:root {
  --primary-color: #00b894; /* Màu xanh Leli */
  --primary-hover: #00a884;
}

body {
  background: linear-gradient(
    135deg,
    #e0f7fa 0%,
    #e8f5e9 100%
  ); /* Gradient xanh nhạt */
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: "Segoe UI", sans-serif;
}

.auth-container {
  width: 100%;
  padding: 15px;
  display: flex;
  justify-content: center;
}

.auth-card {
  background: white;
  width: 400px;
  padding: 40px;
  border-radius: 20px;
  border: none;
  position: relative;
  overflow: hidden;
}

/* Tab Switcher */
.auth-tabs {
  background: #f1f2f6;
  border-radius: 30px;
  padding: 5px;
  display: flex;
  position: relative;
}

.tab-btn {
  flex: 1;
  border: none;
  background: transparent;
  padding: 10px;
  border-radius: 25px;
  font-weight: 600;
  color: #636e72;
  transition: 0.3s;
  cursor: pointer;
}

.tab-btn.active {
  background: white;
  color: var(--primary-color);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* Input Styles */
.form-control {
  background-color: #f8f9fa;
  border: 1px solid #dfe6e9;
  padding: 12px;
  font-size: 0.9rem;
}

.form-control:focus {
  background-color: white;
  box-shadow: none;
  border-color: var(--primary-color);
}

.input-group-text {
  background-color: #f8f9fa;
  border: 1px solid #dfe6e9;
  color: #b2bec3;
}

/* Button */
.btn-auth {
  padding: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: 8px;
  transition: 0.3s;
}

.btn-primary {
  background-color: var(--primary-color);
  border: none;
}

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

.btn-success {
  background-color: #2d3436; /* Nút đăng ký màu tối để phân biệt */
  border: none;
}

.btn-success:hover {
  background-color: #000;
}

/* Responsive */
@media (max-width: 576px) {
  .auth-card {
    width: 100%;
    padding: 25px;
  }
}

.btn-home-back {
  position: absolute;
  top: 15px;
  left: 20px;
  color: #b2bec3;
  font-size: 1.2rem;
  transition: 0.3s;
  z-index: 10;
}

.btn-home-back:hover {
  color: var(--primary-color);
  transform: scale(1.1); /* Phóng to nhẹ khi di chuột */
}

a {
  text-decoration: none;
}

/* OAuth Buttons */
.btn-oauth {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 500;
  border: none;
  transition: all 0.3s ease;
  color: white;
}

.btn-google {
  background: linear-gradient(135deg, #ea4335 0%, #c33d2e 100%);
}

.btn-google:hover {
  background: linear-gradient(135deg, #c33d2e 0%, #a83229 100%);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(234, 67, 53, 0.4);
}

.btn-facebook {
  background: linear-gradient(135deg, #1877f2 0%, #1565c0 100%);
}

.btn-facebook:hover {
  background: linear-gradient(135deg, #1565c0 0%, #0d47a1 100%);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(24, 119, 242, 0.4);
}

/* Error message */
.alert-oauth-error {
  background: #fff5f5;
  border: 1px solid #feb2b2;
  color: #c53030;
  border-radius: 8px;
  padding: 10px 15px;
  font-size: 0.85rem;
  margin-bottom: 15px;
}