* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  font-family:
    Inter,
    "Noto Sans Thai",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  background: var(--bg);
  color: var(--text);
}

button,
input,
select {
  font: inherit;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 22px 14px;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.main-area {
  min-width: 0;
}

.topbar {
  height: 68px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.page-content {
  padding: 26px 28px 40px;
  max-width: 1600px;
  margin: 0 auto;
}

.page-header {
  margin-bottom: 22px;
}

.page-title {
  margin: 0;
  font-size: 26px;
  font-weight: 700;
}

.page-description {
  margin: 6px 0 0;
  color: var(--text-soft);
  font-size: 14px;
}