:root {
  --bg: #0f172a;
  --bg-soft: #111827;
  --card: #1f2937;
  --text: #f9fafb;
  --muted: #cbd5e1;
  --accent: #22c55e;
  --accent-hover: #16a34a;
  --danger: #f87171;
  --border: #374151;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(circle at top right, #1d4ed8 0%, var(--bg) 35%, #020617 100%);
}

.container {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.card {
  width: min(680px, 100%);
  background: color-mix(in srgb, var(--card) 92%, #000);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

h1 {
  margin: 0;
  font-size: clamp(1.5rem, 2.5vw, 2rem);
}

.subtitle {
  margin: 8px 0 20px;
  color: var(--muted);
}

.invite-image-wrap {
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  margin-bottom: 20px;
}

.invite-image {
  width: 100%;
  max-height: 420px;
  object-fit: contain;
  display: block;
}

.image-fallback {
  padding: 28px;
  text-align: center;
  color: var(--muted);
}

.form {
  display: grid;
  gap: 10px;
}

label {
  font-weight: 600;
  font-size: 0.95rem;
}

input {
  width: 100%;
  border: 1px solid var(--border);
  background: #111827;
  color: var(--text);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 1rem;
}

input:focus {
  outline: 2px solid #2563eb;
  outline-offset: 1px;
}

button {
  margin-top: 10px;
  border: 0;
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 1rem;
  font-weight: 700;
  color: #052e16;
  background: var(--accent);
  cursor: pointer;
  transition: background 0.2s ease;
}

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

button:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.message {
  min-height: 1.4em;
  margin: 14px 0 0;
  font-weight: 500;
}

.message.ok {
  color: #86efac;
}

.message.error {
  color: var(--danger);
}