/* Классная комната — оформление кабинета и комнат.
   Тёмная тема по умолчанию, светлая переключателем (запоминается в браузере). */

:root,
:root[data-theme="dark"] {
  --bg:        #0e1117;
  --bg-soft:   #151a23;
  --panel:     #161c27;
  --panel-2:   #1c2331;
  --ink:       #e8edf6;
  --ink-dim:   #9aa8bd;
  --line:      #263041;
  --line-soft: #1e2634;
  --accent:    #4c8dff;
  --accent-2:  #6ba4ff;
  --accent-ink:#0b1220;
  --ok:        #35c97b;
  --warn:      #f0a63c;
  --danger:    #ff6b6b;
  --shadow:    0 1px 2px rgba(0,0,0,.4), 0 12px 32px rgba(0,0,0,.28);
  --radius:    14px;
}

:root[data-theme="light"] {
  --bg:        #f5f7fb;
  --bg-soft:   #eef1f7;
  --panel:     #ffffff;
  --panel-2:   #f7f9fc;
  --ink:       #17202e;
  --ink-dim:   #64748b;
  --line:      #dfe5ee;
  --line-soft: #eaeff6;
  --accent:    #2f6df6;
  --accent-2:  #1d5ae0;
  --accent-ink:#ffffff;
  --ok:        #129a58;
  --warn:      #d98016;
  --danger:    #d9403a;
  --shadow:    0 1px 2px rgba(20,32,44,.06), 0 10px 28px rgba(20,32,44,.08);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1 { font-size: 21px; margin: 0; letter-spacing: -.01em; }
h2 { font-size: 15px; margin: 0; letter-spacing: -.01em; }
.muted { color: var(--ink-dim); font-size: 13px; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px 72px; }

/* ---------- шапка ---------- */
.topnav {
  position: sticky; top: 0; z-index: 30;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 26px;
}
.topnav .inner { max-width: 1120px; margin: 0 auto; padding: 13px 20px; display: flex; align-items: center; gap: 14px; }
.logo { display: flex; align-items: center; gap: 9px; font-weight: 700; letter-spacing: -.02em; }
.logo .mark {
  width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center;
  background: linear-gradient(140deg, var(--accent), #7f5bff); color: #fff; font-size: 16px;
}
.navlinks { display: flex; gap: 4px; margin-left: 12px; }
.navlinks a { padding: 6px 11px; border-radius: 8px; color: var(--ink-dim); font-size: 14px; font-weight: 500; }
.navlinks a:hover { background: var(--panel-2); color: var(--ink); text-decoration: none; }
.navlinks a.cur { background: var(--panel-2); color: var(--ink); }
.spacer { flex: 1; }

/* ---------- карточки ---------- */
.card {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 20px; margin-bottom: 20px;
}
.card-head { display: flex; align-items: center; gap: 12px; margin-bottom: 4px; }
.card-head .muted { margin: 0; }
.section-title { font-size: 12px; text-transform: uppercase; letter-spacing: .09em; color: var(--ink-dim); font-weight: 700; margin: 26px 0 12px; }

.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.row.tight { gap: 6px; }
.stack { display: flex; flex-direction: column; gap: 14px; }

/* ---------- формы ---------- */
input[type=text], input[type=password], input[type=url], input[type=file], select, textarea {
  font: inherit; padding: 9px 12px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--panel-2); color: var(--ink); min-width: 0; outline: none;
}
input:focus, select:focus, textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent); }
input[type=file] { padding: 7px 10px; }
select { cursor: pointer; }
label.field { display: flex; flex-direction: column; gap: 5px; font-size: 12px; color: var(--ink-dim); font-weight: 600; }

button, .btn {
  font: inherit; font-weight: 550; cursor: pointer; padding: 9px 14px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--panel-2); color: var(--ink);
  text-decoration: none; display: inline-flex; align-items: center; gap: 7px; white-space: nowrap;
  transition: background .12s, border-color .12s, transform .06s;
}
button:hover, .btn:hover { background: var(--panel); border-color: var(--accent); text-decoration: none; }
button:active, .btn:active { transform: translateY(1px); }
.primary, .btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 650; }
.primary:hover, .btn-primary:hover { background: var(--accent-2); border-color: var(--accent-2); color: var(--accent-ink); }
button.ghost { background: transparent; }
button.danger { color: var(--danger); border-color: transparent; background: transparent; }
button.danger:hover { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 12%, transparent); }
button.on { background: var(--warn); border-color: var(--warn); color: #17202e; }
button:disabled { opacity: .45; cursor: default; }
.icon-btn { padding: 8px 10px; }

/* ---------- ученики ---------- */
.student { border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); box-shadow: var(--shadow); overflow: hidden; }
.student-top { display: flex; align-items: center; gap: 12px; padding: 16px 18px; flex-wrap: wrap; }
.avatar {
  width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center;
  background: linear-gradient(140deg, color-mix(in srgb, var(--accent) 75%, #7f5bff), #7f5bff);
  color: #fff; font-weight: 700; font-size: 16px; flex: none;
}
.student-name { font-weight: 650; font-size: 16px; }
.student-body { padding: 0 18px 16px; display: flex; flex-direction: column; gap: 12px; }

.linkbox { display: flex; align-items: stretch; gap: 0; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--panel-2); }
.linkbox a { flex: 1; padding: 9px 12px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13px; color: var(--accent); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.linkbox button { border: 0; border-left: 1px solid var(--line); border-radius: 0; background: transparent; }

.pill { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border-radius: 999px; font-size: 12px; font-weight: 550; background: var(--panel-2); color: var(--ink-dim); border: 1px solid var(--line-soft); }
.pill.live { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 40%, transparent); }
.dot { width: 8px; height: 8px; border-radius: 50%; background: #6b7a8d; display: inline-block; flex: none; }
.dot.live { background: var(--ok); box-shadow: 0 0 0 3px color-mix(in srgb, var(--ok) 25%, transparent); }
.dot.off { background: #6b7a8d; }

details.replace { border-top: 1px solid var(--line-soft); padding-top: 12px; }
details.replace summary { cursor: pointer; color: var(--ink-dim); font-size: 13px; font-weight: 600; list-style: none; }
details.replace summary::-webkit-details-marker { display: none; }
details.replace summary:before { content: "＋ "; color: var(--accent); }
details.replace[open] summary:before { content: "− "; }
details.replace .inner { margin-top: 12px; display: flex; gap: 10px; flex-wrap: wrap; align-items: flex-end; }

/* ---------- таблицы ---------- */
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 11px 10px; border-bottom: 1px solid var(--line-soft); vertical-align: middle; }
tr:last-child td { border-bottom: 0; }
th { font-size: 11px; text-transform: uppercase; letter-spacing: .07em; color: var(--ink-dim); font-weight: 700; }
code, .mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13px; color: var(--ink-dim); }

.empty { padding: 26px; text-align: center; color: var(--ink-dim); border: 1px dashed var(--line); border-radius: var(--radius); }
.hint { font-size: 12px; color: var(--ink-dim); margin-top: 8px; }
.err { color: var(--danger); }
.notice { border-left: 3px solid var(--accent); background: var(--panel-2); padding: 12px 14px; border-radius: 0 10px 10px 0; font-size: 14px; }

/* ---------- комната урока ---------- */
.room { display: flex; flex-direction: column; height: 100vh; background: var(--bg); }
.bar {
  display: flex; align-items: center; gap: 9px; padding: 9px 14px; background: var(--panel);
  border-bottom: 1px solid var(--line); flex-wrap: wrap; row-gap: 6px; z-index: 3;
}
.bar .title { font-weight: 650; }
.split { display: flex; flex: 1; min-height: 0; }
.stage { flex: 1; position: relative; background: #fff; }
.stage iframe { width: 100%; height: 100%; border: 0; display: block; background: #fff; }
.overlay {
  position: absolute; inset: 0; display: none; align-items: center; justify-content: center;
  background: rgba(10,14,22,.76); color: #fff; text-align: center; padding: 24px; z-index: 5;
  backdrop-filter: blur(3px); font-size: 22px; font-weight: 650;
}
.overlay.show { display: flex; }
.overlay small { display: block; font-weight: 400; font-size: 15px; opacity: .82; margin-top: 8px; }

.steps { display: flex; gap: 6px; align-items: center; }
.stepnum { font-variant-numeric: tabular-nums; min-width: 78px; text-align: center; font-weight: 600; }
.steplist { max-height: 250px; overflow: auto; border: 1px solid var(--line); border-radius: 10px; background: var(--panel-2); }
.steplist button {
  display: block; width: 100%; text-align: left; border: 0; border-bottom: 1px solid var(--line-soft);
  border-radius: 0; padding: 9px 11px; font-size: 13px; background: transparent; white-space: normal;
}
.steplist button:hover { background: var(--panel); }
.steplist button.cur { background: color-mix(in srgb, var(--accent) 18%, transparent); font-weight: 650; }
.steplist button.atstudent { box-shadow: inset 3px 0 0 var(--ok); }
.steplist button .n { color: var(--ink-dim); font-variant-numeric: tabular-nums; }
.side { width: 306px; border-left: 1px solid var(--line); background: var(--panel); padding: 14px; overflow: auto; }
.side h2 { margin: 16px 0 8px; font-size: 12px; text-transform: uppercase; letter-spacing: .08em; color: var(--ink-dim); }
.side h2:first-child { margin-top: 0; }

.side-video { width: 290px; background: var(--panel); border-left: 1px solid var(--line); padding: 9px; }
.side-video iframe { width: 100%; height: 236px; border: 0; border-radius: 11px; background: #11161d; display: block; }
.videobox iframe { width: 100%; height: 200px; border: 1px solid var(--line); border-radius: 11px; }

@media (max-width: 900px) {
  .side { display: none; }
  .split { flex-direction: column; }
  .side-video { width: auto; border-left: 0; border-bottom: 1px solid var(--line); padding: 6px; order: -1; }
  .side-video iframe { height: 150px; }
  .bar { padding: 7px 10px; font-size: 14px; }
  .navlinks { display: none; }
}