/* ============================================================
   THE AI ATLAS — Enhanced Styles
   All classes prefixed with .atlas- to avoid collisions
   with the parent portfolio style.css
   ============================================================ */

/* ---------- Custom Properties ---------- */
:root {
  --atlas-bg: #0a0a0a;
  --atlas-card: #111;
  --atlas-card-hover: #161616;
  --atlas-border: #1e1e1e;
  --atlas-border-hover: #333;
  --atlas-accent: #4a9eff;
  --atlas-accent-dim: rgba(74, 158, 255, 0.12);
  --atlas-accent-glow: rgba(74, 158, 255, 0.2);
  --atlas-text: #e0e0e0;
  --atlas-text-dim: #777;
  --atlas-era1: #ff6b6b;
  --atlas-era2: #ffa500;
  --atlas-era3: #4ecdc4;
  --atlas-era4: #a855f7;
  --atlas-era5: #22c55e;
  --atlas-radius: 14px;
  --atlas-radius-sm: 8px;
  --atlas-ease: cubic-bezier(0.4, 0, 0.2, 1);
  --atlas-tooltip-bg: rgba(8, 8, 12, 0.94);
}

[data-theme="dark"] {
  --atlas-bg: #0a0a0a;
  --atlas-card: #111;
  --atlas-card-hover: #161616;
  --atlas-border: #1e1e1e;
  --atlas-border-hover: #333;
  --atlas-text: #e0e0e0;
  --atlas-text-dim: #777;
  --atlas-tooltip-bg: rgba(8, 8, 12, 0.94);
}

html:not([data-theme="dark"]) {
  --atlas-bg: #f5f5f5;
  --atlas-card: #ffffff;
  --atlas-card-hover: #fafafa;
  --atlas-border: #e5e5e5;
  --atlas-border-hover: #ccc;
  --atlas-text: #1a1a1a;
  --atlas-text-dim: #666;
  --atlas-accent-dim: rgba(74, 158, 255, 0.08);
  --atlas-accent-glow: rgba(74, 158, 255, 0.12);
  --atlas-tooltip-bg: rgba(15, 15, 20, 0.92);
}

/* ---------- Keyframe Animations ---------- */
@keyframes atlas-gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes atlas-fade-up {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes atlas-pulse-soft {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}

@keyframes atlas-edge-flow {
  to { stroke-dashoffset: -20; }
}

@keyframes atlas-shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes atlas-highlight-pulse {
  0% { box-shadow: 0 0 0 0 var(--atlas-accent-glow); }
  70% { box-shadow: 0 0 0 12px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}

/* ---------- Scroll Animations ---------- */
[data-atlas-animate] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--atlas-ease), transform 0.7s var(--atlas-ease);
}

[data-atlas-animate].atlas-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Hero ---------- */
.atlas-hero {
  padding: 10rem 0 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  background-image: radial-gradient(circle, var(--atlas-border) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* Radial glow behind title */
.atlas-hero::before {
  content: '';
  position: absolute;
  top: 18%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(74, 158, 255, 0.08) 0%, rgba(78, 205, 196, 0.05) 40%, transparent 70%);
  filter: blur(60px);
  pointer-events: none;
  z-index: 0;
}

/* Era color orbs at bottom */
.atlas-hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 200px;
  background:
    radial-gradient(ellipse at 10% 80%, rgba(255, 107, 107, 0.05), transparent 50%),
    radial-gradient(ellipse at 30% 80%, rgba(255, 165, 0, 0.05), transparent 50%),
    radial-gradient(ellipse at 50% 80%, rgba(78, 205, 196, 0.05), transparent 50%),
    radial-gradient(ellipse at 70% 80%, rgba(168, 85, 247, 0.05), transparent 50%),
    radial-gradient(ellipse at 90% 80%, rgba(34, 197, 94, 0.05), transparent 50%);
  pointer-events: none;
  z-index: 0;
}

.atlas-hero > .container {
  position: relative;
  z-index: 1;
}

/* --- Line-Reveal System --- */
.atlas-line-wrap {
  overflow: hidden;
  display: block;
}

.atlas-line-inner {
  display: block;
  transform: translateY(105%);
  will-change: transform;
}

.atlas-line-inner.atlas-revealed {
  transform: translateY(0);
  transition: transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Reveal Items (non-text elements) --- */
.atlas-reveal-item {
  opacity: 0;
  transform: translateY(24px);
  will-change: opacity, transform;
}

.atlas-reveal-item.atlas-revealed {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Hero Elements --- */
.atlas-hero-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--atlas-accent);
  margin-bottom: 1.25rem;
}

.atlas-hero-title {
  font-size: clamp(3.2rem, 8vw, 6rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 1.25rem;
}

.atlas-hero-title .atlas-line-inner {
  background: linear-gradient(
    135deg,
    var(--atlas-era1) 0%,
    var(--atlas-era2) 20%,
    var(--atlas-era3) 40%,
    var(--atlas-era4) 60%,
    var(--atlas-era5) 80%,
    var(--atlas-era1) 100%
  );
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: atlas-gradient-shift 10s ease infinite;
}

[data-theme="dark"] .atlas-hero-title .atlas-line-inner {
  filter: drop-shadow(0 0 30px rgba(74, 158, 255, 0.15));
}

html:not([data-theme="dark"]) .atlas-hero-title .atlas-line-inner {
  background: linear-gradient(
    135deg,
    #c04040 0%,
    #b07000 20%,
    #2a8a80 40%,
    #7040a8 60%,
    #1a8040 80%,
    #c04040 100%
  );
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: atlas-gradient-shift 10s ease infinite;
}

.atlas-hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--atlas-text-dim);
  max-width: 560px;
  margin: 0 auto 2rem;
  line-height: 1.65;
}

/* --- Era Timeline --- */
.atlas-era-timeline {
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 320px;
  margin: 0 auto 2.5rem;
}

.atlas-era-timeline-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
  transform: scale(0);
  will-change: transform;
}

.atlas-era-timeline-dot.atlas-revealed {
  transform: scale(1);
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.atlas-era-timeline-segment {
  flex: 1;
  height: 2px;
  opacity: 0.4;
  transform: scaleX(0);
  will-change: transform;
}

.atlas-era-timeline-segment.atlas-revealed {
  transform: scaleX(1);
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Stats Bar --- */
.atlas-stats-bar {
  display: flex;
  justify-content: center;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.atlas-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
  padding: 0 1.5rem;
  border-right: 1px solid var(--atlas-border);
}

.atlas-stat:last-child {
  border-right: none;
}

.atlas-stat-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
}

.atlas-stat-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--atlas-text-dim);
}

/* Per-stat era colors */
.atlas-stat[data-color="teal"] .atlas-stat-num { color: var(--atlas-era3); }
.atlas-stat[data-color="purple"] .atlas-stat-num { color: var(--atlas-era4); }
.atlas-stat[data-color="orange"] .atlas-stat-num { color: var(--atlas-era2); }
.atlas-stat[data-color="green"] .atlas-stat-num { color: var(--atlas-era5); }

/* --- How-To Strip --- */
.atlas-how-to-use {
  max-width: 750px;
  margin: 0 auto;
}

.atlas-how-grid {
  display: flex;
  justify-content: center;
  text-align: left;
}

.atlas-how-item {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  padding: 0 1.25rem;
  position: relative;
}

.atlas-how-item + .atlas-how-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 1px;
  background: var(--atlas-border);
}

.atlas-how-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--atlas-accent);
  opacity: 0.7;
}

.atlas-how-item strong {
  display: block;
  font-size: 0.78rem;
  margin-bottom: 0.15rem;
}

.atlas-how-item p {
  font-size: 0.72rem;
  color: var(--atlas-text-dim);
  line-height: 1.5;
  margin: 0;
}

/* ---------- Graph Section ---------- */
.atlas-graph-section {
  padding: 2rem 0 4rem;
}

.atlas-era-legend {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.atlas-era-tag {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.72rem;
  color: var(--atlas-text-dim);
  cursor: pointer;
  padding: 0.35rem 0.7rem;
  border-radius: 100px;
  border: 1px solid transparent;
  background: transparent;
  transition: all 0.25s var(--atlas-ease);
}

.atlas-era-tag:hover {
  border-color: var(--atlas-border-hover);
  background: var(--atlas-card);
}

.atlas-era-tag.active {
  border-color: var(--atlas-border-hover);
  background: var(--atlas-card);
  color: var(--atlas-text);
}

.atlas-era-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* Graph wrapper */
.atlas-graph-wrap {
  position: relative;
  width: 100%;
  height: clamp(400px, 50vh, 700px);
  background: var(--atlas-card);
  border: 1px solid var(--atlas-border);
  border-radius: var(--atlas-radius);
  overflow: hidden;
}

.atlas-graph-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--atlas-text-dim);
  font-size: 0.9rem;
}

.atlas-graph-wrap svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* Graph elements */
.atlas-graph-wrap .atlas-link {
  fill: none;
  stroke: var(--atlas-border-hover);
  stroke-width: 1;
  stroke-opacity: 0.35;
  stroke-dasharray: 6, 4;
  opacity: 0;
  transition: stroke-opacity 0.3s var(--atlas-ease), stroke-width 0.3s var(--atlas-ease);
}

.atlas-graph-wrap .atlas-link.highlighted {
  stroke-opacity: 0.9;
  stroke-width: 2;
  stroke-dasharray: 8, 4;
  animation: atlas-edge-flow 1s linear infinite;
}

.atlas-graph-wrap .atlas-link.dimmed {
  stroke-opacity: 0.05;
  animation: none;
}

.atlas-graph-wrap .atlas-node {
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.3s var(--atlas-ease);
}

/* Graph entrance reveal — nodes and links start invisible, revealed era-by-era */
.atlas-graph-wrap .atlas-node.atlas-graph-revealed {
  opacity: 1;
  transition: opacity 0.6s var(--atlas-ease);
}

.atlas-graph-wrap .atlas-link.atlas-graph-revealed {
  opacity: 1;
  transition: opacity 0.6s var(--atlas-ease);
}

.atlas-graph-wrap.atlas-graph-complete .atlas-node,
.atlas-graph-wrap.atlas-graph-complete .atlas-link {
  opacity: 1;
}

/* Hovered node glow */
.atlas-graph-wrap .atlas-node.atlas-hovered .atlas-node-circle {
  filter: url(#atlas-glow);
}

.atlas-graph-wrap .atlas-node.dimmed {
  opacity: 0.12;
}

.atlas-graph-wrap .atlas-node .atlas-node-circle {
  stroke-width: 2;
  transition: r 0.25s var(--atlas-ease), stroke-width 0.25s var(--atlas-ease), filter 0.25s var(--atlas-ease);
}

.atlas-graph-wrap .atlas-node:hover .atlas-node-circle {
  stroke-width: 3;
}

.atlas-graph-wrap .atlas-node.highlighted .atlas-node-circle {
  stroke-width: 3;
}

/* Featured node indicator */
.atlas-graph-wrap .atlas-node .atlas-node-featured-ring {
  fill: none;
  stroke-width: 1.5;
  stroke-dasharray: 2, 2;
  opacity: 0.5;
  animation: atlas-pulse-soft 3s ease-in-out infinite;
}

.atlas-graph-wrap .atlas-node text {
  font-family: 'Inter', sans-serif;
  font-size: 8.5px;
  fill: var(--atlas-text-dim);
  pointer-events: none;
  text-anchor: middle;
  transition: fill 0.25s var(--atlas-ease);
}

.atlas-graph-wrap .atlas-node.highlighted text {
  fill: var(--atlas-text);
  font-weight: 600;
}

/* Graph tooltip */
/* Compact fixed-position tooltip — sits at top of graph, never blocks nodes */
.atlas-tooltip {
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  padding: 0.35rem 1rem;
  background: var(--atlas-tooltip-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 100px;
  color: #fff;
  font-size: 0.7rem;
  line-height: 1.4;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s var(--atlas-ease), transform 0.2s var(--atlas-ease);
  z-index: 100;
  max-width: 85%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: center;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.atlas-tooltip.visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.atlas-tooltip-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  margin-right: 0.4rem;
  vertical-align: middle;
}

.atlas-tooltip-title {
  font-weight: 600;
}

.atlas-tooltip-year {
  color: rgba(255, 255, 255, 0.5);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  margin-left: 0.3rem;
}

/* Mobile list (hidden on desktop) */
.atlas-mobile-list {
  display: none;
}

/* ---------- Learning Paths ---------- */
.atlas-paths-section {
  padding: 4rem 0;
}

.atlas-section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 0.5rem;
  overflow: hidden;
}

/* Character reveal animation for section titles */
.atlas-section-title .char {
  display: inline-block;
  opacity: 0;
  transform: translateY(100%);
  transition: opacity 0.4s var(--atlas-ease), transform 0.4s var(--atlas-ease);
  transition-delay: calc(var(--i, 0) * 25ms);
}

.atlas-section-title .char.space-char {
  width: 0.3em;
}

.atlas-section-title.visible .char {
  opacity: 1;
  transform: translateY(0);
}

.atlas-section-subtitle {
  text-align: center;
  color: var(--atlas-text-dim);
  font-size: 0.95rem;
  margin-bottom: 2.5rem;
}

.atlas-paths-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 0.75rem;
}

/* --- Learning Path Card --- */
.atlas-path-card {
  position: relative;
  overflow: hidden;
  background: var(--atlas-card);
  border: 1px solid var(--atlas-border);
  border-radius: var(--atlas-radius);
  padding: 1.3rem 1.4rem 1.2rem;
  cursor: pointer;
  transition: all 0.4s var(--atlas-ease);
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

/* Accent strip along left edge */
.atlas-path-card::before {
  content: '';
  position: absolute;
  top: 12px;
  bottom: 12px;
  left: 0;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: var(--path-accent, var(--atlas-accent));
  opacity: 0.5;
  transition: opacity 0.4s var(--atlas-ease), box-shadow 0.4s var(--atlas-ease);
}

/* Subtle radial glow behind card on hover */
.atlas-path-card::after {
  content: '';
  position: absolute;
  top: -30%;
  left: -30%;
  width: 160%;
  height: 160%;
  background: radial-gradient(ellipse at 10% 50%, var(--path-glow, rgba(74,158,255,0.06)), transparent 60%);
  opacity: 0;
  transition: opacity 0.5s var(--atlas-ease);
  pointer-events: none;
  z-index: 0;
}

.atlas-path-card:hover {
  border-color: var(--atlas-border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.2);
}

.atlas-path-card:hover::before {
  opacity: 1;
  box-shadow: 0 0 8px var(--path-accent, var(--atlas-accent));
}

.atlas-path-card:hover::after {
  opacity: 1;
}

.atlas-path-card.active {
  border-color: var(--path-accent, var(--atlas-accent));
  box-shadow: 0 0 0 1px var(--path-accent, var(--atlas-accent)), 0 4px 20px var(--path-glow, var(--atlas-accent-glow));
}

.atlas-path-card.active::before {
  opacity: 1;
  width: 4px;
}

.atlas-path-card.active::after {
  opacity: 1;
}

/* Top row: number + title + count */
.atlas-path-header {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  position: relative;
  z-index: 1;
}

.atlas-path-number {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.58rem;
  font-weight: 700;
  color: var(--path-accent, var(--atlas-accent));
  background: var(--path-number-bg, rgba(74,158,255,0.1));
  border: 1px solid var(--path-number-border, rgba(74,158,255,0.2));
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  flex-shrink: 0;
  letter-spacing: 0.04em;
}

.atlas-path-name {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--atlas-text);
  flex: 1;
  letter-spacing: -0.01em;
}

.atlas-path-count {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  color: var(--path-accent, var(--atlas-accent));
  opacity: 0.7;
  white-space: nowrap;
  flex-shrink: 0;
}

/* Description */
.atlas-path-desc {
  font-size: 0.78rem;
  color: var(--atlas-text-dim);
  line-height: 1.5;
  position: relative;
  z-index: 1;
  padding-left: 0.1rem;
}

/* Paper dots trail — shows which papers belong to the path */
.atlas-path-trail {
  display: flex;
  align-items: center;
  gap: 4px;
  padding-top: 0.15rem;
  position: relative;
  z-index: 1;
}

.atlas-path-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  opacity: 0.2;
  transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  flex-shrink: 0;
}

.atlas-path-dot.read {
  opacity: 1;
  box-shadow: 0 0 6px currentColor;
}

.atlas-path-card:hover .atlas-path-dot {
  opacity: 0.5;
}

.atlas-path-card:hover .atlas-path-dot.read {
  opacity: 1;
  transform: scale(1.15);
}

/* Connector line behind dots */
.atlas-path-trail::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--atlas-border);
  z-index: -1;
}

/* Progress fraction */
.atlas-path-progress {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.58rem;
  color: var(--atlas-text-dim);
  margin-left: auto;
  padding-left: 0.5rem;
  white-space: nowrap;
  flex-shrink: 0;
  opacity: 0.7;
}

/* ---------- Search ---------- */
.atlas-search-wrap {
  position: relative;
  max-width: 500px;
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
}

.atlas-search-icon {
  position: absolute;
  left: 14px;
  color: var(--atlas-text-dim);
  pointer-events: none;
  transition: color 0.25s var(--atlas-ease);
}

.atlas-search-wrap:focus-within .atlas-search-icon {
  color: var(--atlas-accent);
}

.atlas-search-input {
  width: 100%;
  padding: 0.7rem 2.5rem 0.7rem 2.75rem;
  background: var(--atlas-card);
  border: 1px solid var(--atlas-border);
  border-radius: 100px;
  color: var(--atlas-text);
  font-size: 0.85rem;
  font-family: inherit;
  outline: none;
  transition: all 0.3s var(--atlas-ease);
}

.atlas-search-input::placeholder {
  color: var(--atlas-text-dim);
}

.atlas-search-input:focus {
  border-color: var(--atlas-accent);
  box-shadow: 0 0 0 3px var(--atlas-accent-glow);
}

.atlas-search-count {
  position: absolute;
  right: 40px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  color: var(--atlas-text-dim);
  pointer-events: none;
}

.atlas-search-clear {
  position: absolute;
  right: 10px;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: 50%;
  color: var(--atlas-text-dim);
  cursor: pointer;
  transition: all 0.2s var(--atlas-ease);
}

.atlas-search-clear:hover {
  background: var(--atlas-accent-dim);
  color: var(--atlas-accent);
}

.atlas-search-empty {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--atlas-text-dim);
}

.atlas-search-empty svg {
  opacity: 0.3;
  margin-bottom: 1rem;
}

.atlas-search-empty p {
  font-size: 1rem;
  margin-bottom: 0.3rem;
  color: var(--atlas-text);
}

.atlas-search-empty span {
  font-size: 0.85rem;
}

/* ---------- Filter Bar ---------- */
.atlas-filter-bar {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.atlas-filter-btn {
  padding: 0.45rem 1rem;
  background: transparent;
  border: 1px solid var(--atlas-border);
  border-radius: 100px;
  color: var(--atlas-text-dim);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.25s var(--atlas-ease);
}

.atlas-filter-btn:hover {
  border-color: var(--atlas-border-hover);
  color: var(--atlas-text);
  background: var(--atlas-card);
}

.atlas-filter-btn.active {
  background: var(--atlas-accent);
  border-color: var(--atlas-accent);
  color: #fff;
}

/* ---------- Paper Cards ---------- */
.atlas-cards-section {
  padding: 2rem 0 6rem;
}

.atlas-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1rem;
}

/* Individual card */
.atlas-paper-card {
  background: var(--atlas-card);
  border: 1px solid var(--atlas-border);
  border-radius: var(--atlas-radius);
  overflow: hidden;
  transition: all 0.35s var(--atlas-ease);
  border-top: 3px solid var(--atlas-border);
  opacity: 0;
  transform: translateY(20px);
}

.atlas-paper-card.atlas-card-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Era-colored top borders */
.atlas-paper-card[data-era="1"] { border-top-color: var(--atlas-era1); }
.atlas-paper-card[data-era="2"] { border-top-color: var(--atlas-era2); }
.atlas-paper-card[data-era="3"] { border-top-color: var(--atlas-era3); }
.atlas-paper-card[data-era="4"] { border-top-color: var(--atlas-era4); }
.atlas-paper-card[data-era="5"] { border-top-color: var(--atlas-era5); }

.atlas-paper-card:hover {
  border-color: var(--atlas-border-hover);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.atlas-paper-card.atlas-card-highlight {
  animation: atlas-highlight-pulse 1s ease;
  border-color: var(--atlas-accent);
  box-shadow: 0 0 24px var(--atlas-accent-glow);
}

/* Featured indicator */
.atlas-featured-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--atlas-accent);
  padding: 0.15rem 0.5rem;
  background: var(--atlas-accent-dim);
  border-radius: 100px;
  margin-left: 0.5rem;
}

.atlas-featured-badge svg {
  width: 10px;
  height: 10px;
}

/* Card header (always visible) */
.atlas-card-header {
  padding: 1.25rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  outline: none;
}

.atlas-card-header:focus-visible {
  outline: 2px solid var(--atlas-accent);
  outline-offset: -2px;
  border-radius: var(--atlas-radius);
}

.atlas-card-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.atlas-card-era-badge {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  padding: 0.2rem 0.55rem;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.atlas-card-impact {
  display: flex;
  gap: 3px;
}

.atlas-card-impact-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--atlas-border);
  transition: background 0.2s var(--atlas-ease);
}

.atlas-card-impact-dot.filled {
  background: var(--atlas-accent);
}

.atlas-card-title {
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.35;
}

.atlas-card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.73rem;
  color: var(--atlas-text-dim);
  flex-wrap: wrap;
}

.atlas-card-year {
  font-family: 'JetBrains Mono', monospace;
}

.atlas-card-oneliner {
  font-size: 0.84rem;
  color: var(--atlas-text-dim);
  line-height: 1.55;
}

.atlas-card-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.25rem;
}

.atlas-read-toggle {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.32rem 0.65rem;
  background: transparent;
  border: 1px solid var(--atlas-border);
  border-radius: 100px;
  color: var(--atlas-text-dim);
  font-size: 0.68rem;
  cursor: pointer;
  transition: all 0.25s var(--atlas-ease);
}

.atlas-read-toggle:hover {
  border-color: var(--atlas-accent);
  color: var(--atlas-text);
}

.atlas-read-toggle.read {
  background: var(--atlas-accent);
  border-color: var(--atlas-accent);
  color: #fff;
}

.atlas-read-toggle svg {
  width: 13px;
  height: 13px;
}

.atlas-expand-hint {
  font-size: 0.68rem;
  color: var(--atlas-text-dim);
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  transition: color 0.25s var(--atlas-ease);
}

.atlas-paper-card:hover .atlas-expand-hint {
  color: var(--atlas-accent);
}

.atlas-expand-hint svg {
  width: 14px;
  height: 14px;
  transition: transform 0.35s var(--atlas-ease);
}

.atlas-paper-card.expanded .atlas-expand-hint svg {
  transform: rotate(180deg);
}

/* Card body (expandable) — grid-based for smooth animation */
.atlas-card-body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.45s var(--atlas-ease);
}

.atlas-paper-card.expanded .atlas-card-body {
  grid-template-rows: 1fr;
}

.atlas-card-body-wrap {
  overflow: hidden;
}

.atlas-card-body-inner {
  padding: 0 1.25rem 1.25rem;
  border-top: 1px solid var(--atlas-border);
}

.atlas-card-section {
  padding-top: 1rem;
}

.atlas-card-section-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--atlas-accent);
  margin-bottom: 0.5rem;
}

.atlas-card-section p {
  font-size: 0.84rem;
  color: var(--atlas-text-dim);
  line-height: 1.7;
  margin: 0;
}

/* Verdict block */
.atlas-verdict {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.atlas-verdict-item {
  padding: 0.75rem;
  background: var(--atlas-accent-dim);
  border: 1px solid var(--atlas-border);
  border-radius: var(--atlas-radius-sm);
}

.atlas-verdict-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--atlas-accent);
  margin-bottom: 0.3rem;
}

.atlas-verdict-text {
  font-size: 0.8rem;
  color: var(--atlas-text-dim);
  line-height: 1.55;
}

/* Tags */
.atlas-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.75rem;
}

.atlas-card-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  padding: 0.18rem 0.5rem;
  background: var(--atlas-accent-dim);
  border: 1px solid var(--atlas-border);
  border-radius: 4px;
  color: var(--atlas-text-dim);
}

/* Deps / Unlocks links inside card */
.atlas-card-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.4rem;
}

.atlas-card-dep-link {
  font-size: 0.73rem;
  color: var(--atlas-accent);
  cursor: pointer;
  text-decoration: none;
  border-bottom: 1px dashed rgba(74, 158, 255, 0.4);
  transition: all 0.2s;
  padding-bottom: 1px;
}

.atlas-card-dep-link:hover {
  border-bottom-color: var(--atlas-accent);
  text-shadow: 0 0 8px var(--atlas-accent-glow);
}

/* Paper link */
.atlas-paper-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.75rem;
  font-size: 0.8rem;
  color: var(--atlas-accent);
  text-decoration: none;
  transition: all 0.25s var(--atlas-ease);
}

.atlas-paper-link:hover {
  gap: 0.6rem;
}

.atlas-paper-link svg {
  width: 14px;
  height: 14px;
  transition: transform 0.25s var(--atlas-ease);
}

.atlas-paper-link:hover svg {
  transform: translate(2px, -2px);
}

/* Coming soon overlay for non-featured */
.atlas-coming-soon {
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--atlas-border);
  text-align: center;
  color: var(--atlas-text-dim);
  font-size: 0.78rem;
  font-style: italic;
}

/* Search highlight */
.atlas-search-hl {
  background: rgba(74, 158, 255, 0.2);
  color: var(--atlas-accent);
  border-radius: 2px;
  padding: 0 2px;
}

/* ---------- Progress Bar (floating bottom) ---------- */
.atlas-progress-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 90;
  background: var(--atlas-card);
  border-top: 1px solid var(--atlas-border);
  padding: 0.6rem 1.5rem;
  transform: translateY(100%);
  transition: transform 0.35s var(--atlas-ease);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.atlas-progress-bar.visible {
  transform: translateY(0);
}

.atlas-progress-inner {
  max-width: 600px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.atlas-progress-text {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--atlas-text-dim);
  white-space: nowrap;
}

.atlas-progress-track {
  flex: 1;
  height: 4px;
  background: var(--atlas-border);
  border-radius: 4px;
  overflow: hidden;
}

.atlas-progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--atlas-accent), var(--atlas-era3));
  border-radius: 4px;
  transition: width 0.6s var(--atlas-ease);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .atlas-hero {
    padding: 8rem 0 2rem;
  }

  .atlas-stats-bar {
    gap: 0;
  }

  .atlas-stat {
    padding: 0 1rem;
  }

  .atlas-how-grid {
    flex-direction: column;
    align-items: stretch;
  }

  .atlas-how-item {
    padding: 0.75rem 0;
  }

  .atlas-how-item + .atlas-how-item::before {
    left: 20%;
    right: 20%;
    top: 0;
    bottom: auto;
    width: auto;
    height: 1px;
  }

  .atlas-graph-wrap {
    display: none;
  }

  .atlas-mobile-list {
    display: block;
  }

  .atlas-mobile-era {
    margin-bottom: 2rem;
  }

  .atlas-mobile-era-title {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding-bottom: 0.5rem;
    margin-bottom: 0.75rem;
    border-bottom: 2px solid var(--atlas-border);
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .atlas-mobile-era-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex-shrink: 0;
  }

  .atlas-mobile-paper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.65rem 0;
    border-bottom: 1px solid var(--atlas-border);
    cursor: pointer;
    transition: color 0.2s var(--atlas-ease);
    gap: 0.75rem;
  }

  .atlas-mobile-paper:hover {
    color: var(--atlas-accent);
  }

  .atlas-mobile-paper-name {
    font-size: 0.84rem;
    flex: 1;
  }

  .atlas-mobile-paper-year {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.68rem;
    color: var(--atlas-text-dim);
    flex-shrink: 0;
  }

  .atlas-mobile-paper-impact {
    display: flex;
    gap: 2px;
    flex-shrink: 0;
  }

  .atlas-mobile-paper-impact span {
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--atlas-border);
  }

  .atlas-mobile-paper-impact span.filled {
    background: var(--atlas-accent);
  }

  .atlas-cards-grid {
    grid-template-columns: 1fr;
  }

  .atlas-paths-grid {
    grid-template-columns: 1fr;
    gap: 0.6rem;
  }

  .atlas-verdict {
    grid-template-columns: 1fr;
  }

  .atlas-era-legend {
    gap: 0.5rem;
  }

  .atlas-search-wrap {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .atlas-hero {
    padding: 7rem 0 1.5rem;
  }

  .atlas-stats-bar {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .atlas-stat {
    padding: 0.75rem;
    border-right: none;
  }

  .atlas-stat:nth-child(odd) {
    border-right: 1px solid var(--atlas-border);
  }

  .atlas-stat:nth-child(1),
  .atlas-stat:nth-child(2) {
    border-bottom: 1px solid var(--atlas-border);
  }

  .atlas-stat-num {
    font-size: 1.5rem;
  }

  .atlas-card-header {
    padding: 1rem;
  }

  .atlas-card-body-inner {
    padding: 0 1rem 1rem;
  }
}

/* ---------- Print ---------- */
@media print {
  .atlas-graph-section,
  .atlas-progress-bar,
  .atlas-search-wrap {
    display: none;
  }
}

/* ---------- Path Journey Animation ---------- */
/* Node waiting to be activated during journey — barely visible */
.atlas-graph-wrap .atlas-node.atlas-journey-pending {
  opacity: 0.08;
  transition: opacity 0.15s var(--atlas-ease);
}

/* Node activated during journey — pulses to life */
.atlas-graph-wrap .atlas-node.atlas-journey-active {
  opacity: 1;
  transition: opacity 0.25s var(--atlas-ease);
}

.atlas-graph-wrap .atlas-node.atlas-journey-active text {
  fill: var(--atlas-text);
  font-weight: 600;
}

.atlas-graph-wrap .atlas-node.atlas-journey-active .atlas-node-circle {
  animation: atlas-journey-pulse 0.5s var(--atlas-ease) forwards;
  transform-box: fill-box;
  transform-origin: center;
}

/* Edge being drawn — stroke-dasharray/offset set by JS via getTotalLength() */
.atlas-graph-wrap .atlas-link.atlas-journey-drawing {
  stroke-opacity: 0.9;
  stroke-width: 2.5;
  animation: none;
  transition: stroke-dashoffset 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Edge that finished drawing — transitions to flowing dash steady-state */
.atlas-graph-wrap .atlas-link.atlas-journey-complete {
  stroke-opacity: 0.7;
  stroke-width: 2;
  stroke-dasharray: 8, 4;
  animation: atlas-edge-flow 1s linear infinite;
}

/* Journey progress label — "now activating" pill at bottom of graph */
.atlas-journey-label {
  position: absolute;
  bottom: 14px;
  left: 50%;
  transform: translateX(-50%);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  letter-spacing: 0.02em;
  color: var(--atlas-text);
  background: var(--atlas-tooltip-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0.35rem 0.9rem;
  border-radius: 100px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  opacity: 0;
  transition: opacity 0.25s var(--atlas-ease);
  pointer-events: none;
  z-index: 50;
  white-space: nowrap;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.atlas-journey-label.visible {
  opacity: 1;
}

.atlas-journey-label-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  margin-right: 0.4rem;
  vertical-align: middle;
}

@keyframes atlas-journey-pulse {
  0%   { filter: brightness(1); transform: scale(1); }
  40%  { filter: brightness(1.8) drop-shadow(0 0 8px currentColor); transform: scale(1.5); }
  100% { filter: brightness(1.2) drop-shadow(0 0 4px currentColor); transform: scale(1); }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  [data-atlas-animate] {
    opacity: 1;
    transform: none;
  }

  .atlas-paper-card {
    opacity: 1;
    transform: none;
  }

  .atlas-graph-wrap .atlas-link {
    animation: none;
  }

  .atlas-line-inner {
    transform: none !important;
  }

  .atlas-reveal-item {
    opacity: 1 !important;
    transform: none !important;
  }

  .atlas-era-timeline-dot {
    transform: scale(1) !important;
  }

  .atlas-era-timeline-segment {
    transform: scaleX(1) !important;
  }

  .atlas-graph-wrap .atlas-node,
  .atlas-graph-wrap .atlas-link {
    opacity: 1 !important;
  }

  .atlas-section-title .char {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .atlas-graph-wrap .atlas-node.atlas-journey-active .atlas-node-circle {
    animation: none !important;
  }

  .atlas-graph-wrap .atlas-link.atlas-journey-drawing {
    transition: none !important;
  }
}