:root {
  color-scheme: light;
  --bg: #f6f8fb;
  --text: #17202a;
  --muted: #5f6b7a;
  --line: #d9e0e8;
  --panel: #ffffff;
  --accent: #16736b;
  --accent-dark: #0f5c55;
  --warn: #a85d00;
  --danger: #b42318;
  --ok: #0b7a45;
  --soft-ok: #e8f6ef;
  --soft-warn: #fff4e2;
  --soft-danger: #fff0ee;
  --soft-info: #eef5ff;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

.shell {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0 56px;
}

.hero {
  padding: 22px 0 28px;
}

.eyebrow,
.label {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 700;
}

h1,
h2,
h3,
p {
  letter-spacing: 0;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 6vw, 3.75rem);
  line-height: 1.12;
}

h2 {
  margin: 0 0 8px;
  font-size: 1.35rem;
}

h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.lead {
  max-width: 760px;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.8;
}

.panel,
.status-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 10px 26px rgba(23, 32, 42, 0.06);
}

.form-panel {
  display: grid;
  grid-template-columns: 0.9fr 1.4fr;
  gap: 24px;
  align-items: start;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 700;
}

.input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
}

input {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 14px;
  font-size: 1rem;
}

button {
  min-height: 48px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  padding: 0 18px;
  font-weight: 700;
  cursor: pointer;
}

button:hover {
  background: var(--accent-dark);
}

.error {
  min-height: 24px;
  margin: 8px 0 0;
  color: var(--danger);
  font-weight: 700;
}

.result {
  margin-top: 24px;
}

.hidden {
  display: none !important;
}

.status-card {
  margin-bottom: 16px;
}

.status-card.configured {
  background: var(--soft-ok);
  border-color: #a8dec5;
}

.status-card.action_required {
  background: var(--soft-warn);
  border-color: #f2c27d;
}

.status-card.unsupported,
.status-card.dns_error {
  background: var(--soft-danger);
  border-color: #f3b3ad;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.copy-box {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: center;
  margin-top: 16px;
  padding: 12px;
  background: #f2f6f9;
  border: 1px solid var(--line);
  border-radius: 8px;
}

code {
  overflow-wrap: anywhere;
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-size: 0.95rem;
}

.feedback {
  margin: 8px 0 0;
  color: var(--ok);
  font-weight: 700;
}

.definition-list {
  margin: 0;
}

.definition-list div {
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.definition-list div:first-child {
  border-top: 0;
  padding-top: 0;
}

dt {
  color: var(--muted);
  font-size: 0.9rem;
}

dd {
  margin: 4px 0 0;
  overflow-wrap: anywhere;
  font-weight: 700;
}

.dns-details {
  margin-top: 16px;
}

summary {
  cursor: pointer;
  font-weight: 800;
}

.dns-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 18px;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 16px;
}

.dns-summary {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.dns-summary::before {
  content: "診断サマリー";
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.summary-item {
  display: grid;
  gap: 4px;
  align-content: center;
  min-height: 86px;
  padding: 14px 16px;
  background: #f7fafc;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.summary-number {
  color: var(--text);
  font-size: 1.65rem;
  font-weight: 800;
  line-height: 1;
}

.summary-number::after {
  content: "件";
  margin-left: 2px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.summary-label {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
}

.summary-item:has(#summary-secure-ns) {
  background: var(--soft-ok);
  border-color: #a8dec5;
}

.summary-item:has(#summary-secure-mail) {
  background: var(--soft-warn);
  border-color: #f2c27d;
}

.dns-summary .summary-item:nth-child(1) {
  background: var(--soft-ok);
  border-color: #a8dec5;
}

.dns-summary .summary-item:nth-child(3) {
  background: var(--soft-warn);
  border-color: #f2c27d;
}

.summary-grid div,
.result-badges span {
  background: #f2f6f9;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
}

.summary-grid strong {
  display: block;
  font-size: 1.6rem;
}

.summary-grid span {
  color: var(--muted);
  font-size: 0.9rem;
}

.dns-result-list {
  display: grid;
  gap: 16px;
  margin-top: 16px;
}

.dns-result-card.dns_error {
  border-color: #f3b3ad;
  background: var(--soft-danger);
}

.result-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0;
}

.notice {
  margin-top: 12px;
  padding: 14px;
  background: var(--soft-warn);
  border: 1px solid #f2c27d;
  border-radius: 8px;
}

.dns-details-inline {
  margin-top: 14px;
}

.dns-details-inline h4 {
  margin: 0 0 8px;
}

ul {
  margin: 0;
  padding-left: 18px;
}

li {
  margin: 8px 0;
  overflow-wrap: anywhere;
}

.fallback,
.faq {
  margin-top: 24px;
}

.faq h2 {
  margin-bottom: 12px;
}

.faq details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px 20px;
  margin-top: 10px;
}

.faq details.faq-section-break {
  margin-top: 10px;
}

.faq details.faq-section-break summary {
  margin-top: 10px;
  margin-bottom: 10px;
}

.faq details.faq-section-break p {
  margin-top: 6px;
  margin-bottom: 6px;
}

.faq p,
.fallback p,
.panel p {
  color: var(--muted);
  line-height: 1.75;
}

@media (max-width: 760px) {
  .shell {
    width: min(100% - 20px, 1080px);
    padding-top: 20px;
  }

  .form-panel,
  .input-row,
  .grid,
  .summary-grid,
  .dns-summary,
  .dns-grid,
  .copy-box {
    grid-template-columns: 1fr;
  }

  button {
    width: 100%;
  }

  .panel,
  .status-card {
    padding: 18px;
  }
}