:root {
  --bg-primary: #09090b;
  --bg-secondary: #18181b;
  --bg-tertiary: #1c1c1f;
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-tertiary: #71717a;
  --blue: #3b82f6;
  --blue-light: #60a5fa;
  --border: rgba(255, 255, 255, 0.08);
  --radius: 16px;
  --code-bg: rgba(255, 255, 255, 0.05);
  --code-border: rgba(255, 255, 255, 0.08);
  --gradient-accent: #1a2235;
}
html[data-theme="light"] {
  --bg-primary: #f6f7fb;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f8fafc;
  --text-primary: #111827;
  --text-secondary: #374151;
  --text-tertiary: #6b7280;
  --blue: #2563eb;
  --blue-light: #1d4ed8;
  --border: rgba(15, 23, 42, 0.12);
  --code-bg: rgba(0, 0, 0, 0.05);
  --code-border: rgba(0, 0, 0, 0.08);
  --gradient-accent: #dbe4f0;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: radial-gradient(1000px 400px at 50% -120px, var(--gradient-accent) 0%, var(--bg-primary) 65%);
  color: var(--text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  z-index: 20;
  border: 1px solid var(--border);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border-radius: 999px;
  padding: 0.42rem 0.8rem;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.theme-toggle:hover {
  color: var(--blue-light);
  border-color: rgba(59, 130, 246, 0.35);
  background: var(--bg-tertiary);
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: clamp(1rem, 3vw, 2.5rem);
  padding-top: clamp(2rem, 5vw, 4rem);
  padding-bottom: 3rem;
}

.header {
  margin-bottom: 1.25rem;
}

.back-link {
  display: inline-block;
  text-decoration: none;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
  font-size: 0.82rem;
  transition: all 0.2s ease;
}

.back-link:hover {
  color: var(--blue-light);
  border-color: rgba(96, 165, 250, 0.35);
  background: rgba(59, 130, 246, 0.09);
}

.note-shell {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.note-meta {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-tertiary);
}

.note-title {
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  font-weight: 600;
}

.note-file {
  margin-top: 0.2rem;
  color: var(--text-tertiary);
  font-size: 0.82rem;
}

.note-content {
  padding: 1.2rem 1.25rem 1.35rem;
  line-height: 1.62;
}

.note-content h1,
.note-content h2,
.note-content h3 {
  line-height: 1.3;
  margin-top: 1.3rem;
  margin-bottom: 0.7rem;
  letter-spacing: -0.02em;
}

.note-content h1 { font-size: 1.45rem; }
.note-content h2 { font-size: 1.2rem; }
.note-content h3 { font-size: 1.05rem; }

.note-content p,
.note-content ul,
.note-content ol,
.note-content pre,
.note-content blockquote {
  margin: 0.72rem 0;
}

.note-content ul,
.note-content ol {
  padding-left: 1.3rem;
}

.note-content li {
  margin: 0.24rem 0;
  color: var(--text-secondary);
}

.note-content p { color: var(--text-secondary); }

.note-content a {
  color: var(--blue-light);
  text-decoration: none;
}

.note-content a:hover { text-decoration: underline; }

.note-content code {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 0.08rem 0.32rem;
  font-size: 0.9em;
}

.note-content pre {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.9rem;
  overflow-x: auto;
}

.note-content pre code {
  background: transparent;
  border: 0;
  padding: 0;
}

.error {
  color: #fca5a5;
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: 10px;
  padding: 0.7rem 0.85rem;
}

/* Checkboxes */
.note-content input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border: 2px solid var(--text-tertiary);
  border-radius: 4px;
  vertical-align: middle;
  margin-right: 0.4rem;
  position: relative;
  top: -1px;
  cursor: default;
}

.note-content input[type="checkbox"]:checked {
  background: var(--blue);
  border-color: var(--blue);
}

.note-content input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 3px;
  top: 0px;
  width: 5px;
  height: 9px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Horizontal rules */
.note-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
}