:root {
  --bg-primary: #0f1419;
  --bg-secondary: #1a2332;
  --bg-card: #1e2a3a;
  --text-primary: #e8edf4;
  --text-secondary: #8b9cb5;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-green: #22c55e;
  --accent-yellow: #eab308;
  --accent-orange: #f97316;
  --accent-red: #ef4444;
  --border: rgba(139, 156, 181, 0.15);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

.app {
  width: 100%;
}

html {
  scroll-behavior: smooth;
}

/* Site logo - top-left on all pages */
.site-logo {
  position: fixed;
  top: 1.25rem;
  left: 1.25rem;
  z-index: 100;
  display: block;
  opacity: 0.9;
  transition: opacity 0.2s ease;
}
.site-logo:hover {
  opacity: 1;
}
.site-logo img {
  height: 40px;
  width: auto;
  display: block;
}

/* Hero / Landing */
.hero {
  min-height: 100vh;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
  position: relative;
}

.hero-content {
  max-width: 640px;
}

.hero-title {
  font-size: clamp(3rem, 12vw, 6.5rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 60%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transform-origin: center center;
  will-change: transform;
  transition: transform 0.12s ease-out, opacity 0.12s ease-out;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 2.5rem;
  font-weight: 400;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--bg-primary);
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  border: none;
  border-radius: 12px;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(6, 182, 212, 0.35);
}

.hero-scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.7;
  animation: float 2.5s ease-in-out infinite;
}

.hero-scroll-hint svg {
  opacity: 0.8;
}

@keyframes float {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}

/* Intro section (Scroll to explore) */
.intro {
  min-height: 80vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.intro-inner {
  max-width: 960px;
  width: 100%;
  text-align: center;
}

.intro-scheme-img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transform-origin: center center;
  transition: transform 0.2s ease-out, opacity 0.2s ease-out;
}

.intro h2 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.intro-lead {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.intro-eval {
  text-align: left;
  margin: 0 auto 1.5rem;
  max-width: 360px;
}

.intro-eval h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 0.5rem;
}

.intro-eval ul {
  list-style: none;
  padding: 0;
}

.intro-eval li {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  padding: 0.25rem 0;
}

.intro-tail {
  font-size: 1rem;
  color: var(--text-primary);
  font-weight: 500;
  margin-bottom: 2.5rem;
}

.intro-distribution {
  margin-bottom: 2.5rem;
}

.intro-distribution h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.intro-distribution-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  max-width: 600px;
  margin: 0 auto;
}

@media (max-width: 640px) {
  .intro-distribution-cards {
    grid-template-columns: 1fr;
  }
}

.distribution-card--intro {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 1rem;
  border: 1px solid var(--border);
}

.distribution-chart--intro {
  height: 140px;
  margin-bottom: 0.5rem;
}

.hero-cta--secondary {
  margin-top: 0.5rem;
}

/* Intro: scheme/design image */
.intro-scheme-img {
  max-width: 100%;
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
}

/* Intro: scheme/design image - scroll-triggered float effect */
.intro-scheme-img {
  max-width: 100%;
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  transform-origin: center center;
  transition: transform 0.25s ease-out, opacity 0.25s ease-out;
}

/* Upload page header */
.upload-page-header {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 2rem 1.5rem 4.5rem;
  border-bottom: 1px solid var(--border);
}

.upload-page-header h1 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0.5rem;
}

.back-link {
  font-size: 0.875rem;
  color: var(--accent-cyan);
  text-decoration: none;
  transition: opacity 0.2s;
}

.back-link:hover {
  opacity: 0.8;
}

.main-content--upload {
  padding-top: 2rem;
}

/* Main content wrapper + grid */
.main-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
  display: grid;
  grid-template-columns: 1fr minmax(340px, 380px);
  gap: 2rem;
  align-items: start;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: 3rem;
}

.header h1 {
  font-size: 1.875rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  margin-top: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 400;
}

/* Main Layout */
.main-content {
  display: grid;
  grid-template-columns: 1fr minmax(340px, 380px);
  gap: 2rem;
  align-items: start;
}

@media (max-width: 900px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

/* Upload Section */
.upload-section {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 1.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: relative;
}

.upload-area {
  min-height: 320px;
  border: 2px dashed var(--border);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  overflow: hidden;
  position: relative;
}

.upload-area:hover,
.upload-area.dragover {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.05);
}

.upload-placeholder {
  text-align: center;
  padding: 2rem;
}

.upload-icon {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  opacity: 0.7;
}

.upload-icon svg {
  display: block;
  margin: 0 auto;
}

.upload-text {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--text-primary);
}

.upload-hint {
  margin-top: 0.375rem;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.preview-container {
  width: 100%;
  height: 100%;
  min-height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.preview-container img {
  max-width: 100%;
  max-height: 300px;
  object-fit: contain;
  border-radius: 8px;
}

/* Inference Overlay */
.inference-overlay {
  position: absolute;
  inset: 0;
  background: rgba(15, 20, 25, 0.92);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  z-index: 10;
}

.inference-overlay p {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.inference-hint {
  font-size: 0.8125rem !important;
  font-weight: 400 !important;
  color: var(--text-secondary) !important;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border);
  border-top-color: var(--accent-cyan);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
}

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

/* Result Section */
.result-section {
  margin-top: 1.5rem;
}

.result-section h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.result-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 1.5rem;
  border: 1px solid var(--border);
}

.probability-display {
  text-align: center;
  margin-bottom: 1.25rem;
}

.probability-value {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.probability-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.risk-indicator {
  margin-top: 1rem;
}

.risk-bar {
  height: 8px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan), var(--accent-yellow), var(--accent-orange), var(--accent-red));
  border-radius: 4px;
  overflow: hidden;
}

.risk-fill {
  height: 100%;
  width: 0%;
  background: rgba(255, 255, 255, 0.4);
  border-radius: 4px;
  transition: width 0.6s ease;
}

.risk-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.btn-reupload {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent-cyan);
  background: transparent;
  border: 1px solid var(--accent-cyan);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-reupload:hover {
  background: rgba(6, 182, 212, 0.15);
}

/* Distribution Panel */
.distribution-panel {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 1.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.distribution-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 1rem;
  border: 1px solid var(--border);
}

.card-title {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
}

.card-subtitle {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  margin-bottom: 0.75rem;
}

.score-interpretation {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
}

.score-badge {
  font-weight: 500;
  color: var(--accent-cyan);
}

.risk-level {
  font-weight: 500;
  color: var(--text-primary);
}

.population-note {
  font-size: 0.75rem;
  line-height: 1.5;
  color: var(--text-secondary);
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.distribution-chart {
  position: relative;
  height: 175px;
  margin-bottom: 0.5rem;
}

.distribution-chart canvas {
  width: 100%;
  height: 100%;
  border-radius: 8px;
}

.user-marker {
  position: absolute;
  top: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  pointer-events: none;
  transform: translateX(-50%);
  z-index: 5;
}

.marker-line {
  flex: 1;
  width: 2px;
  background: var(--text-primary);
  box-shadow: 0 0 8px rgba(255, 255, 255, 0.6);
}

.marker-label {
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  margin-top: 0.25rem;
}

.distribution-legend {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.legend-gradient {
  flex: 1;
  height: 8px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan), var(--accent-yellow), var(--accent-orange), var(--accent-red));
  border-radius: 4px;
}

.cutoff-hint {
  font-size: 0.7rem;
  color: var(--text-secondary);
  opacity: 0.85;
  margin-top: 0.35rem;
}