/* 로그인 화면
   레이아웃: 왼쪽 브랜드 패널(연세 남색) + 오른쪽 카드. 768px 미만은 위아래로.
   모션 (motion-design, Corporate):
     주   - 단계 전환: 나가는 단계 160ms ease-in 왼쪽 12px, 들어오는 단계 280ms ease-out 오른쪽 16px에서
     보조 - 카드 높이가 단계에 맞춰 240ms로 따라감, 버튼 눌림 0.98
     배경 - 브랜드 패널의 빛 두 개가 18s/24s로 천천히 떠다님 */

.login-body { min-height: 100vh; }
.login {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(320px, 5fr) 7fr;
}

/* ---------------------------------------------------------- 브랜드 패널 */
.login-brand {
  position: relative; overflow: hidden;
  background: #213183;                          /* 연세 남색 (다크에서도 같은 남색) */
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  padding: 48px;
}
.brand-glow {
  position: absolute; border-radius: 50%;
  filter: blur(60px); opacity: 0.55; pointer-events: none;
  will-change: transform;
}
.brand-glow.g1 { width: 420px; height: 420px; background: #2f56c9; top: -120px; left: -100px; animation: drift1 18s ease-in-out infinite alternate; }
.brand-glow.g2 { width: 360px; height: 360px; background: #0075de; bottom: -140px; right: -80px; opacity: 0.4; animation: drift2 24s ease-in-out infinite alternate; }
@keyframes drift1 { to { transform: translate(60px, 40px) scale(1.08); } }
@keyframes drift2 { to { transform: translate(-50px, -30px) scale(0.94); } }

.brand-inner { position: relative; max-width: 340px; animation: brand-in var(--dur-slow) var(--ease-out) both; }
.brand-seal {
  width: 64px; height: 64px; object-fit: contain;
  background: var(--color-surface); border-radius: 50%; padding: 6px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}
.brand-eyebrow { margin: 28px 0 4px; font-size: 13px; font-weight: 600; letter-spacing: 1.2px; text-transform: uppercase; color: rgba(255, 255, 255, 0.78); }
.brand-title { margin: 0; font-size: 54px; font-weight: 800; letter-spacing: -1.5px; line-height: 1.1; }
.brand-copy { margin: 16px 0 0; font-size: 17px; line-height: 1.6; color: rgba(255, 255, 255, 0.86); }
@keyframes brand-in { from { opacity: 0; transform: translateY(12px); } }

/* ---------------------------------------------------------- 카드 */
.login-panel {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 48px 24px; gap: 20px;
}
.login-card {
  width: 100%; max-width: 400px;
  background: var(--color-surface);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2);
  padding: 36px 32px 32px;
  animation: card-in var(--dur-slow) var(--ease-out) 80ms both;
}
@keyframes card-in { from { opacity: 0; transform: translateY(16px) scale(0.985); } }
.login-foot { margin: 0; font-size: 13px; color: var(--color-ink-faint); }

.demo-banner {
  margin: -8px 0 20px; padding: 10px 12px;
  background: var(--color-warn-bg); border: 1px solid var(--color-orange-border); border-radius: var(--radius-md);
  font-size: 13px; color: var(--color-text-orange); line-height: 1.5;
}

/* 단계: 높이는 JS가 재서 부드럽게 바꾼다 */
.steps { position: relative; transition: height var(--dur-std) var(--ease); }
.step { display: flex; flex-direction: column; }
.step.leaving { animation: step-out 160ms var(--ease-in) both; }
.step.entering { animation: step-in 280ms var(--ease-out) both; }
.step.entering.back-dir { animation-name: step-in-back; }
.step.leaving.back-dir { animation-name: step-out-back; }
@keyframes step-out      { to   { opacity: 0; transform: translateX(-12px); } }
@keyframes step-in       { from { opacity: 0; transform: translateX(16px); } }
@keyframes step-out-back { to   { opacity: 0; transform: translateX(12px); } }
@keyframes step-in-back  { from { opacity: 0; transform: translateX(-16px); } }

.step-title { margin: 0; font-size: 24px; font-weight: 700; letter-spacing: -0.5px; }
.step-desc { margin: 6px 0 24px; font-size: 15px; color: var(--color-ink-muted); }
.step-desc b { color: var(--color-ink); font-weight: 600; word-break: break-all; }

/* 입력칸 */
.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 20px; }
.field label { font-size: 14px; font-weight: 600; color: var(--color-ink-secondary); }
.field input {
  height: 48px; padding: 0 14px;
  border: 1px solid var(--color-hairline-strong); border-radius: var(--radius-md); color: var(--color-ink);
  background: var(--color-surface); font-size: 16px;
  transition: border-color var(--dur-quick) var(--ease), box-shadow var(--dur-quick) var(--ease);
}
.field input::placeholder { color: var(--color-ink-faint); }
.field input:hover { border-color: var(--color-ink-faint); }
.field input:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(0, 117, 222, 0.18); }
.field input[aria-invalid="true"] { border-color: var(--color-danger); box-shadow: 0 0 0 3px rgba(198, 40, 40, 0.12); }
#code { font-size: 22px; letter-spacing: 8px; font-variant-numeric: tabular-nums; text-align: center; }
#code::placeholder { letter-spacing: 8px; }
.field-help { margin: 0; font-size: 13px; color: var(--color-ink-faint); }
/* 가입 유형 (RA / RC): 두 칸 토글. 라디오라 키보드 ←→ 로도 바뀐다 */
.role-pick { border: 0; padding: 0; min-width: 0; }
.role-pick legend { padding: 0; margin-bottom: 6px; font-size: 14px; font-weight: 600; color: var(--color-ink-secondary); }
.role-seg { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; padding: 4px; border-radius: 12px; background: var(--color-canvas-soft); }
.role-seg label { position: relative; display: block; cursor: pointer; }
.role-seg input { position: absolute; opacity: 0; inset: 0; width: 100%; height: 100%; margin: 0; padding: 0; border: 0; cursor: pointer; }
.role-seg span {
  display: flex; align-items: center; justify-content: center; min-height: 44px; border-radius: 9px;
  font-size: 15px; font-weight: 600; color: var(--color-ink-secondary);
  transition: background-color var(--dur-quick) var(--ease), color var(--dur-quick) var(--ease), box-shadow var(--dur-std) var(--ease);
}
.role-seg input:checked + span { background: var(--color-surface); color: var(--color-text-primary); box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12); }
.role-seg input:focus-visible + span { outline: 2px solid var(--color-primary); outline-offset: 2px; }
.field-err { margin: 0; min-height: 0; font-size: 13px; color: var(--color-danger); font-weight: 500; }
.field-err:empty { display: none; }
.field-err:not(:empty) { animation: err-in var(--dur-std) var(--ease-out); }
@keyframes err-in { from { opacity: 0; transform: translateY(-4px); } }

/* 오류 흔들림: 3번, 점점 작게, 360ms */
.shake { animation: shake 360ms var(--ease) both; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-10px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-5px); }
  80% { transform: translateX(3px); }
}

/* 버튼 */
.btn-primary {
  position: relative; height: 48px; border: 0; border-radius: var(--radius-md);
  background: var(--color-primary); color: #fff; font-size: 16px; font-weight: 600;
  display: flex; align-items: center; justify-content: center; gap: 8px;
  transition: background-color var(--dur-quick) var(--ease), transform var(--dur-quick) var(--ease), box-shadow var(--dur-std) var(--ease);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}
.btn-primary:hover:not(:disabled) { background: var(--color-primary-active); box-shadow: 0 4px 12px rgba(0, 91, 171, 0.25); }
.btn-primary:active:not(:disabled) { transform: scale(0.98); box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08); }
.btn-primary:disabled { opacity: 0.85; }
.btn-label { transition: transform var(--dur-std) var(--ease), opacity var(--dur-std) var(--ease); }
.spinner {
  position: absolute; width: 20px; height: 20px; border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.35); border-top-color: #fff;
  opacity: 0; transform: scale(0.6);
  transition: opacity var(--dur-std) var(--ease), transform var(--dur-std) var(--ease);
}
.btn-primary.loading .btn-label { opacity: 0; transform: translateY(-6px); }
.btn-primary.loading .spinner { opacity: 1; transform: scale(1); animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.btn-link {
  margin-top: 14px; align-self: center; min-height: 32px; padding: 4px 8px;
  background: none; border: 0; border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 500; color: var(--color-text-primary);
}
.btn-link:hover:not(:disabled) { text-decoration: underline; }
.btn-link:disabled { color: var(--color-ink-faint); }

.back {
  align-self: flex-start; display: inline-flex; align-items: center; gap: 4px;
  margin: -8px 0 16px -8px; min-height: 32px; padding: 4px 8px;
  background: none; border: 0; border-radius: var(--radius-sm);
  font-size: 14px; color: var(--color-ink-muted);
  transition: color var(--dur-quick) var(--ease), background-color var(--dur-quick) var(--ease);
}
.back:hover { color: var(--color-ink); background: var(--color-canvas-soft); }
.back svg { transition: transform var(--dur-std) var(--ease); }
.back:hover svg { transform: translateX(-2px); }

.fine { margin: 16px 0 0; font-size: 13px; color: var(--color-ink-faint); text-align: center; }

/* 성공: 원이 그려지고 → 체크가 그려지고 → 살짝 커졌다 자리잡음 */
.step-done { align-items: center; text-align: center; padding: 16px 0 8px; }
.step-done:focus { outline: none; }   /* 화면 읽기 프로그램용으로만 포커스를 옮김 */
.done-check { margin-bottom: 16px; }
.done-check circle { fill: none; stroke: var(--color-success); stroke-width: 3; stroke-dasharray: 164; stroke-dashoffset: 164; animation: draw 420ms var(--ease-out) forwards; }
.done-check path { fill: none; stroke: var(--color-success); stroke-width: 3.5; stroke-linecap: round; stroke-linejoin: round; stroke-dasharray: 40; stroke-dashoffset: 40; animation: draw 240ms var(--ease-out) 300ms forwards; }
.step-done.entering .done-check { animation: pop 420ms var(--ease-out) 300ms both; }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes pop { 50% { transform: scale(1.06); } }
.step-done .step-desc { margin-bottom: 0; }

/* 페이지 떠날 때 */
.login.page-out .login-card { animation: page-out 240ms var(--ease-in) both; }
@keyframes page-out { to { opacity: 0; transform: translateY(-8px) scale(0.99); } }

/* ---------------------------------------------------------- 좁은 화면 */
@media (max-width: 767px) {
  .login { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  .login-brand { padding: 28px 20px; justify-content: flex-start; }
  .brand-inner { display: grid; grid-template-columns: auto 1fr; column-gap: 14px; align-items: center; }
  .brand-seal { width: 44px; height: 44px; grid-row: span 2; }
  .brand-eyebrow { margin: 0; font-size: 11px; }
  .brand-title { font-size: 28px; letter-spacing: -0.5px; }
  .brand-copy { display: none; }
  .login-panel { justify-content: flex-start; padding: 24px 16px 32px; }
  .login-card { padding: 28px 20px 24px; }
}

/* 문장 안 링크 버튼 (회원가입으로) */
.btn-link.inline { margin: 0; padding: 2px 4px; min-height: 24px; font-size: 13px; }
.step .field:last-of-type { margin-bottom: 20px; }
#stepSignup .field { margin-bottom: 14px; }

#code { font-size: 22px; letter-spacing: 8px; font-variant-numeric: tabular-nums; text-align: center; }

/* 학생 제출 페이지 */
.drop {
  display: flex; flex-direction: column; align-items: center; gap: 6px; margin-bottom: 12px; padding: 22px 16px; text-align: center; cursor: pointer;
  border: 1.5px dashed var(--color-hairline-strong); border-radius: var(--radius-lg); background: var(--color-canvas-soft); color: var(--color-ink-secondary);
  transition: border-color var(--dur-quick) var(--ease), background-color var(--dur-quick) var(--ease), transform var(--dur-std) var(--ease);
}
.drop svg { color: var(--color-text-primary); }
.drop span { font-size: 13px; color: var(--color-ink-muted); }
.drop:hover, .drop:focus-visible, .drop.over { border-color: var(--color-primary); background: var(--color-tint); }
.drop.over { transform: scale(1.01); }
.picked { list-style: none; margin: 0 0 12px; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.picked:empty { display: none; }
.picked li { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 6px 10px; border-radius: var(--radius-md); background: var(--color-canvas-soft); font-size: 14px; word-break: break-all; animation: err-in var(--dur-std) var(--ease-out); }
.picked li button { flex: none; width: 28px; height: 28px; border: 0; border-radius: 50%; background: none; font-size: 18px; cursor: pointer; color: var(--color-ink-muted); }
.picked li button:hover { background: var(--color-canvas-soft); }
.picked.results { width: 100%; text-align: left; margin-top: 4px; }
.picked.results li.ok { background: var(--color-ok-bg); color: var(--color-ok-text); }
.picked.results li.fail { background: var(--color-fail-bg); color: var(--color-fail-text); }
#stepPick .field-err { margin-bottom: 12px; }

.lang-slot { display: flex; justify-content: flex-end; margin-bottom: 8px; }
.lang-slot .lang-pick { width: auto; height: 36px; padding: 0 28px 0 10px; font-size: 13px; border: 1px solid var(--color-hairline-strong); border-radius: 8px; background: var(--color-surface); color: var(--color-ink); }

.found-id { margin: 0 0 20px; padding: 14px 16px; border-radius: var(--radius-md); background: var(--color-canvas-soft); font-size: 18px; font-weight: 700; letter-spacing: 0.02em; color: var(--color-ink); }

.remember { display: flex; align-items: center; gap: 8px; margin: -4px 0 14px; font-size: 14px; color: var(--color-ink-secondary); cursor: pointer; }
.remember .fine { margin: 0; font-size: 12px; color: var(--color-ink-muted); }