/* ====== 變數 ====== */
:root{
  --bg1:#0a4da2;         /* 深藍 */
  --bg2:#2ab1ff;         /* 亮藍 */
  --card:#ffffff;
  --text:#1b1f24;
  --muted:#64748b;
  --primary:#0a4da2;
  --primary-hover:#073a7a;
  --border:#e5e7eb;
  --danger:#c1121f;
  --shadow:0 10px 30px rgba(0,0,0,.15);
}

/* ====== 版面 ====== */
html,body{
  height:100%;
}
body{
  margin:0;
  font-family: "Taipei Sans TC", "Microsoft JhengHei", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: linear-gradient(135deg, var(--bg1), var(--bg2));
  display:flex;
  align-items:center;
  justify-content:center;
  color:var(--text);
}

/* 外層包一層，提高美觀與可擴充性 */
.login-wrap{
  width:100%;
  max-width: 960px;
  padding: 24px;
  display:grid;
  grid-template-rows: 1fr auto;
  gap: 16px;
  min-height: 100vh;
  box-sizing: border-box;
}

/* 卡片 */
.login-card{
  margin: auto;
  width:100%;
  max-width: 460px;
  background: var(--card);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 36px 32px 28px;
  text-align: center;
  animation: fadeIn .6s ease-out both;
  backdrop-filter: blur(3px);
}

/* 品牌區 */
.brand{
  margin-bottom: 22px;
}
.brand .logo{
  width: 92px;
  height: 92px;
  border-radius: 50%;
  object-fit: cover;
  display:inline-block;
  box-shadow: 0 6px 16px rgba(0,0,0,.25);
  border: 3px solid #ffffff;
  background: #fff;
  margin-bottom: 12px;
}
.brand h1{
  margin:0;
  font-size: 22px;
  letter-spacing: .5px;
}
.subtitle{
  margin:6px 0 0;
  font-size: 13px;
  color: var(--muted);
}

/* 表單 */
.login-form{
  text-align: left;
}
.form-group{
  margin-bottom: 16px;
}
label{
  display:block;
  font-size: 14px;
  margin-bottom: 6px;
  color:#374151;
}
input[type="text"],
input[type="password"]{
  width:100%;
  padding: 12px 14px;
  border:1px solid var(--border);
  border-radius: 10px;
  font-size: 15px;
  outline: none;
  transition: border-color .2s, box-shadow .2s, background-color .2s;
  background: #fff;
  box-sizing: border-box;
}
input::placeholder{
  color:#9ca3af;
}
input:focus{
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(10,77,162,.12);
  background: #fff;
}

/* 按鈕 */
.btn-primary,
button{
  width:100%;
  padding: 12px 14px;
  background: var(--primary);
  color:#fff;
  border:0;
  border-radius: 10px;
  font-size: 16px;
  cursor:pointer;
  transition: background .15s, transform .05s ease-in-out;
}
.btn-primary:hover:not(:disabled){
  background: var(--primary-hover);
}
.btn-primary:active{
  transform: translateY(1px);
}
button:disabled{
  background:#b7c3d6;
  cursor:not-allowed;
}

/* 錯誤訊息 */
.error{
  margin-top: 12px;
  color: var(--danger);
  font-size: 14px;
  min-height: 22px;
}

/* 底部 */
.login-footer{
  text-align:center;
  color: #eef6ff;
  font-size: 12px;
  opacity: .95;
}

/* 輔助連結 */
.helper{
  margin-top: 14px;
}
.helper a{
  color: var(--primary);
  font-size: 13px;
  text-decoration: none;
}
.helper a:hover{
  text-decoration: underline;
}

/* 動畫 */
@keyframes fadeIn{
  from{ opacity:0; transform: translateY(-10px); }
  to{ opacity:1; transform: translateY(0); }
}

/* ====== RWD ====== */
@media (max-width: 520px){
  .login-card{
    padding: 28px 22px 22px;
    border-radius: 16px;
  }
  .brand .logo{
    width:84px; height:84px;
  }
  .brand h1{
    font-size: 20px;
  }
}