@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@300;500;700&display=swap');

/* ===== Base ===== */
html, body {
  height: 100%;
  min-height: 100vh;
  margin: 0;
  padding: 0;
  font-family: 'Noto Sans TC', sans-serif;
  background: url('https://www.yzu.edu.tw/library/lib-Tour/image/background.jpg') no-repeat center center fixed;
  background-size: cover;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ===== Card ===== */
.container {
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: blur(15px);
  border-radius: 20px;
  padding: 3rem 8rem;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
  text-align: center;
  color: #333;
  max-width: 90vw;
  width: 400px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 1s ease, transform 1s ease;
  will-change: transform, opacity;
}
.container.show { opacity: 1; transform: translateY(0); }

h1 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 2rem;
  color: #222;
}

/* ===== Language Buttons (clean, no inner scrollbar) ===== */
.button-group{
  display:flex;
  justify-content:center;
  align-items:center;
  gap:.8rem;
  flex-wrap:wrap;        /* 小螢幕自動換行 */
  overflow:visible;      /* 移除中間那條捲軸 */
  margin-top:.5rem;
}

/* <a> 當按鈕用：預設可見，含進場動畫 */
.button-group a{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  text-decoration:none;
  font-weight:700;
  font-size:1rem;
  color:#0f172a;
  padding:.7rem 1.2rem;
  border-radius:12px;
  background:rgba(255,255,255,.9);
  border:1px solid rgba(0,0,0,.08);
  box-shadow:0 6px 18px rgba(0,0,0,.12);
  transition:transform .15s ease, box-shadow .15s ease, background .15s ease;
  animation:langFloatIn .35s ease both;
}

.button-group a:nth-child(2){ animation-delay:.08s; }
.button-group a:nth-child(3){ animation-delay:.16s; }

@keyframes langFloatIn{
  from{ opacity:0; transform:translateY(8px); }
  to  { opacity:1; transform:none; }
}

.button-group a:hover,
.button-group a:focus-visible{
  background:#fff;
  box-shadow:0 8px 24px rgba(0,0,0,.18);
  transform:translateY(-1px);
  outline:none;
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
  .container { padding: 2rem 1.5rem; width: 90vw; }
  .button-group{ gap:.6rem; }
  .button-group a{ padding:.6rem 1rem; font-size:.95rem; }
}

@media (max-width: 360px) {
  .container { padding: 1.5rem 1rem; width: 95vw; }
  h1 { font-size: 1.3rem; }
  .button-group a{ font-size:.9rem; padding:.5rem .8rem; }
}

/* ===== 重要：移除舊的按鈕樣式以免干擾 ===== */
button { all: unset; }