:root{
  --bg1:#fff1f2; --bg2:#eef2ff; --bg3:#ecfeff;
  --surface:#ffffff; --surface-2:#f8fafc;
  --ink:#1f2430; --ink-soft:#5b6472; --line:#e7ebf2;
  --brand:#6d5efc; --brand-ink:#ffffff; --brand-soft:#efeaff;
  --pink:#ff5d8f; --amber:#ffb020; --green:#12b886; --red:#ef4444;
  --shadow:0 10px 30px rgba(31,36,48,.10);
  --shadow-sm:0 3px 10px rgba(31,36,48,.08);
  --radius:18px; --radius-sm:12px;
  --font:-apple-system,BlinkMacSystemFont,"Apple SD Gothic Neo","Pretendard","Segoe UI",Roboto,"Malgun Gothic",sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:var(--font); color:var(--ink); min-height:100vh;
  background:
    radial-gradient(1200px 600px at 8% -5%, var(--bg1), transparent 60%),
    radial-gradient(1000px 700px at 100% 0%, var(--bg3), transparent 55%),
    linear-gradient(160deg, var(--bg2), #ffffff 70%);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
}
.view{min-height:100vh}
[hidden]{display:none !important}

/* ---------- 버튼 ---------- */
.btn{
  font-family:inherit; font-size:14px; font-weight:700; cursor:pointer;
  border:none; border-radius:999px; padding:10px 18px; color:var(--ink);
  background:var(--surface-2); transition:transform .08s ease, box-shadow .15s, background .15s;
  display:inline-flex; align-items:center; gap:7px; line-height:1;
}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn-primary{background:var(--brand); color:var(--brand-ink); box-shadow:var(--shadow-sm)}
.btn-primary:hover{box-shadow:var(--shadow)}
.btn-ghost{background:rgba(255,255,255,.7); color:var(--ink-soft)}
.btn-ghost:hover{background:#fff}
.btn-danger{background:#fff0f0; color:var(--red)}
.btn-block{width:100%; justify-content:center; padding:13px}
.icon-btn{padding:9px 12px; font-size:16px}
.btn-google{background:#fff; color:#3c4043; box-shadow:var(--shadow-sm); border:1px solid var(--line)}
.g-icon{display:inline-grid; place-items:center; width:20px;height:20px;border-radius:50%;
  background:conic-gradient(from -45deg,#ea4335 0 25%,#fbbc05 0 50%,#34a853 0 75%,#4285f4 0);
  color:#fff; font-weight:900; font-size:12px}

/* ---------- 로그인 ---------- */
.login-view{display:flex; flex-direction:column; align-items:center; justify-content:center; padding:24px; gap:18px}
.login-card{
  width:min(420px,100%); background:var(--surface); border-radius:26px;
  box-shadow:var(--shadow); padding:30px 26px 26px;
}
.brand{text-align:center; margin-bottom:20px}
.brand-logo{font-size:44px; line-height:1}
.brand h1{margin:8px 0 2px; font-size:28px; letter-spacing:-.5px}
.brand-sub{margin:0; color:var(--ink-soft); font-size:14px}
.tabs{display:flex; background:var(--surface-2); border-radius:999px; padding:4px; margin-bottom:20px}
.tab{flex:1; border:none; background:transparent; padding:10px; border-radius:999px; font-weight:700;
  color:var(--ink-soft); cursor:pointer; font-family:inherit; font-size:14px}
.tab.is-active{background:#fff; color:var(--brand); box-shadow:var(--shadow-sm)}
.tab-panel{display:none; flex-direction:column; gap:14px}
.tab-panel.is-active{display:flex}
.teacher-note{color:var(--ink-soft); font-size:14px; line-height:1.6; text-align:center; margin:6px 0 4px}
.login-foot{color:var(--ink-soft); font-size:12px; opacity:.8}
.config-warning{margin:16px 0 0; font-size:12.5px; color:#b45309; background:#fffbeb; padding:10px 12px; border-radius:12px; line-height:1.5}
.config-warning code{background:#fef3c7; padding:1px 5px; border-radius:5px}

/* ---------- 폼 필드 ---------- */
.field{display:flex; flex-direction:column; gap:6px; font-size:13px; font-weight:700; color:var(--ink-soft)}
.field small{font-weight:500}
.field input,.field textarea,.new-board input{
  font-family:inherit; font-size:15px; font-weight:500; color:var(--ink);
  border:1.5px solid var(--line); border-radius:var(--radius-sm); padding:12px 14px;
  background:var(--surface-2); transition:border .15s, background .15s;
}
.field textarea{resize:vertical; line-height:1.5}
.field input:focus,.field textarea:focus{outline:none; border-color:var(--brand); background:#fff}
.field input[readonly]{color:var(--ink-soft)}
.field-row{display:flex; gap:12px}
.field-sm{width:96px; flex:0 0 auto}
.field-grow{flex:1}
.hint{font-weight:500; color:var(--ink-soft); font-size:12px; line-height:1.5}
.error-msg{margin:0; color:var(--red); font-size:13px; font-weight:600}

/* ---------- 교사 홈 ---------- */
.home-top{display:flex; align-items:center; justify-content:space-between; padding:18px 22px;
  background:rgba(255,255,255,.75); backdrop-filter:blur(10px); position:sticky; top:0; z-index:5}
.home-id{display:flex; align-items:center; gap:12px}
.home-avatar{width:42px;height:42px;border-radius:50%; background:var(--brand); color:#fff;
  display:grid; place-items:center; font-weight:800; overflow:hidden}
.home-avatar img{width:100%;height:100%;object-fit:cover}
.home-id strong{display:block; font-size:15px}
.home-id small{color:var(--ink-soft); font-size:12.5px}
.home-main{max-width:820px; margin:0 auto; padding:26px 20px 60px}
.home-main h2{font-size:22px; margin:6px 0 16px}
.board-list{display:grid; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); gap:14px; margin-bottom:34px}
.board-tile{background:var(--surface); border-radius:var(--radius); padding:18px; box-shadow:var(--shadow-sm);
  cursor:pointer; border:1.5px solid transparent; transition:transform .1s, border .15s, box-shadow .15s; text-align:left}
.board-tile:hover{transform:translateY(-2px); box-shadow:var(--shadow); border-color:var(--brand-soft)}
.board-tile h4{margin:0 0 6px; font-size:16px}
.board-tile .code{font-size:12.5px; color:var(--brand); font-weight:700; background:var(--brand-soft); padding:3px 9px; border-radius:999px}
.board-tile .meta{margin-top:10px; color:var(--ink-soft); font-size:12.5px}
.new-board{background:var(--surface); border-radius:var(--radius); padding:20px; box-shadow:var(--shadow-sm)}
.new-board h3{margin:0 0 14px; font-size:16px}
.new-board .field-row{margin-bottom:12px}

/* ---------- 게시판 ---------- */
.board-top{display:flex; align-items:center; justify-content:space-between; gap:12px; padding:16px 22px;
  background:rgba(255,255,255,.78); backdrop-filter:blur(10px); position:sticky; top:0; z-index:5; flex-wrap:wrap}
.board-top-left{display:flex; align-items:center; gap:10px; min-width:0}
.board-top h1{font-size:20px; margin:0; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; max-width:52vw}
.board-top-right{display:flex; align-items:center; gap:8px; flex-wrap:wrap}
.user-chip{background:var(--brand-soft); color:var(--brand); font-weight:700; font-size:13px; padding:7px 12px; border-radius:999px}

/* 탭(분류) 바 */
.tab-bar{display:flex; gap:8px; overflow-x:auto; padding:12px 22px; position:sticky; top:64px; z-index:4;
  background:rgba(255,255,255,.7); backdrop-filter:blur(8px); scrollbar-width:thin}
.tab-pill{flex:0 0 auto; border:1.5px solid var(--line); background:var(--surface); color:var(--ink-soft);
  font-weight:700; font-size:13.5px; padding:8px 16px; border-radius:999px; cursor:pointer; font-family:inherit;
  transition:background .12s, border-color .12s, color .12s}
.tab-pill:hover{border-color:var(--brand-soft)}
.tab-pill.is-active{background:var(--brand); border-color:var(--brand); color:var(--brand-ink)}

.board-main{max-width:1400px; margin:0 auto; padding:22px 20px 80px}
.empty-state{text-align:center; color:var(--ink-soft); padding:70px 20px}
.empty-emoji{font-size:52px}

/* 패들렛식 메이슨리 */
.grid{column-gap:20px; column-width:340px}
@media (max-width:420px){ .grid{column-width:100%} }
.card{
  break-inside:avoid; margin:0 0 20px; background:var(--surface); border-radius:var(--radius);
  box-shadow:var(--shadow-sm); overflow:hidden; transition:transform .1s, box-shadow .15s;
}
.card:hover{transform:translateY(-3px); box-shadow:var(--shadow)}
.card-preview{position:relative; background:#0f1222}
.card-preview .frame{position:relative; width:100%; aspect-ratio:4/3; overflow:hidden}
.card-preview iframe{position:absolute; inset:0; width:100%; height:100%; border:0; background:#0f1222}
.card-preview .frame-cover{position:absolute; inset:0; cursor:pointer}
.expand-btn{position:absolute; right:10px; bottom:10px; z-index:2; border:none; cursor:pointer;
  background:rgba(15,18,34,.72); color:#fff; font-weight:700; font-size:12.5px; padding:8px 12px;
  border-radius:999px; backdrop-filter:blur(4px)}
.expand-btn:hover{background:rgba(15,18,34,.9)}
.card-body{padding:14px 16px 16px}
.card-tab-pill{display:inline-block; background:var(--brand-soft); color:var(--brand); font-size:11.5px;
  font-weight:800; padding:3px 9px; border-radius:999px; margin-bottom:8px}
.card-title{margin:0 0 4px; font-size:16px; line-height:1.35}
.card-author{color:var(--ink-soft); font-size:13px; font-weight:600; margin-bottom:12px; display:flex; align-items:center; gap:5px}
.card-admin{margin-top:12px; display:flex; gap:8px; border-top:1px solid var(--line); padding-top:12px}
.card-admin .btn{font-size:12.5px; padding:7px 12px}

/* ---------- 반응 바 ---------- */
.reaction-bar{display:flex; align-items:center; gap:8px; flex-wrap:wrap}
.react{display:inline-flex; align-items:center; gap:5px; border:1.5px solid var(--line); background:var(--surface-2);
  border-radius:999px; padding:7px 12px; font-weight:700; font-size:13px; color:var(--ink-soft); cursor:pointer;
  font-family:inherit; transition:border .12s, background .12s, transform .08s}
.react:hover{transform:translateY(-1px)}
.react.on{background:var(--brand-soft); border-color:transparent; color:var(--brand)}
.react.heart.on{background:#ffe9f0; color:var(--pink)}
.react .emoji{font-size:15px}
.stars{display:inline-flex; align-items:center; gap:2px}
.star{cursor:pointer; font-size:19px; line-height:1; color:#d7dbe4; transition:transform .08s}
.star:hover{transform:scale(1.15)}
.star.lit{color:var(--amber)}
.score-avg{font-size:12.5px; color:var(--ink-soft); font-weight:700; margin-left:2px}
.comment-btn{display:inline-flex; align-items:center; gap:5px; border:1.5px solid var(--line); background:var(--surface-2);
  border-radius:999px; padding:7px 12px; font-weight:700; font-size:13px; color:var(--ink-soft); cursor:pointer; font-family:inherit}
.comment-btn:hover{background:#fff}
.reaction-bar-lg{margin:14px 0}
.reaction-bar-lg .react{padding:9px 15px; font-size:14px}
.reaction-bar-lg .star{font-size:24px}

/* ---------- 모달 ---------- */
.modal{position:fixed; inset:0; z-index:50; background:rgba(20,22,35,.5); backdrop-filter:blur(3px);
  display:flex; align-items:center; justify-content:center; padding:20px; animation:fade .15s ease}
@keyframes fade{from{opacity:0}to{opacity:1}}
.modal-box{background:var(--surface); border-radius:22px; box-shadow:var(--shadow); width:min(520px,100%);
  max-height:92vh; overflow:auto; padding:24px; display:flex; flex-direction:column; gap:16px}
.modal-box h3{margin:0; font-size:19px}
.modal-actions{display:flex; align-items:center; gap:10px; margin-top:4px}
.modal-actions .spacer{flex:1}
.work-preview-wrap{border-radius:var(--radius-sm); overflow:hidden; border:1px solid var(--line)}
.work-preview-frame{position:relative; width:100%; aspect-ratio:4/3; background:#0f1222}
.work-preview-frame iframe{position:absolute; inset:0; width:100%; height:100%; border:0}
.toggles{display:flex; flex-direction:column; gap:10px; background:var(--surface-2); padding:16px; border-radius:var(--radius-sm)}
.toggles-label{font-size:13px; font-weight:700; color:var(--ink-soft)}
.switch{display:flex; align-items:center; gap:10px; font-weight:600; font-size:15px; cursor:pointer}
.switch input{width:18px; height:18px; accent-color:var(--brand)}

.tabs-manage{display:flex; flex-direction:column; gap:10px; background:var(--surface-2); padding:16px; border-radius:var(--radius-sm)}
.tabs-manage-list{display:flex; flex-direction:column; gap:8px}
.tab-row{display:flex; align-items:center; gap:6px}
.tab-row-name{flex:1; font-family:inherit; font-size:14px; font-weight:600; color:var(--ink);
  border:1.5px solid var(--line); border-radius:10px; padding:8px 11px; background:var(--surface)}
.tab-row-name:focus{outline:none; border-color:var(--brand)}
.btn-icon{border:1.5px solid var(--line); background:var(--surface); border-radius:9px; width:32px; height:32px;
  cursor:pointer; font-size:14px; color:var(--ink-soft); flex:0 0 auto}
.btn-icon:hover{background:#fff}
.btn-icon:disabled{opacity:.35; cursor:default}
.btn-icon.tab-del:hover{color:var(--red); border-color:#fecaca}
.tabs-manage-add{display:flex; gap:8px}
.tabs-manage-add input{flex:1; font-family:inherit; font-size:14px; border:1.5px solid var(--line);
  border-radius:10px; padding:9px 12px; background:var(--surface)}
.tabs-manage-add input:focus{outline:none; border-color:var(--brand)}

/* 확대 모달 */
.modal-expand{padding:0}
.expand-box{position:relative; width:100vw; height:100vh; background:var(--surface);
  display:grid; grid-template-columns:1fr 380px}
.expand-close{position:absolute; top:14px; right:14px; z-index:10; width:40px;height:40px; border-radius:50%;
  border:none; cursor:pointer; background:rgba(255,255,255,.9); box-shadow:var(--shadow-sm); font-size:17px; font-weight:700}
.expand-preview{background:#0b0e1c; display:flex; align-items:center; justify-content:center; padding:24px; min-width:0}
.expand-frame-wrap{position:relative; width:100%; max-width:1100px; aspect-ratio:4/3; max-height:100%;
  border-radius:14px; overflow:hidden; box-shadow:0 20px 60px rgba(0,0,0,.4)}
.expand-frame-wrap iframe{position:absolute; inset:0; width:100%; height:100%; border:0; background:#0b0e1c}
.expand-side{display:flex; flex-direction:column; padding:22px 20px; min-height:0; border-left:1px solid var(--line)}
.expand-title{margin:0 6px 2px 0; font-size:19px}
.expand-author{color:var(--ink-soft); font-size:13.5px; font-weight:600; margin-bottom:6px}
.comments-head{display:flex; align-items:center; gap:8px; margin:8px 0 8px; border-top:1px solid var(--line); padding-top:14px}
.comments-head h4{margin:0; font-size:15px}
.pill{background:var(--brand-soft); color:var(--brand); font-size:12px; font-weight:800; padding:2px 9px; border-radius:999px}
.comments-list{flex:1; overflow:auto; display:flex; flex-direction:column; gap:10px; padding-right:4px; min-height:60px}
.comment{background:var(--surface-2); border-radius:14px; padding:11px 13px; position:relative}
.comment .who{font-size:12.5px; font-weight:800; color:var(--brand)}
.comment .txt{font-size:14px; margin-top:3px; line-height:1.5; word-break:break-word; white-space:pre-wrap}
.comment .del{position:absolute; top:8px; right:8px; border:none; background:transparent; color:var(--ink-soft);
  cursor:pointer; font-size:13px; opacity:.5}
.comment .del:hover{opacity:1; color:var(--red)}
.comment-empty{color:var(--ink-soft); font-size:13.5px; text-align:center; padding:24px 0}
.comment-form{display:flex; gap:8px; margin-top:12px}
.comment-form input{flex:1; font-family:inherit; font-size:14.5px; border:1.5px solid var(--line);
  border-radius:999px; padding:11px 15px; background:var(--surface-2)}
.comment-form input:focus{outline:none; border-color:var(--brand); background:#fff}

@media (max-width:820px){
  .expand-box{grid-template-columns:1fr; grid-template-rows:minmax(0,1fr) minmax(0,46vh)}
  .expand-side{border-left:none; border-top:1px solid var(--line)}
  .expand-frame-wrap{aspect-ratio:16/10}
}

/* ---------- 토스트 ---------- */
.toast{position:fixed; left:50%; bottom:26px; transform:translateX(-50%); z-index:80;
  background:var(--ink); color:#fff; padding:12px 20px; border-radius:999px; font-weight:600; font-size:14px;
  box-shadow:var(--shadow); animation:fade .15s ease}

/* ---------- 다크 모드 ---------- */
@media (prefers-color-scheme:dark){
  :root{
    --bg1:#241726; --bg2:#141a2e; --bg3:#0e2226;
    --surface:#191d2a; --surface-2:#222738; --ink:#eef1f7; --ink-soft:#9aa3b5; --line:#2c3243;
    --brand-soft:#2a2650; --shadow:0 12px 34px rgba(0,0,0,.45); --shadow-sm:0 3px 12px rgba(0,0,0,.35);
  }
  body{background:
    radial-gradient(1200px 600px at 8% -5%, var(--bg1), transparent 60%),
    radial-gradient(1000px 700px at 100% 0%, var(--bg3), transparent 55%),
    linear-gradient(160deg, var(--bg2), #0b0e18 70%);}
  .btn-google{background:#222738; color:#eef1f7; border-color:var(--line)}
  .tab.is-active{background:#2c3243}
  .config-warning{background:#2a2412; color:#fcd34d}
  .config-warning code{background:#3a3418}
}