:root {
  --bg: #f4f6f9;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #d9dee5;
  --border-strong: #b9c2cd;
  --text: #1d2530;
  --text-soft: #5b6675;
  --text-faint: #8a94a3;
  --primary: #1565c0;
  --primary-dark: #0d47a1;
  --primary-soft: #e7f0fb;
  --accent: #00897b;
  --danger: #c62828;
  --ok: #2e7d32;
  --shadow: 0 1px 3px rgba(20, 30, 45, .08), 0 6px 18px rgba(20, 30, 45, .06);
  --radius: 10px;
  --radius-sm: 6px;
  --maxw: 1080px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
    "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans KR",
    "Noto Sans JP", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Top navigation bar ---------- */
.topnav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 18px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 2px rgba(20, 30, 45, .05);
}
.topnav .brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 15px;
  color: var(--text);
  white-space: nowrap;
}
.topnav .brand .logo {
  width: 26px; height: 26px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: grid; place-items: center;
  font-size: 14px; font-weight: 800;
}
.topnav .spacer { flex: 1 1 auto; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 13px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s, border-color .15s;
  white-space: nowrap;
}
.btn:hover { background: var(--surface-2); text-decoration: none; }
.btn-primary {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); }
.btn-accent {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn-accent:hover { filter: brightness(.94); }

.lang-select {
  position: relative;
}
.lang-select select {
  appearance: none;
  padding: 7px 30px 7px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'><path d='M2 4l4 4 4-4' fill='none' stroke='%235b6675' stroke-width='1.6'/></svg>") no-repeat right 9px center;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
}

/* ---------- Layout ---------- */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 22px 18px 60px;
}
.page-head { margin-bottom: 18px; }
.page-head h1 {
  margin: 0 0 4px;
  font-size: 22px;
  letter-spacing: .2px;
}
.page-head .sub {
  color: var(--text-soft);
  font-size: 14px;
}
.crumbs {
  font-size: 13px;
  color: var(--text-faint);
  margin-bottom: 8px;
}
.crumbs a { color: var(--text-soft); }

/* ---------- Cards ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px 22px;
  margin-bottom: 18px;
}
.card h2 {
  margin: 0 0 14px;
  font-size: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.card h2 .tag {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-soft);
  padding: 2px 8px;
  border-radius: 20px;
}

/* ---------- Form ---------- */
.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 20px;
}
.field { display: flex; flex-direction: column; gap: 5px; }
.field label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-soft);
}
.field .hint { font-size: 11.5px; color: var(--text-faint); }
.field input,
.field select {
  padding: 9px 11px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-size: 14px;
  width: 100%;
}
.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-soft);
}
.field .unit { font-size: 12px; color: var(--text-faint); }

.actions {
  display: flex;
  gap: 10px;
  margin-top: 18px;
  flex-wrap: wrap;
}

/* ---------- Results ---------- */
.result-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.result-table th,
.result-table td {
  text-align: left;
  padding: 9px 10px;
  border-bottom: 1px solid var(--border);
}
.result-table th {
  color: var(--text-soft);
  font-weight: 600;
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: .4px;
}
.result-table td.val {
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--text);
}
.result-table tr.total td {
  border-top: 2px solid var(--border-strong);
  border-bottom: none;
  font-weight: 800;
  background: var(--surface-2);
}
.result-table tr.total td.val { color: var(--primary-dark); font-size: 15px; }

.note {
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--text-soft);
  background: var(--surface-2);
  border-left: 3px solid var(--border-strong);
  padding: 10px 12px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.note b { color: var(--text); }

/* ---------- Monthly radiation (details) ---------- */
.monthly {
  margin-top: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  padding: 10px 14px;
}
.monthly > summary {
  cursor: pointer;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--primary);
}
.monthly > summary:focus { outline: none; }
.monthly .hint {
  font-size: 12px;
  color: var(--text-soft);
  margin: 8px 0 12px;
  line-height: 1.5;
}
.month-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px 16px;
  margin-bottom: 12px;
}
.btn-small {
  padding: 6px 11px;
  font-size: 12.5px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
}
.btn-small:hover { background: var(--surface-2); }

/* ---------- Home / module grid ---------- */
.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.module-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
  transition: transform .12s, border-color .12s, box-shadow .12s;
  color: var(--text);
}
.module-card:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
  text-decoration: none;
  box-shadow: 0 4px 10px rgba(20,30,45,.1), 0 14px 30px rgba(20,30,45,.08);
}
.module-card .ico {
  width: 40px; height: 40px;
  border-radius: 9px;
  background: var(--primary-soft);
  color: var(--primary);
  display: grid; place-items: center;
  font-size: 20px;
  margin-bottom: 12px;
}
.module-card h3 { margin: 0 0 6px; font-size: 16px; }
.module-card p { margin: 0; color: var(--text-soft); font-size: 13px; }
.module-card .status {
  display: inline-block;
  margin-top: 10px;
  font-size: 11.5px;
  font-weight: 700;
  color: var(--ok);
  background: #e7f5e9;
  padding: 2px 9px;
  border-radius: 20px;
}
.module-card .status.soon {
  color: #8a6d00;
  background: #fbf3d6;
}

footer.foot {
  text-align: center;
  color: var(--text-faint);
  font-size: 12.5px;
  padding: 24px 12px 40px;
}

@media (max-width: 720px) {
  .form-grid { grid-template-columns: 1fr; }
  .topnav .brand span.full { display: none; }
}