/* Sheet Mailer site — one stylesheet, no build step, no external requests.
   Upload the whole website/ folder as-is. */

:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --panel: #f7f7f8;
  --ink: #16181d;
  --muted: #5c6068;
  --line: #e3e4e8;
  --accent: #4338ca;
  --accent-ink: #ffffff;
  --warn-bg: #fff8e6;
  --warn-line: #e8d9a8;
  --warn-ink: #6b5410;
  --maxw: 54rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171b;
    --panel: #1c1f24;
    --ink: #e9eaee;
    --muted: #9ba1ab;
    --line: #2e3238;
    --accent: #8b9cff;
    --accent-ink: #15171b;
    --warn-bg: #241f12;
    --warn-line: #4a4027;
    --warn-ink: #e3cf9a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem; }

/* ---------------------------------------------------------------- header */
header.site {
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
}
header.site .wrap {
  display: flex; align-items: center; gap: 1.25rem;
  min-height: 3.5rem; flex-wrap: wrap;
}
.brand { font-weight: 700; letter-spacing: -0.01em; text-decoration: none; color: var(--ink); }
nav.site { margin-left: auto; display: flex; gap: 1.1rem; flex-wrap: wrap; }
nav.site a { color: var(--muted); text-decoration: none; font-size: .94rem; }
nav.site a:hover, nav.site a[aria-current="page"] { color: var(--ink); }

/* ------------------------------------------------------------------ type */
h1 { font-size: 2.1rem; line-height: 1.2; letter-spacing: -0.02em; margin: 0 0 .6rem; }
h2 { font-size: 1.25rem; margin: 2.6rem 0 .6rem; letter-spacing: -0.01em; }
h3 { font-size: 1.02rem; margin: 1.6rem 0 .35rem; }
p, li { color: var(--ink); }
.lede { font-size: 1.12rem; color: var(--muted); margin: 0 0 1.5rem; }
.muted { color: var(--muted); }
small { color: var(--muted); }
a { color: var(--accent); }
code {
  background: var(--panel); border: 1px solid var(--line);
  padding: .08em .35em; border-radius: 4px; font-size: .88em;
}

main { padding: 2.5rem 0 5rem; }

/* ---------------------------------------------------------------- blocks */
.hero { padding: 1rem 0 .5rem; }
.cta { display: flex; gap: .7rem; flex-wrap: wrap; margin: 1.4rem 0 .4rem; }
.btn {
  display: inline-block; padding: .62rem 1.05rem; border-radius: 7px;
  text-decoration: none; font-weight: 600; font-size: .95rem;
  border: 1px solid var(--line); color: var(--ink); background: var(--panel);
}
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: transparent; }

.grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.card {
  border: 1px solid var(--line); border-radius: 10px;
  padding: 1rem 1.1rem; background: var(--panel);
}
.card h3 { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }

figure { margin: 1.4rem 0; }
figure img {
  width: 100%; height: auto; display: block;
  border: 1px solid var(--line); border-radius: 10px;
}
figcaption { color: var(--muted); font-size: .9rem; margin-top: .5rem; }

.note {
  background: var(--warn-bg); border: 1px solid var(--warn-line);
  color: var(--warn-ink); border-radius: 8px; padding: .85rem 1rem; margin: 1.4rem 0;
}
.note p:first-child { margin-top: 0; }
.note p:last-child { margin-bottom: 0; }

table { border-collapse: collapse; width: 100%; margin: 1rem 0; display: block; overflow-x: auto; }
th, td {
  border: 1px solid var(--line); padding: .5rem .65rem;
  text-align: left; vertical-align: top; font-size: .94rem;
}
th { background: var(--panel); font-weight: 600; }

details { border: 1px solid var(--line); border-radius: 8px; padding: .75rem 1rem; margin: .6rem 0; background: var(--panel); }
details + details { margin-top: .5rem; }
summary { cursor: pointer; font-weight: 600; }
details[open] summary { margin-bottom: .5rem; }

ol.steps { padding-left: 1.2rem; }
ol.steps li { margin: .5rem 0; }

/* ---------------------------------------------------------------- footer */
footer.site {
  border-top: 1px solid var(--line); padding: 1.6rem 0 3rem;
  color: var(--muted); font-size: .92rem;
}
footer.site .wrap { display: flex; gap: 1.1rem; flex-wrap: wrap; align-items: center; }
footer.site a { color: var(--muted); }
footer.site .spacer { margin-left: auto; }

@media (max-width: 34rem) {
  h1 { font-size: 1.7rem; }
  nav.site { gap: .85rem; width: 100%; margin-left: 0; }
}