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

:root {
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-text: #1e293b;
  --color-text-secondary: #64748b;
  --color-primary: #3b82f6;
  --color-green: #22c55e;
  --color-red: #ef4444;
  --color-programming: #3b82f6;
  --color-biotools: #8b5cf6;
  --color-datascience: #f59e0b;
  --color-cloud: #06b6d4;
  --color-domain: #10b981;
  --color-softskills: #ec4899;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
}

body {
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.15s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-primary);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem;
}

/* Cards grid */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.stat-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

.stat-value {
  font-size: 1.75rem;
  font-weight: 700;
}

.stat-sub {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: 0.125rem;
}

/* Section */
.section {
  margin-bottom: 2rem;
}

.section-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

/* Chart card */
.chart-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.chart-container {
  position: relative;
  width: 100%;
  overflow: hidden;
}

/* Rising / Falling */
.rf-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

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

.rf-column-title {
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.rf-column-title.rising {
  color: var(--color-green);
}

.rf-column-title.falling {
  color: var(--color-red);
}

.rf-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.rf-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow);
}

.rf-skill {
  font-weight: 600;
  font-size: 0.875rem;
}

.rf-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.125rem 0.5rem;
  border-radius: 9999px;
}

.rf-badge.up {
  background: #dcfce7;
  color: #166534;
}

.rf-badge.down {
  background: #fee2e2;
  color: #991b1b;
}

/* Trend controls */
.trend-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-bottom: 1rem;
}

.skill-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: 0.75rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  color: var(--color-text-secondary);
}

.skill-toggle.active {
  border-color: transparent;
  color: #fff;
}

.skill-toggle:hover {
  opacity: 0.85;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 2px solid var(--color-border);
  margin-bottom: 1rem;
  overflow-x: auto;
}

.tab-btn {
  padding: 0.5rem 1rem;
  border: none;
  background: none;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  white-space: nowrap;
  transition: all 0.15s;
}

.tab-btn:hover {
  color: var(--color-text);
}

.tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* Category skill bars */
.cat-skill-list {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.cat-skill-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.cat-skill-name {
  width: 120px;
  font-size: 0.8rem;
  font-weight: 600;
  text-align: right;
  flex-shrink: 0;
}

.cat-skill-bar-bg {
  flex: 1;
  height: 24px;
  background: #f1f5f9;
  border-radius: 4px;
  overflow: hidden;
}

.cat-skill-bar-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.4s ease;
  display: flex;
  align-items: center;
  padding-left: 0.5rem;
}

.cat-skill-bar-fill span {
  font-size: 0.7rem;
  font-weight: 700;
  color: #fff;
}

.cat-skill-pct {
  width: 48px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-secondary);
}

/* Heatmap */
.heatmap-wrapper {
  overflow-x: auto;
}

.heatmap-grid {
  display: inline-grid;
  gap: 1px;
}

.heatmap-cell {
  width: 36px;
  height: 36px;
  border-radius: 3px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  cursor: default;
  position: relative;
}

.heatmap-cell[data-value]:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 110%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-text);
  color: #fff;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.7rem;
  white-space: nowrap;
  z-index: 10;
  pointer-events: none;
}

.heatmap-label-x,
.heatmap-label-y {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
}

.heatmap-label-x {
  justify-content: center;
  writing-mode: vertical-lr;
  transform: rotate(180deg);
  height: 80px;
}

.heatmap-label-y {
  justify-content: flex-end;
  padding-right: 4px;
  width: 80px;
}

/* Filter bar */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  align-items: center;
}

.filter-bar select,
.filter-bar input {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.875rem;
  background: var(--color-surface);
  color: var(--color-text);
  min-width: 180px;
}

.filter-bar select:focus,
.filter-bar input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Loading */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
}

/* Two-column layout */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .two-col {
    grid-template-columns: 1fr;
  }
}