main{
  --ground:#E9EFF2; --surface:#F9FBFC; --raise:#E2EAEE;
  --ink:#102A3A; --muted:#5E7480; --line:#BDCCD3;
  --accent:#007C91; --accent-soft:#D5EDF0; --accent-ink:#FFFFFF;
  --signal:#F2A900; --console:#092C3C; --console-2:#0E4154;
  --lv0:#82949D; --lv1:#C94B3A; --lv1s:#F9E3DF;
  --lv2:#B97800; --lv2s:#F7E9C9; --lv3:#16825B; --lv3s:#DCEFE7;
  --lv4:#176DA5; --lv4s:#DDEAF3;
  --font-jp:"Hiragino Sans","Hiragino Kaku Gothic ProN","Noto Sans JP","Yu Gothic UI","Yu Gothic",Meiryo,system-ui,sans-serif;
  --font-mono:ui-monospace,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;
  --r:4px;
}
.ref-screen{padding:0;background:var(--ground);font:14px/1.5 var(--font-jp);color:var(--ink)}
.ref-screen button{min-height:0;color:inherit;cursor:pointer}
.ref-screen .pad{padding:16px}
.ref-screen .vhead{position:sticky; top:0; z-index:6; background:var(--ground);
  background:color-mix(in srgb,var(--ground) 94%,transparent);
  backdrop-filter:blur(9px); margin:-16px -16px 14px; padding:13px 16px 10px;
  border-bottom:2px solid var(--console)}
.ref-screen .vhead::after{content:""; position:absolute; left:16px; bottom:-2px; width:54px; height:2px;
  background:var(--signal)}
.ref-screen .vhead .h{font-size:18px; font-weight:800; letter-spacing:.02em}
.ref-screen .vhead .sub{margin-top:2px}
.ref-screen .sub{color:var(--muted); font-size:12.5px}
.ref-screen .card{background:var(--surface); border:1px solid var(--line); border-radius:var(--r);
  padding:14px; margin-bottom:10px; box-shadow:0 3px 0 rgba(9,44,60,.06)}
.ref-screen .lv{display:flex; flex-direction:column; align-items:center; gap:2px; flex-shrink:0;
  border-radius:2px; padding:6px 8px; min-width:56px; border:1px solid currentColor}
.ref-screen .lv .f{font-family:var(--font-mono); font-size:10px; line-height:1; letter-spacing:.08em}
.ref-screen .lv .n{font-size:9.5px; font-weight:700}
.ref-screen .qs{display:flex; align-items:center; gap:12px; background:var(--surface); border:1px solid var(--line);
  border-left:3px solid var(--accent); border-radius:var(--r); padding:13px 12px;
  margin-bottom:8px; width:100%; text-align:left; box-shadow:0 2px 0 rgba(9,44,60,.05)}
.ref-screen .qs .ic{width:48px; height:38px; border-radius:2px; display:grid; place-items:center;
  font-family:var(--font-mono); font-size:9px; font-weight:700; letter-spacing:.08em;
  border:1px solid currentColor; flex-shrink:0}
.ref-screen .qs .t{font-size:15px; font-weight:700}
.ref-screen .qs .d{font-size:11.5px; color:var(--muted); line-height:1.5}
.ref-screen .qs .cnt{margin-left:auto; font-family:var(--font-mono); font-size:13px; font-weight:700; color:var(--accent)}
.ref-screen .unit{display:flex; align-items:center; gap:11px; background:var(--surface); border:1px solid var(--line);
  border-radius:var(--r); padding:12px 12px 12px 0; margin-bottom:8px; width:100%;
  text-align:left; overflow:hidden; box-shadow:0 2px 0 rgba(9,44,60,.05)}
.ref-screen .unit .bar{width:7px; height:7px; align-self:flex-start; border-radius:0; flex-shrink:0;
  margin:10px 4px 0 11px; box-shadow:0 0 7px currentColor}
.ref-screen .unit .in{flex:1; min-width:0}
.ref-screen .unit .t{font-size:14.5px; font-weight:700; margin-bottom:5px}
.ref-screen .chips{display:flex; gap:5px; flex-wrap:wrap}
.ref-screen .chip{background:var(--raise); border-radius:5px; padding:2px 6px; font-size:10.5px; color:var(--muted);
  white-space:nowrap}
.ref-screen .chip .st{color:#E8A33D}
.ref-screen .chip .fi{color:#D9694A}
.ref-screen .pastunit{padding-top:10px; padding-bottom:10px}
.ref-screen .pastunit .t{font-size:14px; margin-bottom:2px}
.ref-screen .pastmeta{display:flex; align-items:center; gap:7px; min-width:0}
.ref-screen .pastbadge{flex-shrink:0; border-radius:5px; background:var(--accent-soft); color:var(--accent);
  font-size:10.5px; font-weight:700; padding:2px 6px}
.ref-screen .pastsrc{font-size:11px; color:var(--muted); overflow:hidden; text-overflow:ellipsis; white-space:nowrap}
.ref-screen .segbar{display:flex; gap:2px; margin:8px 0 7px}
.ref-screen .segbar i{flex:1; height:7px; border-radius:2px; background:var(--lv0)}
.ref-screen .pct{font-family:var(--font-mono); font-size:13px; font-weight:700; color:var(--lv4)}
.ref-screen .rowsum{display:flex; align-items:center; gap:8px; font-size:11px; color:var(--muted)}
.ref-screen .rowsum .c{display:flex; align-items:center; gap:3px; font-family:var(--font-mono)}
.ref-screen .unitgroup{font-size:12px; color:var(--muted); font-weight:700; margin:14px 2px 7px}
.ref-screen .pastgroup{margin:14px 0 10px}
.ref-screen .pasthead{display:flex; align-items:center; gap:10px; min-height:52px; padding:10px 12px;
  background:var(--console); color:#EAF5F7; border-left:3px solid var(--signal);
  border-radius:var(--r)}
.ref-screen .pasthead::before{content:"EXAM"; display:grid; place-items:center; width:42px; height:24px;
  flex-shrink:0; border:1px solid #8DA9B4; border-radius:2px; color:#8DA9B4;
  font-family:var(--font-mono); font-size:8.5px; letter-spacing:.08em}
.ref-screen .pastgroup .sum{flex:1; min-width:0}
.ref-screen .pastgroup .sum .t{font-size:15px; font-weight:700}
.ref-screen .pastgroup .sum .d{font-size:11.5px; color:#8DA9B4; line-height:1.45}
.ref-screen .pastgroup .count{font-family:var(--font-mono); color:var(--signal); font-size:12px; font-weight:700}
.ref-screen .pastlist{padding-top:8px}
.ref-screen .relbtn{display:flex; align-items:center; gap:8px; width:100%; text-align:left;
  background:var(--surface); border-radius:8px; padding:11px 13px; margin:0 0 8px; font-size:14px}
.ref-screen .relbtn .ar{margin-left:auto; color:var(--muted)}
.ref-screen .relbtn.ulink{margin:6px 0 4px; font-size:13.5px; color:var(--accent)}
.ref-screen .relbtn.uback{color:var(--accent); font-weight:700}
.ref-screen .guide{background:var(--surface); border-radius:var(--r); padding:14px 15px; margin:0 0 14px;
  font-size:13.5px; line-height:1.95; color:var(--ink)}
.ref-screen .guide .lk{font-family:var(--font-mono); font-size:10.5px; letter-spacing:.12em;
  color:var(--accent); margin-bottom:7px}
.ref-screen .guide b{color:var(--accent)}
.ref-screen .legend{display:flex; gap:14px; justify-content:center; font-size:11.5px; color:var(--muted); margin-top:6px}
.ref-screen .legend b{font-family:var(--font-mono)}
.ref-screen .dist{display:grid; grid-template-columns:repeat(3,1fr); gap:8px}
.ref-screen .dist .d{background:var(--raise); border-radius:9px; padding:10px 6px; text-align:center}
.ref-screen .dist .d .v{font-size:20px; font-weight:700; font-family:var(--font-mono)}
.ref-screen .dist .d .p{font-size:10px; color:var(--muted)}
.ref-screen .dist .d .k{font-size:10.5px; margin-top:2px}
.ref-screen .note{font-size:11.5px; color:var(--muted); padding:2px 4px 20px}
.ref-screen .note code{font-family:var(--font-mono); background:var(--raise); padding:1px 5px; border-radius:4px}
.ref-screen .note a{color:var(--accent)}
.ref-screen .note label{display:block;margin-top:8px}

#tabs{display:flex; background:var(--console); border-top:2px solid var(--signal); flex-shrink:0;
  padding-bottom:env(safe-area-inset-bottom)}
#tabs button{flex:1; padding:9px 1px 8px; display:flex; flex-direction:column; align-items:center;
  gap:4px; color:#8DA9B4; font-size:9.5px; position:relative; min-height:58px;
  white-space:nowrap; overflow:hidden}
#tabs button.on{color:#FFFFFF; background:linear-gradient(180deg,var(--console-2),var(--console))}
#tabs button.on::before{content:""; position:absolute; top:0; left:24%; right:24%; height:2px;
  background:var(--signal); box-shadow:0 0 8px var(--signal)}
#tabs .ico{font-family:var(--font-mono); font-size:9px; line-height:1; letter-spacing:.08em;
  min-width:34px; height:20px; padding:0 5px; display:grid; place-items:center;
  border:1px solid currentColor; border-radius:2px}
#tabs{padding:0 0 env(safe-area-inset-bottom);gap:0}
#tabs button{background:transparent;border:none;border-radius:0;min-width:0;line-height:1.5}
main [hidden]{display:none!important}
main:has(#tabs:not([hidden]))>header{display:none}
main:has(#tabs:not([hidden])){background:var(--ground);color:var(--ink);font:14px/1.5 var(--font-jp)}
#page{overscroll-behavior:contain}

.brandcode{font-family:var(--font-mono); font-size:9px; letter-spacing:.18em;
  color:var(--accent); margin-bottom:2px}
.mission{position:relative; overflow:hidden; color:#EAF5F7; background:var(--console);
  border:1px solid var(--console-2); border-radius:var(--r); padding:16px; margin-bottom:10px;
  box-shadow:0 5px 0 rgba(9,44,60,.14)}
.mission::after{content:""; position:absolute; inset:0; pointer-events:none;
  background:repeating-linear-gradient(0deg,transparent 0 5px,rgba(255,255,255,.018) 5px 6px)}
.mission-top{display:flex; justify-content:space-between; align-items:flex-start; gap:16px}
.mission .k{font-family:var(--font-mono); color:#91B5C0; font-size:9.5px; letter-spacing:.14em}
.mission .v{font-family:var(--font-mono); font-size:39px; font-weight:700; line-height:1.05;
  letter-spacing:-.05em; margin-top:3px}
.mission .v small{font-size:15px; color:var(--signal); letter-spacing:0}
.countdown{text-align:right; font-family:var(--font-mono); font-size:24px; font-weight:700;
  color:var(--signal); line-height:1.1}
.countdown small{display:block; font-size:9px; color:#91B5C0; letter-spacing:.12em; margin-bottom:4px}
.trace{height:8px; padding:2px; border:1px solid #3E6673; margin:16px 0 10px;
  background:#061C25}
.trace i{display:block; height:100%; background:linear-gradient(90deg,var(--accent),#48D7CF);
  box-shadow:0 0 9px rgba(64,199,212,.6)}
.mission-foot{display:flex; justify-content:space-between; font-family:var(--font-mono);
  font-size:9px; color:#91B5C0; letter-spacing:.07em}
.tiles{display:grid; grid-template-columns:repeat(5,1fr); gap:5px; margin-top:10px}
.tile{background:var(--surface); border:1px solid var(--line); border-radius:2px;
  padding:9px 2px; text-align:center}
.tile .v{font-size:18px; font-weight:700; font-family:var(--font-mono); line-height:1.2}
.tile .k{font-family:var(--font-mono); font-size:8.5px; color:var(--muted); margin-top:3px}

.sec-t{font-family:var(--font-mono); font-size:10.5px; font-weight:700; color:var(--accent);
  letter-spacing:.14em; margin:19px 0 8px; padding:0 2px; text-transform:uppercase}


.start-choices{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-bottom:14px}
.start-choices button{min-height:52px;padding:12px 8px;background:var(--accent);color:var(--accent-ink);font-size:15px;font-weight:700;border-radius:6px}
.search-label{display:block;font-size:17px;font-weight:700;margin-bottom:10px}
#lesson-search{width:100%;min-height:48px;padding:10px;font-size:16px;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:6px}
main{font-family:var(--font-jp);background:var(--ground);color:var(--ink)}
main>header,#bar,#unit-rating{background:var(--console);color:var(--surface)}
#page:not(.ref-screen) .row,#bar button,#unit-rating button{background:var(--surface);color:var(--ink);border-color:var(--line);border-radius:var(--r)}
#page:not(.ref-screen) .primary,#bar .primary,#unit-rating button[aria-pressed=true]{background:var(--accent);color:var(--accent-ink)}
/* Match the reference reader footer across lessons, practice and review. */
#bar{flex:none;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 12px;
  padding:10px 16px max(10px,env(safe-area-inset-bottom));background:var(--surface);
  color:var(--ink);border-top:1px solid var(--line)}
#bar .primary{grid-column:1/-1;grid-row:1;width:100%;min-height:52px;padding:12px;
  font-size:16px;font-weight:700;border:0}
#bar button:not(.primary){grid-row:2;justify-self:start;min-height:40px;padding:8px 4px;
  border:0;background:transparent;color:var(--muted);font-size:13px;text-align:left}
#bar button:not(.primary)~button:not(.primary){justify-self:end;text-align:right}
#unit-rating{background:var(--surface);color:var(--ink);border-top:1px solid var(--line);padding:8px 16px 0}
#unit-rating:not([hidden])+#bar{border-top:0}
#unit-rating section{gap:6px}
#unit-rating section button{min-height:64px;border-radius:9px;font-size:12px;font-weight:700}
#unit-rating section button[aria-pressed=true]{border:2px solid currentColor}