:root {
    --bg-gradient-start: #F5F7FA;
    --bg-gradient-end: #E4E8F0;
    --card-bg: #FFFFFF;
    --card-border: rgba(0,0,0,0.05);
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --accent-color: #0071E3;
    --accent-light: #EBF4FF;
    --result-bg: #F5F9FF;
    --result-border: rgba(0,113,227,0.1);
    --border-radius: 20px;
    --shadow: 0 8px 30px rgba(0,0,0,0.06);
    --input-bg: #F5F5F7;
    --green: #34C759;
    --orange: #FF9500;
    --red: #FF3B30;
}
* { box-sizing: border-box; margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
body { background: linear-gradient(180deg, var(--bg-gradient-start), var(--bg-gradient-end)); color: var(--text-primary); line-height: 1.5; display: flex; flex-direction: column; min-height: 100vh; }

#lang-switcher { position: relative; }
.lang-toggle { background: var(--input-bg); border: 1px solid transparent; border-radius: 8px; padding: 6px 10px; font-size: 0.75rem; font-weight: 600; color: var(--text-secondary); cursor: pointer; white-space: nowrap; transition: all 0.2s; }
.lang-toggle:hover { background: #E3E3E8; color: var(--text-primary); }
#lang-dropdown { display: none; position: absolute; right: 0; top: calc(100% + 6px); background: #fff; border: 1px solid rgba(0,0,0,0.1); border-radius: 12px; box-shadow: 0 8px 24px rgba(0,0,0,0.12); overflow: hidden; z-index: 200; min-width: 150px; }
#lang-dropdown.open { display: block; }
#lang-dropdown a { display: block; width: 100%; padding: 10px 14px; border: none; background: transparent; text-align: left; font-size: 0.82rem; font-weight: 500; color: var(--text-secondary); text-decoration: none; cursor: pointer; transition: background 0.15s; }
#lang-dropdown a:hover, #lang-dropdown a:focus-visible { background: var(--accent-light); color: var(--accent-color); outline: none; }
#lang-dropdown a.active { color: var(--accent-color); font-weight: 700; background: var(--accent-light); }

header { background: rgba(255,255,255,0.85); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); position: sticky; top: 0; z-index: 100; border-bottom: 1px solid rgba(0,0,0,0.05); padding: 0.8rem 0; }
.nav-container { max-width: 980px; margin: 0 auto; padding: 0 20px; display: flex; align-items: center; justify-content: space-between; gap: 12px; position: relative; }
#header-title { font-size: 1.4rem; font-weight: 700; color: var(--text-primary); margin: 0; letter-spacing: -0.01em; flex-shrink: 0; }
.dot { color: var(--accent-color); }
.main-tabs { background-color: #E3E3E8; padding: 3px; border-radius: 10px; display: inline-flex; position: absolute; left: 50%; transform: translateX(-50%); pointer-events: auto; z-index: 1; }
.main-tab-btn { border: none; background: transparent; padding: 8px 16px; border-radius: 8px; font-size: 0.82rem; font-weight: 600; color: var(--text-secondary); cursor: pointer; transition: all 0.2s ease; white-space: nowrap; }
.main-tab-btn.active { background: #FFFFFF; color: var(--text-primary); box-shadow: 0 2px 4px rgba(0,0,0,0.08); }

main { flex: 1; padding: 30px 20px 40px 20px; max-width: 780px; margin: 0 auto; width: 100%; }
.tab-content { display: none; animation: fadeIn 0.3s ease; }
.tab-content.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }

.calculator-card { background: var(--card-bg); border: 1px solid var(--card-border); border-radius: var(--border-radius); box-shadow: var(--shadow); padding: 30px; }

.mode-switch-container { display: flex; justify-content: center; margin-bottom: 25px; }
.mode-switch { background-color: #E3E3E8; padding: 4px; border-radius: 12px; display: inline-flex; width: 100%; max-width: 400px; }
.mode-btn { flex: 1; border: none; background: transparent; padding: 10px; border-radius: 9px; font-size: 0.9rem; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: all 0.2s ease; }
.mode-btn.active { background: #FFFFFF; color: var(--text-primary); box-shadow: 0 2px 5px rgba(0,0,0,0.08); font-weight: 600; }

.main-input-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; }
.main-input-grid.three-col { grid-template-columns: 1fr 1fr 1fr; }
.input-group { display: flex; flex-direction: column; }
label { display: block; font-size: 0.75rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.05em; }
select, input[type="number"] { width: 100%; padding: 12px 14px; font-size: 1rem; border: 1px solid transparent; background-color: var(--input-bg); border-radius: 12px; color: var(--text-primary); transition: all 0.2s; }
select { appearance: none; background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2386868B' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e"); background-repeat: no-repeat; background-position: right 0.8rem center; background-size: 1.1em; }
select:focus, input:focus { outline: none; background-color: #fff; box-shadow: 0 0 0 3px rgba(0,113,227,0.15); border: 1px solid var(--accent-color); }
.hint { font-size: 0.7rem; color: var(--text-secondary); margin-top: 5px; line-height: 1.3; }

.drafting-section { background: #FAFAFC; border: 1px dashed #E5E5EA; border-radius: 16px; padding: 16px 20px; margin-bottom: 0; }
.drafting-label { font-size: 0.75rem; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 10px; }
.drafting-switch { display: flex; gap: 6px; }
.draft-btn { flex: 1; border: 1px solid #E5E5EA; background: #fff; padding: 9px 6px; border-radius: 10px; font-size: 0.78rem; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: all 0.2s ease; text-align: center; line-height: 1.35; }
.draft-btn small { display: block; font-size: 0.67rem; color: #bbb; }
.draft-btn.active { background: var(--accent-color); color: #fff; border-color: var(--accent-color); box-shadow: 0 2px 8px rgba(0,113,227,0.3); }
.draft-btn.active small { color: rgba(255,255,255,0.65); }

.toggle-container { text-align: center; margin-bottom: 15px; margin-top: 10px; }
.toggle-link { font-size: 0.85rem; color: var(--accent-color); text-decoration: none; font-weight: 500; }
.toggle-link:hover { text-decoration: underline; }
#advanced-fields { margin-top: 15px; margin-bottom: 25px; background: #FAFAFC; border-radius: 16px; padding: 20px; border: 1px dashed #E5E5EA; }
.advanced-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin-bottom: 15px; }

.result-section { background: var(--result-bg); border: 1px solid var(--result-border); border-radius: 16px; padding: 25px; text-align: center; margin-top: 20px; }
.result-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 5px; }
.result-title { color: var(--accent-color); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1px; }
.result-badge { font-size: 0.75rem; background: rgba(0,113,227,0.1); padding: 4px 8px; border-radius: 6px; color: var(--accent-color); font-weight: 500; }
.result-value { font-size: 3.5rem; font-weight: 700; color: var(--accent-color); letter-spacing: -0.03em; line-height: 1.1; margin: 10px 0; }
.result-subtitle { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 10px; }
.cda-reference { display: inline-block; background-color: var(--accent-light); color: #0056B3; padding: 6px 14px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; margin-bottom: 12px; border: 1px solid rgba(0,113,227,0.2); }

.pcda-row { display: flex; align-items: center; justify-content: center; gap: 10px; margin: 8px 0 12px 0; flex-wrap: wrap; }
.pcda-badge { display: inline-flex; align-items: center; gap: 8px; background: linear-gradient(135deg, #1a1a2e, #16213e); color: #fff; padding: 6px 14px; border-radius: 20px; font-size: 0.85rem; }
.pcda-label { opacity: 0.7; font-size: 0.72rem; }
.pcda-value { font-weight: 700; font-size: 1rem; color: #FFD60A; }
.pcda-hint { font-size: 0.72rem; color: var(--text-secondary); }

.breakdown-container { margin-top: 15px; }
.breakdown-divider { border: 0; border-top: 1px solid rgba(0,0,0,0.05); margin-bottom: 15px; }
.breakdown-grid { display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: 10px; }
.bd-item { display: flex; flex-direction: column; align-items: center; }
.bd-label { font-size: 0.7rem; text-transform: uppercase; color: #86868B; margin-bottom: 4px; }
.bd-val { font-size: 1.05rem; font-weight: 700; color: var(--text-primary); }
.bd-item.loss .bd-val { color: var(--red); }

.disclaimer { text-align: center; font-size: 0.75rem; color: #C1C1C4; margin-top: 18px; line-height: 1.6; }
.personal-disclaimer { background: rgba(255,149,0,0.08); border: 1px solid rgba(255,149,0,0.28); border-radius: 12px; padding: 12px 16px; color: #7A4800; font-size: 0.8rem; line-height: 1.5; margin-top: 14px; }

.site-footer { text-align: center; padding: 24px 20px 20px; font-size: 0.78rem; color: #B0B0B8; border-top: 1px solid rgba(0,0,0,0.06); margin-top: 20px; }
.site-footer a { color: var(--accent-color); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }
.copyright { margin-top: 6px; font-size: 0.72rem; color: #C8C8D0; }

.ab-conditions-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 14px; margin-bottom: 24px; background: #FAFAFC; border: 1px dashed #E5E5EA; border-radius: 16px; padding: 18px; }
.ab-flat-grid { display: grid; grid-template-columns: 1fr 56px 1fr; gap: 16px 10px; align-items: center; margin-bottom: 20px; }
.ab-col-header { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-secondary); padding-bottom: 4px; border-bottom: 2px solid #E5E5EA; }
.ab-header-b { color: var(--accent-color); border-bottom-color: rgba(0,113,227,0.3); }
.ab-vs-center { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.vs-circle { width: 44px; height: 44px; border-radius: 50%; background: #E3E3E8; display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 0.78rem; color: var(--text-secondary); flex-shrink: 0; }
.ab-delta-badge { background: linear-gradient(135deg, var(--accent-color), #0056B3); color: #fff; border-radius: 12px; padding: 8px 12px; text-align: center; min-width: 72px; }
.ab-delta-num { font-size: 1.05rem; font-weight: 800; line-height: 1.1; }
.ab-delta-label { font-size: 0.62rem; opacity: 0.8; margin-top: 2px; }
.ab-results { background: var(--result-bg); border: 1px solid var(--result-border); border-radius: 16px; padding: 22px; margin-top: 8px; }
.ab-results-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; }
.ab-result-item { text-align: center; padding: 16px 10px; border-radius: 12px; background: #fff; border: 1px solid rgba(0,0,0,0.05); }
.ab-result-item.feature { background: var(--accent-color); border-color: transparent; box-shadow: 0 4px 16px rgba(0,113,227,0.3); }
.ab-result-icon { font-size: 1.3rem; margin-bottom: 6px; }
.ab-result-num { font-size: 1.45rem; font-weight: 800; color: var(--accent-color); line-height: 1; margin-bottom: 4px; }
.ab-result-item.feature .ab-result-num { color: #fff; }
.ab-result-label { font-size: 0.78rem; font-weight: 600; color: var(--text-primary); }
.ab-result-item.feature .ab-result-label { color: rgba(255,255,255,0.9); }
.ab-result-sub { font-size: 0.68rem; color: var(--text-secondary); margin-top: 2px; }
.ab-result-item.feature .ab-result-sub { color: rgba(255,255,255,0.6); }
.ab-watts-display { display: flex; justify-content: space-between; align-items: center; background: var(--input-bg); border-radius: 10px; padding: 10px 14px; }
.ab-watts-label { font-size: 0.72rem; color: var(--text-secondary); font-weight: 500; }
.ab-watts-val { font-size: 1.1rem; font-weight: 700; color: var(--text-primary); }

.table-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 5px; color: var(--text-primary); }
.table-subtitle { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 20px; }
.budget-bar { background: linear-gradient(135deg, #1a1a2e, #16213e); border-radius: 14px; padding: 14px 18px; margin-bottom: 16px; }
.budget-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.budget-item { text-align: center; flex: 1; min-width: 70px; }
.budget-label { display: block; font-size: 0.63rem; text-transform: uppercase; letter-spacing: 0.06em; color: rgba(255,255,255,0.5); margin-bottom: 3px; }
.budget-val { display: block; font-size: 1rem; font-weight: 700; color: #fff; }
.budget-item.feature .budget-val { color: #FFD60A; font-size: 1.1rem; }
.table-container { overflow-x: auto; border-radius: 12px; border: 1px solid #E5E5EA; }
.gains-table { width: 100%; border-collapse: collapse; text-align: left; font-size: 0.88rem; background: #fff; }
.gains-table th { background: #F5F5F7; padding: 10px 12px; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; font-size: 0.7rem; letter-spacing: 0.05em; border-bottom: 2px solid #E5E5EA; white-space: nowrap; }
.gains-table td { padding: 12px; border-bottom: 1px solid #F0F0F5; color: var(--text-primary); vertical-align: middle; }
.gains-table tr:last-child td { border-bottom: none; }
.gains-table tbody tr:hover td { background-color: #FAFAFC; }
.check-col { width: 36px; text-align: center !important; }
.row-checkbox { width: 17px; height: 17px; cursor: pointer; accent-color: var(--accent-color); }
.sortable { cursor: pointer; user-select: none; }
.sortable:hover { background: #EBEBF0; color: var(--text-primary); }
.sortable.active-sort { color: var(--accent-color); background: #EEF5FF; }
.sort-icon { font-size: 0.7rem; margin-left: 3px; }
.highlight-row td { background-color: #F0F7FF; }
.gains-table tbody tr.checked-row td { background-color: #F0FFF4 !important; }
.watt-save { font-weight: 600; color: var(--accent-color); white-space: nowrap; }
.bang-buck { font-weight: 700; white-space: nowrap; }
.bang-buck.top { color: var(--green); }
.bang-buck.good { color: var(--orange); }
.bang-buck.low { color: var(--red); }
.bang-buck.free { color: var(--green); }

@media (max-width: 620px) {
    .nav-container { flex-wrap: wrap; gap: 8px; padding: 10px 16px; }
    #header-title { font-size: 1.2rem; }
    .main-tabs { order: 2; width: 100%; position: static; transform: none; }
    #lang-switcher { order: 1; margin-left: auto; }
    .main-tab-btn { flex: 1; text-align: center; padding: 7px 6px; font-size: 0.75rem; }
    .main-input-grid, .main-input-grid.three-col, .advanced-grid { grid-template-columns: 1fr; gap: 14px; }
    .ab-conditions-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
    .ab-flat-grid { grid-template-columns: 1fr 1fr; grid-template-rows: auto auto auto auto; column-gap: 10px; row-gap: 10px; }
    .ab-flat-grid > *:nth-child(1) { grid-column: 1; grid-row: 1; }
    .ab-flat-grid > *:nth-child(2) { display: none; }
    .ab-flat-grid > *:nth-child(3) { grid-column: 2; grid-row: 1; }
    .ab-flat-grid > *:nth-child(4) { grid-column: 1; grid-row: 2; }
    .ab-flat-grid > *:nth-child(5) { grid-column: 1 / -1; grid-row: 3; flex-direction: row; justify-content: center; gap: 10px; }
    .ab-flat-grid > *:nth-child(6) { grid-column: 2; grid-row: 2; }
    .ab-flat-grid > *:nth-child(7) { grid-column: 1; grid-row: 4; }
    .ab-flat-grid > *:nth-child(8) { display: none; }
    .ab-flat-grid > *:nth-child(9) { grid-column: 2; grid-row: 4; }
    .ab-results-grid { grid-template-columns: 1fr; gap: 8px; }
    .breakdown-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
    .result-value { font-size: 2.8rem; }
    .drafting-switch { flex-wrap: wrap; gap: 5px; }
    .draft-btn { flex: 0 0 calc(50% - 3px); }
    .budget-inner { gap: 6px; }
}
/* ===== Merknaam-link in de header ===== */
.brand { text-decoration: none; color: inherit; flex-shrink: 0; }
.brand #header-title { font-size: 1.4rem; font-weight: 700; color: var(--text-primary); margin: 0; letter-spacing: -0.01em; }

/* ===== SEO / FAQ sectie ===== */
.seo-content { margin-top: 40px; }
.seo-content h2 { font-size: 1.15rem; font-weight: 700; color: var(--text-primary); margin-bottom: 16px; letter-spacing: -0.01em; }
.faq-item { background: var(--card-bg); border: 1px solid var(--card-border); border-radius: 14px; box-shadow: var(--shadow); margin-bottom: 10px; overflow: hidden; }
.faq-item summary { cursor: pointer; padding: 14px 18px; list-style: none; position: relative; padding-right: 44px; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary h3 { display: inline; font-size: 0.92rem; font-weight: 600; color: var(--text-primary); margin: 0; letter-spacing: 0; }
.faq-item summary::after { content: "+"; position: absolute; right: 18px; top: 50%; transform: translateY(-50%); font-size: 1.25rem; font-weight: 400; color: var(--text-secondary); line-height: 1; }
.faq-item[open] summary::after { content: "\2212"; color: var(--accent-color); }
.faq-item p { padding: 0 18px 16px 18px; font-size: 0.88rem; color: var(--text-secondary); line-height: 1.6; }
.faq-item summary:focus-visible { outline: 2px solid var(--accent-color); outline-offset: -2px; border-radius: 14px; }

@media (max-width: 620px) {
  .seo-content h2 { font-size: 1.05rem; }
  .faq-item summary h3 { font-size: 0.88rem; }
}