/* The Pond Manual — minimal custom stylesheet */
:root {
  --ink: #1c2b26;
  --muted: #5a6d66;
  --pond: #0e7c66;
  --pond-dark: #0a5c4c;
  --bg: #fdfdfa;
  --card: #ffffff;
  --line: #dfe8e4;
  --accent-bg: #eef7f4;
  --warn: #8a5a00;
  --warn-bg: #fdf3e0;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.65;
  font-size: 1.05rem;
}

.wrap { max-width: 44rem; margin: 0 auto; padding: 0 1.25rem; }

.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--card);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  padding-bottom: 0.75rem;
}
.brand {
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--pond-dark);
  text-decoration: none;
}
.site-nav a {
  margin-left: 1rem;
  text-decoration: none;
  color: var(--muted);
  font-size: 0.95rem;
}
.site-nav a:hover { color: var(--pond-dark); }

main.wrap { padding-top: 2rem; padding-bottom: 3rem; }

h1, h2, h3 { line-height: 1.25; color: var(--ink); }
h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.45rem; margin-top: 2.25rem; border-top: 1px solid var(--line); padding-top: 1.5rem; }
h3 { font-size: 1.15rem; }

a { color: var(--pond); }
a:hover { color: var(--pond-dark); }

.lede { font-size: 1.2rem; color: var(--muted); }
.meta { color: var(--muted); font-size: 0.9rem; margin-top: -0.5rem; }

.hero { padding: 1.5rem 0 1rem; }
.hero .accent { color: var(--pond); }

.btn {
  display: inline-block;
  background: var(--pond);
  color: #fff;
  padding: 0.65rem 1.2rem;
  border-radius: 0.4rem;
  text-decoration: none;
  font-weight: 600;
  margin: 0.25rem 0.5rem 0.25rem 0;
}
.btn:hover { background: var(--pond-dark); color: #fff; }
.btn-ghost { background: var(--card); color: var(--pond-dark); border: 2px solid var(--pond); }
.btn-ghost:hover { background: var(--accent-bg); color: var(--pond-dark); }

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  padding: 1rem 1.25rem;
}
.card h3 { margin: 0 0 0.4rem; font-size: 1.05rem; }
.card p { margin: 0; font-size: 0.95rem; color: var(--muted); }

.plain-list { padding-left: 1.25rem; }
.plain-list li { margin-bottom: 0.5rem; }

.affiliate-notice {
  background: var(--warn-bg);
  border-left: 4px solid var(--warn);
  padding: 0.75rem 1rem;
  font-size: 0.92rem;
  border-radius: 0 0.4rem 0.4rem 0;
  color: var(--ink);
}

.callout {
  background: var(--accent-bg);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
}

table { border-collapse: collapse; width: 100%; margin: 1.25rem 0; font-size: 0.95rem; }
th, td { border: 1px solid var(--line); padding: 0.55rem 0.75rem; text-align: left; }
th { background: var(--accent-bg); }
tr:nth-child(even) td { background: #fafcfb; }

/* Tool: Pond System Sizer */
.tool { background: var(--card); border: 1px solid var(--line); border-radius: 0.75rem; padding: 1.5rem; margin: 1.5rem 0; }
.tool-step { margin-bottom: 1.75rem; }
.tool-step h3 { margin-top: 0; }
.tool label { display: block; font-weight: 600; margin: 0.75rem 0 0.25rem; font-size: 0.98rem; }
.tool input[type="number"], .tool select {
  width: 100%;
  max-width: 22rem;
  padding: 0.55rem 0.7rem;
  font-size: 1rem;
  border: 1px solid var(--line);
  border-radius: 0.35rem;
}
.tool .row { display: flex; gap: 1rem; flex-wrap: wrap; }
.tool .row > div { flex: 1 1 12rem; }
.tool button {
  background: var(--pond);
  color: #fff;
  border: 0;
  border-radius: 0.4rem;
  padding: 0.7rem 1.4rem;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  margin-top: 1rem;
}
.tool button:hover { background: var(--pond-dark); }
.tool .math { background: #f6faf8; border: 1px dashed var(--line); border-radius: 0.4rem; padding: 0.9rem 1.1rem; font-size: 0.93rem; margin-top: 0.9rem; }
.tool .math code { background: #eef4f1; padding: 0.1rem 0.35rem; border-radius: 0.25rem; }
.tool .result { font-size: 1.15rem; font-weight: 700; color: var(--pond-dark); margin-top: 0.6rem; }
.tool .warn-msg { background: var(--warn-bg); border-left: 4px solid var(--warn); padding: 0.6rem 0.9rem; margin-top: 0.8rem; font-size: 0.94rem; }

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--card);
  padding: 2rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}
.site-footer .fine { font-size: 0.82rem; }

@media (max-width: 600px) {
  h1 { font-size: 1.6rem; }
  .site-header .wrap { flex-direction: column; align-items: flex-start; gap: 0.4rem; }
  .site-nav a { margin-left: 0; margin-right: 1rem; }
}