.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: none;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-family: var(--font-main);
  font-weight: 600;
  transition: all 0.2s ease;
  padding: 10px 20px;
  font-size: 0.95rem;
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: #fff;
  box-shadow: 0 4px 12px rgba(9,132,227,0.3);
}

.btn-primary:hover {
  box-shadow: 0 6px 16px rgba(9,132,227,0.4);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--border);
  color: var(--text-primary);
}

.btn-outline:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: rgba(0,0,0,0.05);
}

.btn-sm { padding: 6px 14px; font-size: 0.85rem; }
.btn-lg { padding: 14px 28px; font-size: 1.1rem; }

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple));
  border-radius: 3px;
  transition: width 0.3s ease;
  width: 0%;
}

.tab-btn {
  padding: 10px 20px;
  background: transparent;
  border: none;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.tab-btn:hover { color: var(--text-primary); }

.tab-btn.active {
  color: var(--accent-blue);
  border-bottom-color: var(--accent-blue);
}

.tab-content { display: none; padding: 20px; }
.tab-content.active { display: block; }

/* 游戏中浮动退出按钮 */
.game-exit-btn {
  position: absolute;
  top: 10px;
  left: 10px;
  z-index: 15;
  padding: 6px 14px;
  border: none;
  border-radius: 8px;
  background: rgba(0,0,0,0.45);
  color: rgba(255,255,255,0.7);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.game-exit-btn:hover {
  background: rgba(231,76,60,0.7);
  color: #fff;
}

.rank-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 700;
}

.xp-bar {
  width: 100%;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin: 8px 0;
}

.xp-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
  border-radius: 4px;
  transition: width 0.5s ease;
}

#toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--border-radius);
  background: var(--bg-card);
  box-shadow: var(--shadow-lg);
  animation: slideInRight 0.3s ease;
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 250px;
  font-weight: 600;
}

.toast.success { border-left: 4px solid var(--accent-green); }
.toast.error { border-left: 4px solid var(--incorrect); }
.toast.achievement {
  border-left: 4px solid var(--accent-yellow);
  background: linear-gradient(135deg, #fffef0, #fff);
}

@keyframes slideInRight {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

@keyframes slideOutRight {
  from { transform: translateX(0); opacity: 1; }
  to { transform: translateX(100%); opacity: 0; }
}

.star { font-size: 2rem; }
.star.filled { color: var(--accent-yellow); text-shadow: 0 2px 8px rgba(253,203,110,0.5); }
.star.empty { color: var(--border); }

select, input[type="text"] {
  font-family: var(--font-main);
  font-size: 0.95rem;
  border: 2px solid var(--border);
  border-radius: var(--border-radius);
  padding: 8px 12px;
  color: var(--text-primary);
  background: var(--bg-card);
  outline: none;
  transition: border-color 0.2s;
}

select:focus, input[type="text"]:focus {
  border-color: var(--accent-blue);
}