:root {
  color-scheme: light;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: #f5f7f8;
  color: #172026;
  --panel: #ffffff;
  --border: #d8e0e5;
  --muted: #61717d;
  --accent: #116d6e;
  --accent-hover: #0d5a5b;
  --ink: #172026;
  --surface: #eef3f4;
  --danger: #9c2f2f;
  --shadow: 0 18px 40px rgba(24, 39, 50, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(180deg, rgba(17, 109, 110, 0.08), rgba(245, 247, 248, 0) 280px),
    var(--surface);
}

button,
textarea,
input {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

button:disabled {
  cursor: wait;
  opacity: 0.68;
}

.app-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 48px;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 24px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(2rem, 6vw, 4.4rem);
  line-height: 0.95;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 6px;
  font-size: 1.2rem;
}

.panel-heading p,
.diagram-meta,
.file-drop-meta {
  color: var(--muted);
}

.repo-link,
.secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.repo-link,
.secondary-button {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--ink);
}

.repo-link:hover,
.secondary-button:hover {
  background: #f7fafb;
}

.input-panel,
.results-panel {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.input-panel {
  padding: 22px;
}

.results-panel {
  margin-top: 20px;
  padding: 22px;
}

.panel-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.panel-heading p {
  margin-bottom: 0;
}

.file-drop {
  display: grid;
  gap: 4px;
  padding: 18px;
  border: 1px dashed #9db2bd;
  border-radius: 8px;
  background: #f9fbfb;
  cursor: pointer;
}

.file-drop:hover {
  border-color: var(--accent);
}

.file-drop-title {
  font-weight: 800;
}

.file-drop input {
  width: 1px;
  height: 1px;
  opacity: 0;
  position: absolute;
  pointer-events: none;
}

.text-input-label {
  display: block;
  margin: 18px 0 8px;
  font-weight: 800;
}

textarea {
  display: block;
  width: 100%;
  min-height: 320px;
  resize: vertical;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  outline: none;
  background: #fbfcfd;
  color: var(--ink);
  font-family: "Cascadia Code", Consolas, "Liberation Mono", monospace;
  line-height: 1.5;
}

textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(17, 109, 110, 0.14);
}

.results-grid {
  display: grid;
  gap: 18px;
}

.diagram-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}

.diagram-toolbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 16px;
  border-bottom: 1px solid var(--border);
}

.diagram-title {
  margin-bottom: 4px;
  font-size: 1rem;
}

.diagram-meta {
  margin-bottom: 0;
  font-size: 0.92rem;
}

.diagram-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.panel-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.diagram-preview {
  min-height: 180px;
  padding: 18px;
  overflow: auto;
  background:
    linear-gradient(45deg, #f7f9fa 25%, transparent 25%),
    linear-gradient(-45deg, #f7f9fa 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #f7f9fa 75%),
    linear-gradient(-45deg, transparent 75%, #f7f9fa 75%);
  background-position:
    0 0,
    0 10px,
    10px -10px,
    -10px 0;
  background-size: 20px 20px;
}

.diagram-preview svg {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
  background: #fff;
}

.source-details {
  border-top: 1px solid var(--border);
  background: #fbfcfd;
}

.source-details summary {
  padding: 12px 16px;
  cursor: pointer;
  font-weight: 800;
}

.source-details pre {
  margin: 0;
  padding: 0 16px 16px;
  overflow: auto;
}

.source-details code {
  font-family: "Cascadia Code", Consolas, "Liberation Mono", monospace;
  font-size: 0.88rem;
  line-height: 1.5;
}

.empty-state,
.error-state {
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fbfcfd;
}

.error-state {
  border-color: rgba(156, 47, 47, 0.35);
  color: var(--danger);
}

@media (max-width: 720px) {
  .app-shell {
    width: min(100% - 20px, 1180px);
    padding-top: 20px;
  }

  .app-header,
  .panel-heading,
  .diagram-toolbar {
    display: grid;
  }

  .repo-link,
  .secondary-button {
    width: 100%;
  }

  .panel-actions,
  .diagram-actions {
    justify-content: stretch;
  }
}