* {
  box-sizing: border-box;
}

:root {
  font-family: "Segoe UI", "Segoe UI Variable", Arial, sans-serif;
  color: #242424;
  background: #f5f5f5;
  font-synthesis: none;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(ellipse at 15% 10%, rgba(0, 120, 212, 0.10), transparent 35%),
    radial-gradient(ellipse at 90% 90%, rgba(134, 97, 185, 0.10), transparent 32%),
    #f5f5f5;
}

.page-shell {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 32px 20px;
}

.welcome-card {
  width: min(100%, 520px);
  padding: 48px;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08), 0 2px 6px rgba(0, 0, 0, 0.04);
  text-align: center;
  backdrop-filter: blur(16px);
}

.theme-toggle {
  display: block;
  margin: 0 0 20px auto;
  padding: 8px 12px;
  border: 1px solid #8a8886;
  border-radius: 6px;
  background: #fff;
  color: #242424;
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.theme-toggle:focus-visible {
  outline: 2px solid #0078d4;
  outline-offset: 3px;
}

body.dark-mode {
  background:
    radial-gradient(ellipse at 15% 10%, rgba(0, 120, 212, 0.14), transparent 35%),
    radial-gradient(ellipse at 90% 90%, rgba(134, 97, 185, 0.14), transparent 32%),
    #1b1a19;
}

.dark-mode .welcome-card {
  border-color: #484644;
  background: rgba(41, 40, 39, 0.94);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.3), 0 2px 6px rgba(0, 0, 0, 0.2);
}

.dark-mode .title,
.dark-mode .button-secondary,
.dark-mode .theme-toggle {
  color: #f5f5f5;
}

.dark-mode .eyebrow,
.dark-mode .description,
.dark-mode .time-label {
  color: #c8c6c4;
}

.dark-mode .time-panel {
  border-color: #484644;
  background: #323130;
}

.dark-mode .button-secondary,
.dark-mode .theme-toggle {
  border-color: #8a8886;
  background: #292827;
}

.dark-mode .button-secondary:hover,
.dark-mode .theme-toggle:hover {
  background: #3b3a39;
}

.brand-mark {
  display: grid;
  width: 52px;
  height: 52px;
  margin: 0 auto 24px;
  place-items: center;
  border-radius: 14px;
  background: #e8f3fc;
  color: #0078d4;
  font-size: 25px;
}

.eyebrow {
  margin: 0 0 8px;
  color: #616161;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.title {
  margin: 0;
  color: #242424;
  font-size: clamp(32px, 7vw, 44px);
  font-weight: 600;
  letter-spacing: -0.035em;
}

.description {
  margin: 12px 0 32px;
  color: #616161;
  font-size: 15px;
  line-height: 1.6;
}

.time-panel {
  padding: 18px 20px;
  border: 1px solid #e1e1e1;
  border-radius: 8px;
  background: #fafafa;
}

.link-tabs {
  margin-top: 24px;
  text-align: left;
}

.tab-list {
  display: flex;
  gap: 8px;
  border-bottom: 1px solid #e1e1e1;
}

.tab-button {
  padding: 10px 12px;
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: #616161;
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.tab-button[aria-selected="true"] {
  border-bottom-color: #0078d4;
  color: #0078d4;
}

.tab-button:focus-visible {
  outline: 2px solid #0078d4;
  outline-offset: 2px;
}

.tab-panel {
  min-height: 72px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 16px;
}

.dark-mode .tab-list {
  border-bottom-color: #484644;
}

.dark-mode .tab-button {
  color: #c8c6c4;
}

.dark-mode .tab-button[aria-selected="true"] {
  color: #60cdff;
  border-bottom-color: #60cdff;
}

.button {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 150ms ease, box-shadow 150ms ease;
}

.button-primary {
  background: #0078d4;
  color: #fff;
}

.button-primary:hover {
  background: #106ebe;
}

.button-secondary {
  border-color: #8a8886;
  background: #fff;
  color: #242424;
}

.button-secondary:hover {
  background: #f3f2f1;
}

.button:focus-visible {
  outline: 2px solid #0078d4;
  outline-offset: 3px;
}

.time-label {
  color: #616161;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

#currentTime {
  margin: 8px 0 0;
  color: #0078d4;
  font-size: clamp(16px, 4vw, 20px);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 480px) {
  .welcome-card {
    padding: 36px 24px;
  }
}