/* Academic ML Studio — see DESIGN.md */
:root {
  --canvas: #f8fafc;
  --card: #ffffff;
  --border: #e2e8f0;
  --border-dashed: #cbd5e1;
  --text: #0f172a;
  --muted: #64748b;
  --track: #f1f5f9;
  --bar-muted: #94a3b8;

  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-tint: #eff6ff;
  --success: #10b981;
  --success-tint: #f0fdf4;
  --success-text: #006c49;
  --tertiary: #6366f1;
  --tertiary-tint: #eef2ff;
  --error: #ba1a1a;
  --error-container: #ffdad6;
  --on-error-container: #93000a;

  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", monospace;

  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-full: 9999px;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.25rem;
  --gutter: 1.25rem;

  --shadow-ambient: 0 1px 3px 0 rgba(15, 23, 42, 0.04), 0 1px 2px -1px rgba(15, 23, 42, 0.04);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

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

body {
  margin: 0;
  background: var(--canvas);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 20px;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
p,
figure,
dl,
dd {
  margin: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.muted {
  color: var(--muted);
}

.mono {
  font-family: var(--font-mono);
}

.label-ui {
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
  letter-spacing: 0.01em;
}

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(8px);
}

.navbar-inner {
  display: flex;
  align-items: center;
  max-width: 1040px;
  height: 56px;
  margin: 0 auto;
  padding: 0 var(--margin, 1.5rem);
}

.navbar-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.navbar-brand:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 4px;
  border-radius: var(--radius-sm, 0.25rem);
}

.navbar-logo {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius);
  background: var(--primary);
  color: #ffffff;
}

.navbar-group {
  padding: 4px 12px;
  border: 1px solid #c7cdf5;
  border-radius: var(--radius-full);
  background: #e2e7ff;
  color: #434655;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
  letter-spacing: 0.02em;
}

/* Layout */
.page {
  max-width: 1040px;
  margin: 0 auto;
  padding: var(--margin-lg, 3rem) var(--margin, 1.5rem);
}

.header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.title {
  font-size: 32px;
  font-weight: 700;
  line-height: 40px;
  letter-spacing: -0.02em;
}

.subtitle {
  margin-top: var(--space-sm);
  max-width: 560px;
  color: var(--muted);
  font-size: 16px;
  line-height: 24px;
}

.workspace {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: start;
}

.column {
  display: flex;
  flex-direction: column;
  gap: var(--gutter);
  min-width: 0;
}

/* Cards */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--gutter);
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  line-height: 26px;
  letter-spacing: -0.01em;
}

/* Pills & tags */
.pills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
  white-space: nowrap;
}

.pill-success {
  background: #d1fae5;
  color: var(--success-text);
}

.pill-tertiary {
  background: var(--tertiary-tint);
  color: var(--tertiary);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  white-space: normal;
}

.pill-muted {
  background: var(--track);
  color: var(--muted);
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--success);
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm, 0.25rem);
  background: var(--canvas);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  line-height: 16px;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

/* Dropzone */
.dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  min-height: 220px;
  padding: var(--space-lg);
  border: 1.5px dashed var(--border-dashed);
  border-radius: var(--radius);
  background: var(--canvas);
  text-align: center;
  cursor: pointer;
  transition:
    border-color 150ms ease,
    background-color 150ms ease;
}

.dropzone:hover,
.dropzone:focus-within {
  border-style: solid;
  border-color: var(--primary);
  background: var(--primary-tint);
}

.dropzone.is-dragging {
  border-style: dashed;
  border-color: var(--primary);
  background: rgba(37, 99, 235, 0.03);
}

.dropzone-icon {
  color: var(--primary);
}

.dropzone.has-file .dropzone-icon {
  display: none;
}

.dropzone-preview {
  max-width: 100%;
  max-height: 160px;
  border-radius: var(--radius);
  object-fit: contain;
}

.dropzone-text {
  font-size: 13px;
  font-weight: 400;
  line-height: 18px;
  word-break: break-all;
}

.dropzone-hint {
  color: var(--muted);
  font-size: 13px;
  line-height: 18px;
}

/* Buttons */
.actions {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  min-height: 40px;
  padding: 0 var(--space-md);
  border: 1px solid transparent;
  border-radius: var(--radius);
  font: 600 14px/20px var(--font-sans);
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color 150ms ease,
    border-color 150ms ease;
}

.btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.btn-primary {
  flex: 1;
  background: var(--primary);
  color: #ffffff;
}

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

.btn-primary:disabled {
  cursor: progress;
  opacity: 0.85;
}

.btn-secondary {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

.btn-secondary:hover {
  background: var(--track);
}

.spinner {
  display: none;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255, 255, 255, 0.35);
  border-top-color: #ffffff;
  border-radius: var(--radius-full);
  animation: spin 700ms linear infinite;
}

.btn.is-loading .spinner {
  display: inline-block;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Alerts */
.alert {
  margin-top: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 18px;
}

.alert-error {
  background: var(--error-container);
  color: var(--on-error-container);
}

.notice {
  padding: var(--space-md);
  border-left: 3px solid var(--primary);
  border-radius: var(--radius-lg);
  background: var(--canvas);
  color: var(--muted);
  font-size: 13px;
  line-height: 18px;
}

/* Preview */
.preview-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-sm);
}

.preview img {
  display: block;
  width: 100%;
  aspect-ratio: 1;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--canvas);
  object-fit: contain;
}

.preview img.pixelated {
  object-fit: cover;
  image-rendering: pixelated;
}

.preview figcaption {
  margin-top: var(--space-xs);
  color: var(--muted);
  font-size: 12px;
  line-height: 16px;
  text-align: center;
}

.preview-arrow {
  color: var(--muted);
  font-family: var(--font-mono);
}

/* Top prediction */
.top-card {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-md);
  background: var(--canvas);
  box-shadow: var(--shadow-ambient);
}

.top-card-confident {
  background: var(--success-tint);
}

.top-icon {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--card);
  font-size: 26px;
}

.top-body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  min-width: 0;
}

.top-label {
  font-size: 24px;
  font-weight: 700;
  line-height: 32px;
  letter-spacing: -0.015em;
}

.top-metric {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-xs);
}

.metric-display {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 600;
  line-height: 32px;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

/* Probability bars */
.prob-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.prob-row {
  display: grid;
  grid-template-columns: 76px 1fr 64px;
  align-items: center;
  gap: var(--space-sm);
}

.prob-label {
  color: var(--muted);
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
  letter-spacing: 0.01em;
}

.prob-track {
  height: 6px;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--track);
}

.prob-fill {
  display: block;
  width: var(--p);
  height: 100%;
  border-radius: var(--radius);
  background: var(--bar-muted);
  animation: grow 400ms var(--ease-out);
}

@keyframes grow {
  from {
    width: 0;
  }
}

.prob-value {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  line-height: 18px;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.prob-row.is-top .prob-label,
.prob-row.is-top .prob-value {
  color: var(--text);
  font-weight: 600;
}

.prob-row.is-top .prob-fill {
  background: var(--primary);
}

.prob-row.is-high .prob-fill {
  background: var(--success);
}

/* Runtime metadata */
.meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.meta dt {
  color: var(--muted);
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
}

.meta dd {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  line-height: 18px;
}

/* Empty state */
.empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xl) var(--gutter);
  text-align: center;
}

.empty-icon {
  color: var(--bar-muted);
}

.class-chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px;
  margin: var(--space-sm) 0 0;
  padding: 0;
  list-style: none;
}

/* Responsive */
@media (max-width: 1023px) {
  .workspace {
    gap: var(--space-md);
  }
}

@media (max-width: 767px) {
  .page {
    padding: var(--space-lg) var(--gutter);
  }

  .navbar-inner {
    padding: 0 var(--gutter);
  }

  .workspace {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 639px) {
  .title {
    font-size: 26px;
    line-height: 34px;
    letter-spacing: -0.015em;
  }

  .top-card {
    grid-template-columns: auto 1fr;
  }

  .top-metric {
    grid-column: 1 / -1;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (prefers-reduced-motion: reduce) {
  .prob-fill,
  .spinner {
    animation: none;
  }
}