:root {
  --bg: #f4f5f7;
  --card: #ffffff;
  --text: #1d1f24;
  --muted: #5f6672;
  --border: #d6d9e0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --focus: rgba(37, 99, 235, 0.25);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1115;
    --card: #181b22;
    --text: #eceef2;
    --muted: #9aa3b2;
    --border: #2d323c;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --focus: rgba(59, 130, 246, 0.3);
  }
}

:root[data-theme="dark"] {
  --bg: #0f1115;
  --card: #181b22;
  --text: #eceef2;
  --muted: #9aa3b2;
  --border: #2d323c;
  --accent: #3b82f6;
  --accent-hover: #60a5fa;
  --focus: rgba(59, 130, 246, 0.3);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 16px;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.5;
}

main {
  width: 100%;
  max-width: 360px;
  padding: 32px 28px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

h1 {
  margin: 0 0 24px;
  font-size: 1.5rem;
  font-weight: 600;
  text-align: center;
}

form {
  display: grid;
  gap: 16px;
}

label {
  display: grid;
  gap: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 10px 12px;
  font: inherit;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  transition:
    border-color 0.15s,
    box-shadow 0.15s;
}

input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--focus);
}

button {
  margin-top: 8px;
  padding: 11px 16px;
  font: inherit;
  font-weight: 600;
  color: #ffffff;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s;
}

button:hover {
  background: var(--accent-hover);
}

button:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.error {
  margin: 0 0 16px;
  padding: 10px 12px;
  border-radius: 8px;
  color: #dc2626;
  background: rgba(220, 38, 38, 0.1);
  font-size: 0.9rem;
}

.brand {
  display: grid;
  justify-items: center;
  gap: 10px;
  margin-bottom: 24px;
}

.brand h1 {
  margin: 0;
}

.brand-icon {
  width: 44px;
  height: 44px;
  fill: var(--accent);
}