/* =================================================================
   DateCalc — stylesheet
   Theme: developer-tool aesthetic (dark by default, light on toggle)
   ================================================================= */

:root[data-theme="dark"] {
  --bg: #0d1117;
  --surface: #161b22;
  --surface-raised: #1c2129;
  --border: #30363d;
  --text: #c9d1d9;
  --text-dim: #8b949e;
  --accent: #58a6ff;
  --accent-strong: #79c0ff;
  --success: #3fb950;
  --danger: #f78166;
}

:root[data-theme="light"] {
  --bg: #ffffff;
  --surface: #f6f8fa;
  --surface-raised: #eef1f4;
  --border: #d0d7de;
  --text: #1f2328;
  --text-dim: #59636e;
  --accent: #0969da;
  --accent-strong: #0550ae;
  --success: #1a7f37;
  --danger: #cf222e;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.55;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

code, .mono { font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Header ---------- */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.site-header__inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-weight: 600;
  font-size: 17px;
  color: var(--text);
  margin-right: auto;
}
.brand__prompt { color: var(--success); }
.site-nav { display: flex; gap: 20px; }
.site-nav a { color: var(--text-dim); font-size: 14px; font-weight: 500; }
.site-nav a:hover { color: var(--text); text-decoration: none; }
.site-nav a.is-active { color: var(--accent); }

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  border-radius: 6px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }
.theme-toggle .icon { width: 17px; height: 17px; }
.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: none; }
:root[data-theme="light"] .theme-toggle .icon-sun { display: block; }

/* ---------- Ad slots ---------- */
.ad-slot {
  border: 1px dashed var(--border);
  border-radius: 6px;
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-dim);
  font-size: 12px;
  font-family: "SFMono-Regular", Consolas, monospace;
  text-align: center;
  padding: 10px;
}
.ad-slot--banner { max-width: 1180px; margin: 16px auto 0; width: calc(100% - 40px); min-height: 90px; }
.ad-slot--rail { min-height: 500px; }

/* ---------- Page layout ---------- */
.page-shell {
  flex: 1;
  max-width: 1180px;
  margin: 0 auto;
  width: 100%;
  padding: 0 20px 40px;
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr) 160px;
  gap: 20px;
  margin-top: 20px;
}
.page-shell--simple { grid-template-columns: 1fr; max-width: 760px; }

main.content { min-width: 0; }

/* ---------- Instrument / calculator card ---------- */
.tool-intro { margin-bottom: 22px; }
.tool-intro .eyebrow {
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  color: var(--success);
  letter-spacing: 0.05em;
  margin: 0 0 6px;
}
.tool-intro h1 { font-size: 26px; margin: 0 0 8px; }
.tool-intro p { color: var(--text-dim); margin: 0; font-size: 14.5px; }

.dial {
  display: flex;
  gap: 2px;
  background: var(--border);
  border-radius: 6px;
  padding: 3px;
  margin-bottom: 20px;
}
.dial button {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-dim);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12.5px;
  padding: 10px 8px;
  border-radius: 4px;
  cursor: pointer;
}
.dial button.active { background: var(--accent); color: #fff; font-weight: 600; }
.dial button:not(.active):hover { background: var(--surface-raised); color: var(--text); }

.calculator .panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
}
.mode { display: none; }
.mode.active { display: block; }

.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 16px; }
.field { margin-bottom: 16px; }
label {
  display: block;
  font-size: 11px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 6px;
  font-family: "SFMono-Regular", Consolas, monospace;
}
input[type="date"], input[type="time"], input[type="number"], input[type="text"] {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 14.5px;
  padding: 10px 11px;
  border-radius: 6px;
  outline: none;
}
input:focus { border-color: var(--accent); }

.duration-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; margin-bottom: 18px; }
.duration-grid .field { margin-bottom: 0; }
.duration-grid input { padding: 9px 6px; font-size: 13.5px; text-align: center; }

.sign-toggle { display: flex; gap: 2px; background: var(--border); border-radius: 6px; padding: 3px; margin-bottom: 18px; width: fit-content; }
.sign-toggle button { background: transparent; border: none; color: var(--text-dim); font-family: "SFMono-Regular", Consolas, monospace; font-size: 13px; padding: 8px 20px; border-radius: 4px; cursor: pointer; }
.sign-toggle button.active { background: var(--accent); color: #fff; font-weight: 600; }

.divider-arrow { display: flex; justify-content: center; color: var(--text-dim); font-size: 16px; margin: -6px 0 14px; }

.readout { margin-top: 20px; border-top: 1px dashed var(--border); padding-top: 20px; }
.readout-label { font-family: "SFMono-Regular", Consolas, monospace; font-size: 11px; letter-spacing: 0.05em; text-transform: uppercase; color: var(--success); margin-bottom: 10px; }
.flip-display {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 18px 20px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  min-height: 68px;
}
.flip-display .big { font-family: "SFMono-Regular", Consolas, monospace; font-weight: 600; font-size: 22px; }
.flip-display .accent-text { font-family: "SFMono-Regular", Consolas, monospace; font-size: 13px; color: var(--accent-strong); }
.flip-display .meta { width: 100%; font-family: "SFMono-Regular", Consolas, monospace; font-size: 12px; color: var(--text-dim); margin-top: 4px; }
.error-text { color: var(--danger); }

.unit-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--border); margin-top: 12px; border-radius: 6px; overflow: hidden; }
.unit-cell { background: var(--surface-raised); padding: 12px 8px; text-align: center; }
.unit-cell .n { font-family: "SFMono-Regular", Consolas, monospace; font-size: 18px; font-weight: 600; color: var(--accent-strong); display: block; }
.unit-cell .u { font-size: 10px; letter-spacing: 0.05em; text-transform: uppercase; color: var(--text-dim); margin-top: 4px; display: block; }

.now-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  padding: 7px 12px;
  border-radius: 6px;
  cursor: pointer;
  margin-top: -4px;
  margin-bottom: 16px;
}
.now-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Static content pages (About / Privacy / Disclaimer) ---------- */
.content-page h1 { font-size: 26px; margin-bottom: 6px; }
.content-page .updated { color: var(--text-dim); font-size: 13px; margin-bottom: 26px; font-family: "SFMono-Regular", Consolas, monospace; }
.content-page h2 { font-size: 18px; margin-top: 28px; }
.content-page p, .content-page li { color: var(--text-dim); font-size: 14.5px; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border); background: var(--surface); margin-top: 40px; }
.site-footer__inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 20px 16px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}
.brand--footer { display: inline-block; margin-bottom: 8px; }
.site-footer__tagline { color: var(--text-dim); font-size: 13px; max-width: 340px; margin: 0; }
.site-footer__links { display: flex; gap: 18px; flex-wrap: wrap; }
.site-footer__links a { color: var(--text-dim); font-size: 13.5px; }
.site-footer__links a:hover { color: var(--text); }
.site-footer__bottom {
  border-top: 1px solid var(--border);
  max-width: 1180px;
  margin: 0 auto;
  padding: 14px 20px;
  color: var(--text-dim);
  font-size: 12px;
  font-family: "SFMono-Regular", Consolas, monospace;
}

/* Deter drag-selecting the whole tool UI (see include.js note on limits) */
.calculator, .site-header, .site-footer { user-select: none; }
.calculator input { user-select: text; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .page-shell { grid-template-columns: 1fr; }
  .ad-slot--rail { min-height: 120px; order: 3; }
  main.content { order: 1; }
}
@media (max-width: 600px) {
  .duration-grid { grid-template-columns: repeat(3, 1fr); }
  .field-row { grid-template-columns: 1fr; }
  .unit-row { grid-template-columns: repeat(2, 1fr); }
  .tool-intro h1 { font-size: 22px; }
  .site-header__inner { gap: 14px; }
  .site-nav { gap: 12px; }
}