:root {
  --radius: 10px;
  --shadow: 0 6px 24px rgba(0, 0, 0, 0.3);
  --fade-duration: 0.6s;

  /* Light mode defaults */
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #111;
  --accent: #2f81f7;
  --error: #d63c3c;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --card-bg: #161b22;
    --text: #e6edf3;
    --accent: #2f81f7;
    --error: #ff6b6b;
  }
}

/* Dark mode override class */
body.dark {
  --bg: #0d1117;
  --card-bg: #161b22;
  --text: #e6edf3;
  --accent: #2f81f7;
  --error: #ff6b6b;
}

/* Light mode override class */
body.light {
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #111;
  --accent: #2f81f7;
  --error: #d63c3c;
}

body {
  margin: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  transition: background var(--fade-duration) ease, color var(--fade-duration) ease;
}

.topbar {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text);
  transition: transform 0.2s;
}
.theme-toggle:hover {
  transform: scale(1.1);
}

.container {
  width: 90%;
  max-width: 400px;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2rem;
  text-align: center;
  transition: opacity var(--fade-duration) ease, transform var(--fade-duration) ease;
  opacity: 0;
  transform: translateY(20px);
  position: relative;
}

.card.visible {
  opacity: 1;
  transform: translateY(0);
}

.card.hidden {
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
}

h1 {
  margin-top: 0;
}

/* Password + Eye */
.password-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

input[type="password"],
input[type="text"] {
  width: 100%;
  padding: 0.75rem 2.5rem 0.75rem 0.75rem;
  margin: 1rem 0;
  border-radius: var(--radius);
  border: 1px solid rgba(0, 0, 0, 0.1);
  background: var(--bg);
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: background 0.2s;
}

input[type="password"]:focus,
input[type="text"]:focus {
  border-color: var(--accent);
}

.show-btn {
  position: absolute;
  right: 0.75rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text);
  font-size: 1.2rem;
  opacity: 0.7;
  transition: opacity 0.2s;
}
.show-btn:hover {
  opacity: 1;
}

button {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: var(--radius);
  padding: 0.75rem 1.25rem;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s;
}

button:hover {
  background: #3b91ff;
}

.message {
  margin-top: 0.5rem;
  min-height: 1.5rem;
  color: var(--error);
  font-size: 0.9rem;
}

/* Spinner styles */
.spinner {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.loader {
  border: 3px solid rgba(255, 255, 255, 0.2);
  border-top-color: var(--accent);
  border-radius: 50%;
  width: 32px;
  height: 32px;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}