", "Noto Sans KR", sans-serif;
  --font-secondary: "Montserrat", sans-serif;
  --base-font-size: 16px;
  --line-height: 1.6;

  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --border-radius: 8px;
  --border-radius-sm: 4px;
  --border-radius-md: 6px;
  --controls-width: 400px;
  --max-width: 1600px;

  --transition-speed: 0.2s;
}

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

html {
  font-size: var(--base-font-size);
}

body {
  font-family: var(--font-primary);
  background-color: var(--body-bg);
  color: var(--text-color);
  line-height: var(--line-height);
  padding: var(--spacing-lg);
}

.main-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  padding-top: var(--spacing-md);
}

h1 {
  font-family: var(--font-secondary);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(45deg, var(--primary-dark), var(--primary-color));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.05);
  margin: 0 auto;
}

.editor-container {
  display: flex;
  gap: var(--spacing-xl);
  max-width: var(--max-width);
  margin: 0 auto;
  align-items: flex-start;
}

.controls {
  background-color: var(--control-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  box-shadow: 0 4px 15px var(--shadow-light);
  flex: 0 0 var(--controls-width);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.preview {
  background-color: var(--preview-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  flex: 1 1 auto;
  position: sticky;
  top: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 0;
  gap: var(--spacing-md);
}

.orientation-controls {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  width: 100%;
  margin-bottom: var(--spacing-sm);
}

.orientation-controls button {
  padding: var(--spacing-xs) var(--spacing-md);
  min-width: 80px;
}

.orientation-controls button.active {
  background-color: var(--primary-color);
  color: var(--white);
  border-color: var(--primary-color);
  font-weight: 500;
}
.orientation-controls button.active:hover {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
}

.canvas-container {
  width: 100%;
  max-width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

#previewCanvas {
  border: 1px solid var(--border-color);
  background-color: var(--white);
  box-shadow: 0 2px 8px var(--shadow-light);
  display: block;
  max-width: 100%;
  height: auto;
  max-height: 75vh;
}

.canvas-placeholder-text-main {
  font-weight: bold;
}
.canvas-placeholder-text-sub {
  color: var(--text-light);
}

.main-footer {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-md) 0;
  border-top: 1px solid var(--border-color);
}

.footer-content {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--text-lighter);
}

.creator-info a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-speed) ease;
}
.creator-info a:hover {
  color: var(--primary-dark);
}

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

h3.collapsible-header,
h4.collapsible-header {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-color);
  margin: 0;
  padding: var(--spacing-md);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  transition: color var(--transition-speed) ease;
  background-color: var(--body-bg);
  border-top-left-radius: var(--border-radius-sm);
  border-top-right-radius: var(--border-radius-sm);
}

h4.collapsible-header {
  font-size: 1rem;
  padding: var(--spacing-sm) var(--spacing-md);
}

.control-group.collapsed h3.collapsible-header,
.control-group.collapsed h4.collapsible-header {
  border-bottom-color: transparent;
}
h3.collapsible-header:hover,
h4.collapsible-header:hover {
  padding: var(--spacing-md);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  transition: color var(--transition-speed) ease;
  background-color: var(--body-bg);
  border-top-left-radius: var(--border-radius-sm);
  border-top-right-radius: var(--border-radius-sm);
  color: var(--primary-color);
}

h4.layout-subtitle {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-light);
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
  padding-bottom: var(--spacing-xs);
  border-bottom: 1px solid var(--border-color);
}
h4.layout-subtitle:first-of-type {
  margin-top: 0;
}

label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-light);
  display: block;
  margin-bottom: var(--spacing-xs);
  text-align: left;
}

input[type="text"],
input[type="number"],
select,
input[type="file"]::file-selector-button {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  background-color: var(--input-bg);
  font-size: 0.9rem;
  font-family: inherit;
  color: var(--text-color);
  transition: border-color var(--transition-speed) ease,
    box-shadow var(--transition-speed) ease;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

input[type="file"] {
  padding: 0;
  border: none;
  background: none;
}
input[type="file"]::file-selector-button {
  margin-right: var(--spacing-md);
  border: 1px solid var(--primary-color);
  background-color: var(--primary-color);
  color: var(--white);
  cursor: pointer;
  transition: background-color var(--transition-speed) ease;
}
input[type="file"]::file-selector-button:hover {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
}

input[type="color"] {
  padding: 0;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  height: calc(1.6em + var(--spacing-sm) * 2 + 2px);
  width: 100%;
  cursor: pointer;
  background-color: var(--input-bg);
}
input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 4px;
}
input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: calc(var(--border-radius-sm) / 2);
}

button {
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color var(--transition-speed) ease,
    border-color var(--transition-speed) ease,
    color var(--transition-speed) ease;
  text-align: center;
}

.button-primary {
  background-color: var(--primary-color);
  color: var(--white);
  border-color: var(--primary-color);
}
.button-primary:hover {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
}

.button-secondary {
  background-color: var(--white);
  color: var(--text-light);
  border-color: var(--border-color);
}
.button-secondary:hover {
  background-color: var(--body-bg);
  border-color: var(--border-color);
  color: var(--text-color);
}

.button-danger {
  background-color: var(--danger-color);
  color: var(--white);
  border-color: var(--danger-color);
}
.button-danger:hover {
  background-color: var(--danger-dark);
  border-color: var(--danger-dark);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

#downloadButton {
  min-width: 200px;
}

.control-section {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xs);
}

.inline-controls {
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: var(--spacing-sm);
}
.inline-controls label {
  margin-bottom: 0;
}

.button-group {
  display: flex;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-sm);
}
.controls .button-group {
  justify-content: flex-end;
}
.button-group button {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.8rem;
}

.button-group-toggle {
  display: flex;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  overflow: hidden;
}
.button-toggle {
  flex-grow: 1;
  padding: var(--spacing-sm) var(--spacing-xs);
  background-color: var(--input-bg);
  color: var(--text-light);
  border: none;
  border-right: 1px solid var(--border-color);
  font-size: 0.85rem;
  cursor: pointer;
  transition: background-color var(--transition-speed) ease,
    color var(--transition-speed) ease;
}
.button-toggle:last-child {
  border-right: none;
}
.button-toggle.active {
  background-color: var(--primary-color);
  color: var(--white);
  font-weight: 500;
}
.button-toggle:not(.active):hover {
  background-color: var(--body-bg);
}

.control-group {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.8rem;
}

.control-group {
  margin-bottom: var(--spacing-lg);
}
.control-group:last-child {
  margin-bottom: 0;
}

.setting-group {
  margin-bottom: var(--spacing-lg);
}
.setting-group:last-child {
  margin-bottom: 0;
}

.control-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}
.control-item:last-child {
  margin-bottom: 0;
}
.setting-group .control-item:last-child {
  margin-bottom: 0;
}

.slider-group {
  display: grid;
  grid-template-columns: 1fr 80px;
  gap: var(--spacing-md);
  align-items: center;
  margin-bottom: var(--spacing-md);
}
.slider-group label {
  grid-column: 1 / 2;
  margin-bottom: 0;
  align-self: center;
}
.slider-group input[type="range"] {
  grid-row: 2 / 3;
  grid-column: 1 / 2;
}
.slider-group input[type="number"] {
  grid-row: 2 / 3;
  grid-column: 2 / 3;
  text-align: right;
}

input[type="range"] {
  width: 100%;
  height: 6px;
  background: var(--border-color);
  border-radius: 3px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  margin: 0;
}
input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  background: var(--primary-color);
  border-radius: 50%;
  cursor: pointer;
  border: 3px solid var(--white);
  box-shadow: 0 1px 3px var(--shadow-color);
  margin-top: -6px;
}
input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  background: var(--primary-color);
  border-radius: 50%;
  cursor: pointer;
  border: 3px solid var(--white);
  box-shadow: 0 1px 3px var(--shadow-color);
}

.collapsible-content {
  overflow: hidden;
  transition: max-height var(--transition-speed) ease-out;
  padding-top: var(--spacing-lg);
}
.control-group.collapsed .collapsible-content {
  max-height: 0 !important;
  padding-top: 0;
}
.toggle-icon {
  font-weight: bold;
  margin-left: var(--spacing-sm);
  font-size: 1.2em;
  line-height: 1;
  color: var(--text-light);
  transition: transform var(--transition-speed) ease,
    color var(--transition-speed) ease;
  width: 20px;
  height: 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.control-group.collapsed .toggle-icon {
}
hr.separator {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: var(--spacing-lg) 0;
}

.export-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
  width: 100%;
  justify-content: flex-end;
  padding-right: var(--spacing-sm);
}

.download-format-control {
  display: flex;
  align-items: center;
}

.button-like-select {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  background-color: var(--input-bg);
  font-size: 0.9rem;
  font-family: inherit;
  color: var(--text-color);
  cursor: pointer;
  transition: border-color var(--transition-speed) ease,
    box-shadow var(--transition-speed) ease;
}

.button-like-select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

@media (max-width: 1200px) {
  :root {
    --controls-width: 350px;
  }
  .slider-group {
    grid-template-columns: 1fr 70px;
  }
}

@media (max-width: 992px) {
  .editor-container {
    flex-direction: column;
    align-items: stretch;
  }
  .controls {
    flex: 1 1 auto;
    max-width: none;
  }
  .preview {
    position: static;
    margin-top: var(--spacing-xl);
  }
}

@media (max-width: 768px) {
  :root {
    --base-font-size: 15px;
  }
  h1 {
    font-size: 1.8rem;
  }
  .slider-group {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
  .slider-group label {
    grid-row: 1 / 2;
    grid-column: 1 / -1;
    margin-bottom: var(--spacing-xs);
  }
  .slider-group input[type="range"] {
    grid-row: 2 / 3;
    grid-column: 1 / -1;
    order: 0;
  }
  .slider-group input[type="number"] {
    grid-row: 3 / 4;
    grid-column: 1 / -1;
    order: 0;
    text-align: left;
  }

  .inline-controls {
    grid-template-columns: 1fr;
  }
  .inline-controls label {
    text-align: left;
  }
  .controls .button-group {
    width: 100%;
    margin-top: var(--spacing-sm);
    justify-content: space-between;
  }
  .controls .button-group button {
    flex-grow: 1;
  }

  .footer-content {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .orientation-controls {
    margin-bottom: var(--spacing-md);
  }
  #previewCanvas {
    max-height: 65vh;
  }
  .export-controls {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-md);
    padding-right: 0;
  }
}