:root {
  --surface: rgba(15, 23, 42, 0.72);
  --background: radial-gradient(circle at top, #0f172a 0%, #020617 60%);
  --accent: #38bdf8;
  --muted: #94a3b8;
  --font-body: "Segoe UI", Tahoma, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  background: var(--background);
  color: #e2e8f0;
}

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

.landing {
  max-width: 720px;
  width: 100%;
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 4rem);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card {
  background: var(--surface);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 18px;
  padding: clamp(2rem, 6vw, 3rem);
  box-shadow: 0 24px 48px rgba(2, 6, 23, 0.35);
}

.card h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
}

.status {
  margin: 0 0 1.5rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent);
  font-weight: 600;
}

.card p {
  margin: 0 0 1rem;
  color: #cbd5f5;
}

.card a {
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.card a:hover {
  text-decoration: underline;
}

.meta {
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.meta div {
  padding: 0.75rem 1rem;
  border-radius: 12px;
  background-color: rgba(2, 6, 23, 0.55);
  border: 1px solid rgba(148, 163, 184, 0.16);
}

.meta dt {
  margin: 0 0 0.25rem;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.meta dd {
  margin: 0;
  font-size: 0.95rem;
  color: #e2e8f0;
}

@media (max-width: 540px) {
  .card {
    padding: 2rem;
  }
}

.guide-body {
  margin: 0;
  background: var(--background);
  color: #e2e8f0;
  font-family: var(--font-body);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.guide-container {
  width: min(900px, 92vw);
  margin: 0 auto;
}

.guide-header {
  padding: clamp(2.5rem, 6vw, 3.5rem) 0 2rem;
}

.guide-home {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  margin-bottom: 1rem;
}

.guide-tagline {
  margin-top: 1rem;
  color: #cbd5f5;
}

.guide-nav {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.guide-nav a {
  color: #94d2ff;
  background-color: rgba(148, 210, 255, 0.08);
  padding: 0.5rem 0.85rem;
  border-radius: 999px;
  text-decoration: none;
  font-size: 0.9rem;
}

.guide-meta {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.guide-main {
  flex: 1 0 auto;
  padding-bottom: 4rem;
}

.guide-hero {
  padding: 0 0 3rem;
}

.guide-hero-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.guide-links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.guide-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  background-color: var(--accent);
  color: #0b1120;
  text-decoration: none;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.guide-button.secondary {
  background-color: rgba(148, 210, 255, 0.12);
  color: #e2e8f0;
}

.guide-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(56, 189, 248, 0.35);
}

.guide-figure {
  margin: 0;
  background-color: rgba(15, 23, 42, 0.65);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 18px;
  padding: 1.5rem;
  text-align: center;
  box-shadow: 0 24px 48px rgba(2, 6, 23, 0.35);
}

.guide-figure.image-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.guide-figure.image-grid img {
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  box-shadow: 0 18px 36px rgba(2, 6, 23, 0.35);
  object-fit: cover;
  flex: 1 1 280px;
  max-width: 360px;
}

.guide-figure figcaption {
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.guide-figure.narrow {
  margin-top: 2rem;
}

.guide-svg {
  width: min(320px, 100%);
  height: auto;
}

.svg-plate {
  fill: rgba(56, 189, 248, 0.18);
  stroke: rgba(56, 189, 248, 0.5);
  stroke-width: 3;
}

.svg-motor {
  fill: rgba(248, 113, 113, 0.4);
  stroke: rgba(248, 113, 113, 0.7);
  stroke-width: 3;
}

.svg-board {
  fill: rgba(74, 222, 128, 0.35);
  stroke: rgba(74, 222, 128, 0.6);
  stroke-width: 3;
}

.svg-battery {
  fill: rgba(250, 204, 21, 0.35);
  stroke: rgba(250, 204, 21, 0.65);
  stroke-width: 3;
}

.svg-shadow {
  stroke: rgba(2, 6, 23, 0.9);
  stroke-width: 12;
  stroke-linecap: round;
}

.svg-wall {
  fill: none;
  stroke: rgba(248, 171, 108, 0.85);
  stroke-width: 6;
  stroke-linejoin: round;
}

.guide-tips {
  padding: 0 0 3rem;
}

.tips-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.guide-section {
  padding: 0 0 3rem;
}

.step-list {
  display: grid;
  gap: 1.25rem;
  padding-left: 1.25rem;
}

.step-list li {
  line-height: 1.7;
}

.icon {
  font-weight: 600;
}

.tip {
  display: inline-block;
  margin-left: 0.5rem;
  color: #4ade80;
  font-weight: 600;
}

.callout-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-top: 1.5rem;
}

.callout {
  background-color: rgba(15, 23, 42, 0.65);
  border: 1px solid rgba(148, 163, 184, 0.16);
  border-radius: 16px;
  padding: 1.5rem;
}

.callout.success {
  border-color: rgba(74, 222, 128, 0.45);
}

.legend-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.5rem;
}

.challenge-list {
  display: grid;
  gap: 0.75rem;
  padding-left: 1.25rem;
}

.guide-next {
  padding: 1rem 0 3rem;
}

.guide-footer {
  padding: 2rem 0 3rem;
  text-align: center;
  color: var(--muted);
  flex-shrink: 0;
}

.hardware-callout {
  padding: 0 0 3rem;
}

.hardware-card {
  background-color: rgba(15, 23, 42, 0.68);
  border: 1px solid rgba(148, 163, 184, 0.18);
  border-radius: 18px;
  padding: 1.75rem;
  display: grid;
  gap: 1rem;
}

.hardware-card h3 {
  margin: 0;
  font-size: 1.2rem;
}

.hardware-list {
  margin: 0;
  padding-left: 1.25rem;
  display: grid;
  gap: 0.75rem;
  line-height: 1.6;
}

.hardware-note {
  margin: 0;
  color: #cbd5f5;
}

@media (max-width: 640px) {
  .guide-nav {
    gap: 0.5rem;
  }

  .guide-meta {
    flex-direction: column;
    gap: 0.5rem;
  }

  .guide-hero-grid {
    grid-template-columns: 1fr;
  }
}