:root {
  --bg: #0d0f12;
  --card: #161a22;
  --card-border: #30363d;
  --text: #f0f6fc;
  --text-muted: #b0b6bd; /* 調亮對比度，提升強光現場與弱視可讀性 */
  --accent: #4a9eff;
  --accent-glow: rgba(74, 158, 255, 0.25);
  --success: #00b894;
  --danger: #ff4757;
  --border: #21262d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 1.25rem;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang HK", "Microsoft JhengHei", sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  color: var(--text);
  margin-top: 0;
}

p {
  color: var(--text-muted);
  margin: 0.5rem 0;
}

/* 1. 卡片設計與互動反饋 */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  margin-bottom: 0.75rem;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.card[role="button"],
.card.clickable {
  cursor: pointer;
}

.card[role="button"]:hover,
.card.clickable:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* 2. 表單輸入框：移除全域 margin 避免幽靈空白，強化 :focus 環 */
input, textarea {
  width: 100%;
  background: #1a1d24;
  border: 1px solid var(--border);
  color: #fff;
  padding: 0.75rem;
  border-radius: 6px;
  font-size: 1rem;
  font-family: inherit;
  margin: 0; /* 消除定時炸彈 margin，交由結構容器控制 */
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* 3. 按鈕系統：補齊 hover、active 觸控反饋與 disabled 狀態 */
.btn {
  background: #21262d;
  color: #fff;
  border: 1px solid #30363d;
  padding: 0.6rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  user-select: none;
  text-decoration: none;
  transition: background 0.15s ease, border-color 0.15s ease, opacity 0.15s ease, transform 0.08s ease;
}

.btn:hover {
  background: #30363d;
}

.btn:active {
  transform: scale(0.97); /* 行動端觸控微動反饋 */
  opacity: 0.88;
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.btn:disabled,
.btn[disabled] {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
  transform: none;
}

.btn-primary {
  background: #1f6feb;
  border-color: #388bfd;
}
.btn-primary:hover {
  background: #388bfd;
}

.btn-success {
  background: #238636;
  border-color: #2ea043;
}
.btn-success:hover {
  background: #2ea043;
}

.btn-danger {
  background: #da3633;
  border-color: #f85149;
}
.btn-danger:hover {
  background: #f85149;
}

/* 4. 狀態徽章 */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}
.badge-online,
.badge-success {
  background: rgba(0, 184, 148, 0.15);
  color: #00b894;
  border: 1px solid rgba(0, 184, 148, 0.3);
}
.badge-danger {
  background: rgba(255, 71, 87, 0.15);
  color: #ff7675;
  border: 1px solid rgba(255, 71, 87, 0.3);
}

/* 5. 減少動態偏好支援（無障礙 Accessible Motion） */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}