:root {
  color-scheme: light dark;
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1f2430;
  --line: #2a3040;
  --fg: #e8eaf0;
  --muted: #98a0b3;
  --accent: #6aa9ff;
  --known: #37c07a;
  --again: #f0a03c;
  --danger: #e0574f;
  --radius: 14px;
  --jp: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo",
        "MS Gothic", "Malgun Gothic", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: env(safe-area-inset-top) 0 env(safe-area-inset-bottom);
  background: var(--bg);
  color: var(--fg);
  font: 15px/1.6 system-ui, "Malgun Gothic", sans-serif;
  min-height: 100vh;
}

[hidden] { display: none !important; }

/* ---------- 로그인 ---------- */

.login { display: grid; place-items: center; min-height: 100vh; padding: 24px; }

.login-card {
  width: 100%; max-width: 420px;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 32px 28px; text-align: center;
}
.login-card h1 { margin: 0 0 12px; font-size: 22px; }
.login-sub { color: var(--muted); font-size: 14px; margin: 0 0 24px; }
#google-button { display: flex; justify-content: center; min-height: 44px; }
.dev-login { margin-top: 8px; text-align: left; }
.dev-login hr { border: 0; border-top: 1px solid var(--line); margin: 20px 0 16px; }
.dev-login label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.dev-row { display: flex; gap: 8px; }
.dev-row input { flex: 1; min-width: 0; }

/* ---------- 상단 바 ---------- */

.top {
  display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: center;
  padding: 12px 18px; border-bottom: 1px solid var(--line); background: var(--panel);
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 5;
}
.brand { font-weight: 700; letter-spacing: -0.2px; }

.levels { display: flex; gap: 6px; }
.levels label { cursor: pointer; }
.levels input { position: absolute; opacity: 0; pointer-events: none; }
.levels span {
  display: inline-block; padding: 6px 13px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--panel-2);
  font-size: 13px; font-weight: 600; color: var(--muted); user-select: none;
}
.levels input:checked + span { background: var(--accent); border-color: var(--accent); color: #0b1220; }
.levels input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }

.top-right { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-left: auto; }
.toggle { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--muted); cursor: pointer; }
.user { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); }
.user img { width: 26px; height: 26px; border-radius: 50%; }

select, input[type="text"] {
  background: var(--panel-2); color: var(--fg);
  border: 1px solid var(--line); border-radius: 9px; padding: 7px 10px; font: inherit; font-size: 13px;
}

/* ---------- 버튼 ---------- */

.btn {
  background: var(--panel-2); color: var(--fg); border: 1px solid var(--line);
  border-radius: 10px; padding: 9px 15px; font: inherit; font-size: 14px;
  cursor: pointer; text-decoration: none; display: inline-flex;
  align-items: center; justify-content: center; gap: 6px; white-space: nowrap;
}
.btn:hover { border-color: var(--accent); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; border-color: var(--line); }
.btn.ghost { background: transparent; }
.btn.known { background: var(--known); border-color: var(--known); color: #06240f; font-weight: 700; }
.btn.again { background: var(--again); border-color: var(--again); color: #2a1a00; font-weight: 700; }
.btn.danger { background: transparent; border-color: var(--danger); color: var(--danger); }
.btn.nav { min-width: 92px; }

/* ---------- 학습 무대 ---------- */

.stage { max-width: 760px; margin: 0 auto; padding: 22px 18px 40px; }

.progress { margin-bottom: 14px; }
.progress-bar { height: 5px; background: var(--panel-2); border-radius: 999px; overflow: hidden; }
#progress-fill { height: 100%; width: 0; background: var(--accent); transition: width 0.18s; }
.progress-text {
  display: flex; justify-content: space-between; gap: 12px;
  font-size: 12.5px; color: var(--muted); margin-top: 7px;
}

.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 18px;
  padding: 22px 22px 18px; min-height: 340px;
  display: flex; flex-direction: column; gap: 18px;
}
.card:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.card-head { display: flex; gap: 8px; }
.badge {
  font-size: 12px; font-weight: 700; padding: 3px 10px; border-radius: 999px;
  background: var(--panel-2); border: 1px solid var(--line); color: var(--muted);
}
.badge.status.known { color: var(--known); border-color: var(--known); }
.badge.status.again { color: var(--again); border-color: var(--again); }

.card-body { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 16px; text-align: center; }

.term {
  font-family: var(--jp);
  font-size: clamp(38px, 11vw, 66px);
  font-weight: 600; line-height: 1.25; letter-spacing: 1px;
  word-break: keep-all; margin: 6px 0;
}
.term .variant-sep { color: var(--muted); font-weight: 400; margin: 0 6px; }

.reveal-row { width: 100%; }
.reveal {
  width: 100%; background: transparent; color: var(--muted);
  border: 1px dashed var(--line); border-radius: 10px;
  padding: 11px; font: inherit; font-size: 13px; cursor: pointer;
}
.reveal:hover { border-color: var(--accent); color: var(--accent); }

.reading { font-family: var(--jp); font-size: clamp(22px, 6vw, 30px); color: var(--accent); }
.meaning { font-size: clamp(16px, 4vw, 19px); line-height: 1.55; }

.card-tools { display: flex; flex-wrap: wrap; gap: 9px; justify-content: center; }

.controls { display: flex; flex-wrap: wrap; gap: 9px; justify-content: center; margin-top: 16px; }

.empty {
  margin: 20px 0 0; padding: 16px; text-align: center; color: var(--muted);
  background: var(--panel); border: 1px dashed var(--line); border-radius: var(--radius);
}

.hints { margin-top: 22px; text-align: center; font-size: 12px; color: var(--muted); line-height: 2; }
kbd {
  background: var(--panel-2); border: 1px solid var(--line); border-bottom-width: 2px;
  border-radius: 5px; padding: 1px 6px; font: inherit; font-size: 11px; margin: 0 2px;
}

.notice, .error { font-size: 13px; line-height: 1.6; }
.notice { color: var(--again); }
.error { color: var(--danger); }
code { background: var(--panel-2); padding: 1px 5px; border-radius: 5px; font-size: 12.5px; }

/* ---------- 통계 ---------- */

dialog {
  background: var(--panel); color: var(--fg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px; max-width: 560px; width: calc(100% - 32px);
}
dialog::backdrop { background: rgba(0, 0, 0, 0.6); }
dialog h2 { margin: 0 0 16px; font-size: 18px; }
#stats-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
#stats-table th, #stats-table td { padding: 8px 6px; text-align: right; border-bottom: 1px solid var(--line); }
#stats-table th:first-child, #stats-table td:first-child { text-align: left; font-weight: 700; }
#stats-table th { color: var(--muted); font-weight: 600; font-size: 12px; }
#stats-table tfoot td { font-weight: 700; border-bottom: 0; }
.dialog-actions { display: flex; flex-wrap: wrap; gap: 9px; justify-content: flex-end; margin-top: 20px; }

/* ---------- 토스트 ---------- */

.toast {
  position: fixed; left: 50%; transform: translateX(-50%);
  bottom: calc(24px + env(safe-area-inset-bottom, 0px));
  background: var(--panel-2); border: 1px solid var(--line); border-radius: 999px;
  padding: 10px 18px; font-size: 13.5px; z-index: 50;
}

@media (max-width: 560px) {
  .top { padding: 10px 14px; }
  .top-right { width: 100%; }
  .stage { padding: 16px 14px 32px; }
  .btn.nav { min-width: 0; flex: 1; }
  .controls .btn { flex: 1 1 44%; }
  .hints { display: none; }
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f4f6fa; --panel: #ffffff; --panel-2: #eef1f7; --line: #d8dee9;
    --fg: #1a1f2b; --muted: #5f6b80; --accent: #2563eb;
    --known: #0f9d58; --again: #c9760a; --danger: #c62828;
  }
}