:root {
  --bg: #0f1115;
  --bg-elev: #171a21;
  --bg-elev2: #1e222b;
  --border: #2a2f3a;
  --text: #e6e8ee;
  --text-dim: #9aa3b2;
  --accent: #7c8cff;
  --accent-2: #42b883;   /* vue green */
  --accent-3: #ff5757;   /* laravel red */
  --accent-4: #9c6cff;   /* inertia purple */
  --ok: #3fb950;
  --warn: #d29922;
  --err: #f85149;
  --code-bg: #12151c;
  --radius: 12px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
[data-theme="light"] {
  --bg: #f6f7fb;
  --bg-elev: #ffffff;
  --bg-elev2: #eef0f6;
  --border: #dde1ea;
  --text: #1a1d24;
  --text-dim: #5b6472;
  --code-bg: #f0f2f8;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
}
#app { display: flex; min-height: 100vh; }

/* ---------- Sidebar ---------- */
#sidebar {
  width: 300px; flex: 0 0 300px;
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  height: 100vh; position: sticky; top: 0;
  padding: 18px 14px; gap: 14px;
  overflow-y: auto;
}
.brand { display: flex; align-items: center; gap: 12px; cursor: pointer; border-radius: 10px; padding: 2px; }
.brand:hover { background: var(--bg-elev2); }
#crumb .crumb-home { cursor: pointer; color: var(--accent); }
#crumb .crumb-home:hover { text-decoration: underline; }
.brand-mark {
  width: 42px; height: 42px; border-radius: 10px;
  display: grid; place-items: center; font-weight: 800; font-size: 13px;
  background: linear-gradient(135deg, var(--accent-3), var(--accent-4));
  color: #fff; letter-spacing: -1px;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong { font-size: 15px; }
.brand-text span { font-size: 11px; color: var(--text-dim); }

.overall-progress { background: var(--bg-elev2); padding: 12px; border-radius: 10px; }
.op-labels { display: flex; justify-content: space-between; font-size: 12px; color: var(--text-dim); margin-bottom: 6px; }
.op-labels span:last-child { color: var(--accent-2); font-weight: 700; }
.op-sub { font-size: 11px; color: var(--text-dim); margin-top: 6px; }
.progress-bar { height: 8px; background: var(--border); border-radius: 99px; overflow: hidden; }
.progress-fill { height: 100%; width: 0; background: linear-gradient(90deg, var(--accent-2), var(--accent)); transition: width .4s ease; }

#search {
  width: 100%; padding: 9px 12px; border-radius: 9px;
  border: 1px solid var(--border); background: var(--bg-elev2);
  color: var(--text); font-size: 13px; outline: none;
}
#search:focus { border-color: var(--accent); }

#nav { display: flex; flex-direction: column; gap: 6px; flex: 1; }
.mod { border-radius: 10px; overflow: hidden; }
.mod-head {
  display: flex; align-items: center; gap: 9px; cursor: pointer;
  padding: 9px 10px; user-select: none; border-radius: 8px;
}
.mod-head:hover { background: var(--bg-elev2); }
.mod-dot { width: 9px; height: 9px; border-radius: 99px; flex: 0 0 auto; }
.mod-title { font-weight: 600; font-size: 13.5px; flex: 1; }
.mod-count { font-size: 10.5px; color: var(--text-dim); }
.mod-chev { font-size: 10px; color: var(--text-dim); transition: transform .2s; }
.mod.collapsed .mod-chev { transform: rotate(-90deg); }
.mod.collapsed .lessons { display: none; }
.lessons { display: flex; flex-direction: column; padding: 2px 0 6px 6px; }
.lesson-link {
  display: flex; align-items: center; gap: 8px; text-align: left;
  padding: 6px 10px; border-radius: 7px; cursor: pointer; font-size: 12.5px;
  color: var(--text-dim); border: none; background: none; width: 100%;
}
.lesson-link:hover { background: var(--bg-elev2); color: var(--text); }
.lesson-link.active { background: color-mix(in srgb, var(--accent) 22%, transparent); color: var(--text); }
.lesson-link .check {
  width: 16px; height: 16px; border-radius: 99px; border: 1.5px solid var(--border);
  flex: 0 0 auto; display: grid; place-items: center; font-size: 10px;
}
.lesson-link.done .check { background: var(--ok); border-color: var(--ok); color: #04210c; }
.lesson-link .lt { flex: 1; }

.sidebar-footer { display: flex; flex-direction: column; gap: 6px; }
.ghost-btn {
  background: var(--bg-elev2); border: 1px solid var(--border); color: var(--text-dim);
  padding: 8px; border-radius: 8px; cursor: pointer; font-size: 12px; text-align: left;
}
.ghost-btn:hover { color: var(--text); border-color: var(--accent); }
.ghost-btn.danger:hover { color: var(--err); border-color: var(--err); }

/* ---------- Main ---------- */
#main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
#topbar {
  display: flex; align-items: center; gap: 14px;
  padding: 12px 26px; border-bottom: 1px solid var(--border);
  position: sticky; top: 0; background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px); z-index: 10;
}
#menu-toggle { display: none; background: none; border: none; color: var(--text); font-size: 20px; cursor: pointer; }
#crumb { font-size: 13px; color: var(--text-dim); flex: 1; }
#crumb b { color: var(--text); }
.topbar-actions { display: flex; align-items: center; gap: 12px; }
#theme-toggle { background: none; border: 1px solid var(--border); border-radius: 8px; padding: 5px 9px; cursor: pointer; font-size: 14px; }
#confidence-widget { display: flex; gap: 5px; align-items: center; font-size: 12px; color: var(--text-dim); }
.conf-btn { width: 22px; height: 22px; border-radius: 6px; border: 1px solid var(--border); cursor: pointer; background: var(--bg-elev2); }
.conf-btn.red.on { background: var(--err); }
.conf-btn.yellow.on { background: var(--warn); }
.conf-btn.green.on { background: var(--ok); }

#content { padding: 34px 40px 90px; max-width: 900px; margin: 0 auto; width: 100%; }

/* ---------- Content blocks ---------- */
.lesson-head { margin-bottom: 22px; }
.lesson-eyebrow { font-size: 12px; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); font-weight: 700; }
.lesson-head h1 { margin: 6px 0 6px; font-size: 27px; line-height: 1.2; }
.lesson-meta { font-size: 12.5px; color: var(--text-dim); display: flex; gap: 14px; }

.prose { margin: 16px 0; }
.prose p { margin: 10px 0; }
.prose h3 { margin: 26px 0 8px; font-size: 18px; }
.prose ul, .prose ol { margin: 10px 0; padding-left: 22px; }
.prose li { margin: 5px 0; }
.prose code { font-family: var(--mono); background: var(--bg-elev2); padding: 1.5px 6px; border-radius: 5px; font-size: 12.5px; }
.prose strong { color: var(--text); }
.prose a { color: var(--accent); }
.prose table { border-collapse: collapse; width: 100%; margin: 14px 0; font-size: 13px; }
.prose th, .prose td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
.prose th { background: var(--bg-elev2); }

.code-block { margin: 16px 0; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.code-head { display: flex; justify-content: space-between; align-items: center; background: var(--bg-elev2); padding: 6px 12px; font-size: 11.5px; color: var(--text-dim); }
.code-lang { font-family: var(--mono); text-transform: uppercase; letter-spacing: .05em; }
.copy-btn { background: none; border: 1px solid var(--border); color: var(--text-dim); border-radius: 6px; padding: 2px 8px; cursor: pointer; font-size: 11px; }
.copy-btn:hover { color: var(--text); }
pre { margin: 0; padding: 14px 16px; overflow-x: auto; background: var(--code-bg); }
pre code { font-family: var(--mono); font-size: 12.8px; line-height: 1.65; white-space: pre; color: #cdd6e6; background: none; padding: 0; }
.tok-key { color: #ff7b9c; }
.tok-str { color: #9ece6a; }
.tok-com { color: #5c6370; font-style: italic; }
.tok-fn { color: #7aa2f7; }
.tok-var { color: #e0af68; }
.tok-tag { color: #f7768e; }

/* Light-theme syntax palette (dark tokens on a light code surface) */
[data-theme="light"] pre code { color: #24292f; }
[data-theme="light"] .tok-key { color: #cf222e; }
[data-theme="light"] .tok-str { color: #0a7d33; }
[data-theme="light"] .tok-com { color: #6e7781; font-style: italic; }
[data-theme="light"] .tok-fn  { color: #1d4ed8; }
[data-theme="light"] .tok-var { color: #953800; }
[data-theme="light"] .tok-tag { color: #cf222e; }

.callout { display: flex; gap: 12px; margin: 16px 0; padding: 13px 16px; border-radius: 10px; border: 1px solid var(--border); background: var(--bg-elev); font-size: 13.5px; }
.callout .ico { font-size: 18px; }
.callout.tip { border-left: 3px solid var(--accent-2); }
.callout.warn { border-left: 3px solid var(--warn); }
.callout.gotcha { border-left: 3px solid var(--err); }
.callout.senior { border-left: 3px solid var(--accent-4); }
.callout.analogy { border-left: 3px solid var(--accent); background: color-mix(in srgb, var(--accent) 7%, var(--bg-elev)); }
.callout.concept { border-left: 3px solid #56b6c2; }
.callout .c-title { font-weight: 700; display: block; margin-bottom: 2px; }

/* Q&A flashcard */
.qa { margin: 16px 0; border: 1px solid var(--border); border-radius: 10px; background: var(--bg-elev); overflow: hidden; }
.qa-q { padding: 14px 16px; cursor: pointer; display: flex; gap: 10px; align-items: flex-start; font-weight: 600; }
.qa-q .badge { font-size: 10px; background: var(--accent-4); color: #fff; padding: 2px 7px; border-radius: 99px; flex: 0 0 auto; }
.qa-a { padding: 0 16px; max-height: 0; overflow: hidden; transition: max-height .3s ease, padding .3s ease; font-size: 13.5px; color: var(--text-dim); }
.qa.open .qa-a { max-height: 800px; padding: 0 16px 16px; }

/* Quiz */
.quiz { margin: 18px 0; border: 1px solid var(--border); border-radius: 10px; background: var(--bg-elev); padding: 16px; }
.quiz-q { font-weight: 600; margin-bottom: 12px; display: flex; gap: 8px; }
.quiz-q .badge { font-size: 10px; background: var(--accent); color: #fff; padding: 2px 7px; border-radius: 99px; height: fit-content; flex: 0 0 auto; }
.quiz-opt { display: block; width: 100%; text-align: left; padding: 10px 12px; margin: 6px 0; border-radius: 8px; border: 1px solid var(--border); background: var(--bg-elev2); color: var(--text); cursor: pointer; font-size: 13.5px; }
.quiz-opt:hover { border-color: var(--accent); }
.quiz-opt.correct { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 18%, transparent); }
.quiz-opt.wrong { border-color: var(--err); background: color-mix(in srgb, var(--err) 15%, transparent); }
.quiz-opt:disabled { cursor: default; }
.quiz-explain { margin-top: 10px; font-size: 13px; color: var(--text-dim); border-top: 1px dashed var(--border); padding-top: 10px; display: none; }
.quiz-explain.show { display: block; }

/* Code drill */
.drill { margin: 18px 0; border: 1px solid var(--border); border-left: 3px solid var(--accent-2); border-radius: 10px; background: var(--bg-elev); padding: 4px 16px 16px; }
.drill-label { font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--accent-2); font-weight: 700; margin: 14px 0 2px; }
.drill-prompt { font-weight: 600; margin: 8px 0; }
.reveal-btn { background: var(--accent-2); color: #04210c; border: none; padding: 8px 16px; border-radius: 8px; cursor: pointer; font-weight: 700; font-size: 12.5px; }
.drill-answer { display: none; margin-top: 12px; font-size: 13.5px; }
.drill-answer.show { display: block; }

/* lesson footer nav */
.lesson-footer { display: flex; justify-content: space-between; align-items: center; margin-top: 40px; gap: 14px; flex-wrap: wrap; }
.complete-btn { background: var(--ok); color: #04210c; border: none; padding: 11px 20px; border-radius: 9px; font-weight: 700; cursor: pointer; font-size: 14px; }
.complete-btn.done { background: var(--bg-elev2); color: var(--text-dim); border: 1px solid var(--border); }
.nav-btns { display: flex; gap: 8px; }
.nav-btns button { background: var(--bg-elev2); border: 1px solid var(--border); color: var(--text); padding: 10px 16px; border-radius: 9px; cursor: pointer; font-size: 13px; }
.nav-btns button:hover:not(:disabled) { border-color: var(--accent); }
.nav-btns button:disabled { opacity: .4; cursor: default; }

/* Home dashboard */
.dash-hero { margin-bottom: 26px; }
.dash-hero h1 { font-size: 30px; margin: 0 0 8px; }
.dash-hero p { color: var(--text-dim); font-size: 15px; max-width: 640px; }
.mod-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 14px; margin-top: 22px; }
.mod-card { border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; background: var(--bg-elev); cursor: pointer; transition: transform .15s, border-color .15s; }
.mod-card:hover { transform: translateY(-2px); border-color: var(--accent); }
.mod-card .mc-dot { width: 12px; height: 12px; border-radius: 99px; margin-bottom: 12px; }
.mod-card h3 { margin: 0 0 6px; font-size: 16px; }
.mod-card p { margin: 0 0 14px; font-size: 12.5px; color: var(--text-dim); }
.mod-card .mc-bar { height: 6px; background: var(--border); border-radius: 99px; overflow: hidden; }
.mod-card .mc-fill { height: 100%; background: var(--accent-2); }
.mod-card .mc-meta { font-size: 11px; color: var(--text-dim); margin-top: 7px; }

/* Modal */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,.6); display: grid; place-items: center; z-index: 100; padding: 20px; }
.modal-overlay.hidden { display: none; }
.modal-card { background: var(--bg-elev); border: 1px solid var(--border); border-radius: 14px; max-width: 560px; width: 100%; max-height: 85vh; overflow-y: auto; padding: 26px; position: relative; }
.modal-close { position: absolute; top: 12px; right: 14px; background: none; border: none; color: var(--text-dim); font-size: 24px; cursor: pointer; }
.modal-card h2 { margin-top: 0; }
.plan-day { border-left: 2px solid var(--accent); padding: 4px 0 12px 16px; margin-left: 6px; position: relative; }
.plan-day::before { content: ''; position: absolute; left: -6px; top: 6px; width: 10px; height: 10px; border-radius: 99px; background: var(--accent); }
.plan-day h4 { margin: 0 0 4px; }
.plan-day p { margin: 0; font-size: 13px; color: var(--text-dim); }
.confirm-actions { display: flex; gap: 10px; margin-top: 18px; }
.confirm-actions button { flex: 1; padding: 10px; border-radius: 9px; border: none; cursor: pointer; font-weight: 600; }
.btn-cancel { background: var(--bg-elev2); color: var(--text); border: 1px solid var(--border) !important; }
.btn-danger { background: var(--err); color: #fff; }

.hidden { display: none !important; }

/* Responsive */
@media (max-width: 860px) {
  #sidebar { position: fixed; left: 0; top: 0; z-index: 50; transform: translateX(-100%); transition: transform .25s; }
  #sidebar.open { transform: translateX(0); }
  #menu-toggle { display: block; }
  #content { padding: 22px 18px 80px; }
}