:root {
  --ink: #121212;
  --ink-soft: #1a1a1a;
  --line: #2a2a2a;
  --paper: #f2f2f2;
  --mint: #9fb3ac;
  --amber: #f0a94e;
  --amber-bright: #ffc879;
  --claude-color: #d97757;
  --chatgpt-color: #74aa9c;
  --gemini-color: #4285f4;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  min-height: 100vh;
  background: var(--ink);
  color: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

.bg-grid {
  position: fixed;
  inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 42px 42px;
  pointer-events: none;
  z-index: 0;
}

.wrap {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 40px clamp(20px, 4vw, 56px) 56px;
}

.logo-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 40px;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1.5px solid var(--amber);
  border-radius: 8px;
  color: var(--amber);
  font-weight: 700;
  font-size: 14px;
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
}

.logo-word {
  font-weight: 700;
  font-size: 15px;
}

h1 {
  font-size: clamp(32px, 6vw, 52px);
  line-height: 1.1;
  margin: 0 0 16px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.accent {
  color: var(--amber);
}

.lede {
  font-size: clamp(15px, 2.2vw, 18px);
  color: #b8b8b8;
  max-width: 620px;
  line-height: 1.6;
  margin: 0 0 40px;
}

.setup-card {
  width: 100%;
  background: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: clamp(20px, 4vw, 32px);
  margin-bottom: 48px;
}

.setup-card h2 {
  margin: 0 0 8px;
  font-size: clamp(18px, 2.5vw, 22px);
}

.setup-sub {
  margin: 0 0 24px;
  color: #999;
  font-size: 14px;
  line-height: 1.6;
  max-width: 560px;
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

@media (max-width: 680px) {
  .platform-grid {
    grid-template-columns: 1fr;
  }
}

.platform-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 18px;
  background: var(--ink);
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--paper);
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.platform-btn:hover {
  border-color: var(--amber);
  transform: translateY(-2px);
}

.platform-btn:active {
  transform: translateY(0);
}

.platform-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.platform-dot.claude {
  background: var(--claude-color);
}

.platform-dot.chatgpt {
  background: var(--chatgpt-color);
}

.platform-dot.gemini {
  background: var(--gemini-color);
}

.platform-name {
  font-weight: 700;
  font-size: 16px;
}

.platform-action {
  font-size: 12px;
  color: var(--amber);
  font-weight: 600;
}

.platform-btn.done {
  border-color: #4caf7d;
  opacity: 0.75;
}

.platform-btn.done .platform-action {
  color: #4caf7d;
}

.features {
  width: 100%;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 56px;
}

@media (max-width: 680px) {
  .features {
    grid-template-columns: 1fr;
  }
}

.feature {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.feature-icon {
  color: var(--amber);
  font-size: 10px;
  margin-top: 6px;
  flex-shrink: 0;
}

.feature h3 {
  margin: 0 0 4px;
  font-size: 15px;
}

.feature p {
  margin: 0;
  font-size: 13px;
  color: #999;
  line-height: 1.5;
}

footer {
  font-size: 12px;
  color: #777;
  border-top: 1px solid var(--line);
  padding-top: 24px;
}

footer a {
  color: var(--amber);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}