/* 主题变量 */
:root {
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --input-bg: #f1f5f9;
  --msg-self: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --msg-other: #f1f5f9;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --border: #334155;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  --input-bg: #1e293b;
  --msg-self: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --msg-other: #1e293b;
}

/* 通用样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: all 0.3s;
}

.container { 
  max-width: 800px; 
  margin: 0 auto; 
  min-height: 100vh; 
  display: flex; 
  flex-direction: column; 
}

.form-input {
  width: 100%;
  padding: 14px 18px;
  background: var(--input-bg);
  border: 2px solid transparent;
  border-radius: 14px;
  color: var(--text);
  font-size: 15px;
  margin-bottom: 14px;
  outline: none;
  transition: all 0.3s;
}

.form-input:focus { 
  border-color: var(--primary); 
  background: var(--card); 
}

.btn-primary {
  width: 100%;
  padding: 16px;
  background: var(--gradient);
  border: none;
  border-radius: 14px;
  color: white;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  margin-bottom: 12px;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
  transition: all 0.3s;
}

.btn-primary:hover { 
  transform: translateY(-2px); 
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4); 
}

.btn-secondary {
  width: 100%;
  padding: 14px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  font-size: 14px;
  cursor: pointer;
}

/* 动画 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in { animation: fadeIn 0.3s ease; }

/* 移动端适配 */
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .form-input { padding: 12px 14px; font-size: 14px; }
  .btn-primary { padding: 14px; font-size: 15px; }
}