/* SP Network PM Study - styles. No external fonts or libraries, works offline. */
:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #eef1f5;
  --border: #d8dde5;
  --text: #1b2330;
  --text-2: #4f5b6b;
  --text-3: #6f7a89;
  --accent: #1f5fbf;
  --accent-soft: #e3ecfa;
  --accent-ink: #ffffff;
  --good: #1e7d4a;
  --good-soft: #e1f3e9;
  --bad: #b3261e;
  --bad-soft: #fbe5e3;
  --warn: #9a6200;
  --warn-soft: #fdf1d8;
  --code-bg: #f1f3f6;
  --shadow: 0 1px 2px rgba(20, 30, 50, .06), 0 2px 8px rgba(20, 30, 50, .05);
  /* diagram tokens */
  --d-line: #8a96a8;
  --d-node: #ffffff;
  --d-node-stroke: #5d6b80;
  --d-c1: #1f5fbf;
  --d-c2: #c2571a;
  --d-c3: #1e7d4a;
  --d-c4: #7b3fb0;
  --d-c5: #a0256a;
  --d-muted: #c9d0da;
  --ink-on: #ffffff;
  --radius: 10px;
  --font: "Segoe UI", system-ui, -apple-system, "Hiragino Sans", "Meiryo", Roboto, sans-serif;
  --mono: Consolas, "Cascadia Mono", ui-monospace, Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12161d; --surface: #1a2029; --surface-2: #222a35; --border: #313b48;
    --text: #e6eaf0; --text-2: #b4bdc9; --text-3: #8d97a5;
    --accent: #6fa3f0; --accent-soft: #1f2f4a; --accent-ink: #0d1420;
    --good: #5cc28a; --good-soft: #17301f; --bad: #f08a80; --bad-soft: #3a1c1a;
    --warn: #e5b45a; --warn-soft: #3a2d12; --code-bg: #20262f;
    --shadow: 0 1px 2px rgba(0,0,0,.3);
    --d-line: #7d8899; --d-node: #222a35; --d-node-stroke: #9aa6b8;
    --d-c1: #6fa3f0; --d-c2: #f0965a; --d-c3: #5cc28a; --d-c4: #b98be6; --d-c5: #e37bb4; --d-muted: #3a4452; --ink-on: #0d1420;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #12161d; --surface: #1a2029; --surface-2: #222a35; --border: #313b48;
  --text: #e6eaf0; --text-2: #b4bdc9; --text-3: #8d97a5;
  --accent: #6fa3f0; --accent-soft: #1f2f4a; --accent-ink: #0d1420;
  --good: #5cc28a; --good-soft: #17301f; --bad: #f08a80; --bad-soft: #3a1c1a;
  --warn: #e5b45a; --warn-soft: #3a2d12; --code-bg: #20262f;
  --shadow: 0 1px 2px rgba(0,0,0,.3);
  --d-line: #7d8899; --d-node: #222a35; --d-node-stroke: #9aa6b8;
  --d-c1: #6fa3f0; --d-c2: #f0965a; --d-c3: #5cc28a; --d-c4: #b98be6; --d-c5: #e37bb4; --d-muted: #3a4452; --ink-on: #0d1420;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body { background: var(--bg); color: var(--text); font: 15px/1.55 var(--font); }
a { color: var(--accent); }
code, pre, kbd { font-family: var(--mono); font-size: .9em; }
code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }
pre { background: var(--code-bg); padding: 12px 14px; border-radius: 8px; overflow-x: auto; line-height: 1.45; margin: 8px 0; }
pre code { background: none; padding: 0; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; }
h1 { font-size: 1.6rem; }
h2 { font-size: 1.25rem; margin-top: 1.2em; }
h3 { font-size: 1.05rem; margin-top: 1em; }
p { margin: 0 0 .8em; }
ul, ol { margin: 0 0 .8em; padding-left: 1.3em; }
li { margin: .2em 0; }
table { border-collapse: collapse; width: 100%; margin: 8px 0 14px; font-size: .93rem; }
th, td { border: 1px solid var(--border); padding: 7px 9px; text-align: left; vertical-align: top; }
th { background: var(--surface-2); font-weight: 600; }
[hidden] { display: none !important; }

.banner { background: var(--warn-soft); color: var(--warn); padding: 8px 16px; font-size: .9rem; border-bottom: 1px solid var(--border); }

/* top bar */
.topbar { position: sticky; top: 0; z-index: 30; display: flex; align-items: center; gap: 12px; height: 52px; padding: 0 16px; background: var(--surface); border-bottom: 1px solid var(--border); }
.brand { font-weight: 700; color: var(--text); text-decoration: none; white-space: nowrap; }
.top-progress { margin-left: auto; display: flex; align-items: center; gap: 8px; font-size: .85rem; color: var(--text-2); }
.top-progress .bar { width: 140px; }
.icon-btn { background: none; border: 1px solid var(--border); color: var(--text); border-radius: 8px; width: 36px; height: 34px; font-size: 18px; cursor: pointer; }

/* layout */
.layout { display: flex; height: calc(100vh - 52px); }
.sidebar { width: 300px; flex: 0 0 300px; overflow-y: auto; background: var(--surface); border-right: 1px solid var(--border); padding: 12px 10px 40px; }
.main { flex: 1; overflow-y: auto; padding: 24px 28px 80px; outline: none; }
.main > .page { max-width: 1040px; margin: 0 auto; }
body.nav-collapsed .sidebar { display: none; }
@media (max-width: 860px) {
  .sidebar { position: fixed; top: 52px; left: 0; bottom: 0; z-index: 25; box-shadow: var(--shadow); width: min(320px, 88vw); }
  body:not(.nav-open) .sidebar { display: none; }
  .main { padding: 16px 16px 80px; }
  .top-progress .bar { width: 70px; }
}

/* sidebar */
.nav-link { display: flex; align-items: center; gap: 8px; padding: 7px 10px; border-radius: 8px; color: var(--text); text-decoration: none; font-size: .93rem; }
.nav-link:hover { background: var(--surface-2); }
.nav-link.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-group-title { font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--text-3); margin: 16px 10px 4px; font-weight: 700; }
.nav-course > summary { list-style: none; cursor: pointer; }
.nav-course > summary::-webkit-details-marker { display: none; }
.nav-course > summary .nav-link::before { content: "\25B8"; font-size: .75rem; color: var(--text-3); width: 10px; transition: transform .15s; }
.nav-course[open] > summary .nav-link::before { transform: rotate(90deg); }
.nav-modules { margin: 2px 0 6px 18px; border-left: 1px solid var(--border); padding-left: 6px; }
.nav-modules .nav-link { font-size: .86rem; padding: 5px 8px; color: var(--text-2); }
.nav-pct { margin-left: auto; font-size: .75rem; color: var(--text-3); font-weight: 400; }
.tick { color: var(--good); font-weight: 700; }

/* generic */
.bar { height: 8px; background: var(--surface-2); border-radius: 99px; overflow: hidden; border: 1px solid var(--border); }
.bar > span { display: block; height: 100%; background: var(--accent); width: 0; transition: width .3s; }
.bar.good > span { background: var(--good); }
.btn { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); padding: 7px 14px; border-radius: 8px; font: inherit; font-size: .92rem; cursor: pointer; text-decoration: none; }
.btn:hover { filter: brightness(1.07); }
.btn:disabled { opacity: .45; cursor: default; filter: none; }
.btn.ghost { background: transparent; color: var(--accent); }
.btn.small { padding: 4px 10px; font-size: .84rem; }
.btn.danger { border-color: var(--bad); background: transparent; color: var(--bad); }
.btn-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 10px 0; }
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; margin: 0 0 16px; box-shadow: var(--shadow); }
.panel.tight { padding: 12px 14px; }
.muted { color: var(--text-2); }
.small { font-size: .86rem; }
.pill { display: inline-block; font-size: .75rem; padding: 2px 9px; border-radius: 99px; background: var(--surface-2); color: var(--text-2); border: 1px solid var(--border); }
.pill.good { background: var(--good-soft); color: var(--good); border-color: transparent; }
.pill.bad { background: var(--bad-soft); color: var(--bad); border-color: transparent; }
.pill.warn { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.pill.accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.stat .num { font-size: 1.7rem; font-weight: 700; }
.stat .lbl { font-size: .82rem; color: var(--text-2); }
.callout { border-left: 4px solid var(--accent); background: var(--accent-soft); padding: 10px 14px; border-radius: 0 8px 8px 0; margin: 10px 0; }
.callout.pm { border-color: var(--d-c2); background: var(--warn-soft); }
.callout.pm::before { content: "PM view: "; font-weight: 700; }
.callout.risk { border-color: var(--bad); background: var(--bad-soft); }

/* course header and tabs */
.course-head { margin-bottom: 8px; }
.course-head .code { font-size: .8rem; color: var(--text-3); font-weight: 700; letter-spacing: .05em; }
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin: 14px 0 18px; overflow-x: auto; }
.tab { padding: 9px 14px; border: none; background: none; color: var(--text-2); font: inherit; font-size: .92rem; cursor: pointer; border-bottom: 2px solid transparent; white-space: nowrap; text-decoration: none; }
.tab:hover { color: var(--text); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }

/* module list */
.module-list { display: grid; gap: 10px; }
.module-item { display: flex; gap: 12px; align-items: center; padding: 12px 14px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); text-decoration: none; color: var(--text); }
.module-item:hover { border-color: var(--accent); }
.module-item .idx { width: 30px; height: 30px; border-radius: 50%; background: var(--surface-2); display: grid; place-items: center; font-weight: 700; font-size: .85rem; flex: none; }
.module-item.done .idx { background: var(--good-soft); color: var(--good); }
.module-item .meta { margin-left: auto; text-align: right; font-size: .8rem; color: var(--text-2); min-width: 110px; }

/* study card */
.deck-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.deck-dots { display: flex; gap: 5px; flex-wrap: wrap; }
.deck-dot { width: 11px; height: 11px; border-radius: 50%; background: var(--surface-2); border: 1px solid var(--border); cursor: pointer; padding: 0; }
.deck-dot.done { background: var(--good); border-color: var(--good); }
.deck-dot.current { outline: 2px solid var(--accent); outline-offset: 1px; }
.study-card { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; box-shadow: var(--shadow); overflow: hidden; }
.study-card .sc-head { padding: 16px 20px; border-bottom: 1px solid var(--border); background: var(--surface-2); }
.study-card .sc-head h2 { margin: 0; }
.study-card .sc-body { padding: 4px 20px 18px; }
.sc-section { margin-top: 16px; }
.sc-section > h4 { font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; color: var(--text-3); margin: 0 0 6px; }
.sc-simple { font-size: 1.05rem; background: var(--accent-soft); border-radius: 10px; padding: 12px 14px; }
.sc-visual { border: 1px solid var(--border); border-radius: 10px; padding: 10px; background: var(--surface); }
.deck-nav { display: flex; justify-content: space-between; align-items: center; margin-top: 14px; gap: 10px; }

/* questions */
.q { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; margin: 0 0 14px; }
.q .q-type { font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; color: var(--text-3); font-weight: 700; }
.q .q-text { font-weight: 600; margin: 4px 0 10px; }
.q .scenario { background: var(--surface-2); border-radius: 8px; padding: 10px 12px; margin: 6px 0 10px; font-size: .93rem; }
.opt { display: flex; gap: 10px; align-items: flex-start; width: 100%; text-align: left; padding: 9px 12px; margin: 6px 0; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--text); font: inherit; cursor: pointer; }
.opt:hover:not(:disabled) { border-color: var(--accent); }
.opt:disabled { cursor: default; }
.opt .letter { font-weight: 700; color: var(--text-3); width: 18px; flex: none; }
.opt.correct { border-color: var(--good); background: var(--good-soft); }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.feedback { margin-top: 10px; padding: 10px 12px; border-radius: 8px; font-size: .93rem; }
.feedback.good { background: var(--good-soft); }
.feedback.bad { background: var(--bad-soft); }
.feedback b { display: block; margin-bottom: 2px; }

/* drag and drop */
.dd-list { list-style: none; padding: 0; margin: 6px 0; }
.dd-item { display: flex; align-items: center; gap: 8px; padding: 8px 10px; margin: 5px 0; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); cursor: grab; user-select: none; }
.dd-item.dragging { opacity: .5; }
.dd-item.over { border-color: var(--accent); border-style: dashed; }
.dd-item .grip { color: var(--text-3); }
.dd-item .mv { margin-left: auto; display: flex; gap: 4px; }
.dd-item.correct { border-color: var(--good); background: var(--good-soft); }
.dd-item.wrong { border-color: var(--bad); background: var(--bad-soft); }
.match-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.match-row { display: flex; align-items: stretch; gap: 8px; margin: 6px 0; }
.match-left { flex: 1; padding: 8px 10px; background: var(--surface-2); border-radius: 8px; font-size: .92rem; }
.match-slot { flex: 1; min-height: 38px; border: 1.5px dashed var(--border); border-radius: 8px; padding: 6px 8px; font-size: .9rem; display: flex; align-items: center; cursor: pointer; }
.match-slot.over, .match-slot.armed { border-color: var(--accent); background: var(--accent-soft); }
.match-slot.correct { border-style: solid; border-color: var(--good); background: var(--good-soft); }
.match-slot.wrong { border-style: solid; border-color: var(--bad); background: var(--bad-soft); }
.chip-pool { display: flex; flex-wrap: wrap; gap: 6px; min-height: 40px; padding: 6px; border: 1px solid var(--border); border-radius: 8px; }
.chip { padding: 6px 10px; border-radius: 99px; background: var(--accent-soft); color: var(--text); border: 1px solid var(--accent); font-size: .88rem; cursor: grab; user-select: none; }
.chip.selected { background: var(--accent); color: var(--accent-ink); }
@media (max-width: 700px) { .match-wrap { grid-template-columns: 1fr; } }

/* visual stepper */
.viz { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 16px; margin: 0 0 20px; box-shadow: var(--shadow); }
.viz h3 { margin: 0 0 4px; }
.viz .viz-intro { color: var(--text-2); font-size: .92rem; margin-bottom: 10px; }
.viz svg { width: 100%; height: auto; display: block; }
.viz-stage { border: 1px solid var(--border); border-radius: 10px; background: var(--bg); overflow: hidden; }
.viz-controls { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: 10px; }
.viz-step { font-size: .82rem; color: var(--text-3); margin-left: auto; }
.viz-caption { margin-top: 10px; padding: 10px 12px; border-radius: 8px; background: var(--surface-2); min-height: 48px; font-size: .94rem; }
.viz-caption b { color: var(--accent); }
.viz-form { display: flex; flex-wrap: wrap; gap: 10px; align-items: flex-end; margin: 6px 0 10px; }
.viz-form label { display: flex; flex-direction: column; font-size: .8rem; color: var(--text-2); gap: 3px; }
.viz-form input, .viz-form select { font: inherit; padding: 6px 8px; border-radius: 6px; border: 1px solid var(--border); background: var(--surface); color: var(--text); min-width: 120px; }
.mono { font-family: var(--mono); }
.bits { font-family: var(--mono); letter-spacing: .02em; word-break: break-all; }
.bits .n { color: var(--d-c1); font-weight: 700; }
.bits .h { color: var(--d-c2); }

/* svg diagram classes */
.dg-node { fill: var(--d-node); stroke: var(--d-node-stroke); stroke-width: 1.4; }
.dg-node.hl { stroke: var(--d-c1); stroke-width: 2.6; }
.dg-node.c2 { stroke: var(--d-c2); } .dg-node.c3 { stroke: var(--d-c3); } .dg-node.c4 { stroke: var(--d-c4); }
.dg-link { stroke: var(--d-line); stroke-width: 2; fill: none; }
.dg-link.hl { stroke: var(--d-c1); stroke-width: 3.5; }
.dg-link.blocked { stroke: var(--bad); stroke-dasharray: 6 5; }
.dg-link.down { stroke: var(--bad); stroke-width: 2; stroke-dasharray: 3 4; opacity: .7; }
.dg-link.c2 { stroke: var(--d-c2); stroke-width: 3; } .dg-link.c3 { stroke: var(--d-c3); stroke-width: 3; }
.dg-text { fill: var(--text); font: 600 13px var(--font); }
.dg-sub { fill: var(--text-2); font: 11.5px var(--font); }
.dg-small { fill: var(--text-3); font: 10.5px var(--font); }
.dg-mono { fill: var(--text); font: 12px var(--mono); }
.dg-box { fill: var(--surface); stroke: var(--border); }
.dg-area { fill: var(--surface-2); stroke: var(--border); stroke-dasharray: 5 4; }
.dg-hdr { stroke: var(--d-node-stroke); stroke-width: 1; }
.fill-c1 { fill: var(--d-c1); } .fill-c2 { fill: var(--d-c2); } .fill-c3 { fill: var(--d-c3); } .fill-c4 { fill: var(--d-c4); } .fill-c5 { fill: var(--d-c5); } .fill-muted { fill: var(--d-muted); }
.ink-on { fill: var(--ink-on); font: 600 11.5px var(--font); }
.fade { opacity: .25; }
.anim { transition: transform .6s ease, opacity .4s ease; }

/* topology */
.topo { display: grid; grid-template-columns: 1fr; gap: 12px; }
.topo .viz-stage svg { max-height: 360px; }
.topo .node-g { cursor: pointer; }
.topo .node-g:focus { outline: none; }
.topo .node-g:focus .dg-node, .topo .node-g.sel .dg-node { stroke: var(--d-c1); stroke-width: 3; }
.topo-cfg h4 { margin: 0 0 6px; }
.topo-cfg pre { max-height: 360px; }
@media (max-width: 860px) { .topo { grid-template-columns: 1fr; } }

/* labs */
.lab-steps { list-style: none; padding: 0; }
.lab-steps li { display: flex; gap: 10px; align-items: flex-start; padding: 6px 0; border-bottom: 1px solid var(--border); }
.lab-steps input { margin-top: 5px; }
.lab-steps li.done span { color: var(--text-3); text-decoration: line-through; }

/* flashcards */
.flash-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 12px; }
.flash { perspective: 900px; height: 170px; cursor: pointer; border: none; background: none; padding: 0; font: inherit; color: inherit; text-align: left; }
.flash-inner { position: relative; width: 100%; height: 100%; transition: transform .45s; transform-style: preserve-3d; }
.flash.flipped .flash-inner { transform: rotateY(180deg); }
.flash-face { position: absolute; inset: 0; backface-visibility: hidden; border: 1px solid var(--border); border-radius: 12px; padding: 14px; overflow: auto; background: var(--surface); box-shadow: var(--shadow); font-size: .92rem; }
.flash-face.front { font-weight: 600; display: flex; flex-direction: column; justify-content: center; }
.flash-face.front small { font-weight: 400; color: var(--text-3); margin-top: 8px; }
.flash-face.back { transform: rotateY(180deg); background: var(--accent-soft); }

/* interview */
.iq { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; }
.iq summary { padding: 12px 16px; cursor: pointer; font-weight: 600; }
.iq .iq-body { padding: 0 16px 14px; }
.iq .tip { font-size: .88rem; color: var(--text-2); border-top: 1px dashed var(--border); padding-top: 8px; margin-top: 8px; }

/* terminal sim */
.term { background: #0f1720; color: #d7e3f0; font: 13px/1.5 var(--mono); border-radius: 10px; padding: 12px; min-height: 260px; max-height: 420px; overflow-y: auto; }
.term .ln { white-space: pre-wrap; }
.term .prompt { color: #7fd1a8; }
.term .err { color: #ff9b8f; }
.term .note { color: #9fb3c8; }
.term-input { display: flex; gap: 6px; margin-top: 6px; }
.term-input input { flex: 1; font: 13px var(--mono); padding: 7px 9px; border-radius: 6px; border: 1px solid var(--border); background: var(--surface); color: var(--text); }

.canvas3d { width: 100%; height: 440px; display: block; border-radius: 10px; background: var(--bg); touch-action: none; }
.kbd-hint { font-size: .8rem; color: var(--text-3); }
.empty { color: var(--text-3); font-style: italic; }
footer.page-foot { margin-top: 36px; font-size: .8rem; color: var(--text-3); }
.viz svg { max-height: 520px; }
.sc-visual .viz { border: none; box-shadow: none; padding: 0; margin: 0; }
.sc-visual { padding: 12px; }
@media (max-width: 600px) {
  .topbar { gap: 8px; padding: 0 10px; }
  .brand { font-size: .92rem; min-width: 0; overflow: hidden; text-overflow: ellipsis; }
  .top-progress .bar { display: none; }
  .main table { display: block; overflow-x: auto; }
  .viz { padding: 10px; }
  .study-card .sc-body, .study-card .sc-head { padding-left: 14px; padding-right: 14px; }
}