/* Studily Study — shared styles.
   Tailwind (vendored, assets/tailwind.js) handles utilities; this file owns
   the theme tokens, component classes and anything Tailwind can't express. */

:root {
  --bg:        #0e0e13;
  --bg-2:      #16161f;
  --surface:   #1b1b26;
  --surface-2: #22222f;
  --border:    #2e2e3e;
  --border-2:  #3a3a4d;
  --fg:        #ececf1;
  --fg-2:      #b4b4c4;
  --fg-3:      #8a8a9e;
  --accent:    #8b7cf0;
  --accent-2:  #a394f5;
  --accent-dim: rgba(139, 124, 240, 0.13);
  --green:     #46c98b;
  --green-dim: rgba(70, 201, 139, 0.13);
  --red:       #f2685f;
  --red-dim:   rgba(242, 104, 95, 0.13);
  --amber:     #e8a552;
  --amber-dim: rgba(232, 165, 82, 0.13);
  --blue:      #5aa9e6;
  --blue-dim:  rgba(90, 169, 230, 0.13);
  --radius:    14px;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, "JetBrains Mono", Menlo, Consolas, monospace;
}

:root[data-theme="light"] {
  --bg:        #f7f7fa;
  --bg-2:      #ffffff;
  --surface:   #ffffff;
  --surface-2: #f1f1f6;
  --border:    #e2e2ec;
  --border-2:  #cfcfdd;
  --fg:        #17171f;
  --fg-2:      #4a4a5c;
  --fg-3:      #74748a;
  --accent:    #6a5ae0;
  --accent-2:  #5847d6;
  --accent-dim: rgba(106, 90, 224, 0.10);
  --green:     #16875a;
  --green-dim: rgba(22, 135, 90, 0.10);
  --red:       #cf3b31;
  --red-dim:   rgba(207, 59, 49, 0.10);
  --amber:     #b1731a;
  --amber-dim: rgba(177, 115, 26, 0.10);
  --blue:      #2a72b5;
  --blue-dim:  rgba(42, 114, 181, 0.10);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 5rem; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- typography ---------- */
.prose-body p { color: var(--fg-2); margin: 0 0 1rem; }
.prose-body ul, .prose-body ol { color: var(--fg-2); margin: 0 0 1rem; padding-left: 1.35rem; }
.prose-body li { margin: 0.3rem 0; }
.prose-body li::marker { color: var(--fg-3); }
.prose-body strong { color: var(--fg); font-weight: 650; }
.prose-body a { color: var(--accent-2); text-decoration: underline; text-underline-offset: 2px; }
.prose-body h3 { color: var(--fg); font-size: 1.05rem; font-weight: 650; margin: 1.9rem 0 .7rem; }
.prose-body h4 { color: var(--fg); font-size: .95rem; font-weight: 650; margin: 1.4rem 0 .5rem; }

code:not(pre code) {
  font-family: var(--mono);
  font-size: 0.855em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 0.1em 0.38em;
  color: var(--accent-2);
  white-space: nowrap;
}

pre {
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.62;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.95rem 1.05rem;
  overflow-x: auto;
  margin: 0 0 1rem;
  color: var(--fg-2);
}
pre code { font-family: inherit; background: none; border: none; padding: 0; color: inherit; white-space: pre; }

/* tiny hand-rolled highlighting — app.js tags these */
.tok-kw  { color: #c48ef5; }
.tok-str { color: #7ecf9a; }
.tok-com { color: var(--fg-3); font-style: italic; }
.tok-num { color: #e8a552; }
.tok-fn  { color: #6db3f2; }
.tok-ann { color: #e0a04a; }

/* ---------- components ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
  border-radius: 9px; padding: .5rem .95rem;
  font-size: .845rem; font-weight: 600; line-height: 1;
  border: 1px solid transparent; cursor: pointer;
  transition: background .13s, border-color .13s, color .13s, transform .06s;
  white-space: nowrap;
}
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--accent-2); }
.btn-ghost { background: transparent; color: var(--fg-2); border-color: var(--border-2); }
.btn-ghost:hover:not(:disabled) { color: var(--fg); border-color: var(--fg-3); background: var(--surface-2); }
.btn-quiet { background: transparent; color: var(--fg-3); }
.btn-quiet:hover:not(:disabled) { color: var(--fg); background: var(--surface-2); }

.tag {
  display: inline-flex; align-items: center; gap: .3rem;
  font-size: .68rem; font-weight: 650; letter-spacing: .04em; text-transform: uppercase;
  padding: .2rem .5rem; border-radius: 5px;
}

/* ---------- callouts ---------- */
.callout {
  border-left: 3px solid var(--border-2);
  background: var(--surface);
  border-radius: 0 10px 10px 0;
  padding: .85rem 1.1rem;
  margin: 0 0 1.15rem;
  font-size: .9rem;
}
.callout p:last-child { margin-bottom: 0; }
.callout-title { font-weight: 680; font-size: .78rem; letter-spacing: .03em; text-transform: uppercase; margin-bottom: .35rem; display: block; }
.callout-concept { border-left-color: var(--blue);   background: var(--blue-dim); }
.callout-concept .callout-title { color: var(--blue); }
.callout-project { border-left-color: var(--accent); background: var(--accent-dim); }
.callout-project .callout-title { color: var(--accent-2); }
.callout-warn    { border-left-color: var(--red);    background: var(--red-dim); }
.callout-warn .callout-title { color: var(--red); }
.callout-win     { border-left-color: var(--green);  background: var(--green-dim); }
.callout-win .callout-title { color: var(--green); }
.callout-say     { border-left-color: var(--amber);  background: var(--amber-dim); }
.callout-say .callout-title { color: var(--amber); }

/* ---------- quiz ---------- */
.qopt {
  display: flex; gap: .7rem; align-items: flex-start;
  width: 100%; text-align: left;
  border: 1px solid var(--border); background: var(--bg-2);
  border-radius: 10px; padding: .7rem .85rem;
  cursor: pointer; font-size: .885rem; color: var(--fg-2);
  transition: border-color .12s, background .12s, color .12s;
}
.qopt:hover:not(.locked) { border-color: var(--border-2); color: var(--fg); }
.qopt.locked { cursor: default; }
.qopt-marker {
  flex-shrink: 0; width: 20px; height: 20px; border-radius: 6px;
  border: 1.5px solid var(--border-2); display: grid; place-items: center;
  font-size: .68rem; font-weight: 700; color: var(--fg-3); margin-top: 1px;
}
.qopt.selected { border-color: var(--accent); background: var(--accent-dim); color: var(--fg); }
.qopt.selected .qopt-marker { border-color: var(--accent); background: var(--accent); color: #fff; }
.qopt.correct { border-color: var(--green); background: var(--green-dim); color: var(--fg); }
.qopt.correct .qopt-marker { border-color: var(--green); background: var(--green); color: #fff; }
.qopt.wrong { border-color: var(--red); background: var(--red-dim); color: var(--fg); }
.qopt.wrong .qopt-marker { border-color: var(--red); background: var(--red); color: #fff; }
.qopt.missed { border-color: var(--green); border-style: dashed; }

.qinput {
  width: 100%; background: var(--bg-2); border: 1px solid var(--border);
  border-radius: 9px; padding: .6rem .8rem; color: var(--fg);
  font-size: .9rem; font-family: inherit; outline: none;
}
.qinput:focus { border-color: var(--accent); }
.qinput.correct { border-color: var(--green); }
.qinput.wrong { border-color: var(--red); }

.qfeedback { font-size: .85rem; border-radius: 9px; padding: .7rem .85rem; margin-top: .7rem; }
.qfeedback.ok  { background: var(--green-dim); color: var(--fg-2); border: 1px solid rgba(70,201,139,.28); }
.qfeedback.no  { background: var(--red-dim);   color: var(--fg-2); border: 1px solid rgba(242,104,95,.28); }
.qfeedback strong { color: var(--fg); }
.qfeedback code { white-space: normal; }

/* ordering */
.qorder-item {
  display: flex; align-items: center; gap: .7rem;
  border: 1px solid var(--border); background: var(--bg-2);
  border-radius: 9px; padding: .55rem .75rem; font-size: .875rem; color: var(--fg-2);
  cursor: grab; user-select: none;
}
.qorder-item.dragging { opacity: .4; }
.qorder-item.correct { border-color: var(--green); background: var(--green-dim); }
.qorder-item.wrong { border-color: var(--red); background: var(--red-dim); }
.qorder-num {
  flex-shrink: 0; width: 22px; height: 22px; border-radius: 6px; background: var(--surface-2);
  color: var(--fg-3); font-size: .72rem; font-weight: 700; display: grid; place-items: center;
}

/* ---------- progress ---------- */
.bar { height: 6px; border-radius: 99px; background: var(--surface-2); overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 99px; transition: width .45s cubic-bezier(.4,0,.2,1); }

/* ---------- reveal ---------- */
.reveal-body { display: none; }
.reveal.open .reveal-body { display: block; animation: fade .2s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(-3px); } to { opacity: 1; transform: none; } }

/* ---------- misc ---------- */
.hairline { border-top: 1px solid var(--border); }
table.data { width: 100%; border-collapse: collapse; font-size: .85rem; margin: 0 0 1.15rem; }
table.data th, table.data td { border: 1px solid var(--border); padding: .5rem .7rem; text-align: left; vertical-align: top; }
table.data th { background: var(--surface-2); color: var(--fg); font-weight: 650; font-size: .78rem; letter-spacing: .02em; }
table.data td { color: var(--fg-2); }
.scroll-x { overflow-x: auto; -webkit-overflow-scrolling: touch; }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 99px; border: 2px solid var(--bg); }
::-webkit-scrollbar-thumb:hover { background: var(--fg-3); }

@media print {
  .no-print { display: none !important; }
  body { background: #fff; color: #000; }
}

/* ==========================================================================
   Mobile, navigation and interactivity — added after the base sheet.
   ========================================================================== */

html { -webkit-text-size-adjust: 100%; }
body { overflow-x: hidden; }

/* Nothing may force the page itself to scroll sideways. Wide things get
   their own scroller (app.js wraps tables automatically). */
main img, main svg { max-width: 100%; height: auto; }

/* ---------- floating next-lesson pill ---------- */
#nextpill {
  position: fixed; right: 14px; bottom: 14px; z-index: 50;
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .6rem .9rem; border-radius: 999px;
  background: var(--accent); color: #fff;
  font-size: .82rem; font-weight: 650; text-decoration: none;
  box-shadow: 0 6px 22px rgba(0,0,0,.35);
  opacity: 0; transform: translateY(10px); pointer-events: none;
  transition: opacity .2s, transform .2s;
}
#nextpill.show { opacity: 1; transform: none; pointer-events: auto; }
#nextpill:active { transform: translateY(1px); }

/* ---------- copy button on code blocks ---------- */
.codewrap { position: relative; }
.codewrap > .copybtn {
  position: absolute; top: 8px; right: 8px;
  padding: .25rem .5rem; border-radius: 6px;
  font-size: .68rem; font-weight: 650; letter-spacing: .02em;
  background: var(--surface-2); color: var(--fg-3);
  border: 1px solid var(--border); cursor: pointer;
  opacity: 0; transition: opacity .15s, color .15s, border-color .15s;
}
.codewrap:hover > .copybtn,
.codewrap > .copybtn:focus-visible { opacity: 1; }
.codewrap > .copybtn:hover { color: var(--fg); border-color: var(--fg-3); }
.codewrap > .copybtn.done { color: var(--green); border-color: var(--green); opacity: 1; }
@media (hover: none) { .codewrap > .copybtn { opacity: .65; } }

/* ---------- TOC active state ---------- */
[data-toc] a.active {
  color: var(--accent-2) !important;
  font-weight: 650;
}

/* ---------- keyboard hint sheet ---------- */
#keyhelp {
  position: fixed; inset: 0; z-index: 90;
  display: none; place-items: center; padding: 1rem;
  background: rgba(0,0,0,.5);
}
#keyhelp.open { display: grid; }
#keyhelp kbd {
  display: inline-block; min-width: 22px; text-align: center;
  padding: .1rem .35rem; border-radius: 5px;
  background: var(--surface-2); border: 1px solid var(--border-2);
  font-family: var(--mono); font-size: .72rem; color: var(--fg);
}

/* ==========================================================================
   Small screens
   ========================================================================== */
@media (max-width: 640px) {
  body { font-size: 14.5px; }

  main { padding-left: 1rem !important; padding-right: 1rem !important; padding-top: 1.25rem !important; }

  h1 { font-size: 1.6rem !important; line-height: 1.22; }
  main h2 { font-size: 1.25rem !important; margin-top: 2.25rem !important; }
  .prose-body h3 { font-size: 1rem; }

  pre { font-size: 11.5px; padding: .75rem .8rem; border-radius: 8px; }
  code:not(pre code) { font-size: .82em; white-space: normal; overflow-wrap: anywhere; }

  .card { border-radius: 12px; }
  .callout { padding: .75rem .85rem; font-size: .875rem; }

  /* quiz: bigger tap targets, room for long options */
  .qopt { padding: .8rem .75rem; font-size: .875rem; }
  .qopt-marker { width: 22px; height: 22px; }
  .qorder-item { padding: .65rem .6rem; font-size: .84rem; }
  .btn { padding: .6rem 1rem; font-size: .875rem; }

  /* tables become horizontally scrollable cards, never page-wideners */
  table.data { font-size: .8rem; }
  table.data th, table.data td { padding: .45rem .55rem; }

  /* stacked two-column grids already collapse via Tailwind's sm: prefix */
  #nextpill { right: 10px; bottom: 10px; font-size: .78rem; }
}

@media (max-width: 400px) {
  pre { font-size: 10.8px; }
  .qopt { font-size: .845rem; }
}

/* respect users who don't want motion */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
}