:root {
  --ink-900: #121724;
  --ink-700: #2d3b57;
  --ink-500: #52617f;
  --paper: #f8f7f4;
  --card: rgba(255, 255, 255, 0.84);
  --line: rgba(18, 23, 36, 0.14);
  --teal: #0f8f8f;
  --orange: #d67436;
  --berry: #ad4a59;
  --mint: #b7e5df;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: "Sora", sans-serif;
  background:
    radial-gradient(circle at 15% 10%, #f5e7cd 0%, transparent 38%),
    radial-gradient(circle at 88% 82%, #d6efe8 0%, transparent 42%),
    linear-gradient(170deg, #f4f1ea 0%, #e8edf5 100%);
  color: var(--ink-900);
  min-height: 100vh;
  padding: 1.5rem;
  position: relative;
  overflow-x: hidden;
}

.bg-orb {
  position: fixed;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  filter: blur(36px);
  opacity: 0.38;
  z-index: -1;
}

.bg-orb-a {
  background: #efc08d;
  top: -110px;
  left: -80px;
}

.bg-orb-b {
  background: #86c9c1;
  bottom: -120px;
  right: -70px;
}

.topbar {
  max-width: 1200px;
  margin: 0 auto 1.2rem auto;
  animation: rise 0.7s ease;
}

.brand-kicker {
  margin: 0;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.75rem;
  color: var(--ink-500);
  font-weight: 600;
}

h1,
h2,
h3 {
  font-family: "Fraunces", serif;
  margin: 0;
}

h1 {
  margin-top: 0.45rem;
  font-size: clamp(1.6rem, 3vw, 2.45rem);
  line-height: 1.15;
}

.subline {
  color: var(--ink-700);
  margin: 0.8rem 0 0;
  max-width: 720px;
  line-height: 1.55;
}

.layout {
  max-width: 1200px;
  margin: 0 auto;
}

.card {
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--card);
  backdrop-filter: blur(6px);
  box-shadow: 0 18px 34px rgba(17, 20, 27, 0.08);
}

.controls {
  padding: 0.9rem;
  display: grid;
  gap: 0.8rem;
  margin-bottom: 1rem;
}

.algo-switch,
.stepper {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.algo-btn,
.ghost-btn,
.small-btn {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.58rem 0.92rem;
  background: rgba(255, 255, 255, 0.86);
  font: inherit;
  font-size: 0.92rem;
  color: var(--ink-700);
  cursor: pointer;
  transition: all 0.25s ease;
}

.algo-btn.active,
.step-indicator.active {
  background: linear-gradient(145deg, #18334f, #266383);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 10px 18px rgba(21, 63, 96, 0.25);
}

.step-indicator {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.58rem 0.92rem;
  background: rgba(255, 255, 255, 0.86);
  font-size: 0.92rem;
  color: var(--ink-700);
  user-select: none;
}

.ghost-btn:hover,
.algo-btn:hover,
.small-btn:hover {
  transform: translateY(-1px);
}

.step-nav {
  display: flex;
  gap: 0.5rem;
}

.stage-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 1rem;
}

.visual {
  padding: 1rem;
}

.viz-panel {
  display: grid;
  gap: 0.9rem;
  animation: fade-in 0.4s ease;
}

.hidden {
  display: none;
}

.viz-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
}

.viz-heading h2 {
  font-size: clamp(1.2rem, 2vw, 1.45rem);
}

#linear-svg,
#network-svg {
  width: 100%;
  border-radius: 14px;
  border: 1px solid rgba(20, 30, 46, 0.14);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(244, 248, 252, 0.9));
}

.control-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.8rem;
  color: var(--ink-700);
  font-size: 0.9rem;
}

.ann-actions {
  grid-template-columns: auto;
  justify-content: flex-start;
}

input[type="range"] {
  accent-color: var(--teal);
}

.stat-line {
  margin: 0;
  color: var(--ink-700);
  min-height: 1.4em;
}

.deep-bottom {
  margin-top: 0.2rem;
}

.bars {
  display: grid;
  gap: 0.55rem;
}

.bar-row {
  display: grid;
  grid-template-columns: 70px 1fr 52px;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.86rem;
  color: var(--ink-700);
}

.bar-track {
  background: rgba(19, 28, 44, 0.08);
  height: 10px;
  border-radius: 999px;
  overflow: hidden;
}

.bar-fill {
  background: linear-gradient(90deg, var(--teal), #23b9aa);
  height: 100%;
  transition: width 0.35s ease;
}

.explain {
  padding: 1rem;
  display: grid;
  align-content: start;
  gap: 0.9rem;
}

.tag {
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.74rem;
  color: var(--ink-500);
  font-weight: 600;
}

#stage-title {
  font-size: 1.37rem;
}

#stage-copy,
#watch-copy {
  margin: 0;
  line-height: 1.6;
  color: var(--ink-700);
  font-size: 0.94rem;
}

.watch-box {
  border: 1px dashed rgba(20, 30, 46, 0.2);
  border-radius: 12px;
  padding: 0.74rem 0.8rem;
  background: rgba(255, 255, 255, 0.58);
}

.watch-title {
  margin: 0 0 0.4rem 0;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--ink-500);
}

.progress-wrap {
  margin-top: 0.2rem;
  background: rgba(18, 23, 36, 0.08);
  border-radius: 999px;
  height: 10px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 33.33%;
  background: linear-gradient(90deg, var(--orange), #eb9f61);
  transition: width 0.35s ease;
}

@keyframes rise {
  from {
    transform: translateY(10px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(5px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 1080px) {
  .stage-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  body {
    padding: 1rem;
  }

  .control-row {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }

  .ann-actions {
    grid-template-columns: 1fr;
  }

  .step-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
}