:root {
  --bg:#f8fafc;
  --surface:#ffffff;
  --ink:#0f172a;
  --muted:#64748b;
  --line:#e2e8f0;
  --accent:#14b8a6;
  --accent-dark:#0f766e;
  --shadow:0 18px 50px rgba(15,23,42,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:linear-gradient(180deg,#f8fafc 0%,#eef6f5 100%);line-height:1.5}
a{color:inherit}
.site-header{max-width:1120px;margin:0 auto;padding:24px 20px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:800;font-size:1.25rem;letter-spacing:-.02em}
.brand-mark{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:var(--ink);color:white;font-weight:900}
.tagline{color:var(--muted);font-size:.95rem}
main{max-width:1120px;margin:0 auto;padding:18px 20px 64px}
.hero{display:grid;grid-template-columns:1fr 500px;gap:56px;align-items:center;padding:52px 0 62px}
.eyebrow{display:inline-block;font-size:.78rem;font-weight:800;letter-spacing:.14em;color:var(--accent-dark);margin-bottom:12px}
h1{font-size:clamp(2.5rem,6vw,4.8rem);line-height:.98;letter-spacing:-.055em;margin:0 0 22px;max-width:760px}
.hero-copy p{font-size:1.12rem;color:var(--muted);max-width:630px;margin:0}
.calculator-card{background:rgba(255,255,255,.95);border:1px solid rgba(226,232,240,.9);border-radius:24px;padding:26px;box-shadow:var(--shadow);backdrop-filter:blur(10px)}
.field{display:flex;flex-direction:column;gap:8px;margin-bottom:20px}.field>span,.custom-tip-row label{font-size:.9rem;font-weight:700}
.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.input-wrap{height:52px;display:flex;align-items:center;border:1px solid var(--line);border-radius:14px;background:white;overflow:hidden;transition:.2s}
.input-wrap:focus-within{border-color:var(--accent);box-shadow:0 0 0 4px rgba(20,184,166,.12)}
.input-wrap input{border:0;outline:0;width:100%;font:inherit;font-size:1.05rem;padding:0 12px;background:transparent;color:var(--ink)}
.prefix,.suffix{color:var(--muted);font-weight:700;padding:0 12px}.prefix{padding-right:0}.suffix{padding-left:0}
.tip-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.tip-buttons button,.stepper button{border:1px solid var(--line);background:white;border-radius:12px;height:44px;font-weight:800;color:var(--ink);cursor:pointer}.tip-buttons button.active,.tip-buttons button:hover{background:var(--ink);color:white;border-color:var(--ink)}
.custom-tip-row{display:flex;align-items:center;justify-content:space-between;margin-top:10px;gap:16px}.input-wrap.small{width:120px;height:44px}
.stepper{display:grid;grid-template-columns:44px 1fr 44px;border:1px solid var(--line);border-radius:14px;overflow:hidden;height:52px;background:white}.stepper button{border:0;border-radius:0;font-size:1.4rem}.stepper input{border:0;text-align:center;font:inherit;font-size:1.05rem;font-weight:800;width:100%;outline:0}
.checkbox-field{justify-content:flex-end}.switch-row{height:52px;display:flex;align-items:center;gap:10px;border:1px solid var(--line);border-radius:14px;padding:0 14px;background:white;font-weight:600}.switch-row input{width:18px;height:18px;accent-color:var(--accent)}
.results{margin-top:8px;border-top:1px solid var(--line);padding-top:14px;display:grid;gap:6px}.results>div{display:flex;align-items:center;justify-content:space-between;padding:8px 2px}.results span{color:var(--muted)}.results strong{font-size:1.08rem}.results .highlight{margin-top:8px;background:var(--ink);border-radius:16px;padding:16px}.results .highlight span{color:#cbd5e1}.results .highlight strong{color:white;font-size:1.4rem}
.content-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:24px}.content-grid article,.faq{background:rgba(255,255,255,.75);border:1px solid var(--line);border-radius:20px;padding:24px}.content-grid h2,.faq h2{margin-top:0;letter-spacing:-.03em}.content-grid p{color:var(--muted);margin-bottom:0}
.faq{margin-top:18px}.faq details{border-top:1px solid var(--line);padding:16px 0}.faq details:first-of-type{border-top:0}.faq summary{cursor:pointer;font-weight:800}.faq p{color:var(--muted);margin-bottom:0}
footer{max-width:1120px;margin:0 auto;padding:24px 20px 40px;display:flex;justify-content:space-between;color:var(--muted);font-size:.9rem}.footer-links{display:flex;gap:18px}.footer-links a{text-decoration:none}
@media(max-width:900px){.hero{grid-template-columns:1fr;gap:28px;padding-top:32px}.hero-copy{text-align:center}.hero-copy p{margin-left:auto;margin-right:auto}.content-grid{grid-template-columns:1fr}.calculator-card{max-width:560px;width:100%;margin:0 auto}}
@media(max-width:560px){.site-header{padding-top:18px}.tagline{display:none}main{padding-left:14px;padding-right:14px}.hero{padding-top:22px}.calculator-card{padding:18px;border-radius:20px}.field-grid{grid-template-columns:1fr}.tip-buttons{grid-template-columns:repeat(4,1fr);gap:6px}.tip-buttons button{font-size:.9rem}.content-grid article,.faq{padding:20px}footer{padding-left:16px;padding-right:16px}}