*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --cream: #FAF8F4; --off: #F3F0EA; --card: #fff;
  --ink: #1A1A18; --muted: #6B6860; --faint: #A8A49E;
  --g: #2D6A4F; --gl: #D8EFE4; --gd: #1B4332;
  --border: #E2DDD6; --sidebar: 260px; --header: 64px;
}
html { scroll-behavior: smooth; }
body { font-family: "DM Sans", sans-serif; background: var(--cream); color: var(--ink); font-size: 15px; line-height: 1.6; min-height: 100vh; }

/* HEADER */
header { position: sticky; top: 0; z-index: 100; height: var(--header); background: var(--cream); border-bottom: 1px solid var(--border); display: flex; align-items: center; padding: 0 2rem; gap: 1.5rem; }
.logo { font-family: "DM Serif Display", serif; font-size: 1.5rem; color: var(--ink); text-decoration: none; letter-spacing: -.02em; flex-shrink: 0; }
.logo em { color: var(--g); font-style: italic; }
.search-wrap { flex: 1; max-width: 420px; position: relative; }
.search-wrap svg { position: absolute; left: 11px; top: 50%; transform: translateY(-50%); width: 16px; height: 16px; stroke: var(--faint); fill: none; stroke-width: 2; pointer-events: none; }
#search { width: 100%; padding: 9px 12px 9px 36px; border: 1px solid var(--border); border-radius: 8px; background: var(--card); font: 14px "DM Sans",sans-serif; color: var(--ink); outline: none; transition: border-color .15s; }
#search:focus { border-color: var(--g); }
#search::placeholder { color: var(--faint); }
#search-results { display: none; position: absolute; top: calc(100% + 6px); left: 0; right: 0; background: var(--card); border: 1px solid var(--border); border-radius: 10px; box-shadow: 0 6px 20px rgba(0,0,0,.09); z-index: 200; max-height: 280px; overflow-y: auto; }
#search-results.vis { display: block; }
.sr-item { display: flex; align-items: center; gap: 9px; padding: 9px 14px; text-decoration: none; color: var(--ink); font-size: 14px; transition: background .1s; }
.sr-item:hover { background: var(--off); }
.sr-cat { font-size: 11px; color: var(--faint); margin-left: auto; white-space: nowrap; }
.mob-btn { display: none; background: none; border: none; cursor: pointer; padding: 4px; color: var(--ink); }
.overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,.3); z-index: 49; }

/* LAYOUT */
.layout { display: flex; min-height: calc(100vh - var(--header)); }

/* SIDEBAR */
.sidebar { width: var(--sidebar); flex-shrink: 0; border-right: 1px solid var(--border); padding: 1.5rem 0; position: sticky; top: var(--header); height: calc(100vh - var(--header)); overflow-y: auto; background: var(--cream); }
.sb-sec { padding: 0 1rem; margin-bottom: 1.5rem; }
.sb-lbl { font-size: 11px; font-weight: 500; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); padding: 0 .5rem; margin-bottom: .35rem; }
.sb-link { display: flex; align-items: center; gap: 9px; padding: 7px 10px; border-radius: 7px; text-decoration: none; color: var(--muted); font-size: 14px; transition: background .12s, color .12s; }
.sb-link:hover { background: var(--off); color: var(--ink); }
.sb-link.active { background: var(--gl); color: var(--gd); font-weight: 500; }
.sb-icon { width: 26px; height: 26px; border-radius: 6px; display: flex; align-items: center; justify-content: center; font-size: 13px; flex-shrink: 0; }

/* MAIN */
main { flex: 1; padding: 2.5rem 3rem; max-width: 860px; }

/* ─── HOMEPAGE ──────────────────────────────────────────── */
.hero { margin-bottom: 2.5rem; }
.hero h1 { font-family: "DM Serif Display",serif; font-size: 2.6rem; line-height: 1.12; letter-spacing: -.03em; margin-bottom: .7rem; }
.hero h1 em { color: var(--g); }
.hero p { color: var(--muted); font-size: 15px; max-width: 460px; margin-bottom: 1.5rem; }
.hero-stats { display: flex; gap: 1.5rem; }
.hstat { background: var(--gl); border-radius: 8px; padding: .45rem .9rem; font-size: 13px; color: var(--gd); font-weight: 500; }

.popular { margin-bottom: 2.5rem; }
.section-label { font-size: 11px; font-weight: 500; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); margin-bottom: .75rem; padding-bottom: .4rem; border-bottom: 1px solid var(--border); }
.pop-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px,1fr)); gap: 10px; }
.pop-card { display: flex; flex-direction: column; align-items: center; gap: 7px; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: .9rem .6rem; text-decoration: none; transition: border-color .15s, transform .1s, box-shadow .15s; text-align: center; }
.pop-card:hover { border-color: var(--g); transform: translateY(-2px); box-shadow: 0 4px 14px rgba(45,106,79,.1); }
.pop-icon { font-size: 24px; }
.pop-name { font-size: 12px; font-weight: 500; color: var(--ink); line-height: 1.3; }
.pop-rating { font-size: 10px; color: var(--g); min-height: 13px; }

.cat-block { margin-bottom: 2.5rem; }
.calc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(168px,1fr)); gap: 11px; }
.calc-card { display: block; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 1.05rem 1.15rem; text-decoration: none; transition: border-color .15s, transform .1s, box-shadow .15s; }
.calc-card:hover { border-color: var(--g); transform: translateY(-2px); box-shadow: 0 4px 14px rgba(45,106,79,.08); }
.cc-icon { font-size: 20px; margin-bottom: .45rem; display: block; }
.cc-name { font-size: 14px; font-weight: 500; color: var(--ink); display: block; margin-bottom: 2px; }
.cc-desc { font-size: 12px; color: var(--faint); display: block; }
.cc-rating { font-size: 11px; color: var(--g); display: block; margin-top: 5px; min-height: 14px; }

/* ─── CALC PAGE ──────────────────────────────────────────── */
.calc-header { margin-bottom: 1.5rem; }
.back-btn { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; color: var(--muted); text-decoration: none; padding: 4px 0; margin-bottom: 1rem; transition: color .12s; }
.back-btn:hover { color: var(--g); }
h1.calc-title { font-family: "DM Serif Display",serif; font-size: 1.9rem; letter-spacing: -.025em; margin-bottom: .3rem; font-weight: 400; }
.calc-sub { color: var(--muted); font-size: 14px; }

.how { background: var(--off); border: 1px solid var(--border); border-radius: 12px; padding: 1.2rem 1.5rem; margin-bottom: 1.25rem; }
.how-lbl { font-size: 11px; font-weight: 500; letter-spacing: .07em; text-transform: uppercase; color: var(--faint); margin-bottom: .45rem; }
.how-body { font-size: 14px; color: var(--muted); line-height: 1.75; }
.how-body strong { color: var(--ink); font-weight: 500; }

.panel { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 1.9rem; margin-bottom: 1.25rem; }
.field { margin-bottom: 1.2rem; }
.field:last-child { margin-bottom: 0; }
.field > label { display: block; font-size: 13px; font-weight: 500; color: var(--muted); margin-bottom: 5px; }
.row { display: flex; gap: 10px; }
.row .field { flex: 1; margin-bottom: 0; }
input[type=number], input[type=text], input[type=date], select {
  width: 100%; padding: 10px 13px; border: 1px solid var(--border); border-radius: 8px;
  font: 15px "DM Sans",sans-serif; color: var(--ink); background: var(--card); outline: none; transition: border-color .15s;
  -moz-appearance: textfield;
}
input::-webkit-outer-spin-button, input::-webkit-inner-spin-button { -webkit-appearance: none; }
input:focus, select:focus { border-color: var(--g); }
.iw { position: relative; }
.iw input { padding-right: 54px; }
.iunit { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); font-size: 13px; color: var(--faint); font-weight: 500; pointer-events: none; }
.calc-btn { width: 100%; padding: 13px; background: var(--g); color: #fff; border: none; border-radius: 9px; font: 16px "DM Serif Display",serif; cursor: pointer; transition: background .15s; display: block; margin-top: .5rem; }
.calc-btn:hover { background: var(--gd); }
.formula { background: var(--off); border-left: 3px solid var(--g); border-radius: 0 8px 8px 0; padding: .7rem 1rem; font-size: 13px; color: var(--muted); margin-top: 1.2rem; }
.formula strong { color: var(--ink); }
.rg { display: flex; gap: 7px; flex-wrap: wrap; margin-top: 5px; }
.rg label { display: inline-flex; align-items: center; gap: 6px; padding: 7px 13px; border: 1px solid var(--border); border-radius: 20px; cursor: pointer; font-size: 13px; color: var(--muted); background: var(--card); transition: all .12s; }
.rg input[type=radio] { display: none; }
.rg label:has(input:checked) { border-color: var(--g); background: var(--gl); color: var(--gd); font-weight: 500; }

/* RESULT */
.result { display: none; background: var(--gl); border: 1px solid rgba(45,106,79,.15); border-radius: 14px; padding: 1.7rem 2rem; margin-bottom: 1.25rem; animation: fadeIn .25s ease; }
.result.show { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
.r-lbl { font-size: 12px; font-weight: 500; letter-spacing: .06em; text-transform: uppercase; color: var(--g); margin-bottom: .35rem; }
.r-main { font-family: "DM Serif Display",serif; font-size: 2.4rem; color: var(--gd); letter-spacing: -.03em; line-height: 1; margin-bottom: .45rem; }
.r-sub { font-size: 13px; color: var(--gd); opacity: .7; line-height: 1.8; }
.r-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(138px,1fr)); gap: 9px; margin-top: 1rem; }
.r-item { background: rgba(255,255,255,.65); border-radius: 8px; padding: .7rem .9rem; }
.r-item-lbl { font-size: 11px; color: var(--g); text-transform: uppercase; letter-spacing: .05em; margin-bottom: 2px; }
.r-item-val { font-family: "DM Serif Display",serif; font-size: 1.15rem; color: var(--gd); word-break: break-all; }

/* SCIENTIFIC */
.sci-disp { background: var(--ink); color: #fff; border-radius: 10px; padding: 1rem 1.2rem; margin-bottom: 1rem; text-align: right; }
.sci-expr { font-size: 12px; color: rgba(255,255,255,.35); min-height: 16px; word-break: break-all; }
.sci-val { font-family: "DM Serif Display",serif; font-size: 2.1rem; line-height: 1.1; word-break: break-all; }
.sci-grid { display: grid; grid-template-columns: repeat(5,1fr); gap: 5px; }
.sci-btn { padding: 11px 4px; border: 1px solid var(--border); border-radius: 8px; background: var(--card); cursor: pointer; font: 14px "DM Sans",sans-serif; color: var(--ink); transition: all .1s; }
.sci-btn:hover { background: var(--off); border-color: var(--g); }
.sci-btn.op { background: var(--off); }
.sci-btn.fn { font-size: 12px; }
.sci-btn.clr { color: #c0392b; }
.sci-btn.eq { background: var(--g); color: #fff; border-color: var(--g); font-size: 16px; }
.sci-btn.eq:hover { background: var(--gd); }

/* RATING */
.rating { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 1.5rem 1.9rem; margin-bottom: 2rem; }
.r-title { font-size: 14px; font-weight: 500; color: var(--ink); margin-bottom: 1rem; }
.r-btns { display: flex; gap: 10px; flex-wrap: wrap; }
.r-btn { display: inline-flex; align-items: center; gap: 7px; padding: 9px 17px; border-radius: 8px; border: 1px solid var(--border); background: none; cursor: pointer; font: 14px "DM Sans",sans-serif; color: var(--muted); transition: all .15s; }
.r-btn:hover:not(:disabled) { border-color: var(--g); color: var(--ink); }
.r-btn:disabled { cursor: default; }
.r-btn svg { width: 15px; height: 15px; fill: none; stroke-width: 2; stroke: currentColor; flex-shrink: 0; }
.r-btn.yes { background: var(--gl); border-color: var(--g); color: var(--gd); font-weight: 500; }
.r-btn.no  { background: #fef2f0; border-color: #d97060; color: #7a3020; font-weight: 500; }
.r-bar { margin-top: 13px; }
.r-bar-top { display: flex; justify-content: space-between; margin-bottom: 5px; font-size: 12px; }
.r-bar-pct { font-weight: 500; color: var(--gd); font-size: 14px; }
.r-bar-cnt { color: var(--faint); }
.r-bar-track { height: 5px; background: var(--off); border-radius: 3px; overflow: hidden; }
.r-bar-fill { height: 100%; background: var(--g); border-radius: 3px; transition: width .5s cubic-bezier(.4,0,.2,1); }
.r-thanks { font-size: 13px; color: var(--g); margin-top: 9px; display: none; }
.r-thanks.show { display: block; }
.r-novotes { font-size: 13px; color: var(--faint); margin-top: 9px; }

/* RESPONSIVE */
@media (max-width: 860px) {
  .sidebar { position: fixed; top: var(--header); left: -100%; height: calc(100vh - var(--header)); z-index: 50; transition: left .25s; }
  .sidebar.open { left: 0; }
  .overlay.open { display: block; }
  .mob-btn { display: flex; }
  main { padding: 1.5rem; }
  .hero h1 { font-size: 1.9rem; }
  .r-main { font-size: 1.9rem; }
  .sci-grid { grid-template-columns: repeat(4,1fr); }
  .sci-btn.fn { display: none; }
}

/* FAQ SECTIE */
.faq { margin-bottom: 1.25rem; }
.faq-title { font-family: "DM Serif Display",serif; font-size: 1.3rem; letter-spacing:-.02em; color: var(--ink); margin-bottom: 1rem; font-weight: 400; }
.faq-item { border: 1px solid var(--border); border-radius: 10px; background: var(--card); margin-bottom: 8px; overflow: hidden; transition: border-color .15s; }
.faq-item:hover { border-color: var(--g); }
.faq-item summary { padding: .9rem 1.2rem; cursor: pointer; font-weight: 500; font-size: 14px; color: var(--ink); list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 18px; color: var(--g); flex-shrink: 0; transition: transform .2s; font-weight: 300; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item[open] { border-color: var(--g); }
.faq-body { padding: 0 1.2rem 1rem; font-size: 14px; color: var(--muted); line-height: 1.7; border-top: 1px solid var(--border); margin-top: 0; padding-top: .8rem; }

/* ─── GRAFIEKEN ───────────────────────────────── */
.chart-wrap{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:1.5rem 1.75rem;margin-bottom:1.25rem;display:none;}
.chart-wrap.show{display:block;}
.chart-title{font-size:13px;font-weight:500;color:var(--muted);margin-bottom:1rem;text-transform:uppercase;letter-spacing:.05em;}
.chart-tabs{display:flex;gap:6px;margin-bottom:1rem;flex-wrap:wrap;}
.chart-tab{padding:5px 12px;border:1px solid var(--border);border-radius:6px;background:none;cursor:pointer;font:13px "DM Sans",sans-serif;color:var(--muted);transition:all .12s;}
.chart-tab.active{background:var(--gl);border-color:var(--g);color:var(--gd);font-weight:500;}
canvas.chart-canvas{width:100%!important;max-height:280px;}
.related{margin-bottom:1.25rem;}
.related-title{font-size:13px;font-weight:500;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:.75rem;}
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:8px;}
.related-card{display:flex;align-items:center;gap:9px;background:var(--card);border:1px solid var(--border);border-radius:9px;padding:.65rem .9rem;text-decoration:none;font-size:13px;color:var(--muted);transition:all .12s;}
.related-card:hover{border-color:var(--g);color:var(--g);background:var(--gl);}
.related-card span{font-size:16px;}

/* ═══════════════════════════════════════════════════
   DARK MODE
═══════════════════════════════════════════════════ */

/* Dark mode variabelen */
:root[data-theme="dark"],
[data-theme="dark"] {
  --cream:  #141412;
  --off:    #1E1C1A;
  --card:   #1E1C1A;
  --ink:    #F0EDE8;
  --muted:  #A8A49E;
  --faint:  #6B6860;
  --g:      #4ABA80;
  --gl:     #1A3328;
  --gd:     #7DE0AA;
  --border: #2E2C29;
}

/* Systeemvoorkeur dark — tenzij gebruiker licht heeft gekozen */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --cream:  #141412;
    --off:    #1E1C1A;
    --card:   #1E1C1A;
    --ink:    #F0EDE8;
    --muted:  #A8A49E;
    --faint:  #6B6860;
    --g:      #4ABA80;
    --gl:     #1A3328;
    --gd:     #7DE0AA;
    --border: #2E2C29;
  }
}

/* Toggle knop in header */
.theme-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  padding: 6px 9px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1;
  transition: border-color .15s, color .15s, background .15s;
  flex-shrink: 0;
}
.theme-btn:hover {
  border-color: var(--g);
  color: var(--g);
  background: var(--gl);
}

/* Dark mode aanpassingen voor specifieke elementen */
[data-theme="dark"] .result,
:root:not([data-theme="light"]):is(@media (prefers-color-scheme: dark)) .result {
  border-color: rgba(74,186,128,0.15);
}

[data-theme="dark"] .r-item,
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .r-item {
  background: rgba(255,255,255,0.05);
}}

/* Zorgt voor correcte achtergrond result items in dark */
:root[data-theme="dark"] .r-item {
  background: rgba(255,255,255,0.05);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .r-item {
    background: rgba(255,255,255,0.05);
  }
}

/* Sci calculator donkere achtergrond blijft donker */
:root[data-theme="dark"] .sci-disp {
  background: #0A0A09;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .sci-disp {
    background: #0A0A09;
  }
}

/* Zoekveld schaduw in dark */
:root[data-theme="dark"] #search-results {
  box-shadow: 0 6px 20px rgba(0,0,0,.4);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) #search-results {
    box-shadow: 0 6px 20px rgba(0,0,0,.4);
  }
}

/* Transitie voor kleurwisseling */
body, header, .sidebar, .panel, .result, .chart-wrap,
.faq-item, .rating, .related-card, .calc-card, .tool-card,
.r-item, #search, .sb-link, .how, input, select {
  transition: background-color .25s ease, border-color .25s ease, color .2s ease;
}

/* ─── REKENGESCHIEDENIS ──────────────────────────────────── */
.hist-wrap{background:var(--card);border:1px solid var(--border);border-radius:14px;margin-bottom:1.25rem;overflow:hidden;}
.hist-header{display:flex;align-items:center;justify-content:space-between;padding:1rem 1.5rem;border-bottom:1px solid var(--border);cursor:pointer;user-select:none;}
.hist-header-left{display:flex;align-items:center;gap:9px;}
.hist-header-icon{font-size:16px;}
.hist-header-title{font-size:14px;font-weight:500;color:var(--ink);}
.hist-header-count{font-size:12px;color:var(--faint);background:var(--off);border-radius:10px;padding:1px 8px;}
.hist-chevron{font-size:16px;color:var(--faint);transition:transform .2s;}
.hist-chevron.open{transform:rotate(180deg);}
.hist-body{display:none;padding:0 1.5rem 1rem;}
.hist-body.open{display:block;}
.hist-empty{padding:1.2rem 0;font-size:13px;color:var(--muted);line-height:1.7;}
.hist-list{display:flex;flex-direction:column;gap:8px;padding-top:1rem;}
.hist-item{background:var(--off);border-radius:9px;padding:.9rem 1rem;transition:background .12s;}
.hist-item:hover{background:var(--gl);}
.hist-item-top{display:flex;align-items:baseline;justify-content:space-between;gap:8px;margin-bottom:.5rem;}
.hist-lbl{font-size:13px;font-weight:500;color:var(--ink);}
.hist-time{font-size:11px;color:var(--faint);white-space:nowrap;}
.hist-outputs{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:.65rem;}
.hist-out-item{display:flex;align-items:center;gap:5px;background:var(--card);border:1px solid var(--border);border-radius:6px;padding:3px 9px;}
.hist-out-lbl{font-size:11px;color:var(--faint);}
.hist-out-val{font-size:12px;font-weight:500;color:var(--gd);}
.hist-actions{display:flex;gap:8px;}
.hist-btn-load{background:var(--gl);border:1px solid var(--g);color:var(--gd);border-radius:6px;padding:5px 11px;font:13px "DM Sans",sans-serif;cursor:pointer;transition:all .12s;}
.hist-btn-load:hover{background:var(--g);color:#fff;}
.hist-btn-del{background:none;border:1px solid var(--border);color:var(--faint);border-radius:6px;padding:5px 11px;font:13px "DM Sans",sans-serif;cursor:pointer;transition:all .12s;}
.hist-btn-del:hover{border-color:#D97060;color:#7A3020;}
.hist-clear-btn{margin-top:.75rem;background:none;border:none;font:13px "DM Sans",sans-serif;color:var(--faint);cursor:pointer;padding:4px 0;transition:color .12s;}
.hist-clear-btn:hover{color:#D97060;}

/* ─── EMBED NAV KNOP IN HEADER ──────────────────────────── */
.embed-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  text-decoration: none;
  font: 13px "DM Sans", sans-serif;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
  transition: all .15s;
  flex-shrink: 0;
}
.embed-nav-btn:hover {
  border-color: var(--g);
  color: var(--g);
  background: var(--gl);
}
.embed-nav-btn.active {
  background: var(--gl);
  border-color: var(--g);
  color: var(--gd);
}
.embed-nav-btn svg {
  flex-shrink: 0;
}
@media (max-width: 600px) {
  .embed-nav-btn span { display: none; }
  .embed-nav-btn { padding: 6px 9px; }
}