:root {
  color-scheme: light dark;
  --bg: #0f1115;
  --panel: #171a21;
  --border: #2a2e38;
  --text: #e6e8ec;
  --muted: #9aa1ac;
  --accent: #5b8def;
  --warn-bg: #3a2a10;
  --warn-border: #7a5a1a;
  --warn-text: #f0c674;
  --error: #e35d5d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.page-header {
  padding: 32px 24px 16px;
  max-width: 1100px;
  margin: 0 auto;
}

.page-header h1 {
  margin: 0 0 4px;
}

.page-header p {
  color: var(--muted);
  margin: 0;
}

.layout {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px 48px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

@media (min-width: 900px) {
  .layout {
    grid-template-columns: 1fr 1.3fr;
    align-items: start;
  }
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}

.panel h2 {
  font-size: 16px;
  margin: 0 0 12px;
}

.panel h2:not(:first-child) {
  margin-top: 24px;
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: 10px;
  padding: 32px 16px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
  color: var(--muted);
}

.dropzone.dragover {
  border-color: var(--accent);
  background: rgba(91, 141, 239, 0.08);
  color: var(--text);
}

.mode-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mode-option {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
}

.mode-option input {
  margin-top: 4px;
}

.mode-option p {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.field {
  margin-top: 12px;
}

.field label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 4px;
}

.field input {
  width: 100%;
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: #10131a;
  color: var(--text);
}

.notice {
  margin-top: 16px;
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  color: var(--warn-text);
  font-size: 13px;
}

button {
  margin-top: 16px;
  padding: 10px 18px;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.file-name {
  color: var(--muted);
  font-size: 13px;
  margin: 8px 0 0;
}

.error-message {
  color: var(--error);
  font-size: 13px;
  margin-top: 8px;
}

.base-url-info {
  padding: 10px 12px;
  border-radius: 8px;
  background: rgba(91, 141, 239, 0.12);
  border: 1px solid var(--accent);
  color: var(--text);
  font-size: 13px;
  margin: 0 0 12px;
  word-break: break-all;
}

.warnings {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.warning-item {
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  color: var(--warn-text);
  font-size: 13px;
}

.result-actions {
  display: flex;
  gap: 10px;
}

.result-actions button {
  margin-top: 0;
}

#preview-frame {
  width: 100%;
  height: 480px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  margin-top: 8px;
}

#html-source {
  width: 100%;
  height: 220px;
  margin-top: 8px;
  background: #10131a;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  resize: vertical;
}