SVG-волны

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  <path fill="#6366f1" d="M 0 160 C 10 154.67, 40 137.24, 60 128 C 80 118.76, 100 109.91, 120 104.57 C 140 99.24, 160 96, 180 96 C 200 96, 220 99.24, 240 104.57 C 260 109.91, 280 118.76, 300 128 C 320 137.24, 340 149.33, 360 160 C 380 170.67, 400 182.76, 420 192 C 440 201.24, 460 210.09, 480 215.43 C 500 220.76, 520 224, 540 224 C 560 224, 580 220.76, 600 215.43 C 620 210.09, 640 201.24, 660 192 C 680 182.76, 700 170.67, 720 160 C 740 149.33, 760 137.24, 780 128 C 800 118.76, 820 109.91, 840 104.57 C 860 99.24, 880 96, 900 96 C 920 96, 940 99.24, 960 104.57 C 980 109.91, 1000 118.76, 1020 128 C 1040 137.24, 1060 149.33, 1080 160 C 1100 170.67, 1120 182.76, 1140 192 C 1160 201.24, 1180 210.09, 1200 215.43 C 1220 220.76, 1240 224, 1260 224 C 1280 224, 1300 220.76, 1320 215.43 C 1340 210.09, 1360 201.24, 1380 192 C 1400 182.76, 1430 165.33, 1440 160 L 1440 320 L 0 320 Z"/>
</svg>

.wave {
  height: 320px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 320' width='1440' height='320' preserveAspectRatio='none'%3E %3Cpath fill='%236366f1' d='M 0 160 C 10 154.67, 40 137.24, 60 128 C 80 118.76, 100 109.91, 120 104.57 C 140 99.24, 160 96, 180 96 C 200 96, 220 99.24, 240 104.57 C 260 109.91, 280 118.76, 300 128 C 320 137.24, 340 149.33, 360 160 C 380 170.67, 400 182.76, 420 192 C 440 201.24, 460 210.09, 480 215.43 C 500 220.76, 520 224, 540 224 C 560 224, 580 220.76, 600 215.43 C 620 210.09, 640 201.24, 660 192 C 680 182.76, 700 170.67, 720 160 C 740 149.33, 760 137.24, 780 128 C 800 118.76, 820 109.91, 840 104.57 C 860 99.24, 880 96, 900 96 C 920 96, 940 99.24, 960 104.57 C 980 109.91, 1000 118.76, 1020 128 C 1040 137.24, 1060 149.33, 1080 160 C 1100 170.67, 1120 182.76, 1140 192 C 1160 201.24, 1180 210.09, 1200 215.43 C 1220 220.76, 1240 224, 1260 224 C 1280 224, 1300 220.76, 1320 215.43 C 1340 210.09, 1360 201.24, 1380 192 C 1400 182.76, 1430 165.33, 1440 160 L 1440 320 L 0 320 Z'/%3E %3C/svg%3E");
  background-size: 100% 100%;
  background-repeat: no-repeat;
}

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