:root {
  --paper: #F2F4F7;
  --card: #FFFFFF;
  --ink: #16202E;
  --ink-2: #45566C;
  --muted: #7A889C;
  --line: #D9DFE8;
  --brand: #0B4F86;
  --brand-soft: #E4EDF6;
  --on-brand: #FFFFFF;
  --money: #0B4F86;
  --alert: #A83A16;
  --alert-soft: #F7E7E0;
  --radius: 10px;
  --gothic: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", YuGothic, "Noto Sans JP", "Helvetica Neue", Arial, sans-serif;
  --num: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0F141B;
    --card: #171E28;
    --ink: #E6EBF2;
    --ink-2: #AEBBCB;
    --muted: #7E8CA0;
    --line: #2A3543;
    --brand: #5AA6E0;
    --brand-soft: #13293D;
    --on-brand: #0F141B;
    --money: #7CBDF0;
    --alert: #E58A63;
    --alert-soft: #33211A;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--gothic);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
}

.app {
  max-width: 480px;
  margin: 0 auto;
  padding: 28px 16px 48px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* ---------- head ---------- */

.head { display: flex; flex-direction: column; gap: 6px; }

.head__day {
  margin: 0;
  font-family: var(--num);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--brand);
}

.head__title {
  margin: 0;
  font-size: 25px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: .01em;
  text-wrap: balance;
}

.head__lede { margin: 2px 0 0; font-size: 13.5px; color: var(--ink-2); }
.head__lede b { color: var(--ink); }

.head__unofficial {
  margin: 4px 0 0;
  font-size: 12px;
  color: var(--alert);
  background: var(--alert-soft);
  border-radius: 6px;
  padding: 7px 11px;
  line-height: 1.6;
}

.head__unofficial b { font-weight: 700; }

/* ---------- panel ---------- */

.panel, .result, .burden, .notes, .why {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
}

.panel { display: flex; flex-direction: column; gap: 18px; }

.field { display: flex; flex-direction: column; gap: 8px; }

/* .field の display:flex がブラウザ標準の [hidden]{display:none} に勝ってしまうため打ち消す */
[hidden] { display: none !important; }

.field__label {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-2);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
}

.field__out {
  font-family: var(--num);
  font-size: 16px;
  font-weight: 700;
  color: var(--money);
  font-variant-numeric: tabular-nums;
}

.field__note { margin: 0; font-size: 12px; color: var(--muted); line-height: 1.6; }
.field__note b { color: var(--ink-2); }

/* segmented control */

.seg { display: flex; gap: 6px; }

.seg button {
  flex: 1 1 0;
  min-width: 0;
  font-family: var(--gothic);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-2);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 9px 4px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
  transition: background .12s, color .12s, border-color .12s;
}

.seg button small { font-size: 10px; font-weight: 400; opacity: .75; }
.seg button:hover { border-color: var(--brand); color: var(--brand); }

.seg button[aria-checked="true"] {
  background: var(--brand);
  border-color: var(--brand);
  color: var(--on-brand);
}

.seg button[aria-checked="true"] small { opacity: .85; }

/* slider */

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 26px;
  background: transparent;
  cursor: pointer;
  margin: 0;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 3px;
  background: var(--line);
}

input[type="range"]::-moz-range-track {
  height: 6px;
  border-radius: 3px;
  background: var(--line);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 24px;
  height: 24px;
  margin-top: -9px;
  border-radius: 50%;
  background: var(--brand);
  border: 3px solid var(--card);
  box-shadow: 0 1px 4px rgba(0, 0, 0, .28);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--brand);
  border: 3px solid var(--card);
  box-shadow: 0 1px 4px rgba(0, 0, 0, .28);
}

:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; }

/* ---------- result ---------- */

.result { text-align: center; padding: 22px 16px 18px; }

.result__lead { margin: 0; font-size: 13px; color: var(--ink-2); }

.result__age { margin: 2px 0 6px; display: flex; align-items: baseline; justify-content: center; gap: 4px; }

.result__age-num {
  font-family: var(--num);
  font-size: 68px;
  font-weight: 700;
  line-height: 1;
  color: var(--money);
  font-variant-numeric: tabular-nums;
  letter-spacing: -.02em;
}

.result__age-unit { font-size: 22px; font-weight: 700; color: var(--ink-2); }

.result__pay { margin: 0; font-size: 15px; color: var(--ink-2); }

.result__pay b {
  font-family: var(--num);
  font-size: 24px;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  margin-left: 2px;
}

.result__span { margin: 2px 0 0; font-size: 12.5px; color: var(--muted); }
.result__span span { font-family: var(--num); font-variant-numeric: tabular-nums; color: var(--ink-2); }

.figures {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px 4px;
}

.figures div { display: flex; flex-direction: column; gap: 1px; min-width: 0; }
.figures dt { font-size: 11px; color: var(--muted); }

.figures dd {
  margin: 0;
  font-family: var(--num);
  font-size: 14px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  word-break: break-all;
}

/* ---------- burden ---------- */

.burden { display: flex; flex-direction: column; gap: 12px; }
.burden__line { margin: 0; font-size: 14px; color: var(--ink-2); }

.burden__line b {
  font-family: var(--num);
  font-size: 19px;
  color: var(--alert);
  font-variant-numeric: tabular-nums;
}

.bar { height: 9px; border-radius: 5px; background: var(--alert-soft); overflow: hidden; }

.bar__fill {
  display: block;
  height: 100%;
  background: var(--alert);
  border-radius: 5px;
  transition: width .25s ease;
}

/* ---------- why ---------- */

.why { padding: 0; }

.why summary {
  padding: 14px 16px;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  color: var(--brand);
  list-style: none;
}

.why summary::-webkit-details-marker { display: none; }
.why summary::before { content: "＋ "; font-family: var(--num); }
.why[open] summary::before { content: "− "; }
.why[open] summary { border-bottom: 1px solid var(--line); }

.why__text { margin: 0; padding: 14px 16px 10px; font-size: 13px; color: var(--ink-2); }
.why__text b { color: var(--ink); }

/* 年数が決まるまでの道筋。表を丸ごと出さず、該当する区分と計算だけを見せる */

.path { padding: 4px 16px 0; display: flex; flex-direction: column; }

.path__step {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--paper);
}

.path__k { font-size: 12px; color: var(--ink-2); }

.path__v {
  font-family: var(--num);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.path__step--result { border-color: var(--brand); background: var(--brand-soft); }
.path__step--result .path__k { font-family: var(--num); font-variant-numeric: tabular-nums; color: var(--brand); }
.path__step--result .path__v { color: var(--brand); }

.path__arrow {
  margin: 0;
  padding: 7px 12px 7px 26px;
  font-size: 11.5px;
  color: var(--muted);
  position: relative;
  line-height: 1.5;
}

.path__arrow::before {
  content: "↓";
  position: absolute;
  left: 10px;
  top: 6px;
  font-family: var(--num);
  color: var(--brand);
}

.why__more { margin: 0; padding: 14px 16px 16px; font-size: 11.5px; color: var(--muted); line-height: 1.7; }
.why__more a { color: var(--brand); }

/* ---------- notes ---------- */

.notes { display: flex; flex-direction: column; gap: 10px; }
.notes__h { margin: 0; font-size: 13px; font-weight: 700; color: var(--ink-2); }
.notes__list { margin: 0; padding-left: 18px; display: flex; flex-direction: column; gap: 7px; font-size: 12.5px; color: var(--ink-2); }
.notes__list b { color: var(--ink); }
.notes__src { margin: 4px 0 0; font-size: 11.5px; color: var(--muted); line-height: 1.75; }

.notes__disc {
  margin: 6px 0 0;
  padding: 10px 12px;
  border-left: 2px solid var(--alert);
  background: var(--alert-soft);
  border-radius: 0 6px 6px 0;
  font-size: 11.5px;
  color: var(--ink-2);
  line-height: 1.8;
}

.notes__disc b { color: var(--alert); }
.notes a { color: var(--brand); }

/* ---------- foot ---------- */

.foot { text-align: center; padding-top: 4px; }
.foot__link { font-size: 12.5px; color: var(--muted); text-decoration: none; }
.foot__link:hover { color: var(--brand); }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}