:root{
  --brand:#282b73;
  --muted:#8f92a0;
  --bg:#fbfdfe;
  --accent:#3b3fcf;
  --invest:#e7eaff;
  --border:#e9eef6;
}
*{box-sizing:border-box}
.sip-wrap{max-width:1100px;margin:18px auto;padding:18px}
.sip-inner{display:grid;grid-template-columns:1fr 460px;gap:28px;background:var(--bg);padding:24px;border-radius:12px;border:1px solid var(--border);align-items:start}
@media(max-width:900px){.sip-inner{grid-template-columns:1fr;gap:18px} .sip-chart-area{order:2} .sip-form{order:1}}

.sip-title{font-size:28px;color:var(--brand);margin:0 0 18px 0}
.sip-label{display:block;color:var(--muted);margin:8px 0;font-weight:600}

.sip-input{width:100%;padding:10px 12px;border-radius:8px;border:1px solid var(--border);font-size:15px;background:#fff;margin-bottom:8px}
.sip-range{width:100%;height:6px;background:#eee;border-radius:99px;appearance:none;cursor:pointer;margin-bottom:12px}
.sip-range::-webkit-slider-thumb{appearance:none;width:16px;height:16px;border-radius:50%;background:var(--accent);box-shadow:0 0 0 6px rgba(59,63,207,0.08)}

.sip-results-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px 18px;margin-top:18px;align-items:center}
.label{color:var(--muted);font-size:15px}
.value{font-weight:800;color:var(--brand);text-align:right;font-size:18px}

.sip-chart-area{display:flex;flex-direction:column;align-items:center;justify-content:flex-start}
.chart-wrapper{width:100%;max-width:420px;position:relative;}
/* padding-top creates a perfect square for the wrapper; canvas will absolutely fill it */
.chart-wrapper:before{content:"";display:block;padding-top:100%;}
.chart-wrapper canvas{position:absolute;left:0;top:0;width:100% !important;height:100% !important;display:block !important;}

.sip-legend{display:flex;gap:16px;margin-top:12px;flex-wrap:wrap;justify-content:center}
.leg{display:flex;align-items:center;gap:8px;color:var(--muted);font-size:14px}
.dot{display:inline-block;width:36px;height:12px;border-radius:3px}
.dot.invested{background:var(--invest);}
.dot.returns{background:var(--accent);}

/* Mobile fine-tuning */
@media(max-width:480px){
  .sip-inner{padding:12px}
  .sip-title{font-size:22px}
  .value{font-size:20px}
  .chart-wrapper{max-width:340px}
}