body {
  font-family: 'Inter', sans-serif;
  margin: 0;
  transition: background-color 0.3s, color 0.3s;
  background-color: #f3f4f6;
}
.dark body {
  background-color: #0f172a;
}

.container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.dark .container {
  background: #0f172a;
}

.card {
  width: 100%;
  max-width: 380px;
  background: #ffffff;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.08);
  border-radius: 14px;
  padding: 24px;
  animation: fadeIn 0.5s ease-out;
  position: relative;
}
@media (max-width: 500px) {
  .card {
    max-width: 90%;
  }
}
.dark .card {
  background: #1e293b;
  color: #f9fafb;
}

.card img.logo {
  width: 100%;
  height: 150px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 16px;
}

.title {
  text-align: center;
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 8px;
  color: #1e293b;
  letter-spacing: 0.5px;
}
.dark .title {
  color: #f9fafb;
}

.title-line {
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, #3b82f6, #60a5fa);
  border-radius: 2px;
  margin: 0 auto 20px auto;
}

form {
  display: flex;
  flex-direction: column;
}

label {
  font-size: 14px;
  margin-bottom: 4px;
  color: #334155;
}
.dark label {
  color: #cbd5e1;
}

input[type=text],
input[type=email],
input[type=password] {
  padding: 10px;
  margin-bottom: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 14px;
  background: #f9fafb;
  color: #1e293b;
}
.dark input {
  background: #334155;
  color: #f1f5f9;
  border-color: #475569;
}

input:focus {
  outline: none;
  border-color: #3b82f6;
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.3);
}

button {
  padding: 12px;
  border: none;
  background: linear-gradient(135deg, #60a5fa, #3b82f6);
  color: #fff;
  font-weight: 600;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-top: 12px;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}
button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(59, 130, 246, 0.3);
}

.checkbox {
  display: flex;
  align-items: center;
  margin-bottom: 12px;
  font-size: 13px;
  color: #334155;
}
.dark .checkbox {
  color: #cbd5e1;
}
.checkbox input {
  margin-right: 6px;
}
.checkbox a {
  color: #3b82f6;
  cursor: pointer;
  text-decoration: underline;
}
.checkbox a:hover {
  opacity: 0.8;
}

.footer {
  text-align: center;
  margin-top: 12px;
  font-size: 13px;
}
.footer a {
  color: #3b82f6;
  text-decoration: none;
}
.footer a:hover {
  text-decoration: underline;
}

.theme-switch {
  margin: 15px auto 0 auto;
  width: 80px;
  height: 24px;
  background: #e5e7eb;
  border-radius: 20px;
  position: relative;
  cursor: pointer;
  transition: background 0.3s ease;
}
.dark .theme-switch {
  background: #475569;
}
.theme-switch .thumb {
  width: 20px;
  height: 20px;
  background: white;
  border-radius: 50%;
  position: absolute;
  top: 2px;
  left: 2px;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  color: #6b7280;
}
.dark .theme-switch .thumb {
  left: 58px;
  background: #1e293b;
  color: #f9fafb;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  background: #fff;
  color: #1e293b;
  padding: 10px 14px;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 220px;
  opacity: 0;
  transform: translateY(-20px);
  transition: all 0.4s ease;
  z-index: 999;
}
.toast.show {
  opacity: 1;
  transform: translateY(0);
}
.toast-icon {
  font-size: 20px;
}
.toast-success { border-left: 4px solid #16a34a; }
.toast-error { border-left: 4px solid #dc2626; }
.toast-info { border-left: 4px solid #2563eb; }
.dark .toast {
  background: #1e293b;
  color: #f9fafb;
}

#welcome-toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  background: #fff;
  color: #1e293b;
  padding: 10px 14px;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 220px;
  opacity: 0;
  transition: all 0.4s ease;
  z-index: 1000;
}
#welcome-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.dark #welcome-toast {
  background: #1e293b;
  color: #f9fafb;
}

.divider {
  display: flex;
  align-items: center;
  text-align: center;
  margin: 20px 0 12px;
  color: #64748b;
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.5px;
}
.divider::before,
.divider::after {
  content: "";
  flex: 1;
  border-bottom: 1px solid #94a3b8;
  margin: 0 10px;
}

.github-login {
  background-color: #000 !important;
  color: #fff;
  font-size: 0.9rem;
  padding: 10px 16px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  transition: background-color 0.3s ease, transform 0.2s ease;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}
.github-login i {
  font-size: 1.2rem;
}
.github-login:hover {
  background-color: #111;
  transform: scale(1.03);
}