/* Eris: tokens, app shell, shared components.

   Calm and warm, like a well-made writing app: a warm off-white page, a soft grey sidebar, white cards with
   generous rounded corners and hairline borders, near-black buttons, and lavender as the one quiet accent.
   Figtree for the interface; Newsreader, a book serif, for headings and big numbers. The Kalam handwriting is kept
   only for the lesson board, where it is the teacher writing. */

:root {
  --bg: #fbfaf7;            /* the page */
  --sidebar: #f4f2ee;
  --dot: transparent;
  --surface: #ffffff;       /* cards, panels, controls */
  --surface-2: #f5f3ef;
  --surface-3: #ebe8e2;
  --border: #ebe7e0;
  --border-strong: #ddd8cf;
  --text: #1c1a17;
  --text-2: #57524a;
  --muted: #8b857b;
  --primary: #1f1d1a;       /* near-black: the main action */
  --primary-hover: #000000;
  --primary-soft: #eceae5;  /* selected nav and tabs */
  --on-primary: #ffffff;
  --accent: #6b46c1;        /* lavender, used sparingly */
  --accent-soft: #f1ebfb;
  --success: #2f7d53;
  --success-soft: #e6f3ea;
  --warning: #a8660f;
  --warning-soft: #fbefdc;
  --danger: #c2412d;
  --danger-soft: #fbe7e2;
  --violet: #6b46c1;
  --violet-soft: #f1ebfb;
  --sky: #2b6f8a;
  --sky-soft: #e4f0f4;
  --marker: #ffe08a;
  --shadow-sm: 0 1px 2px rgba(28, 26, 23, .04);
  --shadow: 0 1px 2px rgba(28, 26, 23, .04), 0 4px 16px rgba(28, 26, 23, .04);
  --shadow-lg: 0 18px 48px rgba(28, 26, 23, .14);
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 18px;
  --font: "Figtree", system-ui, -apple-system, "Segoe UI", sans-serif;
  --display: "Newsreader", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --hand: "Kalam", "Comic Sans MS", cursive;
  --sidebar-w: 256px;
  color-scheme: light;
}

/* Dark: warm charcoal, never blue-black; the main action turns to warm white. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #161513; --sidebar: #1b1a18; --dot: transparent; --surface: #211f1c; --surface-2: #282622; --surface-3: #322f2b;
    --border: #2e2b27; --border-strong: #3d3933; --text: #f2efe9; --text-2: #cfc9bf; --muted: #9a9389;
    --primary: #f2efe9; --primary-hover: #ffffff; --primary-soft: #2c2a26; --on-primary: #161513;
    --accent: #b9a1ef; --accent-soft: #2b2538; --success: #82c79d; --success-soft: #1e3126;
    --warning: #e4b062; --warning-soft: #352a19; --danger: #ef8b78; --danger-soft: #3a211c;
    --violet: #b9a1ef; --violet-soft: #2b2538; --sky: #85c3d8; --sky-soft: #1c2f36; --marker: #e8c34e;
    --shadow-sm: none; --shadow: 0 1px 2px rgba(0, 0, 0, .3); --shadow-lg: 0 18px 48px rgba(0, 0, 0, .5);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #161513; --sidebar: #1b1a18; --dot: transparent; --surface: #211f1c; --surface-2: #282622; --surface-3: #322f2b;
  --border: #2e2b27; --border-strong: #3d3933; --text: #f2efe9; --text-2: #cfc9bf; --muted: #9a9389;
  --primary: #f2efe9; --primary-hover: #ffffff; --primary-soft: #2c2a26; --on-primary: #161513;
  --accent: #b9a1ef; --accent-soft: #2b2538; --success: #82c79d; --success-soft: #1e3126;
  --warning: #e4b062; --warning-soft: #352a19; --danger: #ef8b78; --danger-soft: #3a211c;
  --violet: #b9a1ef; --violet-soft: #2b2538; --sky: #85c3d8; --sky-soft: #1c2f36; --marker: #e8c34e;
  --shadow-sm: none; --shadow: 0 1px 2px rgba(0, 0, 0, .3); --shadow-lg: 0 18px 48px rgba(0, 0, 0, .5);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0; color: var(--text); font: 14px/1.55 var(--font); -webkit-font-smoothing: antialiased;
  background: var(--bg);
}
a { color: var(--primary); text-decoration: none; }
button, input, textarea, select { font: inherit; color: inherit; }
svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; flex: none; }
h1, h2, h3, h4 { margin: 0; letter-spacing: -.01em; }
code, pre, .mono { font-family: var(--mono); }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.hand { font-family: var(--hand); }
::selection { background: color-mix(in srgb, var(--marker) 55%, transparent); }

/* ---------- shell: a full-height soft grey sidebar beside the page ---------- */
.app { display: grid; grid-template-columns: var(--sidebar-w) 1fr; height: 100vh; transition: grid-template-columns .25s ease; }
.app.collapsed { --sidebar-w: 84px; }
.sidebar {
  display: flex; flex-direction: column; gap: 6px; min-width: 0; overflow: hidden;
  background: var(--sidebar); border-right: 1px solid var(--border); padding: 18px 12px;
}
.brand { display: flex; align-items: center; gap: 11px; padding: 4px 6px 14px; color: var(--text); }
.brand-mark {
  width: 40px; height: 40px; border-radius: 50%; display: grid; place-items: center; flex: none; overflow: hidden;
  background: var(--surface-2) url("../assets/tutor/tutor-idle-poster.webp") center / cover no-repeat;
  box-shadow: 0 0 0 2px var(--surface), 0 0 0 3.5px var(--primary-soft); color: transparent; font-size: 0;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; white-space: nowrap; }
.brand-text strong { font: 600 21px var(--display); letter-spacing: -.01em; }
.brand-text small { color: var(--muted); font-size: 12px; }
.nav { display: flex; flex-direction: column; gap: 2px; }
.nav-item {
  display: flex; align-items: center; gap: 10px; width: 100%; padding: 9px 12px; border: 0; border-radius: 10px;
  background: none; color: var(--text-2); cursor: pointer; white-space: nowrap; text-align: left;
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item.active { background: var(--primary-soft); color: var(--text); font-weight: 600; }
.sidebar-section { flex: 1; min-height: 0; display: flex; flex-direction: column; margin-top: 12px; }
.sidebar-heading {
  display: flex; align-items: center; justify-content: space-between; padding: 0 6px 6px 13px;
  font-size: 12px; font-weight: 600; color: var(--muted);
}
.lecture-list { list-style: none; margin: 0; padding: 0; overflow-y: auto; flex: 1; }
.lecture-link {
  display: flex; align-items: center; gap: 10px; padding: 7px 10px; border-radius: 10px; color: var(--text-2);
}
.lecture-link:hover { background: var(--surface-2); color: var(--text); }
.lecture-link.active { background: var(--surface-2); color: var(--text); font-weight: 600; }
.lecture-avatar {
  width: 28px; height: 28px; border-radius: 50%; flex: none; display: grid; place-items: center;
  font-size: 11px; font-weight: 700; text-transform: uppercase; background: var(--accent-soft); color: var(--accent);
}
.lecture-link .name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sidebar-footer { border-top: 1px solid var(--border); padding-top: 8px; display: flex; flex-direction: column; gap: 2px; }
/* Folded to an icon rail (lecture pages). While the mouse is on it (.peek) it slides out over the page at full
   width, without moving the page. */
.app.collapsed:not(.peek) .brand-text, .app.collapsed:not(.peek) .nav-item span, .app.collapsed:not(.peek) .sidebar-heading span,
.app.collapsed:not(.peek) .lecture-link .name, .app.collapsed:not(.peek) .lecture-link .dot { display: none; }
.app.collapsed:not(.peek) .sidebar-heading { justify-content: center; padding: 0 0 6px; }
.app.collapsed:not(.peek) .nav-item, .app.collapsed:not(.peek) .lecture-link { justify-content: center; padding: 8px 0; }
.app.collapsed:not(.peek) .brand { justify-content: center; padding-left: 0; padding-right: 0; }
.app.collapsed .sidebar { position: relative; z-index: 40; width: 72px; transition: width .2s ease, box-shadow .2s ease; }
.app.collapsed.peek .sidebar { width: 256px; box-shadow: var(--shadow-lg); }
.main { min-width: 0; overflow-y: auto; display: flex; flex-direction: column; }

/* ---------- page header ---------- */
.page-header {
  position: sticky; top: 0; z-index: 5; display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  padding: 18px 28px 14px; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: blur(10px);
}
.page-title { display: flex; flex-direction: column; min-width: 0; }
.page-title .crumb { font-size: 12px; color: var(--muted); }
.page-title h1 { font: 600 24px/1.2 var(--display); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.page-header .spacer { flex: 1; }
.tabs { display: inline-flex; padding: 4px; gap: 2px; background: var(--surface-2); border-radius: var(--radius); border: 1px solid var(--border); }
.tab {
  display: inline-flex; align-items: center; gap: 7px; padding: 7px 15px; border-radius: var(--radius); border: 0;
  background: none; color: var(--text-2); cursor: pointer; font-weight: 500; font-size: 13px;
}
.tab:hover { color: var(--text); }
.tab.active { background: var(--surface); color: var(--text); font-weight: 600; box-shadow: 0 1px 3px rgba(28, 26, 23, .08); }
.tab svg { width: 16px; height: 16px; }
.page { padding: 20px 28px 40px; max-width: 1480px; width: 100%; margin: 0 auto; }

/* ---------- buttons & inputs ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 7px; height: 38px; padding: 0 16px;
  border-radius: 10px; border: 1px solid var(--border-strong); background: var(--surface); color: var(--text);
  font-weight: 500; font-size: 13.5px; cursor: pointer; white-space: nowrap; box-shadow: var(--shadow-sm);
  transition: background .15s, border-color .15s, opacity .15s, transform .15s, box-shadow .15s;
}
.btn:hover:not(:disabled) { background: var(--surface-2); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn svg { width: 16px; height: 16px; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.btn.primary:disabled { background: var(--surface-3); border-color: var(--surface-3); color: var(--muted); box-shadow: none; opacity: 1; }
.btn.primary:hover:not(:disabled) { background: var(--primary-hover); border-color: var(--primary-hover); }
.btn.success { background: var(--success); border-color: var(--success); color: var(--on-primary); }
.btn.success:hover:not(:disabled) { filter: brightness(1.06); }
.btn.danger { color: var(--danger); }
.btn.danger:hover:not(:disabled) { background: var(--danger-soft); border-color: var(--danger); }
.btn.ghost { border-color: transparent; background: none; box-shadow: none; }
.btn.ghost:hover:not(:disabled) { background: var(--surface-2); }
.btn.outline { background: transparent; box-shadow: none; }
.btn.sm { height: 32px; padding: 0 12px; font-size: 12.5px; }
.btn.lg { height: 46px; padding: 0 22px; font-size: 15px; }
.icon-btn {
  display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; border: 1px solid transparent;
  background: none; color: var(--text-2); cursor: pointer;
}
.icon-btn:hover { background: var(--surface-2); color: var(--text); }
.icon-btn.sm { width: 28px; height: 28px; }
.icon-btn.sm svg { width: 15px; height: 15px; }
.spinner { width: 15px; height: 15px; border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; animation: spin .7s linear infinite; flex: none; }
@keyframes spin { to { transform: rotate(360deg); } }

.field { display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.field > span { font-size: 12.5px; font-weight: 600; color: var(--text-2); }
.field small { color: var(--muted); font-size: 12px; }
.input, .textarea, .select {
  width: 100%; padding: 9px 13px; border-radius: var(--radius-lg); border: 1px solid var(--border-strong);
  background: var(--surface); color: var(--text); outline: none; transition: border-color .15s, box-shadow .15s;
}
.input { height: 40px; }
.select {
  height: 40px; padding-right: 40px; cursor: pointer; -webkit-appearance: none; appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%238c8276' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 14px center; background-size: 16px;
}
.textarea { resize: vertical; min-height: 64px; line-height: 1.5; }
.input::placeholder, .textarea::placeholder { color: var(--muted); }
.input:focus, .textarea:focus, .select:focus { border-color: var(--primary); box-shadow: 0 0 0 4px var(--primary-soft); }
.input.invalid { border-color: var(--danger); box-shadow: 0 0 0 4px var(--danger-soft); }

/* ---------- cards, badges ---------- */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.card-header { display: flex; align-items: center; gap: 10px; padding: 14px 20px; border-bottom: 1px solid var(--border); }
.card-header h3 { font: 600 16px var(--display); }
.card-header .sub { color: var(--muted); font-size: 12.5px; }
.card-header .spacer { flex: 1; }
.card-body { padding: 16px 20px; }
.step-num {
  width: 24px; height: 24px; border-radius: 50%; display: grid; place-items: center; flex: none;
  background: var(--primary-soft); color: var(--primary); font: 600 12px var(--font);
}
.step-num.done { background: var(--success-soft); color: var(--success); }

.badge {
  display: inline-flex; align-items: center; gap: 6px; height: 24px; padding: 0 10px; border-radius: var(--radius);
  font-size: 11.5px; font-weight: 600; text-transform: capitalize; white-space: nowrap;
  background: var(--surface-3); color: var(--text-2);
}
.badge::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.badge.indexed { background: var(--sky-soft); color: var(--sky); }
.badge.draft { background: var(--warning-soft); color: var(--warning); }
.badge.approved { background: var(--success-soft); color: var(--success); }
.badge.completed { background: var(--violet-soft); color: var(--violet); }
.badge.running { background: var(--primary-soft); color: var(--primary); }
.badge.failed { background: var(--danger-soft); color: var(--danger); }
.model-tag { display: inline-flex; align-items: center; gap: 5px; height: 24px; padding: 0 10px; border-radius: var(--radius); background: var(--violet-soft); color: var(--violet); font-size: 11.5px; font-weight: 600; white-space: nowrap; align-self: flex-start; }
.model-tag svg { width: 12px; height: 12px; }
.model-tag.center { align-self: center; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--border-strong); flex: none; }
.dot.indexed { background: var(--sky); } .dot.draft { background: var(--warning); }
.dot.approved { background: var(--success); } .dot.completed { background: var(--violet); }

.empty {
  display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; gap: 10px;
  padding: 48px 24px; color: var(--muted);
}
.empty .empty-icon {
  width: 56px; height: 56px; border-radius: 50%; display: grid; place-items: center;
  background: var(--primary-soft); color: var(--primary);
}
.empty .empty-icon svg { width: 24px; height: 24px; }
.empty h3 { color: var(--text); font: 600 19px var(--display); }
.empty p { margin: 0; max-width: 420px; }

.callout { display: flex; gap: 10px; padding: 12px 14px; border-radius: var(--radius-lg); font-size: 13px; line-height: 1.5; }
.callout svg { margin-top: 1px; }
.callout.error { background: var(--danger-soft); color: var(--danger); }
.callout.warn { background: var(--warning-soft); color: var(--warning); }
.callout.info { background: var(--primary-soft); color: var(--primary); }
.callout.ok { background: var(--success-soft); color: var(--success); }

/* ---------- toasts & modal ---------- */
.toasts { position: fixed; right: 20px; bottom: 20px; z-index: 50; display: flex; flex-direction: column; gap: 8px; }
.toast {
  display: flex; align-items: flex-start; gap: 10px; min-width: 260px; max-width: 420px; padding: 12px 16px;
  background: #1f1d1a; color: #f5f3ef; border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); font-size: 13px;
  animation: toast-in .2s ease;
}
.toast.error { background: var(--danger); color: #fff; }
.toast.success svg { color: #8cc4a2; }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } }
.modal-root:empty { display: none; }
.modal-backdrop {
  position: fixed; inset: 0; z-index: 40; display: grid; place-items: center; padding: 16px;
  background: rgba(43, 30, 16, .38); backdrop-filter: blur(3px); animation: fade .15s ease;
}
@keyframes fade { from { opacity: 0; } }
.modal { width: min(480px, 100%); background: var(--surface); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); border: 1px solid var(--border); animation: toast-in .2s ease; }
.modal-head { padding: 22px 24px 4px; }
.modal-head h2 { font: 600 22px var(--display); }
.modal-head p { margin: 6px 0 0; color: var(--muted); }
.modal-body { padding: 16px 24px; display: flex; flex-direction: column; gap: 14px; }
.modal-foot { display: flex; justify-content: flex-end; gap: 8px; padding: 12px 24px 22px; }

/* ---------- overview (home) ---------- */
.hero {
  position: relative; overflow: hidden; display: flex; align-items: center; gap: 36px; margin-bottom: 26px;
  padding: 34px 40px; border-radius: var(--radius-lg); background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow);
}
.hero-copy { flex: 1; min-width: 0; }
.hero-kicker { font-size: 13px; color: var(--muted); }
.hero h1 { font: 600 40px/1.12 var(--display); letter-spacing: -.02em; margin-top: 4px; }
.hero h1 .mark { color: inherit; }
.hero p { margin: 14px 0 22px; max-width: 600px; color: var(--text-2); font-size: 15px; line-height: 1.6; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-tutor { position: relative; flex: none; width: 210px; height: 210px; margin-right: 24px; }
.hero-tutor video, .hero-tutor img { width: 100%; height: 100%; border-radius: 50%; object-fit: cover; border: 6px solid var(--surface); box-shadow: var(--shadow); background: var(--surface-2); }
.hero-bubble { position: absolute; left: -96px; top: 14px; padding: 8px 14px; border-radius: 18px 18px 4px 18px; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); font-size: 14px; color: var(--text); white-space: nowrap; }
.pipeline { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; margin-bottom: 30px; }
.pipe-step { padding: 18px 18px 16px; position: relative; }
.pipe-step .pipe-icon { width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center; background: var(--primary-soft); color: var(--primary); margin-bottom: 12px; }
.pipe-step .pipe-num { position: absolute; top: 14px; right: 16px; font: 600 20px var(--display); color: var(--border-strong); }
.pipe-step h4 { font-size: 14px; font-weight: 600; }
.pipe-step p { margin: 4px 0 0; font-size: 12.5px; color: var(--muted); line-height: 1.5; }
.section-title { display: flex; align-items: center; justify-content: space-between; margin: 0 0 14px; }
.section-title h2 { font: 600 21px var(--display); }
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-bottom: 30px; }
.stat { padding: 16px 20px; }
.stat .label { font-size: 12.5px; color: var(--muted); font-weight: 500; }
.stat .value { font: 600 32px/1.1 var(--display); margin-top: 4px; letter-spacing: -.02em; }
.lecture-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 14px; }
.lecture-card { padding: 18px; display: flex; flex-direction: column; gap: 14px; color: var(--text); transition: border-color .15s, transform .15s, box-shadow .15s; }
.lecture-card:hover { border-color: var(--border-strong); box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.lecture-card .top { display: flex; align-items: center; gap: 11px; }
.lecture-card .top .lecture-avatar { width: 40px; height: 40px; font-size: 13px; }
.lecture-card h3 { font: 600 16px var(--display); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lecture-card .progress { display: flex; gap: 5px; }
.lecture-card .progress i { flex: 1; height: 5px; border-radius: 3px; background: var(--surface-3); }
.lecture-card .progress i.on { background: var(--primary); }
.lecture-card .foot { display: flex; align-items: center; justify-content: space-between; font-size: 12.5px; color: var(--muted); }
.lecture-card.new-card { align-items: center; justify-content: center; border: 1.5px dashed var(--border-strong); color: var(--muted); min-height: 136px; background: transparent; box-shadow: none; cursor: pointer; font: 500 14px var(--font); }
.lecture-card.new-card:hover { color: var(--primary); border-color: var(--primary); background: color-mix(in srgb, var(--primary-soft) 40%, transparent); }

@media (max-width: 1100px) {
  .pipeline { grid-template-columns: repeat(3, 1fr); } .stat-row { grid-template-columns: repeat(2, 1fr); }
  .hero-tutor { width: 160px; height: 160px; } .hero-bubble { display: none; }
}
@media (max-width: 760px) {
  .app { grid-template-columns: 84px 1fr; }
  .app .brand-text, .app .nav-item span, .app .sidebar-heading span, .app .lecture-link .name, .app .lecture-link .dot { display: none; }
  .app .nav-item, .app .lecture-link { justify-content: center; padding: 8px 0; }
  .page, .page-header { padding-left: 16px; padding-right: 16px; }
  .pipeline { grid-template-columns: 1fr 1fr; }
  .hero { flex-direction: column-reverse; align-items: flex-start; padding: 26px 22px; } .hero h1 { font-size: 30px; }
  .hero-tutor { margin: 0; width: 120px; height: 120px; }
}
.new-lecture-fields { display: flex; flex-direction: column; gap: 14px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }