diff --git a/site/app/icon.svg b/site/app/icon.svg
new file mode 100644
index 0000000..4c6eb32
--- /dev/null
+++ b/site/app/icon.svg
@@ -0,0 +1,35 @@
+<!-- Favicon: the stampstack 3D mark. Next.js App Router auto-serves app/icon.svg
+     and injects the <link rel="icon"> tags. The artwork is the brand logo, kept
+     intact; only the outer <svg> is reframed to a square viewBox (centered on the
+     art, with padding) so the tall portrait mark renders square without the
+     stretch that preserveAspectRatio="none" would cause. Fill falls back to the
+     brand blue when the CSS var isn't defined (i.e. everywhere outside the app). -->
+<svg width="32" height="32" viewBox="-20.56 -4.01 83 83" fill="none" xmlns="http://www.w3.org/2000/svg">
+<g id="stamp stack logo">
+<g id="post stamp outline" filter="url(#filter0_dddd_0_10)">
+<path d="M15.4681 29.6891C15.4682 30.3605 15.8527 30.5202 16.327 30.0459C16.8011 29.5716 17.1854 28.6431 17.1854 27.9718C17.1854 27.9427 17.1838 27.9155 17.1824 27.8883L17.9747 27.096C17.9733 27.126 17.9717 27.1565 17.9717 27.1855C17.9717 27.8569 18.3563 28.0166 18.8305 27.5424C19.3048 27.0681 19.6893 26.1393 19.6894 25.4678C19.6894 25.4388 19.6877 25.4116 19.6863 25.3844L20.4786 24.5921C20.4772 24.622 20.4756 24.6525 20.4756 24.6816C20.4756 25.353 20.8602 25.5127 21.3344 25.0384C21.8087 24.5642 22.1932 23.6353 22.1933 22.9639C22.1933 22.9349 22.1917 22.9076 22.1902 22.8805L22.9822 22.0885C22.9808 22.1185 22.9791 22.149 22.9791 22.1781C22.9792 22.8494 23.3638 23.009 23.838 22.5349C24.3122 22.0606 24.6968 21.1318 24.6968 20.4604C24.6968 20.4313 24.6952 20.4041 24.6938 20.3769L25.4861 19.5846C25.4847 19.6146 25.4831 19.6451 25.4831 19.6741C25.4831 20.3455 25.8677 20.5052 26.3419 20.031C26.8162 19.5567 27.2007 18.6279 27.2008 17.9564C27.2008 17.9274 27.1991 17.9001 27.1977 17.873L27.9901 17.0807C27.9886 17.1106 27.987 17.1411 27.987 17.1702C27.987 17.8415 28.3713 18.0014 28.8455 17.5274C29.3197 17.0532 29.7043 16.1243 29.7043 15.4529C29.7043 15.4238 29.7027 15.3966 29.7013 15.3695L30.4936 14.5771C30.4922 14.6071 30.4905 14.6376 30.4905 14.6667C30.4906 15.338 30.8752 15.4976 31.3494 15.0235C31.8237 14.5492 32.2082 13.6204 32.2082 12.949C32.2082 12.9199 32.2066 12.8927 32.2052 12.8655L32.9975 12.0732C32.9961 12.1032 32.9945 12.1337 32.9945 12.1627C32.9945 12.8341 33.3791 12.9938 33.8533 12.5196C34.3275 12.0453 34.7121 11.1164 34.7122 10.445C34.7122 10.416 34.7105 10.3887 34.7091 10.3616L35.5011 9.56964C35.4997 9.59961 35.498 9.63012 35.498 9.65918C35.4981 10.3305 35.8827 10.4902 36.3569 10.016C36.8311 9.54175 37.2157 8.61294 37.2157 7.94148C37.2157 7.91241 37.2141 7.88519 37.2127 7.85805L38.005 7.0657C38.0036 7.09568 38.002 7.12618 38.002 7.15525C38.002 7.82662 38.3865 7.98634 38.8608 7.51208C39.3351 7.03781 39.7196 6.109 39.7197 5.43755C39.7197 5.40848 39.718 5.38126 39.7166 5.35412L41.1908 3.87989V5.19557C40.7968 5.7003 40.4998 6.48827 40.4998 7.07744C40.4998 7.66658 40.7968 7.85985 41.1908 7.57666V8.7318C40.7968 9.23657 40.4998 10.0245 40.4998 10.6137C40.4998 11.2028 40.7968 11.3961 41.1908 11.1129V12.2675C40.7968 12.7722 40.4999 13.5602 40.4998 14.1494C40.4998 14.7385 40.7968 14.9324 41.1908 14.6491V15.8037C40.7968 16.3085 40.4998 17.0964 40.4998 17.6856C40.4998 18.2747 40.7968 18.468 41.1908 18.1848V19.3394C40.7968 19.8442 40.4998 20.6326 40.4998 21.2218C40.4998 21.8108 40.7969 22.0042 41.1908 21.721V22.8756C40.7968 23.3804 40.4998 24.1683 40.4998 24.7575C40.4998 25.3466 40.7968 25.5399 41.1908 25.2567V26.4119C40.7968 26.9166 40.4998 27.7046 40.4998 28.2937C40.4998 28.8828 40.7969 29.0761 41.1908 28.7929V29.9475C40.7968 30.4523 40.4998 31.2402 40.4998 31.8294C40.4998 32.4186 40.7968 32.6124 41.1908 32.3292V33.4838C40.7968 33.9885 40.4998 34.7765 40.4998 35.3656C40.4998 35.9548 40.7968 36.1481 41.1908 35.8649V37.0195C40.7968 37.5242 40.4998 38.3127 40.4998 38.9019C40.4999 39.4908 40.7969 39.6843 41.1908 39.4011V40.5557C40.7968 41.0604 40.4998 41.8484 40.4998 42.4376C40.4998 43.0267 40.7968 43.22 41.1908 42.9368V44.0919C40.7968 44.5967 40.4998 45.3846 40.4998 45.9738C40.4998 46.5628 40.7969 46.7562 41.1908 46.473V47.7892L39.5878 49.3923C39.4766 49.0146 39.1533 48.9841 38.771 49.3664C38.3886 49.7487 38.065 50.4261 37.9538 51.0262L37.0842 51.8958C36.973 51.5181 36.6494 51.4879 36.2671 51.8703C35.8847 52.2527 35.5611 52.93 35.4499 53.5302L34.5803 54.3997C34.4691 54.022 34.1455 53.9919 33.7631 54.3742C33.3809 54.7566 33.0575 55.4337 32.9463 56.0337L32.0768 56.9033C31.9655 56.5255 31.6419 56.4954 31.2596 56.8778C30.8772 57.2601 30.5536 57.9375 30.4424 58.5377L29.5728 59.4072C29.4616 59.0295 29.138 58.9993 28.7556 59.3817C28.3733 59.7641 28.0497 60.4414 27.9385 61.0416L27.0693 61.9108C26.9581 61.533 26.6344 61.503 26.2521 61.8852C25.8697 62.2676 25.5461 62.945 25.4349 63.5451L24.5654 64.4147C24.4541 64.0369 24.1305 64.0068 23.7482 64.3892C23.3658 64.7715 23.0422 65.4489 22.931 66.0491L22.0614 66.9186C21.9502 66.541 21.6269 66.5106 21.2446 66.8927C20.8623 67.2751 20.5387 67.9524 20.4274 68.5526L19.5579 69.4222C19.4467 69.0444 19.123 69.0144 18.7407 69.3967C18.3583 69.779 18.0347 70.4564 17.9235 71.0565L17.0539 71.9261C16.9427 71.5484 16.6191 71.5182 16.2368 71.9006C15.8545 72.2829 15.5312 72.96 15.42 73.5601L14 74.98V73.5682C14.3808 73.0625 14.6647 72.2977 14.6647 71.7218C14.6646 71.146 14.3808 70.9484 14 71.2044V70.0325C14.3807 69.5269 14.6646 68.762 14.6647 68.1862C14.6647 67.6102 14.3808 67.4127 14 67.6687V66.4962C14.3808 65.9906 14.6647 65.2258 14.6647 64.6499C14.6647 64.074 14.3808 63.8765 14 64.1324V62.9605C14.3808 62.4549 14.6647 61.6896 14.6647 61.1137C14.6646 60.5379 14.3808 60.3402 14 60.5962V59.4243C14.3808 58.9187 14.6647 58.1539 14.6647 57.578C14.6647 57.0021 14.3808 56.8046 14 57.0605V55.8881C14.3808 55.3825 14.6647 54.6177 14.6647 54.0418C14.6646 53.466 14.3808 53.2683 14 53.5243V52.3524C14.3807 51.8468 14.6646 51.082 14.6647 50.5061C14.6647 49.9302 14.3808 49.7327 14 49.9886V48.8162C14.3808 48.3105 14.6647 47.5458 14.6647 46.9699C14.6647 46.394 14.3808 46.1964 14 46.4524V45.2805C14.3807 44.7749 14.6646 44.0101 14.6647 43.4342C14.6647 42.8582 14.3808 42.6601 14 42.9162V41.7443C14.3808 41.2386 14.6647 40.4739 14.6647 39.898C14.6647 39.322 14.3808 39.1245 14 39.3805V38.2086C14.3808 37.7029 14.6647 36.9377 14.6647 36.3617C14.6646 35.7859 14.3808 35.5883 14 35.8442V34.6724C14.3808 34.1667 14.6646 33.4019 14.6647 32.826C14.6647 32.2501 14.3808 32.0526 14 32.3086V31.0707L15.4712 29.5996C15.4698 29.6295 15.4681 29.66 15.4681 29.6891Z" fill="var(--fill-0, #295DF6)"/>
+</g>
+</g>
+<defs>
+<filter id="filter0_dddd_0_10" x="0.697514" y="4.4825e-08" width="40.4933" height="74.9801" filterUnits="userSpaceOnUse" color-interpolation-filters="sRGB">
+<feFlood flood-opacity="0" result="BackgroundImageFix"/>
+<feColorMatrix in="SourceAlpha" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0" result="hardAlpha"/>
+<feOffset dx="-13.3025" dy="-3.87989"/>
+<feColorMatrix type="matrix" values="0 0 0 0 0.0664706 0 0 0 0 0.188824 0 0 0 0 0.548824 0 0 0 1 0"/>
+<feBlend mode="normal" in2="BackgroundImageFix" result="effect1_dropShadow_0_10"/>
+<feColorMatrix in="SourceAlpha" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0" result="hardAlpha"/>
+<feOffset dx="-9.97686" dy="-2.90992"/>
+<feColorMatrix type="matrix" values="0 0 0 0 0.077549 0 0 0 0 0.220294 0 0 0 0 0.640294 0 0 0 1 0"/>
+<feBlend mode="normal" in2="effect1_dropShadow_0_10" result="effect2_dropShadow_0_10"/>
+<feColorMatrix in="SourceAlpha" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0" result="hardAlpha"/>
+<feOffset dx="-6.65124" dy="-1.93995"/>
+<feColorMatrix type="matrix" values="0 0 0 0 0.0886275 0 0 0 0 0.251765 0 0 0 0 0.731765 0 0 0 1 0"/>
+<feBlend mode="normal" in2="effect2_dropShadow_0_10" result="effect3_dropShadow_0_10"/>
+<feColorMatrix in="SourceAlpha" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0" result="hardAlpha"/>
+<feOffset dx="-3.32562" dy="-0.969973"/>
+<feColorMatrix type="matrix" values="0 0 0 0 0.0997059 0 0 0 0 0.283235 0 0 0 0 0.823235 0 0 0 1 0"/>
+<feBlend mode="normal" in2="effect3_dropShadow_0_10" result="effect4_dropShadow_0_10"/>
+<feBlend mode="normal" in="SourceGraphic" in2="effect4_dropShadow_0_10" result="shape"/>
+</filter>
+</defs>
+</svg>