/* ============================================================
   NORTHRIDGE — DEPARTMENT OF COMPUTER SCIENCE
   Design tokens
   Color:   --navy (bg), --graphite (surface), --parchment (warm light),
            --blue (primary accent), --violet (research accent),
            --green (signal / status), --ink (parchment-surface text)
   Type:    "Fraunces" (display, academic serif with character) +
            "IBM Plex Sans" (interface/body) + "IBM Plex Mono" (data —
            course codes, credits, numerals only)
   Layout:  12-col desktop / 8-col tablet / 4-col mobile grid
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,340;9..144,460;9..144,560;9..144,650&family=IBM+Plex+Sans:wght@400;500;600;700&family=IBM+Plex+Mono:wght@400;500;600&display=swap');

:root{
  --navy:#0d1526;
  --navy-deep:#080e1a;
  --graphite:#1a2233;
  --graphite-2:#222b3f;
  --hairline:rgba(226,222,208,0.14);
  --hairline-strong:rgba(226,222,208,0.24);
  --parchment:#f2ecdd;
  --parchment-dim:#e7dfc9;
  --ink:#1c1a14;
  --ink-soft:#4a4738;
  --blue:#4c8dfd;
  --blue-soft:#274a86;
  --violet:#9084e8;
  --green:#4fd28f;
  --amber:#e0a94c;
  --text-hi:#f4f1e8;
  --text-mid:#c7ccd9;
  --text-dim:#8892a6;
  --radius-s:3px;
  --radius-m:6px;
  --maxw:1320px;
  --gap:24px;
  --font-display:'Fraunces', Georgia, serif;
  --font-body:'IBM Plex Sans', -apple-system, sans-serif;
  --font-mono:'IBM Plex Mono', ui-monospace, monospace;
  --dur-1:120ms;
  --dur-2:260ms;
  --ease:cubic-bezier(.2,.7,.3,1);
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{animation-duration:0.001ms!important;animation-iteration-count:1!important;transition-duration:0.001ms!important;scroll-behavior:auto!important;}
}

body{
  margin:0;
  background:var(--navy);
  color:var(--text-hi);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
}

img,svg{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer;}
input,select,textarea{font:inherit;color:inherit;}
ul{list-style:none;margin:0;padding:0;}
h1,h2,h3,h4,p{margin:0;}

/* ---------- Focus & accessibility ---------- */
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,[tabindex]:focus-visible{
  outline:2px solid var(--blue);
  outline-offset:3px;
  border-radius:2px;
}
.visually-hidden{
  position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;
  clip:rect(0,0,0,0);white-space:nowrap;border:0;
}
.skip-link{
  position:fixed;top:-60px;left:12px;z-index:999;background:var(--blue);color:#06121f;
  padding:10px 16px;border-radius:var(--radius-s);font-weight:600;transition:top var(--dur-1) var(--ease);
}
.skip-link:focus{top:12px;}

/* ---------- Typography scale ---------- */
.t-display{font-family:var(--font-display);font-weight:560;letter-spacing:-0.01em;line-height:0.96;}
.t-dept-title{font-size:clamp(2.6rem,7vw,5.6rem);}
.t-page-title{font-family:var(--font-display);font-weight:560;font-size:clamp(2.1rem,4.4vw,3.4rem);letter-spacing:-0.01em;line-height:1.03;}
.t-section-heading{font-family:var(--font-display);font-weight:500;font-size:clamp(1.5rem,2.4vw,2.05rem);letter-spacing:-0.005em;line-height:1.15;}
.t-course-code{font-family:var(--font-mono);font-weight:600;letter-spacing:0.03em;}
.t-course-title{font-family:var(--font-display);font-weight:500;font-size:1.4rem;line-height:1.2;}
.t-body{font-family:var(--font-body);font-size:1rem;line-height:1.65;color:var(--text-mid);}
.t-meta{font-family:var(--font-body);font-size:0.82rem;color:var(--text-dim);letter-spacing:0.01em;}
.t-label{font-family:var(--font-body);font-weight:600;font-size:0.72rem;letter-spacing:0.09em;text-transform:uppercase;color:var(--text-dim);}
.t-numeral{font-family:var(--font-mono);font-weight:600;font-variant-numeric:tabular-nums;}
.t-nav{font-family:var(--font-body);font-weight:500;font-size:0.92rem;}
.t-caption{font-family:var(--font-body);font-size:0.8rem;color:var(--text-dim);font-style:italic;}

.on-parchment{color:var(--ink);}
.on-parchment .t-body{color:var(--ink-soft);}
.on-parchment .t-meta{color:var(--ink-soft);}

/* ---------- Layout grid ---------- */
.shell{max-width:var(--maxw);margin:0 auto;padding:0 32px;}
.grid{display:grid;gap:var(--gap);grid-template-columns:repeat(12,1fr);}
@media (max-width:1000px){
  .grid{grid-template-columns:repeat(8,1fr);}
  .shell{padding:0 24px;}
}
@media (max-width:640px){
  .grid{grid-template-columns:repeat(4,1fr);gap:16px;}
  .shell{padding:0 18px;}
}

.surface{background:var(--graphite);border:1px solid var(--hairline);border-radius:var(--radius-m);}
.surface-2{background:var(--graphite-2);border:1px solid var(--hairline);border-radius:var(--radius-m);}
.surface-parchment{background:var(--parchment);border-radius:var(--radius-m);}
.hairline-top{border-top:1px solid var(--hairline);}
.hairline-bottom{border-bottom:1px solid var(--hairline);}

.section{padding:88px 0;}
.section-tight{padding:52px 0;}
@media (max-width:640px){ .section{padding:56px 0;} .section-tight{padding:36px 0;} }

.eyebrow{
  font-family:var(--font-mono);font-size:0.72rem;letter-spacing:0.08em;color:var(--blue);
  display:flex;align-items:center;gap:10px;margin-bottom:14px;
}
.eyebrow::before{content:"";width:22px;height:1px;background:var(--blue);display:inline-block;}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:13px 22px;border-radius:2px;
  font-family:var(--font-body);font-weight:600;font-size:0.94rem;transition:transform var(--dur-1) var(--ease),background var(--dur-1) var(--ease),border-color var(--dur-1) var(--ease);
  white-space:nowrap;
}
.btn-primary{background:var(--blue);color:#071426;}
.btn-primary:hover{background:#6ba0ff;}
.btn-outline{border:1px solid var(--hairline-strong);color:var(--text-hi);}
.btn-outline:hover{border-color:var(--blue);color:var(--blue);}
.btn-ghost{color:var(--text-mid);padding:13px 8px;}
.btn-ghost:hover{color:var(--text-hi);}
.btn-sm{padding:8px 14px;font-size:0.82rem;}
.btn:active{transform:scale(0.98);}
.btn[disabled]{opacity:0.4;cursor:not-allowed;}

/* ---------- Header ---------- */
.site-header{position:sticky;top:0;z-index:100;background:rgba(13,21,38,0.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--hairline);}
.header-row{display:flex;align-items:center;justify-content:space-between;gap:24px;height:78px;}
.brand{display:flex;align-items:center;gap:12px;}
.brand-mark{width:38px;height:38px;flex:none;}
.brand-text{display:flex;flex-direction:column;line-height:1.1;}
.brand-text .uni{font-family:var(--font-mono);font-size:0.62rem;letter-spacing:0.12em;color:var(--text-dim);text-transform:uppercase;}
.brand-text .dept{font-family:var(--font-display);font-weight:560;font-size:1.08rem;}
.primary-nav{display:flex;align-items:center;gap:2px;}
.primary-nav a{padding:10px 14px;border-radius:2px;color:var(--text-mid);transition:color var(--dur-1),background var(--dur-1);}
.primary-nav a:hover,.primary-nav a.active{color:var(--text-hi);background:rgba(255,255,255,0.05);}
.header-actions{display:flex;align-items:center;gap:10px;}
.icon-btn{width:38px;height:38px;display:grid;place-items:center;border-radius:2px;color:var(--text-mid);}
.icon-btn:hover{color:var(--text-hi);background:rgba(255,255,255,0.06);}
.explore-cta{
  display:flex;align-items:center;gap:8px;padding:9px 16px;border:1px solid var(--blue-soft);
  border-radius:2px;color:var(--blue);font-weight:600;font-size:0.85rem;background:rgba(76,141,253,0.08);
}
.explore-cta:hover{background:rgba(76,141,253,0.16);}
.nav-toggle{display:none;}
@media (max-width:960px){
  .primary-nav, .header-actions .explore-cta-desktop{display:none;}
  .nav-toggle{display:grid;place-items:center;width:40px;height:40px;}
}

/* mobile drawer */
.drawer-backdrop{position:fixed;inset:0;background:rgba(6,10,20,0.6);z-index:200;opacity:0;pointer-events:none;transition:opacity var(--dur-2) var(--ease);}
.drawer-backdrop.open{opacity:1;pointer-events:auto;}
.drawer{
  position:fixed;top:0;right:0;bottom:0;width:min(340px,86vw);background:var(--graphite);z-index:201;
  transform:translateX(100%);transition:transform var(--dur-2) var(--ease);border-left:1px solid var(--hairline);
  display:flex;flex-direction:column;padding:22px;
}
.drawer.open{transform:translateX(0);}
.drawer-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px;}
.drawer-nav a{display:block;padding:14px 6px;font-family:var(--font-display);font-size:1.3rem;border-bottom:1px solid var(--hairline);}
.drawer-explore{margin-top:auto;}

/* ---------- Footer ---------- */
.site-footer{background:var(--navy-deep);border-top:1px solid var(--hairline);padding:64px 0 28px;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr 1fr;gap:32px;}
@media (max-width:960px){.footer-grid{grid-template-columns:1fr 1fr;}}
@media (max-width:640px){.footer-grid{grid-template-columns:1fr;}}
.footer-col h4{font-family:var(--font-body);font-weight:600;font-size:0.78rem;letter-spacing:0.07em;text-transform:uppercase;color:var(--text-dim);margin-bottom:14px;}
.footer-col a, .footer-col p{color:var(--text-mid);font-size:0.92rem;display:block;margin-bottom:9px;}
.footer-col a:hover{color:var(--text-hi);}
.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:48px;padding-top:24px;border-top:1px solid var(--hairline);color:var(--text-dim);font-size:0.8rem;}

/* ---------- Cards ---------- */
.card{background:var(--graphite);border:1px solid var(--hairline);border-radius:var(--radius-m);padding:26px;transition:border-color var(--dur-1) var(--ease);}
.card:hover{border-color:var(--hairline-strong);}
.card-link{display:block;height:100%;}
.stat-strip{display:grid;grid-template-columns:repeat(5,1fr);gap:1px;background:var(--hairline);border:1px solid var(--hairline);border-radius:var(--radius-m);overflow:hidden;}
.stat-cell{background:var(--navy);padding:22px 18px;}
@media (max-width:900px){.stat-strip{grid-template-columns:repeat(2,1fr);} }
.stat-num{font-family:var(--font-mono);font-weight:600;font-size:1.9rem;color:var(--blue);}
.stat-label{font-family:var(--font-body);font-size:0.78rem;color:var(--text-dim);margin-top:4px;}

.pill{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:2px;font-size:0.72rem;font-weight:600;letter-spacing:0.04em;font-family:var(--font-body);}
.pill-core{background:rgba(76,141,253,0.14);color:var(--blue);}
.pill-elective{background:rgba(144,132,232,0.16);color:var(--violet);}
.pill-green{background:rgba(79,210,143,0.14);color:var(--green);}
.pill-neutral{background:rgba(255,255,255,0.07);color:var(--text-mid);}

/* ---------- Course Explorer ---------- */
.explorer-shell{border:1px solid var(--hairline);border-radius:var(--radius-m);background:var(--graphite);overflow:hidden;}
.explorer-stages{display:grid;grid-template-columns:repeat(3,1fr);}
@media (max-width:900px){.explorer-stages{grid-template-columns:1fr;}}
.explorer-stage{border-right:1px solid var(--hairline);min-height:340px;display:flex;flex-direction:column;}
.explorer-stage:last-child{border-right:none;}
@media (max-width:900px){.explorer-stage{border-right:none;border-bottom:1px solid var(--hairline);min-height:0;}}
.stage-head{padding:16px 20px;border-bottom:1px solid var(--hairline);display:flex;align-items:center;justify-content:space-between;}
.stage-num{font-family:var(--font-mono);font-size:0.72rem;color:var(--text-dim);}
.stage-body{padding:10px;flex:1;overflow-y:auto;}
.stage-option{
  width:100%;text-align:left;padding:13px 14px;border-radius:var(--radius-s);color:var(--text-mid);
  display:flex;align-items:center;justify-content:space-between;gap:10px;transition:background var(--dur-1),color var(--dur-1);
}
.stage-option:hover{background:rgba(255,255,255,0.05);color:var(--text-hi);}
.stage-option.selected{background:rgba(76,141,253,0.14);color:var(--blue);}
.stage-option .opt-meta{font-family:var(--font-mono);font-size:0.72rem;color:var(--text-dim);}
.stage-empty{padding:28px 18px;color:var(--text-dim);font-size:0.9rem;}

/* mobile stepper */
.stepper-bar{display:none;}
@media (max-width:900px){
  .stepper-bar{display:flex;gap:8px;padding:14px 16px;border-bottom:1px solid var(--hairline);overflow-x:auto;}
  .stepper-step{font-family:var(--font-mono);font-size:0.7rem;color:var(--text-dim);padding:6px 10px;border:1px solid var(--hairline);border-radius:20px;white-space:nowrap;}
  .stepper-step.active{color:var(--blue);border-color:var(--blue-soft);background:rgba(76,141,253,0.1);}
  .stepper-step.done{color:var(--green);}
}

.course-detail{padding:0;}
.course-detail-head{padding:34px;border-bottom:1px solid var(--hairline);}
.course-detail-body{padding:34px;display:grid;grid-template-columns:2fr 1fr;gap:36px;}
@media (max-width:900px){.course-detail-body{grid-template-columns:1fr;padding:24px;} .course-detail-head{padding:24px;}}

.week-row{border:1px solid var(--hairline);border-radius:var(--radius-s);margin-bottom:8px;overflow:hidden;}
.week-toggle{width:100%;display:flex;align-items:center;gap:14px;padding:14px 16px;text-align:left;}
.week-toggle:hover{background:rgba(255,255,255,0.03);}
.week-num{font-family:var(--font-mono);color:var(--text-dim);font-size:0.82rem;flex:none;width:52px;}
.week-title{flex:1;font-weight:500;}
.week-caret{transition:transform var(--dur-1) var(--ease);color:var(--text-dim);}
.week-row.open .week-caret{transform:rotate(180deg);}
.week-panel{max-height:0;overflow:hidden;transition:max-height var(--dur-2) var(--ease);}
.week-row.open .week-panel{max-height:240px;}
.week-panel-inner{padding:0 16px 16px 82px;color:var(--text-mid);font-size:0.92rem;}

.assess-bar{height:10px;border-radius:6px;overflow:hidden;display:flex;background:var(--navy-deep);border:1px solid var(--hairline);}
.assess-seg{height:100%;}
.assess-legend{display:flex;flex-wrap:wrap;gap:14px;margin-top:10px;}
.assess-legend-item{display:flex;align-items:center;gap:7px;font-size:0.8rem;color:var(--text-mid);}
.assess-dot{width:9px;height:9px;border-radius:2px;}

.prereq-graph{padding:20px;border:1px solid var(--hairline);border-radius:var(--radius-m);background:var(--navy-deep);overflow-x:auto;}

.compare-table{width:100%;border-collapse:collapse;}
.compare-table th,.compare-table td{border:1px solid var(--hairline);padding:12px 14px;text-align:left;vertical-align:top;font-size:0.9rem;}
.compare-table th{background:var(--graphite-2);font-family:var(--font-body);font-weight:600;font-size:0.78rem;color:var(--text-dim);text-transform:uppercase;letter-spacing:0.04em;}
@media (max-width:700px){
  .compare-table{display:block;overflow-x:auto;white-space:nowrap;}
}

/* filter bar */
.filter-bar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;}
.filter-select, .search-input{
  background:var(--graphite);border:1px solid var(--hairline-strong);color:var(--text-hi);
  padding:10px 14px;border-radius:2px;font-size:0.88rem;min-width:140px;
}
.search-input{min-width:220px;flex:1;}
.filter-select:focus,.search-input:focus{border-color:var(--blue);}

/* tables -> cards on mobile handled per-page with data attrs */

/* forms */
.field{display:flex;flex-direction:column;gap:6px;margin-bottom:18px;}
.field label{font-size:0.82rem;font-weight:600;color:var(--text-mid);}
.field input,.field select,.field textarea{
  background:var(--navy-deep);border:1px solid var(--hairline-strong);border-radius:2px;padding:12px 14px;color:var(--text-hi);
}
.field input:focus,.field select:focus,.field textarea:focus{border-color:var(--blue);}
.field-error{color:#ff9d8a;font-size:0.8rem;}
.field.has-error input,.field.has-error select,.field.has-error textarea{border-color:#ff9d8a;}

/* skeleton loading */
.skeleton{background:linear-gradient(90deg,var(--graphite) 25%,var(--graphite-2) 37%,var(--graphite) 63%);background-size:400% 100%;animation:skeleton-shine 1.4s ease infinite;border-radius:var(--radius-s);}
@keyframes skeleton-shine{0%{background-position:100% 50%;}100%{background-position:0 50%;}}

/* command palette */
.palette-backdrop{position:fixed;inset:0;background:rgba(6,10,20,0.7);z-index:300;display:flex;align-items:flex-start;justify-content:center;padding-top:12vh;}
.palette{width:min(600px,90vw);background:var(--graphite);border:1px solid var(--hairline-strong);border-radius:var(--radius-m);overflow:hidden;box-shadow:0 30px 80px rgba(0,0,0,0.5);}
.palette-input{width:100%;padding:18px 20px;background:transparent;border:none;border-bottom:1px solid var(--hairline);color:var(--text-hi);font-size:1.05rem;}
.palette-results{max-height:50vh;overflow-y:auto;padding:8px;}
.palette-item{display:flex;justify-content:space-between;padding:12px 14px;border-radius:var(--radius-s);}
.palette-item:hover,.palette-item.active{background:rgba(76,141,253,0.12);}

/* diagrams */
.diagram-node{fill:var(--graphite-2);stroke:var(--hairline-strong);}
.diagram-edge{stroke:var(--hairline-strong);stroke-width:1;}
.diagram-label{font-family:var(--font-mono);font-size:11px;fill:var(--text-mid);}

/* print */
@media print{
  .site-header,.site-footer,.no-print,.mobile-search-btn,.drawer,.drawer-backdrop{display:none!important;}
  body{background:#fff;color:#000;}
  .surface,.surface-2,.card{border-color:#ccc;background:#fff;}
}

.mono-num{font-family:var(--font-mono);}
.underline-link{border-bottom:1px solid var(--hairline-strong);padding-bottom:1px;}
.underline-link:hover{border-color:var(--blue);color:var(--blue);}

.tag-row{display:flex;flex-wrap:wrap;gap:8px;}

.empty-state{padding:64px 24px;text-align:center;border:1px dashed var(--hairline-strong);border-radius:var(--radius-m);}
.empty-state svg{margin:0 auto 20px;}

.route-fade{animation:route-fade var(--dur-2) var(--ease);}
@keyframes route-fade{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:translateY(0);}}

.divider{height:1px;background:var(--hairline);border:none;margin:0;}

.badge-dot{width:8px;height:8px;border-radius:50%;display:inline-block;}

/* Hero computational network — subtle motion, disabled under reduced motion via the global rule above */
.hero-node{ animation: node-pulse 3.6s ease-in-out infinite; transform-origin:center; transform-box:fill-box; }
.hero-node:nth-of-type(2){ animation-delay:0.4s; }
.hero-node:nth-of-type(3){ animation-delay:0.8s; }
.hero-node:nth-of-type(4){ animation-delay:1.2s; }
@keyframes node-pulse{ 0%,100%{ opacity:0.85; transform:scale(1);} 50%{ opacity:1; transform:scale(1.18);} }

/* Breadcrumbs (multipage navigation) */
.breadcrumbs{ display:flex; gap:8px; align-items:center; font-family:var(--font-body); font-size:0.82rem; color:var(--text-dim); flex-wrap:wrap; }
.breadcrumbs a{ color:var(--text-dim); }
.breadcrumbs a:hover{ color:var(--blue); }
.breadcrumbs .crumb-sep{ opacity:0.5; }
.breadcrumbs span:last-child{ color:var(--text-mid); }

/* History timeline responsive swap (static pages: both blocks exist, CSS switches) */
.hist-mobile{ display:none; }
@media (max-width:800px){ .hist-desktop{ display:none; } .hist-mobile{ display:block; } }

/* Filtering (client-side show/hide on static list pages) */
.filtered-hidden{ display:none !important; }

/* Explorer semester/course groups default to native [hidden]; ensure stage-option consistent whether <a> or <button> */
.stage-option{ border:0; background:none; font: inherit; }
a.stage-option{ text-decoration:none; }