/* Student app styles aligned with landing/teacher */
:root { --bg:#f8fafc; --panel:#ffffff; --text:#0f172a; --muted:#64748b; --accent:#2563eb; --accent-600:#1d4ed8; --border:#e2e8f0; --shadow:0 6px 16px rgba(2,6,23,.06); }
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:linear-gradient(180deg,#f9fbff 0%,#f7fafc 100%);color:var(--text);font-family:'Inter',system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif}
.student-login-screen{min-height:100vh;align-items:center;justify-content:center;padding:24px;background:
  radial-gradient(120% 120% at 0% 0%,rgba(37,99,235,.12),transparent 40%),
  radial-gradient(90% 90% at 100% 100%,rgba(14,165,233,.10),transparent 42%),
  linear-gradient(180deg,#f8fbff 0%,#eff6ff 100%)}
.student-login-card{width:min(100%,460px);display:grid;gap:16px;padding:28px;border:1px solid rgba(148,163,184,.28);border-radius:24px;background:rgba(255,255,255,.92);box-shadow:0 22px 60px rgba(15,23,42,.12);backdrop-filter:blur(12px)}
.student-login-card h1{margin:0;font-size:32px;line-height:1.05;letter-spacing:-.03em}
.student-login-card p{margin:0;color:var(--muted);line-height:1.6}
.student-login-brand{font-size:14px}
.auth-message{min-height:20px;color:#b91c1c;font-size:13px}
.header{position:sticky;top:0;background:rgba(255,255,255,.9);backdrop-filter:saturate(140%) blur(8px);border-bottom:1px solid var(--border);z-index:2}
.container{max-width:1100px;margin:0 auto;padding:16px}
.header-row{display:flex;align-items:center;justify-content:space-between;gap:12px}
.header-tools{display:flex;align-items:center;gap:12px}
.ql-brand{display:flex;align-items:center;gap:8px;color:var(--text);text-decoration:none;font-weight:700}
.ql-brand .logo{width:20px;height:20px;display:inline-block;background:url('/static/ql-icon.svg') no-repeat center/contain}
.brand{display:flex;align-items:center;gap:10px;font-weight:700}
.brand .dot{width:12px;height:12px;border-radius:999px;background:var(--accent)}
.student-brand{margin-left:auto}
.user-chip{padding:8px 12px;border:1px solid var(--border);border-radius:999px;background:rgba(255,255,255,.88);font-size:13px;font-weight:600}
.main{padding:16px;flex:1 1 0;overflow:auto}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
@media (min-width: 900px){
  /* Keep card size stable and add more columns instead of stretching cards */
  .grid{grid-template-columns:repeat(auto-fill,minmax(220px,220px));justify-content:start}
}
.card{border:1px solid var(--border);background:var(--panel);border-radius:14px;padding:14px;box-shadow:var(--shadow)}
.card.clickable{cursor:pointer}
.card.clickable:hover{outline:2px solid #c7d2fe}
.card h3{margin:0 0 6px;font-size:16px}
.card p{margin:0;color:var(--muted);font-size:13px}
.action,.btn.primary{appearance:none;border:1px solid var(--accent);background:var(--accent);color:#fff;padding:8px 12px;border-radius:10px;font-weight:700;cursor:pointer}
.action:hover,.btn.primary:hover{background:var(--accent-600);border-color:var(--accent-600)}
.btn{appearance:none;border:1px solid var(--border);background:#fff;color:var(--text);padding:8px 12px;border-radius:10px;cursor:pointer}
.btn[disabled]{opacity:.6;cursor:not-allowed}
.section{display:flex;align-items:center;justify-content:space-between;margin:10px 0}
.breadcrumb{display:flex;align-items:center;gap:8px;color:var(--muted)}
.link{color:var(--accent);text-decoration:none}
.link:hover{text-decoration:underline}
.list{display:grid;gap:10px}
.row{display:flex;align-items:center;gap:10px;border:1px solid var(--border);background:var(--panel);border-radius:12px;padding:10px;box-shadow:var(--shadow)}
.row.clickable{cursor:pointer}
.row.clickable:hover{outline:2px solid #c7d2fe}
.row .t{flex:1}
.badge{font-size:12px;padding:3px 8px;border-radius:999px;border:1px solid #c7d2fe;background:#eef2ff;color:#1e3a8a}
.badge.neutral{background:#f1f5f9;border-color:var(--border);color:#334155}
.small{font-size:12px;color:var(--muted)}
.subtitle{margin:4px 0 0;color:var(--muted)}
.player-wrap{border:1px solid var(--border);border-radius:16px;overflow:hidden;background:var(--panel)}
.footer{margin:24px 0;color:var(--muted);font-size:12px}
.checkbox{accent-color:var(--accent)}
@media (max-width: 760px){
  .container{padding:12px}
  .ql-brand{font-size:14px}
  .student-login-card{padding:24px}
  .student-login-card h1{font-size:28px}
  .header-tools{gap:8px;flex-wrap:wrap;justify-content:flex-end}
  .student-brand{margin-left:0}
}

/* Preview player for student */
.device-frame{display:flex;justify-content:center;padding:10px}
.device-frame .device-screen{background:#f8fafc;border:1px solid var(--border);border-radius:16px;box-shadow:var(--shadow);width:100%}
.device-frame.desktop .device-screen{width:min(1000px,100%);min-height:560px}
.device-frame.tablet .device-screen{width:820px;max-width:100%;min-height:560px;border-radius:20px}
.device-frame.phone .device-screen{width:420px;max-width:100%;min-height:560px;border-radius:28px;font-size:14px}
.device-frame.responsive .device-screen{width:100%;max-width:100%;min-height:clamp(420px,72vh,760px);border-radius:16px}
.pv-deck{display:flex;gap:12px;overflow-x:auto;padding:8px 0;align-items:stretch;scroll-behavior:smooth}
.pv-deck .device-frame.phone{flex:0 0 auto;scroll-snap-align:start}
.pv-deck .device-frame{padding:6px}
.pv-deck .device-screen{height:clamp(540px,74vh,860px)}
.pv-deck .player-body{flex:1 1 0;min-height:0;overflow-y:auto}
.pv-past-part{opacity:.8;transition:opacity .2s}
.pv-past-part:hover{opacity:1}
.pv-active-part .device-screen{border-color:var(--accent);box-shadow:0 0 0 2px rgba(37,99,235,.15),var(--shadow)}

.player{display:flex;flex-direction:column;height:100%}
.player-head{display:flex;align-items:center;justify-content:space-between;padding:12px 14px}
.player-head .ph-title{font-weight:700}
.player-head .ph-sub{color:var(--muted);font-size:12px}
.progress{width:100%;height:6px;background:#e2e8f0}
.progress .bar{height:100%;background:#6366f1;border-radius:999px}
.player-body{padding:14px;overflow:auto;flex:1 1 0;min-height:0}
.player-foot{display:flex;gap:8px;padding:12px 14px;border-top:1px solid var(--border)}
.shake{animation:shake .3s linear}
@keyframes shake{20%{transform:translateX(-2px)}40%{transform:translateX(2px)}60%{transform:translateX(-2px)}80%{transform:translateX(2px)}}
.prose{line-height:1.65}
.prose h1,.prose h2,.prose h3{margin:10px 0 8px;font-weight:700}
.prose p{margin:8px 0}
.prose code{background:#0b1020;color:#e5edff;padding:2px 6px;border-radius:6px;font-size:90%}
.prose pre{background:#0b1020;color:#e5edff;padding:10px;border-radius:10px;overflow:auto}
.scenario-box{background:#fff7ed;border:1px solid #fed7aa;border-radius:12px;padding:10px}
.prompt-box{background:#f8fafc;border:1px dashed #cbd5e1;border-radius:12px;padding:10px;color:#475569;font-size:14px}
.opt{display:flex;align-items:center;gap:10px;padding:10px 12px;border:1px solid var(--border);border-radius:12px;cursor:pointer;background:#f8fafc}
.opt:hover{background:#eef2ff;border-color:#c7d2fe}
.opt.correct{background:#ecfdf5;border-color:#86efac;color:#14532d}
.opt.wrong{background:#fff1f2;border-color:#fecdd3;color:#9f1239}
.explain{margin-top:8px;color:#475569;font-size:14px}
.match-game{
  position:relative;
  display:flex;
  flex-direction:column;
  gap:8px;
  touch-action:none;
  -ms-touch-action:none;
  user-select:none;
  -webkit-user-select:none;
  min-height:280px;
  margin-top:10px;
  padding:14px;
  border-radius:18px;
  border:1px solid #dbeafe;
  background:
    radial-gradient(130% 90% at 14% 8%, rgba(56,189,248,.2), transparent 48%),
    radial-gradient(110% 80% at 86% 92%, rgba(20,184,166,.14), transparent 46%),
    linear-gradient(180deg,#ffffff 0%,#f8fbff 100%);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.8),0 12px 30px rgba(30,64,175,.08);
}
.match-row{display:grid;grid-template-columns:1fr 1fr;gap:clamp(20px,6%,80px);align-items:stretch;position:relative;z-index:2}
.match-item{
  appearance:none;
  width:100%;
  border:1px solid #cfe2ff;
  border-radius:14px;
  padding:12px;
  background:rgba(255,255,255,.88);
  color:var(--text);
  display:flex;
  align-items:center;
  justify-content:flex-start;
  gap:10px;
  text-align:left;
  cursor:pointer;
  backdrop-filter:blur(6px) saturate(130%);
  transition:transform .16s ease,border-color .16s ease,background-color .16s ease,box-shadow .16s ease;
}
.match-item:hover{transform:translateY(-1px);border-color:#7dd3fc;background:rgba(240,249,255,.9);box-shadow:0 8px 16px rgba(2,132,199,.14)}
.match-item.selected{border-color:#0ea5e9;background:linear-gradient(180deg,#eff8ff 0%,#e8f6ff 100%);box-shadow:0 0 0 2px rgba(14,165,233,.26),0 10px 18px rgba(14,165,233,.16)}
.match-item.connected{border-color:#93c5fd;background:#eff6ff}
.match-item.correct{border-color:#34d399;background:linear-gradient(180deg,#ecfdf5 0%,#d1fae5 100%);color:#065f46;box-shadow:0 8px 16px rgba(16,185,129,.16)}
.match-item.wrong{border-color:#fb7185;background:linear-gradient(180deg,#fff1f2 0%,#ffe4e6 100%);color:#9f1239;box-shadow:0 8px 16px rgba(225,29,72,.16)}
.match-label{display:flex;gap:8px;align-items:flex-start;min-width:0;flex:1 1 auto}
.match-label span:last-child{white-space:normal;overflow-wrap:anywhere;line-height:1.35}
.match-num{font-weight:700;color:#334155;min-width:18px;flex:0 0 auto}
.match-left-item .match-node{margin-left:auto}
.match-right-item .match-node{margin-right:8px}
.match-node{
  width:18px;height:18px;border-radius:999px;border:2px solid #64748b;
  background:radial-gradient(circle at 40% 32%, #ffffff 0%, #dbeafe 72%);
  box-shadow:0 0 0 2px rgba(255,255,255,.95),0 2px 8px rgba(15,23,42,.2);
  flex:0 0 18px
}
.match-item.selected .match-node{border-color:#0ea5e9;background:radial-gradient(circle at 40% 32%, #e0f2fe 0%, #7dd3fc 84%)}
.match-item.correct .match-node{border-color:#10b981;background:radial-gradient(circle at 40% 32%, #d1fae5 0%, #34d399 84%)}
.match-item.wrong .match-node{border-color:#f43f5e;background:radial-gradient(circle at 40% 32%, #ffe4e6 0%, #fb7185 84%)}
.match-lines{position:absolute;inset:0;pointer-events:none;overflow:visible;z-index:3}
.match-link{stroke:#93c5fd;stroke-width:4;stroke-linecap:round;opacity:.95;filter:drop-shadow(0 2px 5px rgba(30,64,175,.2))}
.match-link.correct{stroke:#10b981;filter:drop-shadow(0 2px 6px rgba(16,185,129,.32))}
.match-link.wrong{stroke:#f43f5e;filter:drop-shadow(0 2px 6px rgba(244,63,94,.32))}
.match-link.draft{stroke:#0ea5e9;stroke-dasharray:8 6;animation:dash-flow .5s linear infinite}
@keyframes dash-flow{to{stroke-dashoffset:-14}}
/* App layout */
.app{display:flex;flex-direction:column;height:100vh;height:100dvh}

/* Fullscreen focus for lecture */
body.lecture-full .header{display:none}
body.lecture-full .main{padding:18px 24px 24px}
body.lecture-full .player-wrap{
  min-height:0;
  border:1px solid var(--border);
  border-radius:18px;
  overflow:hidden;
  background:var(--panel);
  box-shadow:0 14px 34px rgba(2,6,23,.10);
}

/* Floating action buttons */
.fab{position:fixed;top:12px;left:12px;z-index:20;appearance:none;border:1px solid var(--border);background:#fff;color:var(--text);padding:10px 12px;border-radius:12px;cursor:pointer;box-shadow:var(--shadow)}
.fab.right{left:auto;right:12px;top:auto;bottom:12px;background:var(--accent);color:#fff;border-color:var(--accent)}
#backFab{position:static;display:inline-flex;margin:12px 0 8px 12px;z-index:auto}

body.lecture-full .section{display:none}
body.lecture-full .container{max-width:none;padding:0 12px}
body.lecture-full .device-frame{padding:14px}
body.lecture-full .device-frame .device-screen,
body.lecture-full .device-frame.phone .device-screen,
body.lecture-full .device-frame.responsive .device-screen{min-height:0;border-radius:16px}
body.lecture-full .panel{border:1px solid var(--border);background:var(--panel);box-shadow:var(--shadow)}
body.lecture-full .panel-header{display:none}
body.lecture-full #backFab{position:sticky;top:12px;z-index:10}

@media (max-width: 980px){
  body.lecture-full .main{padding:0;overflow:hidden}
  body.lecture-full .container{max-width:100%;padding:0;height:100%}
  body.lecture-full #lectureView{height:100%}
  body.lecture-full .player-wrap{
    height:100%;
    min-height:0;
    border:none;
    border-radius:0;
    box-shadow:none;
  }
  body.lecture-full .player-wrap>.panel{height:100%}
  body.lecture-full .panel .panel-body{height:100%;padding:0}
  body.lecture-full .panel .panel-body>#pvHost{height:100%}
  body.lecture-full .device-frame{padding:0;height:100%}
  body.lecture-full .device-frame .device-screen,
  body.lecture-full .device-frame.phone .device-screen,
  body.lecture-full .device-frame.responsive .device-screen{min-height:0;border-radius:0;height:100%}
  body.lecture-full .panel{border:none;background:transparent;box-shadow:none}
  body.lecture-full .player-foot{padding-bottom:calc(12px + env(safe-area-inset-bottom,0px))}
}
/* Student wide view: responsive multi-part deck showing past parts + active part. */