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

/* 側邊選單 */
#sidebar {
  position: fixed;
  top: 0;
  left: -220px;
  width: 220px;
  height: 100%;
  background: #444;
  transition: left 0.3s;
  padding-top: 60px;
  z-index: 10;
}

#sidebar ul li {
  color: white;
  padding: 15px;
}

/* 主畫面包裝 */
#wrapper {
  transition: margin-left 0.3s;
}

/* Header */
header {
  height: 60px;
  background: #333;
  color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 15px;
}

header button {
  padding: 8px 16px;
  border: none;
  cursor: pointer;
}

/* 登入按鈕圓角 */
#loginBtn {
  border-radius: 20px;
}

/* 主內容 */
main {
  padding: 40px;
  text-align: center;
}

/* 遮罩 */
#overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: none;
  z-index: 5;
}

/* 登入視窗 */
#loginModal {
  position: fixed;
  inset: 0;
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 20;
}

.login-box {
  background: white;
  width: 300px;
  padding: 20px;
  border-radius: 20px;
}

.login-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 15px;
}

.login-header button {
  border: none;
  background: none;
  cursor: pointer;
}

.login-box input {
  width: 100%;
  margin-bottom: 10px;
  padding: 8px;
}

.login-submit {
  width: 100%;
  padding: 8px;
  border-radius: 20px;
  border: none;
  background: #333;
  color: white;
}

.login-links {
  display: flex;
  justify-content: space-between;
  margin-top: 10px;
}

.red {
  color: red;
}

/* ===== 選單打開狀態 ===== */
body.menu-open #sidebar {
  left: 0;
}

body.menu-open #wrapper {
  margin-left: 220px;
}

body.menu-open #overlay {
  display: block;
}

/* 響應式 */
@media (max-width: 768px) {
  body.menu-open #wrapper {
    margin-left: 0;
  }
}