/* ============================================================
   Smart Campus V2G — global stylesheet
   Sober, elegant design. Single source of truth for site styling.
   Palette and layout tokens are defined as CSS variables below so
   the whole look can be retuned from one place.
   ============================================================ */

:root {
  --c-bg:        #ffffff;
  --c-bg-alt:    #f5f7f9;
  --c-ink:       #1c2733;
  --c-ink-soft:  #54606c;
  --c-line:      #e2e8ee;
  --c-primary:   #0b3c5d;   /* deep blue (ULiège-like) */
  --c-primary-d: #082b43;
  --c-accent:    #2a9d8f;   /* energy teal/green */
  --c-accent-d:  #1f7d72;
  --c-solar:     #e9a23b;   /* PV / solar */
  --c-grid:      #5b7c99;
  --c-danger:    #c0563b;

  --radius:   10px;
  --shadow:   0 1px 3px rgba(16,32,48,.08), 0 6px 24px rgba(16,32,48,.06);
  --maxw:     1120px;
  --font:     "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  --mono:     ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { color: var(--c-primary); line-height: 1.25; font-weight: 700; }
h1 { font-size: clamp(1.9rem, 3.5vw, 2.8rem); margin: 0 0 .4em; }
h2 { font-size: clamp(1.4rem, 2.4vw, 1.9rem); margin: 0 0 .6em; }
h3 { font-size: 1.18rem; margin: 1.4em 0 .4em; }
a  { color: var(--c-accent-d); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem; }
.section { padding: 3.5rem 0; }
.section--alt { background: var(--c-bg-alt); }
.muted { color: var(--c-ink-soft); }
.center { text-align: center; }
.lead { font-size: 1.15rem; color: var(--c-ink-soft); max-width: 60ch; }

/* ---------- Site header / nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--c-line);
}
.nav {
  display: flex; align-items: center; gap: 1rem;
  height: 64px;
}
.nav__brand { display: flex; align-items: center; gap: .6rem; font-weight: 700; color: var(--c-primary); font-size: 1.05rem; }
.nav__brand img { height: 34px; width: auto; display: block; }
.nav__spacer { flex: 1; }
.nav__links { display: flex; gap: .25rem; align-items: center; }
.nav__links a {
  color: var(--c-ink); padding: .5rem .75rem; border-radius: 8px;
  font-size: .95rem; font-weight: 500;
}
.nav__links a:hover { background: var(--c-bg-alt); text-decoration: none; }
.nav__links a.active { color: var(--c-primary); background: var(--c-bg-alt); }
.nav__toggle { display: none; background: none; border: 0; font-size: 1.5rem; cursor: pointer; color: var(--c-primary); }

@media (max-width: 820px) {
  .nav__toggle { display: block; }
  .nav__links {
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; align-items: stretch;
    background: #fff; border-bottom: 1px solid var(--c-line);
    padding: .5rem 1rem 1rem; gap: .1rem;
    display: none;
  }
  .nav__links.open { display: flex; }
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-d) 60%, #06314c 100%);
  color: #fff; overflow: hidden;
}
.hero::after {
  content:""; position:absolute; inset:0;
  background:
    radial-gradient(circle at 80% 20%, rgba(42,157,143,.35), transparent 45%),
    radial-gradient(circle at 15% 90%, rgba(233,162,59,.25), transparent 40%);
}
.hero .container { position: relative; z-index: 1; padding-top: 4.5rem; padding-bottom: 4.5rem; }
.hero h1 { color: #fff; max-width: 18ch; }
.hero p { font-size: 1.2rem; color: #d7e4ee; max-width: 56ch; }
.hero .badge-row { margin-top: 1.4rem; }

.badge {
  display: inline-block; background: rgba(255,255,255,.14);
  border: 1px solid rgba(255,255,255,.25);
  padding: .3rem .7rem; border-radius: 999px; font-size: .85rem; margin: 0 .4rem .4rem 0;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block; padding: .7rem 1.3rem; border-radius: 8px;
  font-weight: 600; cursor: pointer; border: 1px solid transparent;
  transition: transform .05s ease, background .15s ease;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn--primary { background: var(--c-accent); color: #fff; }
.btn--primary:hover { background: var(--c-accent-d); }
.btn--ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.5); }
.btn--ghost:hover { background: rgba(255,255,255,.12); }
.btn--outline { background:#fff; color: var(--c-primary); border-color: var(--c-line); }
.btn--outline:hover { background: var(--c-bg-alt); }
.btn-row { display: flex; gap: .8rem; flex-wrap: wrap; margin-top: 1.6rem; }

/* ---------- Cards / grids ---------- */
.grid { display: grid; gap: 1.25rem; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 900px) { .grid--3, .grid--4 { grid-template-columns: repeat(2,1fr);} }
@media (max-width: 620px) { .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr;} }

.card {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 1.4rem; box-shadow: var(--shadow);
}
.card h3 { margin-top: 0; }
.card__icon { font-size: 1.6rem; }

/* Stat cards (live KPIs) */
.kpi { text-align: center; }
.kpi__value { font-size: 2rem; font-weight: 700; color: var(--c-primary); font-variant-numeric: tabular-nums; }
.kpi__unit  { font-size: 1rem; color: var(--c-ink-soft); font-weight: 500; }
.kpi__label { font-size: .9rem; color: var(--c-ink-soft); text-transform: uppercase; letter-spacing: .03em; }

/* ---------- Placeholders ---------- */
.placeholder {
  border: 2px dashed var(--c-line); border-radius: var(--radius);
  background: repeating-linear-gradient(45deg, #fafbfc, #fafbfc 12px, #f3f5f7 12px, #f3f5f7 24px);
  color: var(--c-ink-soft); display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 2rem; min-height: 160px; font-size: .95rem;
}
.placeholder--img { min-height: 220px; }
.placeholder small { display:block; margin-top:.4rem; opacity:.8; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; }
table.data {
  width: 100%; border-collapse: collapse; font-size: .92rem; background:#fff;
}
table.data th, table.data td { text-align: left; padding: .55rem .7rem; border-bottom: 1px solid var(--c-line); vertical-align: top; }
table.data thead th { background: var(--c-primary); color: #fff; position: sticky; top: 0; }
table.data tbody tr:nth-child(even) { background: var(--c-bg-alt); }
table.data td.num { text-align: right; font-variant-numeric: tabular-nums; }

/* ---------- Live status diagram ---------- */
.flow {
  display: grid; grid-template-columns: repeat(3,1fr); gap: 1rem; align-items: stretch;
}
.flow .node {
  border: 1px solid var(--c-line); border-radius: var(--radius); padding: 1rem; text-align: center; background:#fff;
}
.flow .node .v { font-weight: 700; color: var(--c-primary); font-variant-numeric: tabular-nums; }
.status-dot { display:inline-block; width:.6rem; height:.6rem; border-radius:50%; background: var(--c-danger); margin-right:.4rem; }
.status-dot.live { background: var(--c-accent); }

/* ---------- Technical doc layout ---------- */
.doc { display: grid; grid-template-columns: 240px 1fr; gap: 2.5rem; align-items: start; }
.doc__toc { position: sticky; top: 80px; font-size: .92rem; }
.doc__toc a { display:block; color: var(--c-ink-soft); padding: .2rem 0; }
.doc__toc a:hover { color: var(--c-primary); }
.doc__toc h4 { margin: 1rem 0 .3rem; text-transform: uppercase; font-size:.78rem; letter-spacing:.05em; color: var(--c-ink-soft);}
.doc__body { min-width: 0; }
.doc__body h2 { border-bottom: 2px solid var(--c-line); padding-bottom: .3rem; margin-top: 2.2rem; }
@media (max-width: 900px) { .doc { grid-template-columns: 1fr; } .doc__toc { position: static; } }

.note { border-left: 4px solid var(--c-accent); background: var(--c-bg-alt); padding: .8rem 1rem; border-radius: 0 8px 8px 0; margin: 1rem 0; }
.note--warn { border-left-color: var(--c-solar); }

/* ---------- Funding / footer ---------- */
.funding {
  background: var(--c-bg-alt); border-top: 1px solid var(--c-line);
  padding: 2rem 0;
}
.funding__logos { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 2rem; }
.funding__logos img { height: 60px; width: auto; object-fit: contain; }
.funding__logos a { display:inline-flex; }
.funding p { text-align: center; color: var(--c-ink-soft); font-size: .85rem; max-width: 70ch; margin: 1rem auto 0; }

.site-footer {
  background: var(--c-primary-d); color: #c3d3df; padding: 2rem 0; font-size: .9rem;
}
.site-footer a { color: #fff; }
.site-footer .cols { display: flex; flex-wrap: wrap; gap: 2rem; justify-content: space-between; }
.site-footer h4 { color: #fff; margin: 0 0 .5rem; font-size: .95rem; }
.site-footer .copyright { margin-top: 1.5rem; border-top: 1px solid rgba(255,255,255,.15); padding-top: 1rem; font-size: .82rem; }

/* utilities */
.mt-0{margin-top:0}.mb-0{margin-bottom:0}.mt-2{margin-top:1rem}.tag{display:inline-block;font-size:.75rem;background:var(--c-bg-alt);border:1px solid var(--c-line);border-radius:6px;padding:.1rem .5rem;color:var(--c-ink-soft)}