:root {
  --bg: #ffffff;
  --card: #ffffff;
  --text: #111827;
  --border: #d1d5db;
  --primary: #4f46e5;
}

body.dark {
  --bg: #020617;
  --card: #020617;
  --text: #e5e7eb;
  --border: #334155;
  --primary: #6366f1;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", sans-serif;
}

body {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--primary), #06b6d4);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: 0.4s;
}

.auth-card {
  background: var(--card);
  width: 100%;
  max-width: 400px;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
  position: relative;
}

h2 {
  text-align: center;
  color: var(--text);
}

.subtitle {
  text-align: center;
  color: #6b7280;
  font-size: 14px;
  margin-bottom: 20px;
}

.form {
  display: none;
  animation: fade 0.4s ease;
}

.form.active {
  display: block;
}

@keyframes fade {
  from {opacity:0; transform:translateY(15px);}
  to {opacity:1; transform:translateY(0);}
}

.input-group {
  position: relative;
  margin-bottom: 20px;
}

.input-group input {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text);
}

.input-group label {
  position: absolute;
  top: 50%;
  left: 12px;
  transform: translateY(-50%);
  background: var(--card);
  padding: 0 4px;
  color: #9ca3af;
  transition: 0.3s;
  font-size: 13px;
}

.input-group input:focus + label,
.input-group input:not(:placeholder-shown) + label {
  top: -6px;
  font-size: 11px;
  color: var(--primary);
}

.password-group {
  position: relative;
}

.toggle-password {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  cursor: pointer;
}

.primary-btn {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  cursor: pointer;
}

.primary-btn:hover {
  opacity: 0.9;
}

.options {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  margin-bottom: 20px;
  color: var(--text);
}

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

.switch-text {
  text-align: center;
  margin-top: 15px;
  font-size: 13px;
}

#message {
  text-align: center;
  font-size: 13px;
  margin-bottom: 10px;
}

.error { color: #dc2626; }
.success { color: #16a34a; }

.theme-toggle {
  position: absolute;
  top: 15px;
  right: 15px;
}

.theme-toggle input {
  display: none;
}

.theme-toggle label {
  cursor: pointer;
}

.otp-box {
  display: flex;
  justify-content: space-between;
  margin: 20px 0;
}

.otp-box input {
  width: 45px;
  height: 50px;
  text-align: center;
  font-size: 18px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
}