/* 제작: 고수스튜디오 (홈·선생님 화면 맨 아래) */
.studio-foot { text-align: center; padding: 34px 16px 26px; margin-top: 18px; position: relative; }
.studio-foot::before { content: ""; position: absolute; left: 12%; right: 12%; top: 0; height: 1px; background: linear-gradient(90deg, transparent, rgba(27, 63, 196, .25), transparent); }
.sf-mark { width: 54px; height: 54px; margin: 0 auto 14px; border-radius: 16px; display: grid; place-items: center; position: relative;
  background: linear-gradient(135deg, #1A5CFF 0%, #7a3cff 55%, #ff4f9a 100%);
  box-shadow: 0 10px 24px -10px rgba(122, 60, 255, .7), inset 0 1px 0 rgba(255,255,255,.45); transform: rotate(-6deg); }
.sf-mark::after { content: ""; position: absolute; inset: 3px; border-radius: 13px; border: 1.5px solid rgba(255,255,255,.35); }
.sf-mark span { color: #fff; font-weight: 900; font-size: 20px; letter-spacing: -1px; transform: rotate(6deg); font-family: "Pretendard Variable", sans-serif; }
.sf-made { display: flex; align-items: center; justify-content: center; gap: 10px; font-size: 11.5px; font-weight: 700; letter-spacing: 4px; color: #8a94ad; }
.sf-made::before, .sf-made::after { content: ""; width: 26px; height: 1px; background: #c3cbe0; }
.sf-name { margin-top: 6px; font-size: 24px; font-weight: 900; letter-spacing: -1px;
  background: linear-gradient(90deg, #1A5CFF 0%, #7a3cff 50%, #ff4f9a 100%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sf-en { margin-top: 2px; font-size: 11.5px; font-weight: 800; letter-spacing: 7px; color: #0d1b3e; padding-left: 7px; }
.sf-apps { margin-top: 14px; font-size: 12.5px; color: #667085; font-weight: 600; }
.sf-copy { margin-top: 6px; font-size: 11px; color: #98a2b3; letter-spacing: .3px; }
.studio-foot.sm { padding: 26px 16px 20px; }
.studio-foot.sm .sf-mark { width: 44px; height: 44px; border-radius: 13px; }
.studio-foot.sm .sf-mark span { font-size: 16px; }
.studio-foot.sm .sf-name { font-size: 20px; }
@media print { .studio-foot { display: none; } }

/* 맨 아래 작은 열쇠 (관리자 들어가기) — 티 안 나게 */
.sf-key { display: block; margin: 14px auto 0; width: 30px; height: 30px; min-height: 0; padding: 5px; border: 0; border-radius: 50%; background: transparent; color: #b8c0d4; opacity: .55; box-shadow: none; }
.sf-key svg { width: 100%; height: 100%; }
.sf-key:active { opacity: 1; color: #1b3fc4; }
.key-sheet { display: flex; flex-direction: column; gap: 10px; }
.key-sheet h3 { margin: 0 0 4px; font-size: 26px; }
.key-sheet input { font-size: 17px; padding: 12px 14px; border-radius: 12px; }
.key-sheet #kGo { padding: 13px; border: 0; border-radius: 12px; font-size: 16px; font-weight: 800; color: #fff; background: #1b3fc4; }

/* 열쇠 창은 화면 위쪽에 — 자판이 올라와도 비밀번호 칸이 가려지지 않게 */
.ins-back.key-back { align-items: flex-start; z-index: 70; }
.key-back .ins-sheet { border-radius: 0 0 24px 24px; padding-top: calc(18px + env(safe-area-inset-top)); animation: keyDown .25s cubic-bezier(.2,.9,.3,1); }
@keyframes keyDown { from { transform: translateY(-100%); } to { transform: none; } }