/* =====================================================================
   AI Teacher Assistant Platform — project-local SaaS chrome
   ---------------------------------------------------------------------
   Layered ON TOP of the shared portfolio design-system.css.
   Adds the commercial "app" feel: side rail, command palette, FAB,
   generator workspace, toasts, dark mode. Vanilla CSS, no dependencies.
   All AI is simulated client-side for demonstration.
   ===================================================================== */

/* ---------- Product accent (distinct identity within the portfolio) ---------- */
:root {
  --ats-accent: #5b6cf0;        /* indigo — the product's signature */
  --ats-accent-2: #18b6a6;      /* mint */
  --ats-accent-dark: #3f4fd0;
  --ats-glow: rgba(91, 108, 240, 0.16);
  --ats-rail-w: 248px;
}

/* ---------- Dark mode: re-theme shared tokens ---------- */
body.ats-dark {
  --navy: #1b2740; --navy-dark: #131c30; --navy-deep: #0c1322;
  --ink: #e8edf6; --ink-soft: #9fb0c6; --slate: #b6c4d8;
  --bg: #0f1626; --bg-warm: #131b2c;
  --surface: #18233a; --surface-alt: #1f2c46; --border: #2c3a57;
  --shadow: rgba(0,0,0,0.4); --shadow-lg: rgba(0,0,0,0.55);
}
body.ats-dark { background: var(--bg); color: var(--ink); }
body.ats-dark .site-header { background: rgba(15,22,38,0.92); }
body.ats-dark .card, body.ats-dark .metric, body.ats-dark .chat,
body.ats-dark .gen-output, body.ats-dark .app-rail { background: var(--surface); }
body.ats-dark .muted, body.ats-dark .m-label { color: var(--ink-soft); }
body.ats-dark .metric .m-num, body.ats-dark .card h3, body.ats-dark .card h4 { color: #eaf0fb; }
body.ats-dark input, body.ats-dark select, body.ats-dark textarea {
  background: #111a2c; color: var(--ink); border-color: var(--border);
}
body.ats-dark .out-body { background: #111a2c; }
.theme-toggle { background: none; border: 1px solid var(--border); color: inherit; border-radius: 999px;
  width: 40px; height: 40px; font-size: 1.1rem; cursor: pointer; display: grid; place-items: center; transition: .15s; }
.theme-toggle:hover { border-color: var(--ats-accent); color: var(--ats-accent); }

/* ---------- App shell: side rail + main ---------- */
.app-shell { display: grid; grid-template-columns: var(--ats-rail-w) 1fr; gap: 1.6rem;
  max-width: 1320px; margin: 0 auto; padding: 1.6rem 1.2rem 3rem; align-items: start; }
.app-rail { position: sticky; top: 84px; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.9rem; box-shadow: 0 6px 20px var(--shadow); max-height: calc(100vh - 110px); overflow-y: auto; }
.rail-brand { display: flex; align-items: center; gap: 0.55rem; padding: 0.3rem 0.5rem 0.8rem; border-bottom: 1px solid var(--border); margin-bottom: 0.6rem; }
.rail-brand .mark { width: 34px; height: 34px; border-radius: 9px; background: linear-gradient(135deg, var(--ats-accent), var(--ats-accent-2));
  color: #fff; display: grid; place-items: center; font-weight: 800; font-size: 0.95rem; }
.rail-brand b { font-size: 0.92rem; color: var(--ink); }
.rail-group { font-size: 0.7rem; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink-soft); padding: 0.8rem 0.6rem 0.3rem; }
.rail-link { display: flex; align-items: center; gap: 0.6rem; padding: 0.5rem 0.6rem; border-radius: 9px;
  color: var(--ink); text-decoration: none; font-size: 0.92rem; font-weight: 600; transition: .12s; }
.rail-link .ico { width: 20px; text-align: center; }
.rail-link:hover { background: var(--surface-alt); }
.rail-link.active { background: var(--ats-glow); color: var(--ats-accent-dark); }
body.ats-dark .rail-link.active { color: #cfd5ff; }

.app-main { min-width: 0; }
.app-bar { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.8rem; margin-bottom: 1.2rem; }
.app-bar .crumb { color: var(--ink-soft); font-size: 0.9rem; }
.app-bar .crumb b { color: var(--ink); }
.app-actions { display: flex; align-items: center; gap: 0.5rem; }

/* ---------- Tool head ---------- */
.tool-head { margin-bottom: 1.2rem; }
.tool-head h1 { font-size: clamp(1.5rem, 3vw, 2.1rem); margin: 0.2rem 0; }
.tool-head .lead { color: var(--ink-soft); max-width: 60ch; }
.tool-badge { display: inline-flex; align-items: center; gap: 0.4rem; background: var(--ats-glow);
  color: var(--ats-accent-dark); font-weight: 700; font-size: 0.78rem; padding: 0.25rem 0.8rem; border-radius: 999px; }
body.ats-dark .tool-badge { color: #cfd5ff; }

/* ---------- Generator layout ---------- */
.gen-layout { display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); gap: 1.4rem; align-items: start; }
.gen-form { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.4rem; box-shadow: 0 6px 20px var(--shadow); }
.gen-form h3 { margin-top: 0; }
.field { margin-bottom: 1rem; }
.field > label { display: block; font-weight: 700; font-size: 0.88rem; margin-bottom: 0.35rem; }
.field input, .field select, .field textarea { width: 100%; padding: 0.6rem 0.75rem; border: 1.5px solid var(--border);
  border-radius: var(--radius-sm); font: inherit; background: var(--surface); color: var(--ink); transition: border-color .15s; }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--ats-accent); box-shadow: 0 0 0 3px var(--ats-glow); }
.field textarea { min-height: 90px; resize: vertical; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0.8rem; }
.field .hint { font-size: 0.78rem; color: var(--ink-soft); margin-top: 0.25rem; }
.chip-set { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.chip-toggle { border: 1.5px solid var(--border); background: var(--surface); color: var(--ink);
  border-radius: 999px; padding: 0.35rem 0.85rem; font: inherit; font-size: 0.85rem; font-weight: 600; cursor: pointer; transition: .12s; }
.chip-toggle:hover { border-color: var(--ats-accent); }
.chip-toggle.on { background: var(--ats-accent); border-color: var(--ats-accent); color: #fff; }

/* ---------- Generator output ---------- */
.gen-output { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: 0 6px 20px var(--shadow); overflow: hidden; display: flex; flex-direction: column; min-height: 320px; }
.out-toolbar { display: flex; align-items: center; gap: 0.5rem; padding: 0.7rem 1rem; border-bottom: 1px solid var(--border);
  background: var(--surface-alt); }
.out-toolbar .ai-pill { margin-right: auto; }
.out-btn { border: 1px solid var(--border); background: var(--surface); color: var(--ink); border-radius: 8px;
  padding: 0.35rem 0.75rem; font: inherit; font-size: 0.82rem; font-weight: 700; cursor: pointer; transition: .12s; }
.out-btn:hover { border-color: var(--ats-accent); color: var(--ats-accent); }
.out-btn[disabled] { opacity: 0.45; cursor: not-allowed; }
.out-body { padding: 1.3rem; overflow-y: auto; flex: 1; line-height: 1.6; }
.out-body h3 { margin-top: 0; }
.out-body h4 { color: var(--ats-accent-dark); margin-bottom: 0.3rem; }
body.ats-dark .out-body h4 { color: #aeb7ff; }
.out-body table { width: 100%; }
.out-empty { color: var(--ink-soft); display: grid; place-items: center; text-align: center; height: 100%; padding: 2rem; }
.out-empty .big { font-size: 2.6rem; margin-bottom: 0.5rem; }

/* loading shimmer */
.gen-loading { padding: 1.3rem; }
.shimmer { height: 13px; border-radius: 6px; margin: 0.55rem 0;
  background: linear-gradient(90deg, var(--surface-alt) 25%, var(--border) 37%, var(--surface-alt) 63%);
  background-size: 400% 100%; animation: shimmer 1.3s ease infinite; }
.shimmer.w70 { width: 70%; } .shimmer.w50 { width: 50%; } .shimmer.w90 { width: 90%; }
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* ---------- Stat strip / time saved ---------- */
.stat-strip { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 1rem; margin: 1.2rem 0; }
.stat-tile { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.1rem;
  box-shadow: 0 4px 14px var(--shadow); border-left: 4px solid var(--ats-accent); }
.stat-tile .s-num { font-family: var(--font-head); font-size: 1.8rem; color: var(--ink); line-height: 1.1; }
.stat-tile .s-label { font-size: 0.82rem; color: var(--ink-soft); font-weight: 600; }

/* ---------- Tool grid (home feature cards) ---------- */
.tool-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); gap: 1.1rem; }
.tool-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.3rem;
  box-shadow: 0 5px 16px var(--shadow); text-decoration: none; color: inherit; display: block; transition: transform .16s, box-shadow .16s; }
.tool-card:hover { transform: translateY(-4px); box-shadow: 0 16px 32px var(--shadow-lg); }
.tool-card .t-ico { width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center; font-size: 1.4rem;
  background: var(--ats-glow); margin-bottom: 0.7rem; }
.tool-card h4 { margin: 0 0 0.3rem; }
.tool-card p { color: var(--ink-soft); font-size: 0.9rem; margin: 0; }
.tool-card .t-go { display: inline-block; margin-top: 0.7rem; color: var(--ats-accent); font-weight: 700; font-size: 0.88rem; }

/* ---------- Workspace ---------- */
.ws-grid { display: grid; grid-template-columns: 1fr 300px; gap: 1.4rem; align-items: start; }
.ws-side .panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.1rem;
  box-shadow: 0 4px 14px var(--shadow); margin-bottom: 1.1rem; }
.ws-side h4 { margin: 0 0 0.6rem; font-size: 0.95rem; }
.ws-list { list-style: none; margin: 0; padding: 0; }
.ws-list li { padding: 0.4rem 0; border-bottom: 1px solid var(--border); font-size: 0.88rem; }
.ws-list li:last-child { border-bottom: none; }
.ws-list a { text-decoration: none; color: var(--ink); }
.ws-list a:hover { color: var(--ats-accent); }
.composer { display: flex; gap: 0.5rem; padding: 0.8rem; border-top: 1px solid var(--border); background: var(--surface-alt); }
.composer input { flex: 1; padding: 0.7rem 0.9rem; border: 1.5px solid var(--border); border-radius: 999px; font: inherit; background: var(--surface); color: var(--ink); }
.composer input:focus { outline: none; border-color: var(--ats-accent); box-shadow: 0 0 0 3px var(--ats-glow); }
.composer button { border: none; background: var(--ats-accent); color: #fff; border-radius: 999px; padding: 0 1.2rem; font: inherit; font-weight: 700; cursor: pointer; }
.composer button:hover { background: var(--ats-accent-dark); }

/* ---------- Command palette ---------- */
.cmdk { position: fixed; inset: 0; background: rgba(12,19,34,0.55); backdrop-filter: blur(3px); z-index: 200;
  display: none; align-items: flex-start; justify-content: center; padding-top: 12vh; }
.cmdk.open { display: flex; }
.cmdk-box { width: min(620px, 92vw); background: var(--surface); border: 1px solid var(--border); border-radius: 16px;
  box-shadow: 0 30px 70px rgba(0,0,0,0.4); overflow: hidden; animation: fadeUp .18s ease both; }
.cmdk-input { width: 100%; border: none; border-bottom: 1px solid var(--border); padding: 1.1rem 1.2rem; font: inherit; font-size: 1.05rem;
  background: var(--surface); color: var(--ink); }
.cmdk-input:focus { outline: none; }
.cmdk-list { max-height: 50vh; overflow-y: auto; padding: 0.5rem; }
.cmdk-item { display: flex; align-items: center; gap: 0.7rem; padding: 0.6rem 0.8rem; border-radius: 9px; cursor: pointer; text-decoration: none; color: var(--ink); }
.cmdk-item .ico { width: 22px; text-align: center; }
.cmdk-item small { margin-left: auto; color: var(--ink-soft); font-size: 0.78rem; }
.cmdk-item.active, .cmdk-item:hover { background: var(--ats-glow); }
.cmdk-empty { padding: 1.2rem; color: var(--ink-soft); text-align: center; }

/* ---------- Floating action button ---------- */
.fab { position: fixed; right: 22px; bottom: 22px; z-index: 150; width: 58px; height: 58px; border-radius: 50%;
  border: none; background: linear-gradient(135deg, var(--ats-accent), var(--ats-accent-2)); color: #fff; font-size: 1.5rem;
  cursor: pointer; box-shadow: 0 12px 28px var(--ats-glow), 0 6px 16px rgba(0,0,0,0.2); transition: transform .15s; }
.fab:hover { transform: scale(1.07) rotate(8deg); }

/* ---------- Toasts ---------- */
.toast-wrap { position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%); z-index: 300; display: flex; flex-direction: column; gap: 0.5rem; }
.toast { background: var(--navy); color: #fff; padding: 0.7rem 1.1rem; border-radius: 10px; box-shadow: 0 10px 26px rgba(0,0,0,0.3);
  font-weight: 600; font-size: 0.9rem; animation: fadeUp .25s ease both; display: flex; align-items: center; gap: 0.5rem; }
.toast.ok { background: var(--success); } .toast.info { background: var(--ats-accent); }

/* ---------- kbd hint ---------- */
.kbd { display: inline-block; border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 6px; padding: 0.05rem 0.45rem;
  font-family: var(--font-head); font-size: 0.78rem; background: var(--surface-alt); color: var(--ink-soft); }

/* ---------- Resource / prompt library items ---------- */
.lib-item { display: flex; align-items: center; gap: 0.8rem; padding: 0.8rem 1rem; border: 1px solid var(--border);
  border-radius: var(--radius-sm); background: var(--surface); margin-bottom: 0.6rem; }
.lib-item .l-ico { font-size: 1.3rem; }
.lib-item .l-body { flex: 1; min-width: 0; }
.lib-item .l-body b { display: block; }
.lib-item .l-body small { color: var(--ink-soft); }
.lib-item .l-tag { font-size: 0.72rem; font-weight: 700; padding: 0.15rem 0.6rem; border-radius: 999px; background: var(--surface-alt); color: var(--ink-soft); }
.fav-btn { border: none; background: none; cursor: pointer; font-size: 1.2rem; color: var(--ink-soft); }
.fav-btn.on { color: var(--gold); }

/* ---------- Roadmap / future badges ---------- */
.soon { font-size: 0.68rem; font-weight: 800; letter-spacing: 0.05em; text-transform: uppercase; color: var(--ats-accent);
  border: 1px solid var(--ats-accent); border-radius: 999px; padding: 0.1rem 0.55rem; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .app-shell { grid-template-columns: 1fr; }
  .app-rail { position: static; max-height: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 0.2rem 0.8rem; }
  .rail-group { grid-column: 1 / -1; }
  .gen-layout, .ws-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .field-row { grid-template-columns: 1fr; }
}