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

:root {
  --gap: 0.25rem;
  --padding: 1rem;
  --content-width: min(90vw, 560px);
}

html,
body {
  height: 100%;
  width: 100%;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: "Hachi Maru Pop", cursive;
}

.page {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--gap);
}

.page-header {
  width: 100%;
  max-width: var(--content-width);
  text-align: left;
  padding: var(--padding);
}

.header-content {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.page-header h1 {
  font-size: clamp(1.5rem, 3vw, 2.5rem);
  line-height: 1;
}

.page-header p {
  margin-top: 0.5rem;
  font-size: clamp(1rem, 2.5vw, 1.5rem);
  line-height: 1.3;
}

.month-select {
  padding: 0.5rem 1rem;
  border: 2px solid #111;
  font-family: inherit;
  font-size: 1rem;
  font-weight: bold;
  background-color: #fff;
  cursor: pointer;
  appearance: none;
}

.month-select:hover {
  background-color: #eee;
}

.month-select:focus {
  outline: none;
  box-shadow: 0 0 0 4px rgba(0, 0, 0, 0.1);
}

.grid-section {
  width: 100%;
  display: flex;
  justify-content: center;
  padding: var(--padding);
}

.grid {
  display: grid;
  width: 100%;
  max-width: var(--content-width);
  aspect-ratio: 1;
  grid-template-columns: repeat(7, 1fr);
  grid-template-rows: repeat(7, 1fr);
  gap: var(--gap);
  padding: var(--padding);
}

.item {
  display: block;
  min-width: 0;
  min-height: 0;
  background-size: cover;
  background-position: center;
  text-decoration: none;
}

.item:focus-visible {
  outline: 2px solid #111;
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 720px) {
  :root {
    --gap: 6px;
  }
}