* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif; }
html, body { min-height: 100vh; transition: all 0.3s ease; }

/* 深浅模式基础配色 */
.light-mode { background-color: #f8fafc; color: #1e293b; }
.light-mode .contact-card, .light-mode .feedback-card { background-color: #ffffff; box-shadow: 0 2px 12px rgba(0,0,0,0.06); }
.light-mode .btn { background-color: #3b82f6; color: #fff; }
.light-mode .btn:hover { background-color: #2563eb; }
.light-mode .copy-btn.copied { background-color: #10b981; }
.light-mode .mode-switch { color: #64748b; }

.dark-mode { background-color: #0f172a; color: #f1f5f9; }
.dark-mode .contact-card, .dark-mode .feedback-card { background-color: #1e293b; box-shadow: 0 2px 12px rgba(0,0,0,0.2); }
.dark-mode .btn { background-color: #2563eb; color: #fff; }
.dark-mode .btn:hover { background-color: #3b82f6; }
.dark-mode .copy-btn.copied { background-color: #059669; }
.dark-mode .mode-switch { color: #94a3b8; }

/* 通用布局 */
.container { max-width: 1200px; margin: 0 auto; padding: 2rem 1rem; }
.header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2.5rem; }
.header h1 { font-size: 1.8rem; font-weight: 600; }
.mode-switch { font-size: 1.5rem; cursor: pointer; transition: all 0.2s ease; }
.mode-switch .fa-sun { display: none; }
.dark-mode .mode-switch .fa-moon { display: none; }
.dark-mode .mode-switch .fa-sun { display: block; }

.content { display: flex; flex-direction: column; gap: 2rem; }
.card-group, .feedback-card { width: 100%; max-width: 980px; margin: 0 auto; }
.contact-card { border-radius: 12px; text-align: center; transition: transform 0.2s ease; padding: 2rem 1.5rem; display: flex; flex-direction: column; justify-content: center; align-items: center; }
.contact-card:hover { transform: translateY(-3px); }

/* 卡片数量自适应布局 */
.card-num-1 { display: flex; justify-content: center; }
.card-num-1 .contact-card { width: 100%; min-height: 480px; }
.card-num-1 .qrcode img { width: 260px; height: 260px; }

.card-num-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.card-num-2 .contact-card { min-height: 400px; }
.card-num-2 .qrcode img { width: 180px; height: 180px; }

.card-num-3, .card-num-4 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.card-num-3 .contact-card, .card-num-4 .contact-card { min-height: 380px; }
.card-num-3 .contact-card:nth-child(3) { grid-column: 1/2; justify-self: start; width: 100%; }
.card-num-3 .qrcode img, .card-num-4 .qrcode img { width: 160px; height: 160px; }

/* 卡片内部样式 */
.card-header { display: flex; align-items: center; justify-content: center; gap: 0.5rem; margin-bottom: 1.2rem; font-size: 1.3rem; }
.card-header i { font-size: 1.6rem; }
.qrcode img { margin: 0 auto; border-radius: 8px; object-fit: cover; }
.number-box { margin-top: 1.2rem; padding: 1.2rem; border-radius: 8px; background-color: rgba(0,0,0,0.03); display: flex; flex-direction: column; gap: 0.8rem; width: 100%; }
.dark-mode .number-box { background-color: rgba(255,255,255,0.03); }
.num-text { font-size: 1.15rem; font-weight: 500; letter-spacing: 1px; }

/* 按钮通用样式 */
.btn { border: none; outline: none; padding: 0.7rem 1.2rem; border-radius: 8px; cursor: pointer; font-size: 0.95rem; font-weight: 500; transition: all 0.2s ease; text-decoration: none; }
.copy-btn { width: 100%; }

/* 反馈卡片 */
.feedback-card { padding: 2rem; border-radius: 12px; text-align: center; display: none; }
.feedback-card h3 { font-size: 1.3rem; margin-bottom: 0.8rem; }
.desc { color: #64748b; line-height: 1.6; margin-bottom: 1.5rem; }
.dark-mode .desc { color: #94a3b8; }
.feedback-btn { padding: 0.8rem 2rem; font-size: 1rem; }

/* 底部版权 */
.footer { margin-top: 3rem; text-align: center; color: #64748b; font-size: 0.9rem; }
.dark-mode .footer { color: #94a3b8; }
.empty-tip { text-align: center; font-size: 1.1rem; color: #64748b; padding: 2rem; width: 100%; }

/* 全局提示框 前后台共用核心样式 */
.tips-box { position: fixed; top: 20px; right: 20px; padding: 0.9rem 1.5rem; border-radius: 8px; font-size: 1rem; display: flex; align-items: center; gap: 0.8rem; z-index: 99999; opacity: 0; transform: translateY(-20px); transition: all 0.3s ease; box-shadow: 0 4px 12px rgba(0,0,0,0.15); pointer-events: none; }
.tips-box.show { opacity: 1; transform: translateY(0); }
.tips-progress { position: absolute; bottom: 0; left: 0; width: 100%; height: 3px; background-color: rgba(255,255,255,0.6); border-radius: 0 0 0 8px; animation: progressBack 1500ms linear forwards; }
@keyframes progressBack { 0% { width: 100%; } 100% { width: 0%; } }
.tips-success { background-color: #10b981; color: #fff; }
.tips-warning { background-color: #f59e0b; color: #fff; }
.tips-danger { background-color: #ef4444; color: #fff; }
.tips-info { background-color: #3b82f6; color: #fff; }

/* 手机端自适应核心样式 */
@media (max-width: 768px) {
    .header h1 { font-size: 1.5rem; }
    .card-group { display: flex !important; flex-direction: column; gap: 1.5rem; }
    .contact-card { width: 100% !important; max-width: 350px; min-height: auto !important; padding: 1.2rem !important; margin: 0 auto; }
    .card-num-3 .contact-card:nth-child(3) { justify-self: center !important; }
    .qrcode img { width: 150px !important; height: 150px !important; }
    .feedback-card { padding: 1.5rem; }
    .tips-box { max-width: 90%; font-size: 0.9rem; padding: 0.7rem 1.2rem; top:15px; right:10px; }
}