/* ============================================================
   ROOT VARIABLES
   ============================================================ */
:root {
  --bg-primary: #0b0f14;
  --bg-card: #121822;
  --bg-input: #0d1420;
  --border-color: #1f2937;
  --text-primary: #e5e7eb;
  --text-muted: #9ca3af;
  --text-dark: #6b7280;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --danger: #ef4444;
  --success: #22c55e;
  --shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.8);
  --radius: 14px;
  --radius-sm: 10px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================================
   RESET & BASE
   ============================================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(ellipse at top, #0f172a, #05070a 70%);
  color: var(--text-primary);
  padding: 20px;
}

/* ============================================================
   AUTH CONTAINER
   ============================================================ */
.auth-container {
  width: 100%;
  max-width: 450px;
  animation: fadeIn 0.6s ease-out;
}

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

/* ============================================================
   AUTH CARD
   ============================================================ */
.auth-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 40px 32px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

/* ============================================================
   HEADER
   ============================================================ */
.auth-header {
  text-align: center;
  margin-bottom: 32px;
}

.auth-header h1 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, #60a5fa, #3b82f6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.auth-header p {
  color: var(--text-muted);
  font-size: 14px;
  margin-top: 6px;
  letter-spacing: 0.3px;
}

/* ============================================================
   TABS
   ============================================================ */
.auth-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 28px;
  border-bottom: 2px solid var(--border-color);
  border-radius: 0;
}

.auth-tab {
  flex: 1;
  padding: 12px 0;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border-bottom: 3px solid transparent;
  letter-spacing: 0.5px;
}

.auth-tab:hover {
  color: var(--text-primary);
}

.auth-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ============================================================
   FORMS
   ============================================================ */
.auth-form {
  display: none;
  flex-direction: column;
  gap: 20px;
}

.auth-form.active {
  display: flex;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.3px;
}

.form-group input {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-color);
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 14px;
  transition: var(--transition);
  outline: none;
  width: 100%;
}

.form-group input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-group input::placeholder {
  color: var(--text-dark);
}

/* ============================================================
   PASSWORD WRAPPER
   ============================================================ */
.password-wrapper {
  position: relative;
  width: 100%;
}

.password-wrapper input {
  padding-right: 48px;
}

.toggle-password {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 18px;
  padding: 4px;
  transition: var(--transition);
  line-height: 1;
}

.toggle-password:hover {
  color: var(--text-primary);
}

/* ============================================================
   FORM OPTIONS
   ============================================================ */
.form-options {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.remember-me {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 13px;
  cursor: pointer;
}

.remember-me input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn-primary {
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  transition: var(--transition);
  width: 100%;
  letter-spacing: 0.5px;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.link-button {
  border: none;
  background: transparent;
  color: var(--accent);
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  padding: 0;
}

.link-button:hover {
  color: var(--accent-hover);
}

.link-button.full-width {
  width: 100%;
  padding: 2px 0 0;
  text-align: center;
}

/* ============================================================
   MESSAGES
   ============================================================ */
.form-message {
  margin-top: 4px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  display: none;
  font-weight: 500;
}

.form-message.error {
  display: block;
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid var(--danger);
  color: var(--danger);
}

.form-message.success {
  display: block;
  background: rgba(34, 197, 94, 0.12);
  border: 1px solid var(--success);
  color: var(--success);
}

/* ============================================================
   FOOTER
   ============================================================ */
.auth-footer {
  margin-top: 28px;
  text-align: center;
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
}

.auth-footer p {
  color: var(--text-muted);
  font-size: 12px;
  letter-spacing: 0.5px;
}

.auth-footer .version {
  color: var(--text-dark);
  font-size: 11px;
  margin-top: 4px;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 520px) {
  .auth-card {
    padding: 28px 20px;
  }

  .auth-header h1 {
    font-size: 20px;
  }

  .auth-tab {
    font-size: 14px;
  }

  .form-group input {
    font-size: 13px;
    padding: 11px 14px;
  }

  .btn-primary {
    font-size: 14px;
    padding: 12px 20px;
  }
}

@media (max-width: 380px) {
  .auth-card {
    padding: 20px 16px;
  }

  .auth-header h1 {
    font-size: 17px;
  }

  .auth-tabs {
    flex-direction: column;
    border-bottom: none;
  }

  .auth-tab {
    padding: 10px;
    border-bottom: 1px solid var(--border-color);
  }

  .auth-tab.active {
    border-bottom-color: var(--accent);
  }
}