@import url("https://fonts.googleapis.com/css2?family=Fustat:wght@400;500;600;700;800&family=DM+Serif+Display:ital@0;1&display=swap");
:root {
  --ink: #192a43;
  --blue: #145ce6;
  --muted: #5c6b80;
  --line: #dae1eb;
  --paper: #fafbf8;
  --lime: #deee9b;
  font-family: Fustat, system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
a {
  color: inherit;
  text-decoration: none;
}
button {
  font: inherit;
  cursor: pointer;
  border: 0;
}
button:hover {
  filter: brightness(0.94);
}
button:focus-visible,
a:focus-visible {
  outline: 3px solid #ed943f;
  outline-offset: 5px;
}
.wrap {
  width: min(1180px, calc(100% - 96px));
  margin-inline: auto;
}
.nav {
  height: 108px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 27px;
  font-weight: 800;
  letter-spacing: -1px;
}
.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--blue);
  color: white;
  width: 39px;
  height: 39px;
  border-radius: 12px;
  font-size: 25px;
  font-weight: 800;
  letter-spacing: -4px;
  padding-right: 4px;
}
.beta {
  font-size: 9px;
  letter-spacing: 1px;
  background: #e9eef4;
  padding: 4px 6px;
  border-radius: 4px;
}
.nav nav {
  display: flex;
  gap: 35px;
  font-size: 14px;
  font-weight: 600;
}
.nav nav a:hover {
  color: var(--blue);
}
.nav-login {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 20px;
  background: transparent;
  font-weight: 700;
  color: var(--ink);
}
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 55px;
  padding-top: 56px;
  padding-bottom: 85px;
  align-items: center;
}
.eyebrow {
  font-size: 10px;
  letter-spacing: 1.7px;
  font-weight: 800;
  margin: 0 0 24px;
  display: flex;
  align-items: center;
  gap: 9px;
}
.status-dot {
  width: 7px;
  height: 7px;
  background: var(--blue);
  border-radius: 50%;
}
h1 {
  font-size: clamp(62px, 6.7vw, 91px);
  line-height: 0.99;
  letter-spacing: -5px;
  margin: 0 0 26px;
  font-weight: 800;
}
em {
  font-family: "DM Serif Display", Georgia, serif;
  font-weight: 400;
  color: var(--blue);
}
h1 em {
  font-size: 1.12em;
}
.spark {
  color: var(--blue);
  display: inline-block;
  font-size: 80px;
  vertical-align: middle;
  margin-left: 40px;
  transform: rotate(12deg);
}
.lead {
  font-size: 18px;
  line-height: 1.65;
  max-width: 395px;
  color: var(--muted);
  margin-bottom: 27px;
}
.primary {
  display: inline-flex;
  justify-content: space-between;
  align-items: center;
  gap: 26px;
  padding: 17px 23px;
  color: white;
  background: var(--blue);
  font-weight: 700;
  border-radius: 8px;
  font-size: 15px;
  min-height: 54px;
}
.primary span {
  font-size: 21px;
}
.micro {
  font-size: 11px;
  color: var(--muted);
  margin-top: 13px;
}
.hero-board {
  background: #eaf0fa;
  background-image:
    linear-gradient(#145ce609 1px, transparent 1px),
    linear-gradient(90deg, #145ce609 1px, transparent 1px);
  background-size: 24px 24px;
  border: 1px solid #dce5f2;
  border-radius: 14px;
  padding: 25px 26px 49px;
  position: relative;
  transform: rotate(1deg);
}
.board-top {
  display: flex;
  justify-content: space-between;
  font-size: 9px;
  letter-spacing: 1.5px;
  color: #657991;
  font-weight: 700;
  margin-bottom: 28px;
}
.exercise-paper {
  background: #fff;
  padding: 23px;
  border: 1px solid #e2e7ef;
  box-shadow: 0 14px 24px #2234510a;
  transform: rotate(-3deg);
  border-radius: 9px;
}
.paper-label {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 11px;
  font-weight: 700;
}
.mini-icon {
  background: #e8effe;
  padding: 4px 8px;
  color: var(--blue);
  border-radius: 5px;
}
.lesson-tag {
  font-size: 8px;
  font-weight: 500;
  margin-left: auto;
  color: var(--muted);
}
.exercise-question {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  margin: 25px 0 10px;
}
.equation {
  font-size: 45px;
  letter-spacing: -2px;
  text-align: center;
  padding: 13px 0 24px;
  font-family: "DM Serif Display", Georgia, serif;
}
.hint {
  display: flex;
  gap: 10px;
  background: #f0f4fc;
  border-radius: 7px;
  padding: 14px 12px;
  font-size: 11px;
  line-height: 1.5;
}
.hint > span {
  color: var(--blue);
  font-size: 20px;
}
.hint p {
  margin: 3px 0 0;
  color: var(--muted);
}
.working {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 22px;
  font-size: 24px;
  padding: 24px 0;
  font-family: "DM Serif Display", Georgia, serif;
}
.working > span {
  color: #94a0b2;
  font:
    18px Fustat,
    sans-serif;
}
.working strong {
  background: #edf5d3;
  padding: 6px 12px;
  border-radius: 7px;
  font-weight: 400;
}
.check {
  font:
    16px Fustat,
    sans-serif;
  color: #4b711a;
}
.paper-bottom {
  border-top: 1px solid #edf0f4;
  padding-top: 15px;
  font-size: 9px;
  display: flex;
  justify-content: space-between;
  color: var(--muted);
}
.progress-dots {
  color: var(--blue);
  letter-spacing: 3px;
}
.board-note {
  font-size: 11px;
  transform: rotate(-2deg);
  margin: 25px 0 0 7px;
}
.sticker {
  position: absolute;
  right: -19px;
  bottom: -22px;
  background: var(--lime);
  padding: 20px 23px;
  transform: rotate(7deg);
  font-size: 16px;
  line-height: 1.3;
  box-shadow: 0 5px 0 #192a4309;
}
.subject-strip {
  border-block: 1px solid var(--line);
  padding: 23px 0;
}
.subject-strip .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
}
.subject-strip span {
  font-size: 16px;
  font-weight: 600;
  white-space: nowrap;
}
.subject-strip span:first-child {
  font-size: 9px;
  letter-spacing: 1.3px;
  color: var(--muted);
}
.subject-strip b {
  color: var(--blue);
  margin-left: 16px;
  font-size: 20px;
}
.method {
  padding-block: 90px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 90px;
}
h2 {
  font-size: 44px;
  line-height: 1.12;
  letter-spacing: -1.8px;
  margin: 0 0 20px;
}
.section-heading > p:last-child,
.workspace-copy > p:not(.eyebrow) {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
  max-width: 370px;
}
.steps article {
  display: grid;
  grid-template-columns: 35px 1fr;
  column-gap: 20px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.steps article:first-child {
  padding-top: 0;
}
.step-number {
  grid-row: span 2;
  font-size: 12px;
  color: var(--blue);
  font-weight: 700;
  padding-top: 5px;
}
h3 {
  font-size: 20px;
  margin: 0 0 7px;
  letter-spacing: -0.5px;
}
.steps p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 345px;
}
.workspace {
  border-top: 1px solid var(--line);
  padding-block: 76px 95px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 110px;
  align-items: center;
}
.notebook {
  background:
    linear-gradient(90deg, transparent 39px, #ebbbb9 40px, transparent 41px),
    repeating-linear-gradient(#fff 0px, #fff 31px, #e1eaf4 32px);
  padding: 28px 33px 27px 62px;
  transform: rotate(-3deg);
  box-shadow: 0 10px 40px #2437530c;
  border: 1px solid #e1e6ed;
  position: relative;
}
.notebook-tab {
  position: absolute;
  right: 20px;
  top: -15px;
  background: var(--lime);
  font-size: 9px;
  letter-spacing: 1px;
  font-weight: 800;
  padding: 9px 14px;
}
.notebook > p {
  font-size: 11px;
  color: var(--muted);
}
.handwritten {
  font-family: "DM Serif Display", Georgia, serif;
  font-style: italic;
  font-size: 26px;
  line-height: 1.3;
  color: var(--blue);
  margin-top: 25px;
}
.note-equation {
  font-size: 28px;
  font-family: "DM Serif Display", Georgia, serif;
  line-height: 1.5;
  padding: 20px 0 18px 37px;
}
.note-equation span {
  font-size: 21px;
  color: var(--blue);
}
.note-equation strong {
  font-weight: 400;
  background: var(--lime);
}
.note-bottom {
  font-size: 10px;
  color: var(--muted);
}
.workspace-copy ul {
  padding: 0;
  list-style: none;
  margin-top: 27px;
}
.workspace-copy li {
  font-size: 13px;
  margin: 17px 0;
  display: flex;
  gap: 14px;
  align-items: center;
}
.workspace-copy li span {
  color: var(--blue);
  font-size: 19px;
}
.workspace-copy .local-note {
  font-size: 11px !important;
  margin-top: 25px;
}
.closing {
  background: var(--blue);
  color: white;
  border-radius: 14px;
  display: flex;
  align-items: center;
  gap: 30px;
  padding: 48px 43px;
}
.closing-star {
  color: var(--lime);
  font-size: 85px;
}
.closing .eyebrow {
  font-size: 9px;
  color: #d7e4ff;
  margin-bottom: 17px;
}
.closing h2 {
  font-size: 35px;
  margin: 0;
}
.light-button {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 24px;
  background: white;
  color: var(--blue);
  border-radius: 8px;
  padding: 17px 21px;
  font-weight: 800;
  font-size: 13px;
  flex-shrink: 0;
}
footer {
  padding-block: 43px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
footer .logo {
  font-size: 22px;
}
footer .logo-mark {
  width: 30px;
  height: 30px;
  font-size: 20px;
  border-radius: 9px;
}
footer > span {
  font-size: 11px;
  color: var(--muted);
}
dialog {
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 36px;
  width: min(460px, calc(100% - 32px));
  color: var(--ink);
  background: var(--paper);
  box-shadow: 0 25px 100px #192a4340;
  max-height: 90dvh;
  overflow: auto;
}
dialog::backdrop {
  background: #13244170;
  backdrop-filter: blur(5px);
}
.close {
  position: absolute;
  right: 17px;
  top: 12px;
  background: transparent;
  color: var(--muted);
  font-size: 27px;
  width: 36px;
  height: 36px;
}
dialog > .eyebrow {
  margin-top: 24px;
  margin-bottom: 15px;
}
dialog h2 {
  font-size: 37px;
}
dialog > p:not(.eyebrow) {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}
.demo-badge {
  font-size: 10px;
  background: #eaf0fd;
  color: var(--blue);
  padding: 9px 11px;
  border-radius: 5px;
  font-weight: 700;
  margin: 23px 0 14px;
}
.demo-account {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 17px 0 24px;
  font-size: 14px;
}
.account-avatar {
  display: grid;
  place-items: center;
  background: var(--lime);
  border-radius: 50%;
  width: 42px;
  height: 42px;
  font-weight: 800;
}
.demo-account small {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 3px;
}
.demo-account > span:last-child {
  margin-left: auto;
  color: var(--blue);
}
dialog .primary {
  width: 100%;
  font-size: 14px;
  padding-inline: 17px;
}
dialog .auth-disclaimer {
  font-size: 11px !important;
}
.cancel {
  display: block;
  margin: auto;
  padding: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 12px;
}
#login-error {
  color: #a02727;
}
.skip {
  position: absolute;
  top: -100px;
  left: 20px;
  background: white;
  padding: 12px;
  z-index: 10;
}
.skip:focus {
  top: 10px;
}
@media (prefers-reduced-motion: no-preference) {
  .hero-copy,
  .hero-board {
    animation: arrive 0.65s ease-out both;
  }
  .hero-board {
    animation-delay: 0.12s;
  }
  @keyframes arrive {
    from {
      opacity: 0;
      translate: 0 15px;
    }
    to {
      opacity: 1;
      translate: 0 0;
    }
  }
  html {
    scroll-behavior: smooth;
  }
}
@media (max-width: 1000px) {
  .wrap {
    width: calc(100% - 56px);
  }
  .hero {
    gap: 32px;
  }
  .hero-board {
    padding: 20px 18px 40px;
  }
  .exercise-paper {
    padding: 18px;
  }
  .lesson-tag {
    display: none;
  }
  .equation {
    font-size: 37px;
  }
  .spark {
    font-size: 62px;
    margin-left: 25px;
  }
  .method,
  .workspace {
    gap: 50px;
  }
  .subject-strip span:first-child {
    max-width: 130px;
    white-space: normal;
  }
  .closing {
    padding: 35px 28px;
    gap: 20px;
  }
  .closing h2 {
    font-size: 29px;
  }
  .closing-star {
    font-size: 60px;
  }
}
@media (max-width: 700px) {
  .wrap {
    width: calc(100% - 40px);
  }
  .nav {
    height: 85px;
    gap: 12px;
  }
  .logo {
    font-size: 23px;
  }
  .beta {
    display: none;
  }
  .nav nav {
    display: none;
  }
  .nav-login {
    font-size: 12px;
    padding: 10px 12px;
  }
  .hero {
    grid-template-columns: 1fr;
    gap: 42px;
    padding-top: 32px;
    padding-bottom: 64px;
  }
  h1 {
    font-size: 74px;
    letter-spacing: -4px;
  }
  .hero-copy .eyebrow {
    font-size: 9px;
  }
  .lead {
    font-size: 16px;
    max-width: 350px;
  }
  .hero-board {
    margin-inline: 7px;
    max-width: 460px;
  }
  .exercise-paper {
    padding: 22px;
  }
  .lesson-tag {
    display: block;
  }
  .equation {
    font-size: 44px;
  }
  .sticker {
    right: -10px;
    padding: 15px 20px;
    font-size: 14px;
  }
  .subject-strip .wrap {
    flex-wrap: wrap;
    justify-content: flex-start;
    gap: 15px 28px;
  }
  .subject-strip span:first-child {
    flex-basis: 100%;
    max-width: none;
  }
  .subject-strip span {
    font-size: 13px;
  }
  .subject-strip b {
    font-size: 16px;
    margin-left: 7px;
  }
  .method {
    grid-template-columns: 1fr;
    gap: 30px;
    padding-block: 56px;
  }
  h2 {
    font-size: 37px;
  }
  .workspace {
    grid-template-columns: 1fr;
    gap: 48px;
    padding-block: 52px;
  }
  .notebook {
    margin-inline: 10px;
    order: 2;
  }
  .workspace-copy {
    order: 1;
  }
  .closing {
    display: block;
    padding: 30px;
  }
  .closing-star {
    float: right;
    font-size: 50px;
    margin-top: 15px;
  }
  .closing .eyebrow {
    font-size: 8px;
    max-width: 190px;
    line-height: 1.6;
  }
  .closing h2 {
    font-size: 31px;
  }
  .light-button {
    margin: 25px 0 0;
  }
  footer {
    flex-wrap: wrap;
    padding-block: 30px;
    gap: 16px;
  }
  footer .logo {
    flex-basis: 100%;
  }
  footer > span {
    font-size: 10px;
  }
  dialog {
    padding: 28px;
  }
  dialog h2 {
    font-size: 33px;
  }
}
@media (max-width: 370px) {
  h1 {
    font-size: 64px;
  }
  .spark {
    font-size: 54px;
    margin-left: 20px;
  }
  .primary {
    font-size: 13px;
    gap: 15px;
  }
  .working {
    gap: 14px;
  }
  .lesson-tag {
    display: none;
  }
  .exercise-paper {
    padding: 16px;
  }
  .equation {
    font-size: 38px;
  }
}