/* ==========================================================================
   Perun — fælles designsystem
   Tema: fra mørke til lys. Kul-sort baggrund, kobber/messing-accent,
   filament-varm hvid til resultater og tal.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Fraunces:opsz,wght@9..144,300;9..144,500;9..144,700;9..144,900&display=swap');

:root{
  /* farver */
  --void:        #0a0a0b;
  --coal:        #131417;
  --graphite:    #1b1d22;
  --graphite-2:  #24262d;
  --line:        #33353d;
  --line-soft:   #2a2c33;

  --copper:      #c08a3e;
  --copper-dim:  #8a6530;
  --copper-glow: rgba(192, 138, 62, 0.35);

  --filament:    #f2e9d8;
  --ink:         #e7e6e3;
  --muted:       #8b8d96;
  --muted-2:     #5c5e68;

  --danger:      #c2543e;
  --ok:          #6f9c76;

  /* typografi */
  --font-ui:   'Space Grotesk', 'Segoe UI', sans-serif;
  --font-display: 'Fraunces', serif;

  /* layout */
  --max-w: 1120px;
  --radius: 3px;
  --nav-h: 68px;
}

*, *::before, *::after{ box-sizing: border-box; }

html{
  scroll-behavior: smooth;
}

body{
  margin:0;
  background: var(--void);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

@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; }
}

h1,h2,h3{
  font-family: var(--font-display);
  font-weight: 700;
  margin: 0 0 0.5em 0;
  color: var(--filament);
  letter-spacing: -0.01em;
}

p{ margin: 0 0 1em 0; color: var(--muted); }

a{ color: var(--copper); text-decoration: none; }
a:hover{ color: var(--filament); }

::selection{ background: var(--copper-dim); color: var(--filament); }

:focus-visible{
  outline: 2px solid var(--copper);
  outline-offset: 3px;
}

/* ---------- topografisk baggrund (spor af strøm i mørket) ---------- */
.spark-field{
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 60% 40% at 15% 0%, rgba(192,138,62,0.05), transparent 60%),
    radial-gradient(ellipse 50% 30% at 100% 100%, rgba(192,138,62,0.04), transparent 60%),
    var(--void);
}

/* ---------- navigation ---------- */
.site-nav{
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  background: rgba(10,10,11,0.86);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line-soft);
}

.site-nav .nav-inner{
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand{
  display:flex;
  align-items:center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--filament);
}

.brand svg{ width: 22px; height: 22px; flex-shrink:0; }
.brand .bolt-mark{ stroke: var(--copper); }

.nav-links{
  display:flex;
  gap: 8px;
  list-style:none;
  margin:0; padding:0;
}

.nav-links a{
  display:block;
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius);
  transition: color .15s ease, background .15s ease;
}

.nav-links a:hover{ color: var(--filament); background: var(--graphite); }

.nav-links a.active{
  color: var(--filament);
  background: var(--graphite);
  box-shadow: inset 0 -2px 0 var(--copper);
}

.nav-toggle{
  display:none;
  background:none;
  border:1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  width: 40px; height: 36px;
  cursor:pointer;
}

@media (max-width: 760px){
  .nav-links{
    position: fixed;
    top: var(--nav-h);
    left:0; right:0;
    flex-direction: column;
    background: var(--coal);
    border-bottom: 1px solid var(--line-soft);
    padding: 8px;
    gap: 2px;
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity .15s ease, transform .15s ease;
  }
  .nav-links.open{
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-toggle{ display:block; }
}

/* ---------- layout helpers ---------- */
.wrap{
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

main{ display:block; }

.page-head{
  padding: 64px 0 40px;
  border-bottom: 1px solid var(--line-soft);
}

.page-head .eyebrow{
  color: var(--copper);
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 10px;
}

.page-head h1{ font-size: clamp(2rem, 5vw, 2.8rem); margin-bottom: 0.3em; }
.page-head .lede{ max-width: 62ch; font-size: 1.08rem; color: var(--muted); margin:0; }

/* ---------- footer ---------- */
.site-footer{
  border-top: 1px solid var(--line-soft);
  margin-top: 96px;
  padding: 32px 0 48px;
}

.site-footer .wrap{
  display:flex;
  justify-content: space-between;
  align-items:center;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--muted-2);
  font-size: 0.85rem;
}

.site-footer a{ color: var(--muted-2); }
.site-footer a:hover{ color: var(--copper); }

/* ---------- generic components ---------- */
.card{
  background: var(--graphite);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 24px;
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  background: var(--copper);
  color: var(--void);
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  border-radius: var(--radius);
  padding: 11px 22px;
  cursor: pointer;
  transition: background .15s ease, transform .1s ease;
}

.btn:hover{ background: #d69a4e; }
.btn:active{ transform: translateY(1px); }

.btn-ghost{
  background: transparent;
  color: var(--filament);
  border: 1px solid var(--line);
}
.btn-ghost:hover{ background: var(--graphite-2); color: var(--filament); }

/* ---------- tabs (bruges på beregninger + konverter) ---------- */
.tabs{
  display:flex;
  gap: 4px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 32px;
}

.tab-btn{
  background:none;
  border:none;
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 12px 18px;
  cursor:pointer;
  position: relative;
  top: 1px;
  border-bottom: 2px solid transparent;
}

.tab-btn:hover{ color: var(--ink); }

.tab-btn.active{
  color: var(--filament);
  border-bottom-color: var(--copper);
}

.tab-panel{ display:none; }
.tab-panel.active{ display:block; animation: fadein .25s ease; }

@keyframes fadein{
  from{ opacity:0; transform: translateY(4px); }
  to{ opacity:1; transform: translateY(0); }
}

/* ---------- formulartool (beregner/konverter) ---------- */
.tool-grid{
  display:grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

@media (min-width: 720px){
  .tool-grid{ grid-template-columns: 1.1fr 0.9fr; align-items:start; }
}

.field-group{
  display:flex;
  flex-direction: column;
  gap: 16px;
}

.field{
  display:flex;
  flex-direction: column;
  gap: 6px;
}

.field label{
  font-size: 0.85rem;
  color: var(--muted);
  font-weight: 500;
}

.field .hint{
  font-size: 0.78rem;
  color: var(--muted-2);
}

input[type="number"],
input[type="text"],
select{
  background: var(--coal);
  border: 1px solid var(--line);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 1rem;
  border-radius: var(--radius);
  padding: 11px 12px;
  width: 100%;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus{
  border-color: var(--copper);
}

.seg{
  display:inline-flex;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow:hidden;
  width: fit-content;
}

.seg button{
  background: var(--coal);
  color: var(--muted);
  border:none;
  font-family: var(--font-ui);
  font-size: 0.88rem;
  font-weight: 500;
  padding: 9px 16px;
  cursor:pointer;
  border-right: 1px solid var(--line);
}
.seg button:last-child{ border-right:none; }
.seg button.active{ background: var(--graphite-2); color: var(--filament); }

.result-panel{
  background: var(--coal);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 28px;
  position: sticky;
  top: calc(var(--nav-h) + 20px);
}

.result-panel .result-label{
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 6px;
}

.result-value{
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 2.6rem;
  color: var(--filament);
  line-height:1.1;
  text-shadow: 0 0 22px var(--copper-glow);
}

.result-value .unit{
  font-size: 1.3rem;
  color: var(--copper);
  font-weight: 500;
  margin-left: 4px;
}

.result-sub{
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  display:flex;
  flex-direction:column;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--muted);
}

.result-sub strong{ color: var(--ink); font-weight: 600; }

.flag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  font-size: 0.82rem;
  padding: 5px 10px;
  border-radius: var(--radius);
  margin-top: 14px;
}

.flag.warn{ background: rgba(194,84,62,0.12); color: #dd8a78; }
.flag.ok{ background: rgba(111,156,118,0.12); color: var(--ok); }

.note{
  font-size: 0.85rem;
  color: var(--muted-2);
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
}

/* ---------- tommelfingerregler ---------- */
.rule-card{
  background: var(--graphite);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 26px 28px;
  margin-bottom: 22px;
}

.rule-card h3{
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.rule-formula{
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--filament);
  background: var(--coal);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin: 14px 0;
  line-height: 1.7;
}

.rule-formula .cond{
  display:block;
  font-family: var(--font-ui);
  font-weight: 500;
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 2px;
}

.rule-formula .cond:not(:first-child){ margin-top: 10px; }

.rule-example{
  background: var(--coal);
  border-left: 2px solid var(--copper);
  padding: 12px 16px;
  margin: 14px 0;
  font-size: 0.92rem;
  color: var(--ink);
}

.rule-example strong{ color: var(--filament); }

.rule-source{
  font-size: 0.82rem;
  color: var(--muted-2);
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
}

.rule-caveat{
  display:flex;
  gap:8px;
  align-items:flex-start;
  font-size: 0.85rem;
  color: #dd8a78;
  background: rgba(194,84,62,0.1);
  border-radius: var(--radius);
  padding: 10px 14px;
  margin-top: 14px;
}