/* =========================================================
   OptionIncomeTools — Design System
   Theme: contemporary fintech, dark-first, finance-trustworthy
   ========================================================= */

:root {
  --bg: #0b0f17;
  --bg-elev: #121826;
  --bg-elev-2: #1a2233;
  --border: #243049;
  --border-strong: #324166;
  --text: #e8edf7;
  --text-dim: #9aa6bf;
  --text-faint: #6b7691;
  --brand: #4ade80;          /* income green */
  --brand-2: #22d3ee;         /* accent cyan */
  --brand-deep: #16a34a;
  --warn: #fbbf24;
  --danger: #ef4444;
  --gain: #4ade80;
  --loss: #f87171;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 8px 32px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 0 1px rgba(74,222,128,0.2), 0 8px 32px rgba(74,222,128,0.08);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', ui-monospace, monospace;
  --max-w: 1200px;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f7f9fc;
    --bg-elev: #ffffff;
    --bg-elev-2: #f0f3f9;
    --border: #e2e8f0;
    --border-strong: #cbd5e1;
    --text: #0f172a;
    --text-dim: #475569;
    --text-faint: #94a3b8;
    --shadow: 0 4px 24px rgba(15,23,42,0.06);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(circle at 20% 0%, rgba(74,222,128,0.06) 0%, transparent 40%),
    radial-gradient(circle at 80% 20%, rgba(34,211,238,0.05) 0%, transparent 40%);
  background-attachment: fixed;
}

a { color: var(--brand-2); text-decoration: none; }
a:hover { color: var(--brand); }

h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.02em; line-height: 1.2; }
h1 { font-size: clamp(2rem, 4.5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); margin-top: 2.5rem; }
h3 { font-size: 1.25rem; }
code, .mono { font-family: var(--mono); font-size: 0.95em; }

/* ---------- Layout ---------- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.25rem; }
.container-narrow { max-width: 900px; margin: 0 auto; padding: 0 1.25rem; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(12px) saturate(140%);
  background: rgba(11,15,23,0.75);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.9rem 1.25rem; max-width: var(--max-w); margin: 0 auto;
}
.logo {
  display: flex; align-items: center; gap: 0.5rem;
  font-weight: 800; font-size: 1.15rem; color: var(--text); letter-spacing: -0.02em;
}
.logo-mark {
  width: 32px; height: 32px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  color: #0b0f17; font-weight: 900; font-size: 1.1rem;
}
.nav-links { display: flex; gap: 1.5rem; align-items: center; }
.nav-links a { color: var(--text-dim); font-weight: 500; font-size: 0.95rem; }
.nav-links a.active, .nav-links a:hover { color: var(--text); }
.nav-cta {
  background: var(--brand); color: #0b0f17 !important; padding: 0.5rem 1rem;
  border-radius: 8px; font-weight: 600;
}
.nav-cta:hover { background: var(--brand-deep); color: white !important; }

.menu-btn { display: none; background: none; border: 0; color: var(--text); cursor: pointer; }
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0;
    background: var(--bg-elev); padding: 1rem 1.25rem; border-bottom: 1px solid var(--border);
  }
  .menu-btn { display: block; }
}

/* ---------- Hero ---------- */
.hero {
  padding: 4rem 1.25rem 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero-eyebrow {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  background: rgba(74,222,128,0.1);
  border: 1px solid rgba(74,222,128,0.3);
  border-radius: 999px;
  color: var(--brand);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}
.hero h1 {
  margin: 0 0 1rem;
  background: linear-gradient(135deg, var(--text) 0%, var(--brand) 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-sub {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-dim);
  max-width: 720px; margin: 0 auto 2rem;
}
.hero-cta-row { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 0;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  text-decoration: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-deep) 100%);
  color: #0b0f17;
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: var(--shadow-glow); color: #0b0f17; }
.btn-secondary {
  background: var(--bg-elev-2); color: var(--text);
  border: 1px solid var(--border-strong);
}
.btn-secondary:hover { background: var(--bg-elev); border-color: var(--brand); color: var(--text); }
.btn-ghost { background: transparent; color: var(--text-dim); }
.btn-ghost:hover { color: var(--text); }
.btn-sm { padding: 0.45rem 0.9rem; font-size: 0.85rem; }

/* ---------- Cards / Grid ---------- */
.calc-grid {
  display: grid; gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  margin: 2rem 0;
}
.calc-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
  display: flex; flex-direction: column; gap: 0.75rem;
  text-decoration: none; color: inherit;
}
.calc-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand);
  box-shadow: var(--shadow-glow);
  color: inherit;
}
.calc-card-icon {
  width: 48px; height: 48px;
  background: linear-gradient(135deg, rgba(74,222,128,0.15) 0%, rgba(34,211,238,0.15) 100%);
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  color: var(--brand); font-size: 1.5rem;
}
.calc-card h3 { margin: 0; color: var(--text); }
.calc-card p { margin: 0; color: var(--text-dim); font-size: 0.95rem; }
.calc-card-arrow { margin-top: auto; color: var(--brand); font-weight: 600; }

/* ---------- Calculator Layout ---------- */
.calc-layout {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 2rem;
  margin: 2rem 0 3rem;
  align-items: start;
}
@media (max-width: 900px) { .calc-layout { grid-template-columns: 1fr; } }

.panel {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.panel h2, .panel h3 { margin-top: 0; }
.panel-title { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }

/* ---------- Form ---------- */
.field { margin-bottom: 1rem; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 480px) { .field-row { grid-template-columns: 1fr; } }
.field label {
  display: block; font-size: 0.85rem; font-weight: 600;
  color: var(--text-dim); margin-bottom: 0.3rem; letter-spacing: 0.01em;
}
.field input, .field select {
  width: 100%; padding: 0.7rem 0.9rem;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  color: var(--text);
  border-radius: var(--radius-sm);
  font-family: var(--mono);
  font-size: 1rem;
  transition: border-color .15s, box-shadow .15s;
}
.field input:focus, .field select:focus {
  outline: 0; border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(74,222,128,0.15);
}
.field-hint { font-size: 0.8rem; color: var(--text-faint); margin-top: 0.25rem; }
.input-prefix-wrap { position: relative; }
.input-prefix-wrap .prefix {
  position: absolute; left: 0.85rem; top: 50%; transform: translateY(-50%);
  color: var(--text-faint); font-family: var(--mono); pointer-events: none;
}
.input-prefix-wrap input { padding-left: 1.8rem; }

.btn-row { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 1rem; }

/* ---------- Results ---------- */
.kpi-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 0.75rem;
  margin-bottom: 1.25rem;
}
.kpi {
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
}
.kpi-label { font-size: 0.75rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.06em; font-weight: 600; }
.kpi-value { font-family: var(--mono); font-size: 1.4rem; font-weight: 700; color: var(--text); margin-top: 0.25rem; }
.kpi-value.gain { color: var(--gain); }
.kpi-value.loss { color: var(--loss); }
.kpi-value.warn { color: var(--warn); }
.kpi-sub { font-size: 0.75rem; color: var(--text-faint); margin-top: 0.15rem; }

.alert {
  padding: 0.85rem 1rem; border-radius: var(--radius-sm); margin: 1rem 0;
  font-size: 0.9rem; border: 1px solid; display: flex; gap: 0.6rem; align-items: flex-start;
}
.alert-warn { background: rgba(251,191,36,0.08); border-color: rgba(251,191,36,0.3); color: #fde68a; }
.alert-danger { background: rgba(239,68,68,0.08); border-color: rgba(239,68,68,0.3); color: #fecaca; }
.alert-info { background: rgba(34,211,238,0.08); border-color: rgba(34,211,238,0.3); color: #a5f3fc; }
.alert-success { background: rgba(74,222,128,0.08); border-color: rgba(74,222,128,0.3); color: #bbf7d0; }

/* ---------- Chart ---------- */
.chart-wrap { position: relative; height: 320px; margin: 1rem 0; }
.chart-wrap canvas { max-height: 320px; }

/* ---------- Tables ---------- */
.table { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 0.9rem; }
.table th, .table td {
  text-align: right; padding: 0.6rem 0.75rem; border-bottom: 1px solid var(--border);
}
.table th { color: var(--text-faint); font-weight: 600; text-transform: uppercase; font-size: 0.7rem; letter-spacing: 0.06em; }
.table td:first-child, .table th:first-child { text-align: left; font-family: var(--font); }
.table tr:hover td { background: var(--bg-elev-2); }

/* ---------- Ad Slots ---------- */
.ad-slot {
  margin: 2rem auto; max-width: 728px;
  min-height: 90px;
  background: var(--bg-elev);
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-faint); font-size: 0.85rem;
}
.ad-slot[data-format="rectangle"] { max-width: 336px; min-height: 280px; }
.ad-slot[data-format="sidebar"] { max-width: 300px; min-height: 600px; }

/* ---------- FAQ / Content ---------- */
.faq details {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1.1rem;
  margin-bottom: 0.6rem;
}
.faq summary { cursor: pointer; font-weight: 600; color: var(--text); }
.faq summary::-webkit-details-marker { color: var(--brand); }
.faq details[open] { border-color: var(--brand); }
.faq p { margin: 0.75rem 0 0; color: var(--text-dim); }

.prose p { color: var(--text-dim); }
.prose ul { color: var(--text-dim); }
.prose strong { color: var(--text); }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 4rem;
  padding: 2.5rem 1.25rem 2rem;
  background: var(--bg-elev);
  color: var(--text-dim); font-size: 0.9rem;
}
.footer-grid {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 2rem;
  max-width: var(--max-w); margin: 0 auto 2rem;
}
@media (max-width: 700px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-col h4 { color: var(--text); font-size: 0.95rem; margin: 0 0 0.75rem; }
.footer-col a { display: block; color: var(--text-dim); padding: 0.2rem 0; }
.footer-col a:hover { color: var(--brand); }
.disclaimer {
  max-width: var(--max-w); margin: 0 auto; padding-top: 1.5rem;
  border-top: 1px solid var(--border); font-size: 0.8rem; color: var(--text-faint);
}

/* ---------- Animations ---------- */
@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(74,222,128,0.4); }
  50% { box-shadow: 0 0 0 12px rgba(74,222,128,0); }
}
.pulse { animation: pulse-glow 2s infinite; }

@keyframes fade-up {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fade-up .6s ease both; }
.fade-up-2 { animation: fade-up .6s ease .15s both; }
.fade-up-3 { animation: fade-up .6s ease .3s both; }

@keyframes draw-line {
  from { stroke-dashoffset: 1000; }
  to   { stroke-dashoffset: 0; }
}
.draw-line { stroke-dasharray: 1000; animation: draw-line 2.5s ease forwards; }

@keyframes coin-bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}
.coin-bounce { animation: coin-bounce 2s ease-in-out infinite; }

@keyframes spin-slow { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
.spin-slow { animation: spin-slow 30s linear infinite; transform-origin: center; }

/* Strategy explainer SVG */
.strategy-svg {
  width: 100%; max-width: 600px; height: auto; margin: 1rem auto; display: block;
}

/* Loading state */
.loading {
  display: inline-block; width: 16px; height: 16px;
  border: 2px solid var(--border-strong); border-top-color: var(--brand);
  border-radius: 50%; animation: spin-slow 0.8s linear infinite;
}

/* Toggle */
.toggle-group { display: inline-flex; background: var(--bg); border-radius: 8px; padding: 3px; border: 1px solid var(--border); }
.toggle-group button {
  background: transparent; border: 0; color: var(--text-dim);
  padding: 0.4rem 0.9rem; border-radius: 6px; font-weight: 600; cursor: pointer;
  font-size: 0.85rem;
}
.toggle-group button.active { background: var(--brand); color: #0b0f17; }

/* Affiliate banner */
.affiliate-strip {
  background: linear-gradient(90deg, rgba(74,222,128,0.08), rgba(34,211,238,0.08));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 2rem 0;
  display: flex; flex-wrap: wrap; gap: 1rem; align-items: center; justify-content: space-between;
}
.affiliate-strip .copy { color: var(--text); font-size: 0.95rem; }
.affiliate-strip .copy strong { color: var(--brand); }

/* Helpers */
.text-dim { color: var(--text-dim); }
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-0 { margin-bottom: 0; }
.gap-1 { gap: 0.5rem; }
.flex { display: flex; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.flex-wrap { flex-wrap: wrap; }
.hide-mobile { }
@media (max-width: 600px) { .hide-mobile { display: none; } }