/* ===== リセット ===== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ===== 全体レイアウト ===== */
html, body {
  min-height: 100vh;
  width: 100vw;
  overflow-x: hidden;
  overflow-y: auto;
  background: linear-gradient(135deg, #d9ead3, #e7f1e9);
  color: #1a3d2f;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  box-sizing: border-box;
  text-align: center;
  user-select: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  height: 100vh;
  margin: 0;
}

/* ===== コンテナ ===== */
.container {
  width: 100%;
  max-width: 960px;
  padding: 0 1rem;
  box-sizing: border-box;
}

/* ===== タイトル ===== */
h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: #145214;
  letter-spacing: 0.1em;
  text-align: center;
  text-transform: uppercase;
  font-family: "Montserrat", sans-serif;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
}

/* ===== ゾーン全体のグリッド ===== */
.zones {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, auto);
  gap: 2rem;
  justify-items: center;
  align-items: start;
  width: 100%;
  max-width: 960px;
}

/* ===== 各ゾーンカード ===== */
.zone-card {
  background-color: #c3e0c8;
  border-radius: 12px;
  padding: 1.5rem 2rem;
  box-shadow: 0 4px 8px rgba(0, 121, 61, 0.25);
  text-align: center;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
  width: 100%;
  max-width: 440px;
  min-height: 180px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  cursor: default;
}

.zone-card:hover {
  background-color: #a0c7a0;
  box-shadow: 0 6px 12px rgba(0, 121, 61, 0.45);
}

.zone-name {
  font-size: 1.4rem;
  margin-bottom: 0.2rem;
  font-weight: 700;
  color: #145214;
}

.zone-offset {
  font-size: 1rem;
  color: #405c33;
  margin-bottom: 0.6rem;
  min-width: 70px;
  font-variant-numeric: tabular-nums;
}

.date {
  font-size: 1rem;
  color: #405c33;
  margin-bottom: 0.4rem;
}

.time {
  font-size: 2.2rem;
  font-family: monospace;
  font-weight: bold;
  color: #264d25;
  white-space: nowrap;
}

/* ===== カウントダウン表示 ===== */
#countdown {
  font-size: 3.8rem;
  font-weight: 700;
  font-family: "Courier New", Courier, monospace;
  color: #264d25;
  background-color: #c3e0c8;
  padding: 1rem 2rem;
  border-radius: 1rem;
  box-shadow: 0 6px 14px rgba(0, 121, 61, 0.3);
  user-select: text;
  letter-spacing: 0.12em;
  min-width: 320px;
  max-width: 90vw;
  transition: background-color 0.3s ease;
}

#countdown:hover {
  background-color: #a0c7a0;
  box-shadow: 0 8px 18px rgba(0, 121, 61, 0.5);
}

/* ===== メッセージ ===== */
#message {
  margin-top: 1rem;
  font-size: 1.4rem;
  font-weight: 600;
  color: #405c33;
  text-shadow: 1px 1px 1px rgba(0,0,0,0.1);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

/* ===== モバイル対応 ===== */
@media screen and (max-width: 768px) {
  html, body {
    padding: 1rem;
    justify-content: flex-start;
  }

  h1 {
    font-size: 2rem;
  }

  .container {
    max-width: 100%;
    padding: 0 0.5rem;
  }

  .zones {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .zone-card {
    min-height: 140px;
    padding: 1rem 1.5rem;
    max-width: 100%;
  }

  .zone-name {
    font-size: 1.1rem;
  }

  .zone-offset {
    font-size: 0.9rem;
    min-width: auto;
    margin-bottom: 0.4rem;
  }

  .date {
    font-size: 0.9rem;
    margin-bottom: 0.3rem;
  }

  .time {
    font-size: 1.6rem;
  }

  #countdown {
    font-size: 2.8rem;
    padding: 0.8rem 1.5rem;
    min-width: 260px;
  }

  #message {
    font-size: 1.1rem;
  }
}