:root {
  --border: #e0e4e8;
  --ink: #1a1a1a;
  --muted: #6b7280;
  --ok: #22c55e;
  --err: #ef4444;
  --bg: #f8fafc;
  --accent: #3b82f6;
  --card-bg: linear-gradient(145deg, #ffffff, #f1f5f9);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 6px 20px rgba(0, 0, 0, 0.12);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 600px;
  margin: 32px auto;
  padding: 0 24px;
}

h1 {
  font-size: 28px;
  font-weight: 700;
  margin: 24px 0;
  color: var(--ink);
  letter-spacing: -0.025em;
}

.card {
  border: none;
  border-radius: 16px;
  padding: 24px;
  background: var(--card-bg);
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

label {
  display: block;
  margin-top: 16px;
  font-weight: 600;
  color: var(--ink);
  font-size: 14px;
}

input, button {
  width: 100%;
  padding: 12px;
  margin-top: 8px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 16px;
  font-family: inherit;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

input:focus, button:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

button {
  cursor: pointer;
  font-weight: 600;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 14px;
  border-radius: 10px;
  transition: background 0.3s ease, transform 0.2s ease;
}

button:hover:not([disabled]) {
  background: #2563eb;
  transform: translateY(-2px);
}

button[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
  background: #9ca3af;
}

.muted {
  color: var(--muted);
  font-size: 14px;
}

.ok {
  color: var(--ok);
  font-weight: 600;
}

.err {
  color: var(--err);
  font-weight: 600;
}

.small {
  font-size: 13px;
}

.mt {
  margin-top: 16px;
}

.hidden {
  display: none;
}