:root {
  --bg: #f6f1e7; --surface: #fffaf0; --ink: #1b2430;
  --muted: #566170; --line: #d9cfbd; --accent: #c2410c; --focus: #0b63ce;
  --on-accent: #fffaf0;
  color-scheme: light dark;
  font-family: "Avenir Next", "Segoe UI", system-ui, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1720; --surface: #17212c; --ink: #f1ebe0;
    --muted: #a3adb9; --line: #2c3947; --accent: #ff9a5c; --focus: #7ab8ff; --on-accent: #0f1720; }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0 auto; max-width: 900px; padding: 40px 20px;
  background: var(--bg); color: var(--ink); line-height: 1.5; }
h1, h2, p { margin: 0; }
.masthead { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.brand { display: flex; align-items: center; gap: 8px; }
h1 { font-size: 18px; }
.home-line { color: var(--muted); font-size: 14px; }
.converter { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 32px; align-items: start;
  background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 28px; }
.left { min-width: 0; }
.entry { display: flex; flex-direction: column; gap: 10px; }
.entry-label { font-size: 15px; font-weight: 600; }
#email-time { width: 100%; min-width: 0; padding: 12px 14px; border: 1px solid var(--line);
  border-radius: 10px; background: var(--bg); color: var(--ink); font: inherit; font-size: clamp(22px, 4vw, 28px); }
#email-time::placeholder { color: var(--muted); }
#email-time:focus { border-color: var(--accent); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
button { font: inherit; color: var(--ink); cursor: pointer; }
#zones { display: flex; flex-wrap: wrap; gap: 2px; }
#zones button { min-width: 44px; min-height: 40px; padding: 4px 10px; border: 0; border-radius: 8px;
  background: transparent; color: var(--muted); font-size: 15px; font-weight: 600; }
#zones button:hover { background: var(--bg); color: var(--ink); }
#zones button[aria-pressed="true"], #zones button.is-selected { background: var(--ink); color: var(--surface); }
.source-line { color: var(--muted); font-size: 14px; min-height: 21px; }
.source-line:empty { display: none; }
#source-name { font-weight: 600; color: var(--ink); }
#input-message { color: var(--accent); font-size: 14px; }
#input-message:empty { display: none; }
#occurrence-options { display: flex; gap: 8px; }
#occurrence-options button { background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 8px 16px; }
.result { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: 16px; margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--line); }
.result:has(#answer:empty) { display: none; }
#answer { min-width: 0; }
.answer-time { font-size: clamp(40px, 7vw, 68px); font-weight: 750; line-height: 1.1;
  letter-spacing: -.04em; font-variant-numeric: tabular-nums; }
.answer-unit { display: block; margin-top: 4px; font-size: 17px; font-weight: 500; letter-spacing: 0; color: var(--muted); }
.answer-date { margin-top: 12px; font-size: 15px; }
.day-badge { display: inline-block; margin-left: 8px; font-size: 13px; color: var(--accent); font-weight: 700; }
.copy-wrap { display: flex; flex-direction: column; align-items: flex-end; gap: 4px; }
.copy { display: flex; align-items: center; gap: 6px; min-height: 44px; padding: 8px 10px;
  border: 0; border-radius: 8px; background: transparent; font-size: 14px; }
.copy:hover { background: var(--bg); }
#copy-status { color: var(--accent); font-size: 13px; }
.calendar { padding-left: 28px; border-left: 1px solid var(--line); }
.cal-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
#calendar-month { font-size: 15px; font-weight: 650; }
.cal-nav { width: 36px; height: 36px; border: 0; border-radius: 8px; background: transparent; font-size: 22px; line-height: 1; color: var(--muted); }
.cal-nav:hover { background: var(--bg); color: var(--ink); }
.cal-weekdays, .cal-days { display: grid; grid-template-columns: repeat(7, 1fr); }
.cal-weekdays span { text-align: center; font-size: 12px; font-weight: 600; color: var(--muted); padding: 4px 0; }
.calendar-blank { min-height: 36px; }
.calendar-day { height: 36px; border: 0; border-radius: 50%; background: transparent; font-size: 14px;
  font-variant-numeric: tabular-nums; padding: 0; }
.calendar-day:hover { background: var(--bg); }
.calendar-day.is-today { box-shadow: inset 0 0 0 1.5px var(--accent); }
.calendar-day.is-selected, .calendar-day[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); font-weight: 700; }
@media (max-width: 720px) {
  body { padding: 24px 16px; }
  .converter { grid-template-columns: minmax(0, 1fr); gap: 20px; padding: 20px; }
  .calendar { padding: 20px 0 0; border-left: 0; border-top: 1px solid var(--line); max-width: 320px; width: 100%; margin: 0 auto; }
  #zones { display: grid; grid-template-columns: repeat(4, 1fr); }
}