/* --- Base Reset & Typography --- */
* {
  box-sizing: border-box;
}
html {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
body {
  margin: 0;
  padding: 0;
  background: #b9edf6;
  color: #1f2937;
}

/* --- Headings --- */
h1, h2, h3, h4, h5, h6 {
  margin: 1.2em 0 0.6em;
  line-height: 1.25;
  font-weight: 700;
  color: #111827;
}
h1 { font-size: 2.25rem; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1rem; }

/* --- Links --- */
a {
  color: #2563eb;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* --- Paragraphs & Lists --- */
p {
  margin: 1em 0;
  max-width: 65ch;
}
ul, ol {
  margin: 1em 0 1em 2em;
}
li {
  margin: 0.25em 0;
}

/* --- Images --- */
img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

/* --- Buttons & Inputs --- */
button, input[type="submit"], input[type="button"] {
  background: #2563eb;
  color: #fff;
  border: none;
  padding: 0.6em 1.1em;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s ease;
}
button:hover, input[type="submit"]:hover, input[type="button"]:hover {
  background: #1e40af;
}
input, textarea, select {
  padding: 0.5em 0.75em;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  font-size: 1rem;
  width: 100%;
  max-width: 500px;
}
input:focus, textarea:focus, select:focus {
  border-color: #2563eb;
  outline: none;
  box-shadow: 0 0 0 3px rgba(37,99,235,0.2);
}

/* --- Tables --- */
table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.5em 0;
}
th, td {
  border: 1px solid #e5e7eb;
  padding: 0.75em 1em;
  text-align: left;
}
th {
  background: #f3f4f6;
  font-weight: 600;
}

/* --- Layout Helpers --- */
main, section, article {
  padding: 1.5rem;
  margin: 0 auto;
  max-width: 900px;
}
header, footer {
  background: #111827;
  color: #f9fafb;
  padding: 1rem 1.5rem;
  text-align: center;
}
footer {
  font-size: 0.875rem;
  opacity: 0.8;
}

/* --- Blockquotes & Code --- */
blockquote {
  border-left: 4px solid #2563eb;
  padding-left: 1em;
  color: #374151;
  margin: 1em 0;
  font-style: italic;
}
code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  background: #f3f4f6;
  padding: 0.25em 0.5em;
  border-radius: 4px;
}
pre {
  display: block;
  padding: 1em;
  overflow-x: auto;
}

/* --- Responsive tweaks --- */
@media (max-width: 600px) {
  body {
    font-size: 15px;
  }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  main, section, article {
    padding: 1rem;
  }
}