/* ── Design System ─────────────────────────────────────────────────── */
:root {
  --bg:        #080c18;
  --bg-card:   #0f1623;
  --bg-panel:  #0d1420;
  --accent:    #00d4ff;
  --accent2:   #0098d4;
  --accent3:   #006fa8;
  --glow:      rgba(0,212,255,0.18);
  --glow-sm:   rgba(0,212,255,0.08);
  --text:      #ffffff;
  --text-2:    #cbd5e1;
  --text-3:    #94a3b8;
  --border:    #162032;
  --border-2:  #1e2f45;
  --green:     #22c55e;
  --yellow:    #fbbf24;
  --red:       #ef4444;
  --font:      "Inter", system-ui, sans-serif;
  --r:         10px;
  --r-sm:      7px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: var(--font); font-size: 15px; line-height: 1.6; min-height: 100vh; }
@media (min-width: 680px) { body { max-width: 70%; margin: 0 auto; } }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.app-header { padding: 24px 20px 20px; border-bottom: 1px solid var(--border); text-align: center; }
.brand-name { font-size: 22px; font-weight: 900; letter-spacing: -0.5px; }
.brand-name em { color: var(--accent); font-style: normal; }
.brand-tag { font-size: 12px; color: var(--text-3); margin-top: 2px; text-transform: uppercase; letter-spacing: 0.06em; }
.calc-hero { text-align: center; padding: 36px 20px 24px; }
.calc-hero h1 { font-size: clamp(22px, 5vw, 32px); font-weight: 900; line-height: 1.2; background: linear-gradient(135deg, #ffffff 60%, var(--accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin-bottom: 10px; }
.hero-sub { color: var(--text-2); font-size: 15px; max-width: 520px; margin: 0 auto; }
.calc-panel { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 24px 20px; margin: 0 16px 24px; }
.section-label { font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--accent); margin-bottom: 16px; }
.input-grid { display: grid; grid-template-columns: 1fr; gap: 18px; }
@media (min-width: 600px) { .input-grid { grid-template-columns: 1fr 1fr; } }
.input-row { display: flex; flex-direction: column; gap: 5px; }
.input-row.full { grid-column: 1 / -1; }
.input-row label { font-size: 13px; font-weight: 600; color: var(--text-2); }
.input-row input, .input-row select { background: var(--bg-panel); border: 1px solid var(--border-2); border-radius: var(--r-sm); color: var(--text); font-family: var(--font); font-size: 15px; padding: 10px 12px; width: 100%; transition: border-color 0.15s; -webkit-appearance: none; appearance: none; }
.input-row input:focus, .input-row select:focus { outline: none; border-color: var(--accent2); box-shadow: 0 0 0 3px var(--glow-sm); }
.input-row input.error { border-color: var(--red); }
.hint { font-size: 12px; color: var(--text-3); line-height: 1.5; }
.prefix-wrap { position: relative; }
.prefix-wrap .prefix { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--text-3); font-size: 15px; pointer-events: none; }
.prefix-wrap input { padding-left: 24px; }
.field-error { font-size: 12px; color: var(--red); margin-top: 2px; }
.advanced-toggle { background: none; border: 1px solid var(--border-2); border-radius: var(--r-sm); color: var(--text-3); cursor: pointer; font-family: var(--font); font-size: 13px; margin-top: 18px; padding: 8px 14px; transition: border-color 0.15s, color 0.15s; width: 100%; text-align: left; }
.advanced-toggle:hover { border-color: var(--accent2); color: var(--text-2); }
.advanced-section { display: none; margin-top: 18px; }
.advanced-section.open { display: block; }
.state-notice { display: none; background: rgba(0,212,255,0.06); border: 1px solid var(--border-2); border-radius: var(--r-sm); color: var(--text-2); font-size: 13px; margin-top: 6px; padding: 10px 14px; line-height: 1.55; }
.state-notice.visible { display: block; }
.state-notice.warn { background: rgba(251,191,36,0.07); border-color: rgba(251,191,36,0.3); }
.results-panel { display: none; margin: 0 16px 24px; }
.results-panel.visible { display: block; }
.big-result { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 28px 20px 22px; text-align: center; margin-bottom: 16px; }
.big-amount { font-size: clamp(36px, 9vw, 54px); font-weight: 900; letter-spacing: -1px; margin: 4px 0; }
.big-amount.positive { color: var(--green); }
.big-amount.negative { color: var(--yellow); }
.big-result-label { font-size: 13px; font-weight: 600; color: var(--text-3); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 6px; }
.big-result-sub { font-size: 13px; color: var(--text-3); margin-top: 6px; }
.comparison-wrap { overflow-x: auto; border-radius: var(--r); border: 1px solid var(--border); }
.comparison-table { width: 100%; border-collapse: collapse; background: var(--bg-card); }
.comparison-table th { background: var(--bg-panel); font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-3); padding: 10px 14px; text-align: right; border-bottom: 1px solid var(--border); }
.comparison-table th:first-child { text-align: left; }
.comparison-table td { padding: 9px 14px; font-size: 14px; color: var(--text-2); border-bottom: 1px solid var(--border); text-align: right; }
.comparison-table td:first-child { text-align: left; color: var(--text-3); font-size: 13px; }
.comparison-table tr:last-child td { border-bottom: none; }
.comparison-table .row-total td { font-weight: 700; color: var(--text); background: rgba(0,212,255,0.04); }
.comparison-table .row-takehome td { font-weight: 700; font-size: 15px; }
.sc-col { color: var(--accent); }
.val-green { color: var(--green) !important; }
.val-red   { color: var(--red)   !important; }
.val-yellow{ color: var(--yellow)!important; }
.text-muted { color: var(--text-3) !important; }
.breakeven-banner { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 20px; margin: 16px 0 0; display: flex; gap: 14px; align-items: flex-start; }
.breakeven-icon { font-size: 22px; flex-shrink: 0; margin-top: 2px; }
.breakeven-text h3 { font-size: 15px; font-weight: 700; margin-bottom: 4px; }
.breakeven-text p { font-size: 13px; color: var(--text-2); line-height: 1.55; }
.below-fold { padding: 0 16px 60px; }
.section-divider { border: none; border-top: 1px solid var(--border); margin: 32px 0; }
.explainer-block { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); margin-bottom: 24px; overflow: hidden; }
.explainer-block summary { cursor: pointer; font-size: 14px; font-weight: 600; padding: 16px 18px; list-style: none; display: flex; align-items: center; justify-content: space-between; color: var(--text-2); }
.explainer-block summary::-webkit-details-marker { display: none; }
.explainer-block summary::after { content: "BC"; font-size: 11px; color: var(--text-3); transition: transform 0.2s; }
.explainer-block[open] summary::after { transform: rotate(180deg); }
.explainer-body { padding: 0 18px 18px; color: var(--text-2); font-size: 14px; line-height: 1.7; }
.explainer-body h3 { font-size: 14px; font-weight: 700; color: var(--text); margin: 14px 0 6px; }
.explainer-body ul { padding-left: 18px; margin-top: 4px; }
.explainer-body ul li { margin-bottom: 4px; }
.section-title { font-size: 20px; font-weight: 800; margin-bottom: 20px; }
.breakeven-section { margin-bottom: 32px; }
.breakeven-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 22px 20px; }
.breakeven-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 10px; }
.breakeven-card p { color: var(--text-2); font-size: 14px; line-height: 1.7; margin-bottom: 10px; }
.faq-section { margin-bottom: 32px; }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-question { background: none; border: none; color: var(--text); cursor: pointer; display: flex; font-family: var(--font); font-size: 15px; font-weight: 600; justify-content: space-between; align-items: center; padding: 16px 0; text-align: left; width: 100%; gap: 12px; }
.faq-arrow { color: var(--text-3); flex-shrink: 0; font-size: 11px; transition: transform 0.2s; }
.faq-answer { overflow: hidden; max-height: 0; transition: max-height 0.25s ease-out; }
.faq-answer.open { max-height: 800px; }
.faq-answer-inner { color: var(--text-2); font-size: 14px; line-height: 1.75; padding-bottom: 16px; }
.faq-answer-inner strong { color: var(--text); }
.faq-answer-inner ul { padding-left: 18px; margin: 8px 0; }
.faq-answer-inner li { margin-bottom: 4px; }
.faq-answer-inner p { margin-bottom: 10px; }
.caveat-block { background: rgba(251,191,36,0.06); border: 1px solid rgba(251,191,36,0.28); border-radius: var(--r); padding: 20px; margin-bottom: 32px; }
.caveat-block h3 { color: var(--yellow); font-size: 14px; font-weight: 700; margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }
.caveat-block ul { padding-left: 18px; }
.caveat-block ul li { color: var(--text-2); font-size: 13px; line-height: 1.65; margin-bottom: 6px; }
.site-footer { border-top: 1px solid var(--border); color: var(--text-3); font-size: 13px; margin-top: 40px; padding: 20px 16px; text-align: center; }
.site-footer a { color: var(--text-3); }
.site-footer a:hover { color: var(--accent); text-decoration: none; }
.ad-slot { min-height: 90px; text-align: center; padding: 8px 0; }
.breadcrumb { display: flex; gap: 8px; align-items: center; font-size: 13px; color: var(--text-3); margin-bottom: 8px; }
.breadcrumb a { color: var(--text-3); }
.breadcrumb a:hover { color: var(--accent); }