body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: #f0f4f8;
  margin: 0;
  padding: 20px;
}

.container {
  max-width: 500px;
  margin: auto;
  background: #fff;
  padding: 25px 30px;
  border-radius: 8px;
  box-shadow: 0 0 15px rgba(0,0,0,0.1);
}

h1 {
  text-align: center;
  color: #333;
}

.input-group {
  margin-bottom: 15px;
  display: flex;
  flex-wrap: wrap; /* 允許內容換行 */
  justify-content: space-between;
  align-items: center;
}

.input-group label {
  flex: 1;
  font-weight: 600;
  color: #444;
}

.input-group input,
.input-group select {
  flex: 1;
  padding: 6px 10px;
  font-size: 16px;
  border: 1.5px solid #ccc;
  border-radius: 5px;
}

/* 讓成員選擇區塊自動換行且間距適中 */
#memberSelectBlock {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  min-width: 0;
  flex: 2 1 320px;
}

#darkModeBtn {
  position: fixed;
  top: 22px;
  right: 22px;
  z-index: 1001;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: none;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s;
}

#darkModeIcon {
  display: flex;
  align-items: center;
  justify-content: center;
}

.member-card img {
  width: 48px;
  height: 48px;
  border-radius: 50%;
}

#memberSelectBlock .member-card:first-child img {
  border: 2px solid #007bff;
}

.footer {
  text-align: center;
  margin-top: 32px;
  color: #888;
  font-size: 14px;
}

.button-group {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 18px;
}

button {
  width: 160px;
  padding: 10px 0;
  margin-top: 0;
  font-size: 16px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 700;
  transition: background-color 0.3s ease;
}

#calculateBtn {
  background-color: #007bff;
  color: white;
}

#calculateBtn:hover {
  background-color: #0056b3;
}

.result {
  margin-top: 20px;
  padding: 15px;
  background: #fffbe6;
  border-radius: 6px;
  font-size: 16px;
  line-height: 1.5;
  white-space: pre-wrap;
  border: 1.5px solid #ffe066;
  color: #5a4a00;
  box-shadow: 0 2px 8px rgba(255,224,102,0.08);
}

.member-card {
  background: #f7fafd;
  border: 1.5px solid #cce0ff;
  border-radius: 8px;
  padding: 8px 6px;
  text-align: center;
  width: 80px;
  font-size: 13px;
  min-width: 80px;
  margin-bottom: 5px;
  box-sizing: border-box;
}

.member-card select {
  margin-top: 4px;
  width: 60px;
}

/* 響應式：小螢幕下調整成員卡片寬度 */
@media (max-width: 600px) {
  #memberSelectBlock {
    gap: 6px;
    justify-content: flex-start;
  }
  .member-card {
    width: 70px;
    min-width: 70px;
    font-size: 12px;
    padding: 6px 2px;
  }
}

body.dark-mode {
  background: #181c22;
  color: #e2e6ee;
}

body.dark-mode .container {
  background: #23272f;
  box-shadow: 0 0 18px rgba(0,0,0,0.35);
}

body.dark-mode h1 {
  color: #7ecbff;
}

body.dark-mode .input-group label {
  color: #b8d4ff;
}

body.dark-mode .input-group input,
body.dark-mode .input-group select {
  background: #23272f;
  color: #e2e6ee;
  border-color: #3a4a5e;
}

body.dark-mode .member-card {
  background: #23272f;
  border-color: #3a4a5e;
  color: #b8d4ff;
}

body.dark-mode .member-card img {
  background: #23272f;
}

body.dark-mode .result {
  background: #2d2a1a;
  border-color: #ffe066;
  color: #ffe066;
}

body.dark-mode button {
  background-color: #2d3a4a !important;
  color: #e2e6ee !important;
}

body.dark-mode #calculateBtn {
  background-color: #007bff !important;
  color: #fff !important;
}

body.dark-mode #calculateBtn:hover {
  background-color: #0056b3 !important;
}

body.dark-mode #darkModeBtn {
  background: #23272f;
}

body.dark-mode #darkModeBtn:hover {
  background: #2d3a4a;
}

.footer a {
  color: #007bff;
}

body.dark-mode a {
  color: #7ecbff !important;
}