@import url("https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Manrope:wght@400;600;700;800&display=swap");
:root {
  --bg: #f7f8fa;
  --surface: #fff;
  --ink: #18232d;
  --muted: #6b7580;
  --line: #e4e8ec;
  --green: #126b53;
  --soft: #e7f3ed;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font:
    15px "DM Sans",
    sans-serif;
}
body.dark {
  --bg: #121b22;
  --surface: #1b2731;
  --ink: #eef3f5;
  --muted: #a6b4bf;
  --line: #34424c;
  --soft: #183d32;
  --green: #64d6af;
}
a {
  color: inherit;
  text-decoration: none;
}
button,
input,
select {
  font: inherit;
}
button,
a,
input,
select {
  outline-offset: 4px;
}
button {
  cursor: pointer;
}
header {
  height: 88px;
  padding: 0 6%;
  display: flex;
  align-items: center;
  gap: 28px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.brand {
  font: 800 25px Manrope;
  display: flex;
  gap: 12px;
  align-items: center;
}
.brand:first-letter {
  color: var(--green);
}
.light {
  font-weight: 400;
}
nav {
  display: flex;
  gap: 30px;
  margin-left: auto;
  font-size: 14px;
}
#theme {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  border-radius: 50%;
  width: 36px;
  height: 36px;
}
main {
  max-width: 1200px;
  margin: auto;
  padding: 48px 28px 80px;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--green);
  font-size: 12px;
  font-weight: 700;
}
.hero {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 42px;
}
h1 {
  font: 800 clamp(32px, 4vw, 52px)/1.15 Manrope;
  letter-spacing: -2px;
  margin: 18px 0;
}
h1 em {
  color: var(--green);
  font-style: normal;
}
p {
  color: var(--muted);
  line-height: 1.75;
}
.hero p {
  max-width: 570px;
  font-size: 16px;
}
.hero-art {
  background: #173f35;
  color: #fff;
  padding: 30px;
  border-radius: 20px;
  transform: rotate(-2deg);
  box-shadow: 8px 10px 0 #dfebe5;
}
.hero-art .terminal {
  font: 13px/2 monospace;
  color: #b7d7c9;
}
.hero-art strong {
  display: block;
  font: 700 28px Manrope;
  margin: 14px 0;
}
.hero-art .dots {
  letter-spacing: 7px;
  color: #97c0a9;
}
.stats {
  display: flex;
  gap: 32px;
  margin-top: 26px;
  font-size: 12px;
  color: var(--muted);
}
.stats b {
  display: block;
  font-size: 23px;
  color: var(--ink);
  margin-bottom: 5px;
}
.section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 35px 0 18px;
}
h2 {
  font: 700 23px Manrope;
  margin: 0;
}
.company-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.company {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 25px;
  background: var(--surface);
  display: flex;
  align-items: center;
  gap: 18px;
  cursor: pointer;
}
.company.active {
  border-color: var(--green);
  box-shadow: 0 0 0 1px var(--green);
}
.logo {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--soft);
  font: 700 26px Manrope;
}
.anthropic {
  background: #f2e6dc;
  color: #815843;
}
.company h3 {
  margin: 0 0 6px;
  font: 700 18px Manrope;
}
.company p {
  margin: 0;
  font-size: 13px;
}
.arrow {
  margin-left: auto;
  color: var(--green);
}
.workspace {
  display: grid;
  grid-template-columns: 205px 1fr;
  gap: 28px;
  margin-top: 35px;
}
.sidebar {
  padding-top: 8px;
}
.side-label {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--muted);
  margin-bottom: 16px;
}
.tabs {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.tabs button {
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 13px;
  text-align: left;
  border-radius: 8px;
}
.tabs button.active {
  background: var(--soft);
  color: var(--green);
  font-weight: 700;
}
.note {
  border: 1px solid var(--line);
  padding: 17px;
  border-radius: 10px;
  margin-top: 25px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
}
.toolbar {
  display: flex;
  gap: 12px;
  margin: 20px 0;
}
.toolbar input {
  flex: 1;
  min-width: 0;
}
.toolbar input,
.toolbar select {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 12px 14px;
  border-radius: 8px;
  color: var(--ink);
}
.table {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}
.table-head,
.row {
  display: grid;
  grid-template-columns: 1fr 95px 80px;
  gap: 15px;
  align-items: center;
  padding: 18px 22px;
}
.table-head {
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  background: var(--bg);
  color: var(--muted);
}
.row {
  border-top: 1px solid var(--line);
  transition: background 0.2s;
}
.row:hover {
  background: var(--soft);
}
.row strong {
  font-weight: 600;
}
.tags {
  color: var(--muted);
  font-size: 12px;
  margin-top: 7px;
}
.badge {
  font-size: 12px;
  border-radius: 5px;
  background: #e9f3ee;
  color: #227856;
  padding: 5px 8px;
  display: inline-block;
}
.badge.hard {
  background: #faf0e2;
  color: #94641d;
}
.time {
  color: var(--muted);
  font-size: 12px;
}
.breadcrumb {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 25px;
}
.detail {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 38px;
}
.chapters {
  position: sticky;
  top: 25px;
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.chapters a {
  font-size: 13px;
  padding: 10px;
  border-radius: 6px;
}
.chapters a:hover {
  background: var(--soft);
}
.article {
  background: var(--surface);
  padding: 35px;
  border: 1px solid var(--line);
  border-radius: 14px;
}
.article h1 {
  font-size: 36px;
  letter-spacing: -1px;
}
.article h2 {
  margin-top: 35px;
  font-size: 21px;
}
.article p,
.article li {
  line-height: 1.8;
  color: var(--muted);
}
.article pre {
  padding: 22px;
  background: #16252c;
  color: #d7eee3;
  overflow: auto;
  border-radius: 10px;
  font: 13px/1.8 monospace;
}
.diagram {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  background: var(--soft);
  padding: 20px;
  border-radius: 10px;
  margin-top: 20px;
}
.diagram span {
  background: var(--surface);
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 12px;
}
.primary {
  background: var(--green);
  color: var(--surface);
  border: 0;
  padding: 12px 18px;
  border-radius: 8px;
}
.empty {
  padding: 40px;
  text-align: center;
  color: var(--muted);
}
footer {
  padding: 30px 6%;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--muted);
}
@media (max-width: 760px) {
  header {
    height: 72px;
    padding: 0 20px;
  }
  .brand {
    font-size: 20px;
  }
  nav {
    gap: 15px;
  }
  nav a[href="/study-plan"],
  nav a[href="/question-bank"] {
    display: none;
  }
  main {
    padding: 30px 18px;
  }
  .hero {
    grid-template-columns: 1fr;
    gap: 25px;
  }
  .hero-art {
    display: none;
  }
  .company-grid {
    grid-template-columns: 1fr;
  }
  .workspace,
  .detail {
    grid-template-columns: 1fr;
  }
  .tabs {
    flex-direction: row;
  }
  .note,
  .chapters {
    display: none;
  }
  .table-head,
  .row {
    grid-template-columns: 1fr 75px;
    padding: 16px;
  }
  .time {
    display: none;
  }
  .article {
    padding: 22px;
  }
  .toolbar {
    flex-wrap: wrap;
  }
  footer {
    gap: 20px;
    flex-direction: column;
  }
}
@media (max-width: 760px) {
  .table-head span:last-child {
    display: none;
  }
}
@media (max-width: 480px) {
  header {
    gap: 12px;
  }
  .brand {
    font-size: 18px;
    gap: 7px;
  }
  nav a:first-child {
    display: none;
  }
  .section-title {
    gap: 15px;
  }
  .section-title .eyebrow {
    font-size: 10px;
    letter-spacing: 1px;
  }
  .toolbar select {
    flex: 1;
  }
}
.auth-card {
  max-width: 520px;
  margin: 0 auto;
}
.auth-card h1 {
  font-size: 36px;
}
.auth-card form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.auth-card label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-weight: 600;
}
.auth-card input {
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 12px;
  color: var(--ink);
  background: var(--bg);
}
.google-button {
  display: block;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  text-align: center;
  background: var(--surface);
  font-weight: 600;
}
.disabled {
  opacity: 0.6;
  cursor: default;
}
.divider {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  margin: 22px 0;
}
.small {
  font-size: 12px;
}
.error {
  color: #bb3e3e;
  white-space: pre-wrap;
}
.text-link {
  color: var(--green);
  text-decoration: underline;
}
.plans {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.plan .price {
  font-size: 48px;
  margin: 18px 0;
}
.price span {
  font: 400 16px "DM Sans";
}
.plan li {
  font-size: 14px;
}
.plan .primary {
  width: 100%;
}
.notice {
  padding: 16px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 8px;
}
.member-label {
  font-size: 10px;
  padding: 3px 6px;
  border-radius: 4px;
  background: var(--soft);
  color: var(--green);
  white-space: nowrap;
  margin-left: 6px;
}
.locked {
  max-width: 840px;
  margin: auto;
}
.paywall-box {
  padding: 30px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: 10px;
  margin: 25px 0;
}
.paywall-box h2 {
  margin: 0;
}
.price-summary {
  margin: 24px 0;
  color: var(--muted);
}
.price-summary strong {
  font-size: 30px;
  color: var(--ink);
}
.price-summary span {
  margin: 0 12px;
}
.primary {
  display: inline-block;
  text-align: center;
}
button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}
.account-card {
  max-width: 780px;
}
.account-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 25px;
}
.account-actions button {
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  border-radius: 8px;
  padding: 12px;
}
.account-actions .google-button {
  font-size: 14px;
}
@media (max-width: 760px) {
  .plans {
    grid-template-columns: 1fr;
  }
}
@media (max-width: 480px) {
  nav a:not(#account-link) {
    display: none;
  }
  .paywall-box {
    padding: 18px;
  }
  .price-summary span {
    margin: 0 6px;
  }
}