* {
  box-sizing: border-box;
}

:root {
  --bg: #0b1220;
  --bg-soft: #111a2b;
  --card: rgba(17, 26, 43, 0.82);
  --line: rgba(148, 163, 184, 0.26);
  --text: #e2e8f0;
  --muted: #94a3b8;
  --primary: #2563eb;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 15% 20%, rgba(37, 99, 235, 0.22), transparent 45%),
    radial-gradient(circle at 90% 70%, rgba(14, 165, 233, 0.2), transparent 45%),
    var(--bg);
  color: var(--text);
  font-family: "Pretendard", "Noto Sans KR", "Segoe UI", Arial, sans-serif;
  display: grid;
  place-items: center;
  padding: 28px 16px;
}

.layout {
  width: 100%;
  max-width: 1060px;
  display: grid;
  gap: 18px;
  grid-template-columns: 1.2fr 1fr;
  align-items: stretch;
}

.brand-panel {
  border: 1px solid var(--line);
  border-radius: 20px;
  background: linear-gradient(170deg, rgba(30, 41, 59, 0.95), rgba(15, 23, 42, 0.9));
  padding: 28px;
  box-shadow: 0 20px 50px rgba(2, 6, 23, 0.45);
}

.brand-top {
  color: #93c5fd;
  font-size: 12px;
  letter-spacing: 0.14em;
  font-weight: 700;
}

.brand-logo {
  margin-top: 22px;
  width: 108px;
  height: 108px;
  display: block;
  flex: none;
  filter: drop-shadow(0 12px 22px rgba(37, 99, 235, 0.28));
}

.brand-panel h1 {
  margin: 20px 0 8px;
  font-size: 42px;
  letter-spacing: -0.02em;
}

.brand-subtitle {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 28px;
  backdrop-filter: blur(8px);
}

.login-panel h2 {
  margin: 0 0 8px;
}

.login-guide {
  margin: 0 0 18px;
  color: var(--muted);
}

.social-buttons {
  display: grid;
  gap: 10px;
}

.invite-label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
}

.invite-input {
  width: 100%;
  height: 44px;
  border-radius: 10px;
  border: 1px solid #334155;
  background: rgba(15, 23, 42, 0.8);
  color: var(--text);
  padding: 0 12px;
  margin-bottom: 12px;
  outline: none;
}

.invite-input:focus {
  border-color: #60a5fa;
}

button {
  width: 100%;
  height: 50px;
  border-radius: 12px;
  border: 1px solid transparent;
  background: #0a84ff;
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  font-size: 15px;
  transition: transform 0.14s ease, filter 0.14s ease;
}

button:hover {
  transform: translateY(-1px);
  filter: brightness(1.06);
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

button.social.kakao {
  background: #fee500;
  color: #1f2937;
  border-color: #facc15;
}

button.social.google {
  background: #ffffff;
  color: #1f2937;
  border-color: #d1d5db;
}

.row {
  display: flex;
  gap: 8px;
}

.assist {
  color: var(--muted);
  font-size: 13px;
  margin: 14px 0 0;
}

.hidden {
  display: none;
}

.output {
  margin: 0;
  grid-column: 1 / -1;
  background: rgba(2, 6, 23, 0.85);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px;
  min-height: 140px;
  overflow: auto;
  color: #cbd5e1;
  font-size: 12px;
  line-height: 1.45;
}

@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .brand-panel h1 {
    font-size: 34px;
  }
}