:root {
  color-scheme: light;
  --background: #f5f7fb;
  --surface: #ffffff;
  --surface-muted: #eef2f8;
  --text: #172033;
  --muted: #627089;
  --border: #dce3ee;
  --accent: #2457d6;
  --accent-strong: #173f9e;
  --danger: #a32424;
  --shadow: 0 16px 40px rgba(23, 32, 51, 0.08);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--background);
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at top right, rgba(36, 87, 214, 0.10), transparent 32rem),
    var(--background);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

a {
  color: var(--accent);
}

a:hover {
  color: var(--accent-strong);
}

.shell {
  width: min(1120px, calc(100% - 32px));
  margin-inline: auto;
}

.site-header {
  border-bottom: 1px solid rgba(220, 227, 238, 0.85);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(14px);
}

.header-inner,
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}

.brand-mark {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 11px;
  color: #fff;
  background: var(--accent);
  box-shadow: 0 8px 20px rgba(36, 87, 214, 0.24);
}

.service-state {
  color: var(--muted);
  font-size: 0.9rem;
}

.hero {
  max-width: 760px;
  padding: 72px 0 34px;
}

.eyebrow,
.label {
  margin: 0 0 7px;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 700px;
  margin: 0;
  font-size: clamp(2.35rem, 7vw, 4.7rem);
  line-height: 1.02;
  letter-spacing: -0.055em;
}

h2 {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.25;
}

.hero-copy {
  max-width: 680px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.address-card,
.panel,
.notice {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.address-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 20px;
  align-items: center;
  padding: 24px;
}

.address {
  margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: clamp(1rem, 3vw, 1.35rem);
  font-weight: 750;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.button {
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  background: var(--surface);
  font: inherit;
  font-weight: 750;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}

.button:hover:not(:disabled) {
  border-color: #b6c3d8;
  background: var(--surface-muted);
  transform: translateY(-1px);
}

.button:focus-visible,
.message-item:focus-visible {
  outline: 3px solid rgba(36, 87, 214, 0.28);
  outline-offset: 2px;
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.button.primary {
  border-color: var(--accent);
  color: #fff;
  background: var(--accent);
}

.button.primary:hover:not(:disabled) {
  border-color: var(--accent-strong);
  background: var(--accent-strong);
}

.button.compact {
  min-height: 38px;
  padding: 7px 13px;
  font-size: 0.9rem;
}

.small-note {
  grid-column: 1 / -1;
  min-height: 1.2em;
  margin: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.inbox-layout {
  display: grid;
  grid-template-columns: minmax(300px, 0.9fr) minmax(0, 1.4fr);
  gap: 22px;
  margin-top: 22px;
}

.panel {
  min-height: 460px;
  overflow: hidden;
}

.message-list-panel {
  padding: 20px;
}

.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.message-list {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.message-item {
  width: 100%;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 14px;
  color: inherit;
  background: #fff;
  text-align: left;
  cursor: pointer;
}

.message-item:hover {
  border-color: #b6c3d8;
  background: var(--surface-muted);
}

.message-item.is-unread {
  border-left: 4px solid var(--accent);
}

.message-item-subject {
  display: block;
  margin-bottom: 4px;
  font-weight: 800;
}

.message-item-line,
.message-item-intro {
  display: block;
  color: var(--muted);
  font-size: 0.86rem;
}

.message-item-intro {
  margin-top: 7px;
}

.message-viewer {
  padding: 24px;
}

.viewer-placeholder {
  display: grid;
  min-height: 410px;
  place-items: center;
  text-align: center;
}

.empty-state {
  padding: 26px;
  border: 1px dashed #c7d1e1;
  border-radius: 14px;
  color: var(--muted);
  background: #fafbfd;
}

.message-meta {
  display: grid;
  gap: 9px;
  margin: 20px 0;
  padding: 16px;
  border-radius: 14px;
  background: var(--surface-muted);
}

.message-meta div {
  display: grid;
  grid-template-columns: 85px minmax(0, 1fr);
  gap: 10px;
}

.message-meta dt {
  color: var(--muted);
  font-weight: 700;
}

.message-meta dd {
  margin: 0;
  overflow-wrap: anywhere;
}

.message-body {
  min-height: 220px;
  margin: 0;
  padding: 18px;
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text);
  background: #fbfcfe;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.92rem;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

.notice {
  margin: 22px 0 56px;
  padding: 24px;
}

.notice p {
  margin: 12px 0 0;
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  background: var(--surface);
  font-size: 0.9rem;
}

.noscript {
  position: fixed;
  inset: auto 16px 16px;
  padding: 14px 18px;
  border-radius: 12px;
  color: #fff;
  background: var(--danger);
  text-align: center;
}

@media (max-width: 780px) {
  .hero {
    padding-top: 54px;
  }

  .address-card,
  .inbox-layout {
    grid-template-columns: 1fr;
  }

  .address-card {
    align-items: start;
  }

  .panel {
    min-height: auto;
  }

  .viewer-placeholder {
    min-height: 260px;
  }
}

@media (max-width: 540px) {
  .shell {
    width: min(100% - 22px, 1120px);
  }

  .header-inner,
  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    padding-block: 14px;
  }

  .hero {
    padding-top: 42px;
  }

  .address-card,
  .message-list-panel,
  .message-viewer,
  .notice {
    padding: 18px;
  }

  .button-row,
  .button {
    width: 100%;
  }

  .message-meta div {
    grid-template-columns: 1fr;
    gap: 2px;
  }
}