*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background var(--transition), color var(--transition);
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--color-primary);
  color: #fff;
  padding: 8px 16px;
  z-index: 1000;
}

.skip-link:focus {
  top: 0;
}

.header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
}

nav {
  display: flex;
  gap: 4px;
  flex: 1;
}

.tab {
  background: none;
  border: none;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  transition: background var(--transition), color var(--transition);
}

.tab:hover {
  background: var(--color-border);
  color: var(--color-text);
}

.tab.active {
  background: var(--color-primary);
  color: #fff;
}

#theme-toggle {
  background: none;
  border: 2px solid var(--color-border);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color var(--transition);
}

#theme-toggle:hover {
  border-color: var(--color-primary);
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 20px;
  flex: 1;
  width: 100%;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

.card {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  margin-bottom: 16px;
}

.card h2 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  color: var(--color-text);
}

.footer {
  text-align: center;
  padding: 16px;
  color: var(--color-text-secondary);
  font-size: 0.8rem;
  border-top: 1px solid var(--color-border);
  margin-top: 20px;
}

@media (max-width: 600px) {
  .header-inner {
    flex-wrap: wrap;
    gap: 8px;
  }
  nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
  }
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}