:root {
  --bg: #f2f4f6;
  --paper: #ffffff;
  --ink: #101113;
  --muted: #5a5f66;
  --line: #d9d9db;
  --green: #990000;
  --green-dark: #720000;
  --green-soft: #f6eaea;
  --amber: #6b4d00;
  --amber-soft: #fff8e7;
  --red: #990000;
  --red-soft: #fbeeee;
  --radius: 7px;
  --shadow: 0 12px 32px rgb(16 17 19 / 8%);
  font-family: "Hiragino Sans", "Yu Gothic", "Noto Sans JP", sans-serif;
  color: var(--ink);
  background: var(--bg);
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-height: 100vh; background: var(--bg); }
button, input { font: inherit; }
button { cursor: pointer; }
a { color: inherit; }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.site-header { border-top: 4px solid var(--green); border-bottom: 1px solid var(--line); background: rgb(255 255 255 / 97%); }
.header-inner { max-width: 1120px; margin: 0 auto; padding: 13px 24px 14px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-year { display: block; margin: 0; color: var(--green); font-size: 10px; font-weight: 800; letter-spacing: .18em; }
.brand-name { display: block; margin: 2px 0 0; color: var(--ink); font-size: 17px; font-weight: 800; letter-spacing: .02em; }
.admin-link { color: var(--muted); font-size: 14px; font-weight: 700; text-underline-offset: 4px; }

.page-grid { max-width: 1120px; margin: 0 auto; padding: 38px 24px 60px; display: grid; grid-template-columns: minmax(0,1fr) 320px; gap: 32px; }
.page-grid.read-only { grid-template-columns: minmax(0, 780px); justify-content: center; }
.eyebrow { margin: 0 0 8px; color: var(--green); font-size: 13px; font-weight: 800; letter-spacing: .08em; }
h1 { margin: 0; padding-left: 14px; border-left: 5px solid var(--green); font-size: clamp(26px, 4vw, 34px); line-height: 1.3; letter-spacing: -.02em; }
.intro { max-width: 720px; margin: 12px 0 24px; color: var(--muted); font-size: 14px; line-height: 1.9; }

.notice { display: flex; gap: 12px; margin: 0 0 20px; padding: 16px; border: 1px solid #e2cea0; border-left: 4px solid #a87900; border-radius: var(--radius); background: var(--amber-soft); color: #574000; font-size: 14px; line-height: 1.7; }
.notice strong { display: block; }
.notice-icon { font-size: 20px; }
.recovery-panel { margin-bottom: 20px; padding: 14px 16px; }
.recovery-panel summary { cursor: pointer; color: var(--green); font-size: 14px; font-weight: 800; }
.recovery-panel[open] summary { margin-bottom: 10px; }
.recovery-panel .notice { margin: 12px 0 0; }
.inline-form { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 8px; }
.inline-form .button { min-height: 44px; }
.code-input { font-size: 24px; font-weight: 800; letter-spacing: .18em; text-align: center; }
.search-wrap { position: relative; display: block; margin-bottom: 14px; }
.search-wrap::before { content: "⌕"; position: absolute; left: 13px; top: 50%; transform: translateY(-52%); color: var(--muted); font-size: 22px; }
.input { width: 100%; height: 44px; padding: 8px 12px; border: 1px solid #c9cacc; border-radius: 5px; background: #fff; color: var(--ink); outline: none; transition: border-color .15s, box-shadow .15s; }
.search-wrap .input { padding-left: 42px; }
.input:focus { border-color: var(--green); box-shadow: 0 0 0 3px rgb(153 0 0 / 12%); }
.input[aria-invalid="true"] { border-color: var(--red); }
.date-filters { display: flex; gap: 8px; margin-bottom: 20px; overflow-x: auto; padding-bottom: 3px; scrollbar-width: thin; }
.filter-button { flex: 0 0 auto; padding: 8px 13px; border: 1px solid var(--line); border-radius: 4px; background: #fff; color: var(--muted); font-size: 12px; font-weight: 800; }
.filter-button.active { border-color: var(--green); background: var(--green); color: #fff; }

.sessions { display: grid; gap: 12px; }
.session-card { --card-padding: 18px; position: relative; display: block; width: 100%; overflow: hidden; padding: var(--card-padding); border: 1px solid var(--line); border-radius: var(--radius); background: #fff; cursor: pointer; transition: border-color .15s, box-shadow .15s, transform .15s; }
.session-card:hover { border-color: #b4494a; transform: translateY(-1px); }
.session-card.selected { border-color: var(--green); background: #fffafa; box-shadow: inset 4px 0 0 var(--green), 0 0 0 1px rgb(153 0 0 / 8%); }
.session-card.disabled { cursor: default; }
.session-card.disabled:hover { border-color: var(--line); transform: none; }
.session-row { display: grid; grid-template-columns: 20px minmax(0, 1fr); align-items: start; gap: 12px; width: 100%; }
.session-check { width: 20px; height: 20px; margin: 3px 0 0; accent-color: var(--green); flex: 0 0 auto; }
.session-body { min-width: 0; width: 100%; }
.session-top { display: block; width: 100%; min-height: 30px; padding-right: 140px; }
.session-top > .badge { position: absolute; top: var(--card-padding); right: var(--card-padding); }
.seminar-code { display: block; margin-bottom: 2px; color: var(--muted); font-size: 11px; font-weight: 800; }
.teacher { margin: 0; font-size: 17px; }
.badge { display: inline-flex; flex: 0 0 auto; padding: 5px 10px; border-radius: 3px; background: var(--green-soft); color: var(--green-dark); font-size: 12px; font-weight: 800; white-space: nowrap; }
.badge.wait { background: #fff0cc; color: var(--amber); }
.meta { display: flex; flex-wrap: wrap; gap: 7px 16px; margin-top: 12px; color: var(--muted); font-size: 13px; }
.note { margin: 9px 0 0; color: var(--muted); font-size: 12px; }
.empty, .loading { padding: 30px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; color: var(--muted); text-align: center; font-size: 14px; }

.application { position: sticky; top: 20px; align-self: start; padding: 20px; border: 1px solid var(--line); border-top: 4px solid var(--green); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow); }
.summary-title { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.summary-title h2 { margin: 0; font-size: 16px; }
.count { padding: 5px 10px; border-radius: 999px; background: var(--green); color: #fff; font-size: 12px; font-weight: 800; }
.summary-empty { margin: 28px 0; color: var(--muted); text-align: center; font-size: 14px; }
.selected-list { max-height: 240px; margin: 18px 0; padding: 0; list-style: none; overflow-y: auto; }
.selected-list li { margin-top: 8px; padding: 10px 12px; border-left: 3px solid var(--green); border-radius: 3px; background: var(--green-soft); font-size: 13px; line-height: 1.5; }
.selected-list small { color: var(--muted); }
.field-label { display: block; margin: 18px 0 7px; font-size: 13px; font-weight: 800; }
.field-help { margin: 7px 0 0; color: var(--muted); font-size: 11px; line-height: 1.7; }
.form-trap { position: absolute !important; left: -10000px !important; width: 1px !important; height: 1px !important; overflow: hidden !important; }
.error { margin: 14px 0 0; padding: 10px 12px; border-radius: 9px; background: var(--red-soft); color: var(--red); font-size: 13px; line-height: 1.6; }
.button { min-height: 42px; padding: 9px 16px; border: 1px solid transparent; border-radius: 4px; background: var(--green); color: #fff; font-weight: 800; letter-spacing: .02em; transition: opacity .15s, background .15s; }
.button:hover { background: var(--green-dark); }
.button:disabled { cursor: not-allowed; opacity: .45; }
.button.block { width: 100%; margin-top: 18px; }
.button.secondary { border-color: var(--line); background: #fff; color: var(--ink); }
.button.secondary:hover { background: #f2f4f6; }
.button.danger { background: #fff; border-color: #e7bcbc; color: var(--red); }

.mobile-bar { display: none; }
.success-shell { min-height: calc(100vh - 62px); display: grid; place-items: center; padding: 40px 20px; }
.success-card { width: min(100%, 580px); padding: 34px; border: 1px solid var(--line); border-top: 5px solid var(--green); border-radius: 8px; background: #fff; box-shadow: 0 18px 60px rgb(16 17 19 / 10%); }
.success-icon { width: 48px; height: 48px; display: grid; place-items: center; border-radius: 4px; background: var(--green); color: #fff; font-size: 26px; font-weight: 800; }
.success-card h1 { margin-top: 18px; font-size: 26px; }
.success-card .intro { margin-bottom: 18px; }
.success-actions { display: flex; gap: 10px; margin-top: 22px; }
.success-actions .button { flex: 1; }

.simple-main { max-width: 900px; margin: 0 auto; padding: 30px 20px 60px; }
.back-link { display: inline-flex; margin-bottom: 18px; color: var(--muted); font-size: 14px; font-weight: 700; }
.panel { padding: 22px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
.panel + .panel { margin-top: 16px; }
.panel h2, .panel h3 { margin: 0; }
.status-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.sticky-save { position: sticky; bottom: 0; margin-top: 20px; padding: 14px 0; background: rgb(242 244 246 / 96%); backdrop-filter: blur(8px); }

.login-shell { min-height: 100vh; display: grid; place-items: center; padding: 20px; border-top: 6px solid var(--green); background: var(--bg); }
.login-card { width: min(100%, 390px); padding: 28px; border: 1px solid var(--line); border-top: 4px solid var(--green); border-radius: 8px; background: #fff; box-shadow: var(--shadow); }
.login-card h1 { margin-top: 0; font-size: 26px; }
.admin-main { max-width: 1200px; margin: 0 auto; padding: 26px 20px 60px; }
.tabs { display: flex; gap: 8px; margin-bottom: 20px; overflow-x: auto; }
.tab { flex: 0 0 auto; padding: 9px 15px; border: 1px solid var(--line); border-radius: 4px; background: #fff; color: var(--muted); font-size: 13px; font-weight: 800; }
.tab.active { border-color: var(--green); background: var(--green); color: #fff; }
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 18px; }
.metric { padding: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
.metric-label { color: var(--muted); font-size: 12px; }
.metric-value { margin-top: 6px; font-size: 30px; font-weight: 800; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
table { width: 100%; border-collapse: collapse; min-width: 720px; font-size: 13px; }
th { padding: 11px 14px; background: #eff0f2; color: var(--muted); text-align: left; font-size: 11px; }
td { padding: 12px 14px; border-top: 1px solid var(--line); }
.number { text-align: right; }
.capacity-input { width: 88px; height: 36px; }
.toolbar { display: flex; gap: 10px; margin-bottom: 14px; }
.toolbar .search-wrap { flex: 1; margin: 0; }
.settings-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.switch-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 16px; border: 1px solid var(--line); border-radius: 12px; }
.switch-row input { width: 22px; height: 22px; accent-color: var(--green); }
.phase-options { display: grid; gap: 10px; margin: 0; padding: 0; border: 0; }
.phase-option { display: flex; align-items: center; gap: 14px; padding: 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; cursor: pointer; }
.phase-option:has(input:checked) { border-color: var(--green); background: var(--green-soft); box-shadow: 0 0 0 2px rgb(153 0 0 / 8%); }
.phase-option input { width: 20px; height: 20px; margin: 0; accent-color: var(--green); }
.phase-option span { display: grid; gap: 4px; }
.phase-option small { color: var(--muted); line-height: 1.5; }
.mail-failures { margin-top: 18px; }
.section-divider { border: 0; border-top: 1px solid var(--line); margin: 32px 0; }

@media (max-width: 820px) {
  .header-inner { padding-inline: 16px; }
  .page-grid { display: block; padding: 26px 16px 100px; }
  .application { position: static; margin-top: 28px; }
  .mobile-bar { position: fixed; z-index: 20; left: 0; right: 0; bottom: 0; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 16px calc(10px + env(safe-area-inset-bottom)); border-top: 3px solid var(--green); background: rgb(255 255 255 / 97%); backdrop-filter: blur(8px); }
  .mobile-bar p { margin: 0; }
  .mobile-bar small { color: var(--muted); }
  .mobile-bar .button { flex: 0 0 auto; }
  .metrics { grid-template-columns: 1fr; }
  .settings-grid { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .session-card { --card-padding: 15px; }
  .success-card { padding: 24px; }
  .success-actions, .toolbar { flex-direction: column; }
  .inline-form { grid-template-columns: 1fr; }
}