@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

:root {
  --bg: #fafafa;
  --surface: #fff;
  --border: #efefef;
  --border-hover: #d9d9d9;
  --text-primary: #0d0d0d;
  --text-secondary: #6b6b6b;
  --text-tertiary: #a1a1a1;
  --accent: #0d0d0d;
  --radius: 6px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --transition: 150ms cubic-bezier(0.16, 1, 0.3, 1);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'SF Mono', 'Fira Code', 'JetBrains Mono', monospace;
  --font-size-xs: 11px;
  --font-size-sm: 13px;
  --font-size-base: 14px;
  --font-size-lg: 18px;
  --font-size-xl: 24px;
}

html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--text-primary); text-decoration: none; }
a:hover { color: var(--text-secondary); }

/* Header */
.app-header {
  display: flex;
  align-items: center;
  height: 52px;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250,250,250,0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.app-header h1 { font-size: var(--font-size-sm); font-weight: 600; letter-spacing: -0.01em; }
.app-header h1 span { color: var(--text-tertiary); font-weight: 400; }
.app-header .repo-link {
  margin-left: auto;
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
  transition: color var(--transition);
}
.app-header .repo-link:hover { color: var(--text-primary); }

/* Main */
.main { max-width: 1200px; margin: 0 auto; padding: 48px 28px 80px; }

/* Home */
.home-header { margin-bottom: 32px; }
.home-header h2 { font-size: var(--font-size-xl); font-weight: 700; letter-spacing: -0.02em; }
.home-header p { font-size: var(--font-size-base); color: var(--text-secondary); margin-top: 4px; }

.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 10px;
}

.exp-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  cursor: pointer;
  transition: border-color var(--transition);
}
.exp-card:hover { border-color: var(--border-hover); }

.exp-card .num {
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 4px;
}
.exp-card h3 { font-size: var(--font-size-sm); font-weight: 600; letter-spacing: -0.01em; margin-bottom: 2px; }
.exp-card p { font-size: var(--font-size-xs); color: var(--text-secondary); }
.exp-card .parts { margin-top: 10px; display: flex; gap: 4px; flex-wrap: wrap; }
.exp-card .parts span {
  font-size: var(--font-size-xs);
  font-weight: 500;
  padding: 1px 7px;
  border-radius: 3px;
  background: #f2f2f2;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}
.exp-card .parts span:hover { background: #e8e8e8; color: var(--text-secondary); }

/* Back */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: var(--font-size-sm);
  color: var(--text-tertiary);
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font);
  padding: 2px 0;
  margin-bottom: 24px;
  transition: color var(--transition);
}
.back-btn:hover { color: var(--text-primary); }

/* Experiment header */
.exp-header { margin-bottom: 24px; }
.exp-header h2 { font-size: var(--font-size-lg); font-weight: 700; letter-spacing: -0.02em; }
.exp-header .exp-meta { font-size: var(--font-size-sm); color: var(--text-tertiary); margin-top: 2px; }

/* Tabs */
.tabs { display: flex; gap: 0; margin-bottom: 28px; border-bottom: 1px solid var(--border); }
.tab {
  padding: 6px 0 10px;
  margin-right: 24px;
  font-size: var(--font-size-sm);
  font-weight: 450;
  color: var(--text-tertiary);
  cursor: pointer;
  border: none;
  border-bottom: 1px solid transparent;
  margin-bottom: -1px;
  transition: color var(--transition), border-color var(--transition);
  background: none;
  font-family: var(--font);
  letter-spacing: -0.01em;
}
.tab:hover { color: var(--text-primary); }
.tab.active { color: var(--text-primary); border-bottom-color: var(--text-primary); }

/* Content split */
.content-split {
  display: grid;
  grid-template-columns: 0.85fr 1.5fr 0.85fr;
  gap: 20px;
  align-items: start;
}
.content-split > div { min-width: 0; }
@media (max-width: 1100px) {
  .content-split { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 700px) {
  .content-split { grid-template-columns: 1fr; }
  .main { padding: 28px 16px; }
  .app-header { padding: 0 16px; }
  .home-grid { grid-template-columns: 1fr; }
}

/* Info panel */
.info-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
}
.info-panel h3 {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
  margin-bottom: 8px;
}
.info-panel p { font-size: var(--font-size-base); color: var(--text-primary); line-height: 1.7; }
.info-panel ol { padding-left: 18px; }
.info-panel li {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 3px;
}
.info-panel li::marker { color: var(--text-tertiary); }
.info-panel .section { margin-top: 24px; }

/* Code panel */
.code-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  position: relative;
}
.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: var(--font-size-xs);
  font-weight: 500;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text-tertiary);
  cursor: pointer;
  font-family: var(--font);
  opacity: 0;
  transition: opacity var(--transition), background var(--transition), color var(--transition);
  z-index: 2;
  line-height: 1.4;
}
.code-panel:hover .copy-btn { opacity: 1; }
.copy-btn:hover { background: #f4f4f4; color: var(--text-primary); }
.code-panel pre {
  margin: 0;
  padding: 20px;
  overflow-x: auto;
  overflow-y: auto;
  max-height: 70vh;
  font-size: 12.5px;
  line-height: 1.6;
  font-family: var(--mono);
  background: #fafbfc;
}
.code-panel pre code { background: none !important; padding: 0 !important; }

/* Output */
.output-header { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.output-hint { font-size: 11px; color: var(--text-tertiary); font-weight: 400; }
.output-panel h3 {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
}
.output-grid { display: grid; gap: 8px; }
.output-grid img {
  width: 100%;
  border-radius: 5px;
  border: 1px solid var(--border);
  cursor: zoom-in;
  transition: border-color var(--transition);
}
.output-grid img:hover { border-color: var(--border-hover); }

/* Modal */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 999;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.modal-overlay.open { display: flex; }
.modal-overlay img {
  max-width: 90vw;
  max-height: 88vh;
  border-radius: var(--radius);
  box-shadow: 0 30px 80px rgba(0,0,0,0.35);
  cursor: zoom-out;
}