:root{
  --paper:#FCFBF5;
  --line:#C3D6E8;
  --margin-red:#E8A8A0;
  --ink:#33415C;
  --pencil:#5A6478;
  --redpen:#D9442E;
  --blue:#7BB8D9;
}
*{margin:0;padding:0;box-sizing:border-box;}
html,body{height:100%;}
body{
  font-family:"Zen Maru Gothic",sans-serif;
  color:var(--ink);overflow:hidden;background:var(--paper);
}
button{font-family:inherit;}

/* ═════════ fullscreen notebook ═════════ */
.page{
  position:fixed;inset:0;background:var(--paper);
  background-image:
    linear-gradient(to right, transparent 78px, var(--margin-red) 78px, var(--margin-red) 80px, transparent 80px),
    repeating-linear-gradient(to bottom, transparent 0 39px, var(--line) 39px 40px);
  background-position:0 14px;
}
.page::after{
  content:"";position:absolute;left:26px;top:0;bottom:0;width:16px;
  background-image:radial-gradient(circle 8px, #E9E2D2 7px, rgba(51,65,92,.2) 8px, transparent 9px);
  background-size:16px 84px;background-position:center 40px;background-repeat:repeat-y;
  pointer-events:none;
}
.topbar{
  position:fixed;top:0;left:0;right:0;z-index:20;
  display:flex;align-items:center;gap:14px;
  padding:12px 24px 8px 100px;
  background:linear-gradient(var(--paper) 70%, transparent);
}
.logo{font-weight:900;font-size:16px;letter-spacing:.05em;display:flex;align-items:center;gap:9px;white-space:nowrap;}
.logo .badge{width:28px;height:28px;border-radius:8px;background:var(--redpen);color:#fff;display:grid;place-items:center;font-size:14px;transform:rotate(-4deg);}
.demo-tag{font-size:11px;font-weight:700;color:var(--redpen);border:1.5px dashed var(--redpen);border-radius:6px;padding:1px 7px;transform:rotate(-2deg);}
.crumb{display:flex;align-items:center;gap:8px;font-size:13px;font-weight:700;min-width:0;}
.crumb .pill{font-size:13px;font-weight:700;color:var(--ink);background:#FFF6E3;border:1.5px solid #F2B33D;border-radius:999px;padding:5px 14px;cursor:pointer;box-shadow:2px 2px 0 rgba(242,179,61,.4);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:42vw;}
.crumb .sep{background:none;border:none;font-size:13px;font-weight:700;color:var(--pencil);opacity:.6;cursor:pointer;white-space:nowrap;}
.spacer{flex:1;}
.speed{display:flex;align-items:center;gap:6px;font-size:12px;font-weight:700;color:var(--pencil);white-space:nowrap;}
.speed select{font-family:inherit;font-weight:700;font-size:12px;color:var(--ink);border:1.5px solid rgba(51,65,92,.35);border-radius:999px;padding:5px 10px;background:#fff;cursor:pointer;}
.replay{background:none;border:none;color:var(--pencil);cursor:pointer;font-size:12px;font-weight:700;text-decoration:underline dotted;white-space:nowrap;}

/* ═════════ notebook content (board work) ═════════ */
.canvas{
  position:fixed;top:58px;bottom:96px;left:0;right:372px;
  overflow-y:auto;padding:14px 30px 60px 110px;
  font-family:"Klee One",cursive;font-size:18px;line-height:40px;scroll-behavior:smooth;
}
.note-line{opacity:0;transform:translateY(5px);transition:opacity .45s, transform .45s;white-space:pre-wrap;overflow-wrap:anywhere;}
.note-line.show{opacity:1;transform:none;}
.note-line.empty{color:var(--pencil);font-size:16px;}
.note-line.spacer{height:40px;}
.note-title{font-size:22px;font-weight:600;}
.note-title .date{font-family:"Zen Maru Gothic";font-size:11px;color:var(--pencil);letter-spacing:.12em;margin-right:14px;}
.q-line{color:var(--pencil);font-size:16px;}
.q-line::before{content:"Q. ";font-weight:600;color:var(--blue);}
.src-head{font-family:"Zen Maru Gothic";font-size:12px;font-weight:700;color:var(--pencil);letter-spacing:.04em;}
.src-head .srcnum{color:var(--redpen);font-size:14px;margin-right:6px;}
.prob{font-size:16px;}
.prob details{font-family:"Zen Maru Gothic";}
.prob summary{display:inline-block;font-size:12px;font-weight:700;color:#4F93B8;cursor:pointer;list-style:none;}
.prob summary::-webkit-details-marker{display:none;}
.prob summary::before{content:"▸ ";}
.prob details[open] summary::before{content:"▾ ";}
.prob .fulltext{font-family:"Klee One",cursive;font-size:15px;color:var(--pencil);white-space:pre-wrap;}
.ans-line::before{content:"→ ";color:var(--redpen);font-weight:600;}
.ans{position:relative;display:inline-block;max-width:calc(100% - 2em);vertical-align:top;color:var(--redpen);font-weight:600;white-space:pre-wrap;clip-path:inset(0 100% 0 0);}
.ans.writing{animation:sweep var(--dur,1.8s) steps(40) forwards;}
.ans.done{clip-path:none;}
@keyframes sweep{to{clip-path:inset(0 0 0 0);}}
.hl::after{content:"";position:absolute;inset:-6px -10px;border:2.5px solid var(--redpen);border-radius:50%;transform:rotate(-3deg);opacity:0;transition:opacity .5s;pointer-events:none;}
.hl.on::after{opacity:.85;}
.pen{position:absolute;font-size:28px;z-index:5;transform:translate(-6px,-28px) rotate(38deg);opacity:0;pointer-events:none;transition:opacity .2s;filter:drop-shadow(1px 2px 1px rgba(0,0,0,.18));}
.pen.on{opacity:1;}

/* 授業の板書（Gemini の台本: 見出し → 問題 → 板書 → 答え → 参考） */
.note-line .red{color:var(--redpen);font-weight:600;}
.prob-tag{color:var(--blue);font-weight:600;margin-right:6px;}
.ink{position:relative;display:inline-block;max-width:100%;vertical-align:top;white-space:pre-wrap;clip-path:inset(0 100% 0 0);}
.ink.writing{animation:sweep var(--dur,2s) steps(50) forwards;}
.ink.done{clip-path:none;}
.big-line .ink{font-size:26px;padding:0 8px;}
.answer-line .ink{font-size:24px;font-weight:600;color:var(--redpen);padding:0 10px;margin-left:6px;}
.check{display:inline-grid;place-items:center;text-align:center;line-height:1.15;white-space:nowrap;font-family:"Zen Maru Gothic";font-size:11px;font-weight:700;color:var(--redpen);border:2.5px solid var(--redpen);border-radius:50%;width:62px;height:62px;transform:rotate(8deg);opacity:0;transition:opacity .6s;vertical-align:middle;margin:-11px 0 -11px 22px;}
.check.show{opacity:.9;}
.refs{font-family:"Zen Maru Gothic";font-size:12px;font-weight:700;color:var(--pencil);}
.refs-label{margin-right:8px;}
.ref{position:relative;display:inline-block;margin-right:12px;padding:0 4px;cursor:pointer;text-decoration:underline dotted;}
.ref-detail{font-size:15px;color:var(--pencil);}
.ref-detail .red{font-weight:600;}

/* ═════════ chat column (right, scrollable history) ═════════ */
.chatcol{
  position:fixed;top:58px;bottom:96px;right:0;width:360px;z-index:25;
  display:flex;flex-direction:column;
  border-left:2px dashed rgba(51,65,92,.18);
}
.chatlog{
  flex:1;overflow-y:auto;padding:18px 18px 6px;
  display:flex;flex-direction:column;gap:12px;scroll-behavior:smooth;
}
.chatlog::-webkit-scrollbar{width:8px;}
.chatlog::-webkit-scrollbar-thumb{background:rgba(51,65,92,.2);border-radius:8px;}
.scrollhint{
  position:absolute;top:8px;left:50%;transform:translateX(-50%);z-index:2;
  font-size:11px;font-weight:700;color:var(--pencil);
  background:#fff;border:1.5px solid rgba(51,65,92,.25);border-radius:999px;
  padding:4px 12px;box-shadow:1px 1px 0 rgba(51,65,92,.1);cursor:pointer;
  opacity:0;transition:opacity .2s;pointer-events:none;
}
.scrollhint.show{opacity:1;pointer-events:auto;}

.msg{max-width:90%;font-size:14px;line-height:1.8;font-weight:500;position:relative;}
.msg .meta{font-size:10px;font-weight:700;color:var(--pencil);letter-spacing:.08em;margin-bottom:3px;opacity:.7;}
.msg .t{white-space:pre-wrap;overflow-wrap:anywhere;}
.msg.tutor-msg{align-self:flex-start;}
.msg.tutor-msg .body{
  background:#fff;border:2px solid var(--ink);border-radius:4px 16px 16px 16px;
  padding:11px 15px;box-shadow:3px 3px 0 rgba(51,65,92,.13);
}
.msg.tutor-msg.thinking .t{color:var(--pencil);}
.msg.tutor-msg.error .body{border-color:var(--redpen);background:#FFF5F2;}
.msg.user-msg{align-self:flex-end;text-align:right;}
.msg.user-msg .body{
  background:var(--blue);color:#fff;border:2px solid #5C9FC4;border-radius:16px 4px 16px 16px;
  padding:11px 15px;box-shadow:3px 3px 0 rgba(92,159,196,.3);text-align:left;
}
.msg .cursor{display:inline-block;width:8px;height:15px;background:currentColor;vertical-align:-2px;animation:blink .8s steps(1) infinite;}
@keyframes blink{50%{opacity:0;}}
.msg.fresh{opacity:0;transform:translateY(8px);}
.msg.fresh.in{opacity:1;transform:none;transition:opacity .35s, transform .35s;}
.cite{font-size:12px;font-weight:700;color:var(--redpen);background:#FFF0EC;border:1.5px solid var(--redpen);border-radius:999px;padding:0 6px;margin:0 2px;cursor:pointer;vertical-align:1px;}
.cite:hover{background:var(--redpen);color:#fff;}

/* tutor avatar pinned at bottom of column */
.avatar-row{display:flex;align-items:flex-end;justify-content:flex-end;padding:0 14px 4px;}
.avatar{width:120px;height:130px;}
.avatar svg{width:100%;height:100%;filter:drop-shadow(0 6px 10px rgba(51,65,92,.18));}
.talking .mouth-open{display:block;}
.talking .mouth-closed{display:none;}
.mouth-open{display:none;}
@keyframes bob{0%,100%{transform:translateY(0);}50%{transform:translateY(-4px);}}
.talking .avatar{animation:bob 1.1s ease-in-out infinite;}
.eyes{animation:blinkEyes 4.5s infinite;}
@keyframes blinkEyes{0%,94%,100%{transform:scaleY(1);}96%{transform:scaleY(.1);}}

/* ═════════ bottom chat bar ═════════ */
.chatbar{
  position:fixed;left:0;right:0;bottom:0;z-index:40;
  padding:10px 24px 16px 100px;
  background:linear-gradient(transparent, var(--paper) 35%);
  display:flex;flex-direction:column;gap:9px;
  pointer-events:none;
}
.chatbar > *{pointer-events:auto;}
.pills{display:flex;gap:8px;flex-wrap:wrap;min-height:36px;}
.qpill{background:#fff;border:1.5px solid rgba(51,65,92,.35);color:var(--ink);font-size:13px;font-weight:700;padding:8px 16px;border-radius:999px;cursor:pointer;box-shadow:2px 2px 0 rgba(51,65,92,.08);transition:all .15s;white-space:nowrap;}
.qpill:hover{border-color:var(--ink);transform:translateY(-2px);}
.inputrow{display:flex;gap:10px;max-width:760px;}
.input{flex:1;min-width:0;display:flex;align-items:center;gap:10px;background:#fff;border:2px solid var(--ink);border-radius:999px;padding:4px 8px 4px 20px;box-shadow:3px 3px 0 rgba(51,65,92,.15);}
.input input{flex:1;min-width:0;border:none;outline:none;background:none;font-family:inherit;font-size:15px;font-weight:500;color:var(--ink);padding:10px 0;}
.input input::placeholder{color:#A7AFC0;}
.send{border:none;cursor:pointer;font-weight:700;font-size:14px;background:var(--ink);color:#fff;border-radius:999px;padding:9px 20px;white-space:nowrap;}
.mic{width:52px;height:52px;border-radius:50%;border:none;cursor:pointer;background:var(--redpen);color:#fff;font-size:20px;box-shadow:0 4px 0 #A92F1F;flex-shrink:0;transition:transform .1s, box-shadow .1s;position:relative;}
.mic:active{transform:translateY(3px);box-shadow:0 1px 0 #A92F1F;}
.mic::after{content:"";position:absolute;inset:0;border-radius:50%;animation:pulse 1.8s ease-out infinite;}
.mic.listening{background:#A92F1F;}
.mic.listening::after{animation-duration:.9s;}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(217,68,46,.4);}100%{box-shadow:0 0 0 14px rgba(217,68,46,0);}}

/* ═════════ subject modal ═════════ */
.overlay{position:fixed;inset:0;z-index:100;background:rgba(51,65,92,.45);backdrop-filter:blur(3px);display:grid;place-items:center;transition:opacity .35s;}
.overlay.hide{opacity:0;pointer-events:none;}
.modal{background:var(--paper);background-image:repeating-linear-gradient(to bottom, transparent 0 35px, rgba(195,214,232,.5) 35px 36px);border:2.5px solid var(--ink);border-radius:20px;padding:34px 40px 38px;width:min(680px, 92vw);max-height:92vh;overflow-y:auto;box-shadow:8px 10px 0 rgba(51,65,92,.25);text-align:center;transition:transform .35s;}
.overlay.hide .modal{transform:scale(.95);}
.modal h2{font-size:24px;font-weight:900;letter-spacing:.04em;}
.modal p{font-size:13px;color:var(--pencil);margin:8px 0 26px;font-weight:500;}
.subjects{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:24px;}
.subject{border:2px solid rgba(51,65,92,.3);border-radius:14px;background:#fff;cursor:pointer;padding:18px 6px 14px;display:flex;flex-direction:column;align-items:center;gap:8px;transition:all .15s;color:var(--ink);}
.subject .icon{width:50px;height:50px;border-radius:50%;display:grid;place-items:center;font-size:22px;font-weight:900;color:#fff;}
.subject .name{font-weight:900;font-size:14px;}
.subject .cnt{font-size:11px;color:var(--pencil);font-weight:700;}
.subject:hover, .subject.sel{transform:translateY(-4px);box-shadow:4px 5px 0 rgba(51,65,92,.18);}
.subject.sel{border-color:var(--ink);border-width:2.5px;}
.probs{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;max-height:0;overflow:hidden;transition:max-height .4s;}
.probs.open{max-height:400px;margin-bottom:14px;}
.probbtn{font-weight:700;font-size:14px;color:var(--ink);background:#FFF6E3;border:1.5px dashed rgba(51,65,92,.45);border-radius:10px;padding:10px 18px;cursor:pointer;transition:all .15s;}
.probbtn .pcnt{font-size:11px;color:var(--pencil);margin-left:6px;}
.probbtn:hover{border-style:solid;border-color:#F2B33D;box-shadow:2px 2px 0 rgba(242,179,61,.5);transform:translateY(-2px);}
.modal .hint{font-size:12px;color:var(--pencil);font-weight:500;}
.linkbtn{background:none;border:none;color:var(--pencil);font-size:12px;font-weight:700;text-decoration:underline dotted;cursor:pointer;}

/* 下の入力欄は候補ボタンの行を含めて約120pxあるので、チャット欄をその上に置く（モックの96pxだと重なる） */
@media (max-width:860px){
  .canvas{right:0;bottom:328px;padding:14px 24px 30px 100px;font-size:16px;}
  .chatcol{top:auto;bottom:124px;width:100%;height:200px;border-left:none;border-top:2px dashed rgba(51,65,92,.18);}
  .avatar{width:90px;height:98px;}
  .subjects{grid-template-columns:repeat(2,1fr);}
}
@media (max-width:600px){
  .topbar{padding:10px 12px 8px 56px;gap:8px;}
  .logo .name, .speed .label, .replay .label, .crumb .sep, .spacer{display:none;}
  .crumb{flex:1;}
  .speed select{padding:4px 6px;font-size:11px;}
  .crumb .pill{max-width:100%;}
  .note-title{font-size:18px;}
  .chatbar{padding:8px 12px 12px 56px;}
  .pills{flex-wrap:nowrap;overflow-x:auto;}
  .modal{padding:26px 18px 28px;}
}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.001s !important;transition-duration:.001s !important;}}

/* ═════════ 起動に失敗したとき（/meta を取得できない） ═════════ */
.boot-error{position:fixed;left:50%;top:50%;transform:translate(-50%,-50%);z-index:1000;max-width:min(420px,calc(100vw - 32px));padding:18px 22px;background:var(--paper);color:var(--ink);border:2px dashed var(--redpen);border-radius:12px;font-size:15px;font-weight:700;line-height:1.7;text-align:center;box-shadow:0 6px 24px rgba(51,65,92,.18);}