:root {
  --bg-app: #1e1e1e;
  --bg-panel: #1e1e1e;
  --bg-sidebar: #252526;
  --bg-gutter: #1e1e1e;
  --bg-active-line: #282828;
  --border-color: #333333;
  --text-main: #d4d4d4;
  --text-muted: #858585;
  --accent-primary: #007acc;
  --accent-hover: #0062a3;
  --danger-color: #d64646;
  --success-color: #4ec9b0;
  --warning-color: #f0b429;
  --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-code: "JetBrains Mono", "Fira Code", "Consolas", "Monaco", monospace;
  --header-height: 56px;
  --error-bg: #14171d;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  outline: none;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--bg-app);
  color: var(--text-main);
  font-family: var(--font-ui);
}

button,
select,
textarea {
  font: inherit;
}

.icon {
  width: 16px;
  height: 16px;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 0;
}

.icon-stroke {
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  height: var(--header-height);
  padding: 0 16px;
  background-color: var(--bg-sidebar);
  border-bottom: 1px solid var(--border-color);
  user-select: none;
}

.logo {
  display: flex;
  flex-shrink: 0;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.logo-icon {
  display: flex;
  width: 24px;
  height: 24px;
  align-items: center;
  justify-content: center;
  color: var(--accent-primary);
  background: #333;
  border-radius: 6px;
}

.logo span.highlight {
  color: var(--success-color);
  font-weight: 400;
}

.actions {
  display: flex;
  flex: 1;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  min-width: 0;
}

.action-group {
  display: flex;
  align-items: center;
  gap: 6px;
  min-width: 0;
}

.action-group-file {
  justify-content: flex-end;
  flex-wrap: wrap;
}

.action-group-run {
  justify-content: flex-end;
  flex-wrap: wrap;
  padding-left: 12px;
  border-left: 1px solid #444;
}

.btn,
.template-select {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 34px;
  padding: 0 10px;
  color: var(--text-main);
  font-size: 13px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.btn {
  cursor: pointer;
}

.template-select {
  min-width: 124px;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.05);
}

.btn:hover,
.template-select:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  color: #fff;
  font-weight: 500;
  background-color: var(--accent-primary);
}

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

.btn-danger:hover {
  color: var(--danger-color);
  background-color: rgba(214, 70, 70, 0.1);
}

.btn-icon-only {
  padding: 0 8px;
}

.btn-toggle {
  color: #a7d9ff;
  border-color: rgba(0, 122, 204, 0.22);
}

.btn-toggle.is-on {
  background: rgba(0, 122, 204, 0.16);
  border-color: rgba(0, 122, 204, 0.36);
}

.container {
  display: flex;
  width: 100%;
  height: calc(100% - var(--header-height));
}

.editor-wrapper {
  display: flex;
  flex-direction: column;
  width: 50%;
  min-width: 260px;
  background-color: var(--bg-panel);
}

.panel-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: 42px;
  padding: 0 14px;
  color: var(--text-muted);
  font-size: 12px;
  background-color: var(--bg-app);
  border-bottom: 1px solid var(--border-color);
}

.editor-topbar {
  flex-wrap: wrap;
  align-content: center;
  padding-top: 6px;
  padding-bottom: 6px;
}

.tab-row,
.file-meta {
  display: flex;
  align-items: center;
  gap: 8px;
}

.tab-button {
  padding: 7px 12px;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
}

.tab-button.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.1);
}

.badge {
  padding: 2px 6px;
  font-size: 10px;
  background: #333;
  border-radius: 999px;
}

.badge-error {
  background: rgba(240, 180, 41, 0.18);
  color: var(--warning-color);
}

.editor-body {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.gutter {
  width: 45px;
  padding: 15px 8px 15px 0;
  overflow: hidden;
  color: #6e7681;
  font-family: var(--font-code);
  font-size: 14px;
  line-height: 1.5;
  text-align: right;
  user-select: none;
  background-color: var(--bg-gutter);
  border-right: 1px solid var(--border-color);
}

textarea {
  flex: 1;
  padding: 15px;
  overflow: auto;
  color: #d4d4d4;
  font-family: var(--font-code);
  font-size: 14px;
  line-height: 1.5;
  white-space: pre;
  tab-size: 4;
  resize: none;
  background-color: var(--bg-panel);
  border: none;
}

textarea::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

textarea::-webkit-scrollbar-track {
  background: var(--bg-panel);
}

textarea::-webkit-scrollbar-thumb {
  background-color: #424242;
  border: 2px solid var(--bg-panel);
  border-radius: 5px;
}

.resizer {
  z-index: 10;
  display: flex;
  width: 10px;
  align-items: center;
  justify-content: center;
  cursor: col-resize;
  background-color: var(--bg-app);
  border-left: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
  transition: background 0.2s;
}

.resizer:hover {
  background-color: var(--accent-primary);
}

.resizer::after {
  content: "";
  display: block;
  width: 2px;
  height: 16px;
  background: #555;
  border-radius: 1px;
}

.preview-wrapper {
  display: flex;
  flex: 1;
  flex-direction: column;
  min-width: 260px;
  background: #f2f4f7;
}

.preview-bar {
  color: #555;
  background: #f3f3f3;
  border-bottom: 1px solid #ddd;
}

.preview-action {
  padding: 0;
  color: #666;
  background: none;
  border: none;
  cursor: pointer;
}

.preview-stage {
  position: relative;
  flex: 1;
  min-height: 0;
}

iframe {
  width: 100%;
  height: 100%;
  background: #fff;
  border: none;
}

.iframe-mask {
  position: absolute;
  inset: 0;
  z-index: 100;
  display: none;
}

.error-panel {
  min-height: 140px;
  padding: 14px;
  color: #e0e6ef;
  background: var(--error-bg);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.error-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.error-empty {
  color: #8491a3;
  font-size: 13px;
}

.error-list {
  display: grid;
  gap: 8px;
  padding-left: 18px;
  color: #f8c9a8;
  font-family: var(--font-code);
  font-size: 12px;
}

.toast {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 180px;
  max-width: 320px;
  padding: 12px 16px;
  color: #fff;
  background: rgba(25, 25, 25, 0.94);
  border-radius: 12px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.3);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--danger-color);
}

body.resizing {
  cursor: col-resize;
}

body.resizing .iframe-mask {
  display: block;
}

@media (max-width: 1160px) {
  header {
    height: auto;
    align-items: stretch;
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .actions {
    justify-content: space-between;
    align-items: flex-start;
  }

  .action-group {
    flex: 1 1 0;
  }

  .action-group-file {
    justify-content: flex-start;
  }

  .action-group-run {
    justify-content: flex-end;
  }
}

@media (max-width: 920px) {
  header {
    gap: 12px;
  }

  .actions {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
  }

  .action-group {
    flex: none;
    flex-wrap: wrap;
  }

  .action-group-run {
    justify-content: flex-start;
    padding-left: 0;
    border-left: 0;
  }
}

@media (max-width: 768px) {
  html,
  body {
    overflow: auto;
  }

  .container {
    flex-direction: column;
    height: auto;
    min-height: calc(100% - var(--header-height));
  }

  .btn-text {
    display: none;
  }

  .btn,
  .template-select {
    justify-content: center;
  }

  .template-select {
    min-width: 108px;
  }

  .editor-wrapper,
  .preview-wrapper {
    width: 100%;
    min-width: 0;
  }

  .editor-wrapper {
    min-height: 48vh;
  }

  .preview-wrapper {
    min-height: 44vh;
  }

  .resizer {
    width: 100%;
    height: 10px;
    cursor: row-resize;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    border-left: 0;
    border-right: 0;
  }

  body.resizing {
    cursor: row-resize;
  }
}