:root{--ink:#3d3d3d;--peri:#727acf;--peri-d:#5a62b8;--bg:#f9f9f9;--line:#e4e5f2}
*{box-sizing:border-box;margin:0}
body{font-family:"Open Sans",Arial,sans-serif;color:var(--ink);min-height:100vh;
  background:radial-gradient(900px 400px at 85% -5%,#cfe9f5 0,transparent 60%),radial-gradient(700px 400px at 0 10%,#dcd6f5 0,transparent 60%),var(--bg);
  padding-bottom:32px}
.top{background:var(--ink);color:#fff;display:flex;align-items:center;gap:12px;padding:12px 20px}
.logo{display:grid;gap:3px;width:26px}
.logo i{display:block;height:3px;background:#fff;border-radius:1px}
.logo i:nth-child(1){width:60%;margin:0 auto}.logo i:nth-child(2){width:80%;margin:0 auto}
.brand{letter-spacing:.3em;font-weight:600;font-size:18px}
main{max-width:460px;margin:0 auto;padding:0 16px}
.hero{padding:28px 4px 20px}
h1{font-size:clamp(28px,8vw,38px);font-weight:800;line-height:1.15}
h1::after{content:"";display:block;width:64px;height:4px;background:var(--peri);border-radius:2px;margin-top:14px}
.card,.result{background:#fff;border-radius:16px;padding:20px;box-shadow:0 8px 28px rgba(61,61,61,.1)}
.field{display:block;margin-bottom:20px}
.field:last-child{margin-bottom:0}
.field>span{display:block;font-weight:700;font-size:13px;text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.input{display:flex;align-items:center;border:2px solid var(--line);border-radius:12px;padding:0 14px;background:#fff;transition:.15s}
.input:focus-within{border-color:var(--peri)}
.input b{color:var(--peri);font-size:20px}
input{border:0;outline:0;font:inherit;font-size:22px;font-weight:700;color:var(--ink);width:100%;padding:12px 8px;background:transparent;-moz-appearance:textfield}
input::-webkit-outer-spin-button,input::-webkit-inner-spin-button{-webkit-appearance:none}
.tips{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.tips button{font:inherit;font-weight:700;font-size:18px;padding:14px 0;border-radius:12px;border:2px solid var(--line);background:#fff;color:var(--ink);cursor:pointer;transition:.15s}
.tips button:active{transform:scale(.96)}
.tips button.active{background:var(--peri);border-color:var(--peri);color:#fff;box-shadow:0 4px 0 var(--peri-d)}
.custom{grid-column:span 1;padding:0 10px}
.custom input{font-size:16px;padding:12px 2px}
.custom.active{border-color:var(--peri);background:#eef0ff}
.stepper{display:flex;align-items:center;justify-content:space-between;border:2px solid var(--line);border-radius:12px;padding:6px}
.stepper button{width:48px;height:48px;border-radius:10px;border:0;background:var(--peri);color:#fff;font-size:28px;font-weight:700;cursor:pointer;box-shadow:0 3px 0 var(--peri-d)}
.stepper button:active{transform:translateY(2px);box-shadow:none}
.stepper output{font-size:26px;font-weight:800}
.result{margin-top:16px;background:var(--ink);color:#fff}
.big{text-align:center;padding:6px 0 16px;border-bottom:1px solid rgba(255,255,255,.15)}
.big span{text-transform:uppercase;letter-spacing:.12em;font-size:13px;opacity:.8}
.big strong{display:block;font-size:clamp(44px,14vw,60px);font-weight:800;color:#fff;margin-top:4px;
  background:linear-gradient(90deg,#fff,#b9bdf5);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
dl{padding:14px 0 4px}
dl div{display:flex;justify-content:space-between;padding:6px 0}
dt{opacity:.8}dd{font-weight:700}
.reset{width:100%;margin-top:12px;padding:13px;border-radius:12px;border:2px solid var(--peri);background:transparent;color:#fff;font:inherit;font-weight:700;cursor:pointer;letter-spacing:.05em;text-transform:uppercase}
.reset:hover{background:var(--peri)}