:root {
  --catalog-ink: #183127;
  --catalog-muted: #6a7a71;
  --catalog-green: #20c768;
  --catalog-green-dark: #128648;
  --catalog-green-soft: #e8f9ee;
  --catalog-paper: #fff;
  --catalog-warm: #f8faf7;
  --catalog-line: #dfe9e2;
  --catalog-shadow: 0 18px 52px rgba(25, 66, 39, .09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--catalog-ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, #f1faf4 0, #fbfcf9 390px, var(--catalog-warm) 100%);
}
button, a { font: inherit; }
button { cursor: pointer; }
a { color: inherit; }
a:focus-visible, button:focus-visible { outline: 3px solid rgba(32, 199, 104, .38); outline-offset: 3px; }

.catalog-topbar, .catalog-intro, .catalog-library, .catalog-custom,
.catalog-video-section, .catalog-final-cta, .catalog-footer {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.catalog-topbar { display: flex; min-height: 80px; align-items: center; justify-content: space-between; }
.catalog-brand { display: inline-flex; align-items: center; gap: 11px; color: var(--catalog-ink); font-size: 22px; font-weight: 900; letter-spacing: -.04em; text-decoration: none; }
.catalog-brand-mark { display: grid; width: 42px; height: 42px; place-items: center; border-radius: 13px; color: #fff; background: linear-gradient(135deg, #6c8dff, #8cd5ff); box-shadow: 0 8px 20px rgba(80, 120, 255, .24); font-size: 16px; letter-spacing: 0; }
.catalog-nav { display: flex; align-items: center; gap: 24px; }
.catalog-nav a { color: #5c6c63; font-size: 14px; font-weight: 780; text-decoration: none; }
.catalog-nav a:hover, .catalog-nav a.is-current { color: var(--catalog-green-dark); }
.catalog-nav .catalog-login { padding: 9px 17px; border: 1px solid var(--catalog-line); border-radius: 999px; color: var(--catalog-ink); background: rgba(255,255,255,.82); }

.catalog-kicker { color: var(--catalog-green-dark); font-size: 12px; font-weight: 900; letter-spacing: .1em; }
.catalog-intro { display: flex; align-items: flex-end; justify-content: space-between; gap: 40px; padding: 72px 0 58px; }
.catalog-intro h1 { margin: 12px 0 13px; font-size: clamp(38px, 5vw, 60px); line-height: 1.12; letter-spacing: -.055em; }
.catalog-intro p { max-width: 760px; margin: 0; color: var(--catalog-muted); font-size: 17px; line-height: 1.8; }
.catalog-member-link { flex: 0 0 auto; padding-bottom: 7px; color: var(--catalog-green-dark); font-weight: 850; text-decoration: none; }
.catalog-member-link span { display: inline-block; transition: transform 160ms ease; }
.catalog-member-link:hover span { transform: translateX(4px); }

.catalog-library { padding: 45px 0 92px; border-top: 1px solid var(--catalog-line); }
.catalog-section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; margin-bottom: 28px; }
.catalog-section-heading h2, .catalog-custom h2, .catalog-video-heading h2, .catalog-final-cta h2 { margin: 10px 0 0; font-size: clamp(29px, 3.6vw, 43px); line-height: 1.2; letter-spacing: -.045em; }
.catalog-section-heading > p { margin: 0; color: var(--catalog-muted); font-size: 13px; font-weight: 750; }
.catalog-grade-tabs { display: flex; gap: 5px; padding: 5px; border: 1px solid var(--catalog-line); border-radius: 999px; background: #fff; box-shadow: 0 8px 24px rgba(38,72,49,.06); }
.catalog-grade-tabs button { min-height: 39px; padding: 0 16px; border: 0; border-radius: 999px; color: var(--catalog-muted); background: transparent; font-weight: 820; white-space: nowrap; }
.catalog-grade-tabs button:hover { color: var(--catalog-green-dark); background: #f3faf5; }
.catalog-grade-tabs button.is-active { color: #fff; background: var(--catalog-green); }
.catalog-status-dot { display: inline-block; width: 8px; height: 8px; margin-right: 6px; border-radius: 50%; background: var(--catalog-green); box-shadow: 0 0 0 4px rgba(32,199,104,.12); }
.catalog-book-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; }
.catalog-book-card { min-width: 0; padding: 24px; border: 1px solid var(--catalog-line); border-radius: 25px; background: rgba(255,255,255,.92); box-shadow: var(--catalog-shadow); }
.catalog-book-header { display: grid; grid-template-columns: 112px minmax(0, 1fr); gap: 21px; align-items: center; min-height: 166px; padding: 3px 4px 21px; border-bottom: 1px solid var(--catalog-line); }
.catalog-book-header img { display: block; width: 105px; height: 146px; border-radius: 5px 10px 10px 5px; object-fit: cover; box-shadow: 0 12px 24px rgba(24,49,39,.18); }
.catalog-series-name { color: var(--catalog-green-dark); font-size: 12px; font-weight: 900; }
.catalog-book-header h3 { margin: 7px 0 7px; font-size: 23px; line-height: 1.35; letter-spacing: -.025em; }
.catalog-book-header p { margin: 0 0 14px; color: var(--catalog-muted); font-size: 13px; }
.catalog-free-note { display: inline-flex; align-items: center; gap: 7px; color: #147443; font-size: 12px; font-weight: 850; }
.catalog-free-note i { width: 8px; height: 8px; border-radius: 50%; background: var(--catalog-green); }
.catalog-free-note.is-locked { color: #7d8a83; }
.catalog-free-note.is-locked i { background: #aeb9b2; }
.catalog-unit-list { display: grid; gap: 8px; padding-top: 16px; }
.catalog-unit { display: grid; grid-template-columns: auto minmax(0,1fr) auto; align-items: center; gap: 13px; width: 100%; min-width: 0; min-height: 72px; padding: 12px 14px; border: 1px solid var(--catalog-line); border-radius: 15px; color: var(--catalog-ink); background: #fff; text-align: left; text-decoration: none; transition: transform 150ms ease, border-color 150ms ease, box-shadow 150ms ease; }
.catalog-unit:hover { transform: translateY(-1px); box-shadow: 0 8px 20px rgba(29,66,41,.07); }
.catalog-unit-copy { display: flex; min-width: 0; flex-direction: column; }
.catalog-unit-copy small { color: #819087; font-size: 9px; font-weight: 900; letter-spacing: .1em; text-transform: uppercase; }
.catalog-unit-copy strong { margin-top: 3px; overflow: hidden; font-size: 14px; line-height: 1.3; text-overflow: ellipsis; white-space: nowrap; }
.catalog-unit-copy em { margin-top: 4px; overflow: hidden; color: var(--catalog-muted); font-size: 10px; font-style: normal; text-overflow: ellipsis; white-space: nowrap; }
.catalog-unit > b { color: #849089; font-size: 10px; white-space: nowrap; }
.catalog-unit-public { grid-template-columns: auto minmax(0,1fr) auto; min-height: 88px; border-color: rgba(32,199,104,.4); background: linear-gradient(135deg, #effcf4, #fff); }
.catalog-unit-public > b { color: var(--catalog-green-dark); font-size: 11px; }
.catalog-unit-status { padding: 5px 8px; border-radius: 999px; color: #08773a; background: #dff7e8; font-size: 9px; font-weight: 900; white-space: nowrap; }
.catalog-unit-locked { opacity: .82; }
.catalog-unit-lock { display: grid; width: 29px; height: 29px; place-items: center; border-radius: 10px; color: #87948c; background: #eff3f0; font-size: 15px; }

.catalog-custom { display: grid; grid-template-columns: minmax(0, .95fr) minmax(380px, 1.05fr); gap: clamp(50px, 8vw, 110px); align-items: center; padding: 92px clamp(28px, 6vw, 72px); border-radius: 30px; color: #fff; background: linear-gradient(130deg, #173e2d, #176b44); box-shadow: var(--catalog-shadow); }
.catalog-custom .catalog-kicker, .catalog-final-cta .catalog-kicker { color: #8ee7b3; }
.catalog-custom h2 { color: #fff; }
.catalog-custom-copy > p { margin: 20px 0 29px; color: rgba(255,255,255,.72); font-size: 16px; line-height: 1.8; }
.catalog-primary-action { display: inline-flex; min-height: 50px; padding: 0 23px; align-items: center; justify-content: center; border: 0; border-radius: 14px; color: #fff; background: var(--catalog-green); box-shadow: 0 13px 28px rgba(32,199,104,.2); font-weight: 850; text-decoration: none; transition: transform 150ms ease, background 150ms ease; }
.catalog-primary-action:hover { background: #18b95e; transform: translateY(-2px); }
.catalog-custom-flow { display: grid; gap: 8px; }
.catalog-custom-flow article { display: grid; grid-template-columns: 44px 1fr; gap: 14px; align-items: center; padding: 18px; border: 1px solid rgba(255,255,255,.14); border-radius: 17px; background: rgba(255,255,255,.08); }
.catalog-custom-flow article > span { display: grid; width: 44px; height: 44px; place-items: center; border-radius: 13px; color: #c3f5d7; background: rgba(32,199,104,.18); font-size: 12px; font-weight: 900; }
.catalog-custom-flow strong, .catalog-custom-flow small { display: block; }
.catalog-custom-flow strong { font-size: 15px; }
.catalog-custom-flow small { margin-top: 5px; color: rgba(255,255,255,.58); line-height: 1.5; }
.catalog-custom-flow > i { justify-self: center; color: #74d79d; font-style: normal; }

.catalog-video-section { padding: 105px 0 100px; }
.catalog-video-heading { max-width: 760px; margin: 0 auto 34px; text-align: center; }
.catalog-video-heading p { margin: 15px 0 0; color: var(--catalog-muted); font-size: 16px; line-height: 1.75; }
.catalog-video-card { margin: 0; border: 1px solid var(--catalog-line); border-radius: 26px; background: #fff; box-shadow: 0 24px 70px rgba(31,63,43,.12); overflow: hidden; }
.catalog-video-frame { position: relative; aspect-ratio: 16/9; overflow: hidden; background: #dce9e0; }
.catalog-video-frame video { display: block; width: 100%; height: 100%; object-fit: cover; }
.catalog-video-play { position: absolute; inset: 0; display: flex; gap: 12px; align-items: center; justify-content: center; border: 0; color: #fff; background: linear-gradient(rgba(15,43,28,.08), rgba(15,43,28,.34)); font-size: 17px; }
.catalog-video-play span { display: grid; width: 58px; height: 58px; place-items: center; border-radius: 50%; color: #17683c; background: #fff; box-shadow: 0 10px 28px rgba(0,0,0,.2); text-indent: 3px; }
.catalog-video-card.is-playing .catalog-video-play { display: none; }
.catalog-video-card figcaption { padding: 16px 20px; color: var(--catalog-muted); font-size: 13px; text-align: center; }
.catalog-video-card figcaption span { color: var(--catalog-green-dark); font-weight: 900; }

.catalog-final-cta { display: flex; align-items: center; justify-content: space-between; gap: 45px; margin-bottom: 85px; padding: 48px 54px; border-radius: 25px; color: #fff; background: #1b3529; }
.catalog-final-cta h2 { max-width: 790px; color: #fff; font-size: clamp(27px, 3.4vw, 39px); }
.catalog-final-cta .catalog-primary-action { flex: 0 0 auto; }

.catalog-footer { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 20px; padding: 28px 0 42px; border-top: 1px solid var(--catalog-line); color: var(--catalog-muted); font-size: 13px; }
.catalog-footer .catalog-brand { font-size: 18px; }
.catalog-footer .catalog-brand-mark { width: 34px; height: 34px; border-radius: 10px; font-size: 12px; }
.catalog-footer p { margin: 0; text-align: center; }
.catalog-footer > span { justify-self: end; }

.catalog-dialog { width: min(470px, calc(100% - 30px)); padding: 38px; border: 0; border-radius: 25px; color: var(--catalog-ink); background: #fff; box-shadow: 0 30px 90px rgba(16,48,29,.25); text-align: center; }
.catalog-dialog::backdrop { background: rgba(17,39,28,.52); backdrop-filter: blur(5px); }
.catalog-dialog-close { position: absolute; top: 14px; right: 16px; width: 34px; height: 34px; border: 0; border-radius: 50%; color: #728078; background: #f0f4f1; font-size: 24px; line-height: 1; }
.catalog-dialog-icon { display: grid; width: 55px; height: 55px; margin: 0 auto 17px; place-items: center; border-radius: 17px; background: var(--catalog-green-soft); font-size: 24px; }
.catalog-dialog h2 { margin: 10px 0 12px; font-size: 28px; letter-spacing: -.035em; }
.catalog-dialog p { margin: 0; color: var(--catalog-muted); line-height: 1.7; }
.catalog-dialog ul { display: grid; gap: 9px; margin: 24px 0; padding: 18px 20px; border-radius: 16px; color: #4f6258; background: #f6faf7; font-size: 14px; text-align: left; list-style: "✓  "; }
.catalog-dialog li::marker { color: var(--catalog-green); font-weight: 900; }
.catalog-dialog .catalog-primary-action { width: 100%; }
.catalog-dialog-secondary { margin-top: 12px; padding: 9px 15px; border: 0; color: var(--catalog-muted); background: transparent; font-weight: 750; }

@media (max-width: 900px) {
  .catalog-book-grid { grid-template-columns: 1fr; }
  .catalog-custom { grid-template-columns: 1fr; }
  .catalog-final-cta { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 680px) {
  .catalog-topbar, .catalog-intro, .catalog-library, .catalog-custom, .catalog-video-section, .catalog-final-cta, .catalog-footer { width: min(100% - 28px, 560px); }
  .catalog-topbar { min-height: 70px; }
  .catalog-brand { font-size: 19px; }
  .catalog-brand-mark { width: 38px; height: 38px; }
  .catalog-nav { gap: 12px; }
  .catalog-nav a { font-size: 12px; }
  .catalog-nav .catalog-login { display: inline-flex; }
  .catalog-intro { align-items: flex-start; flex-direction: column; gap: 22px; padding: 50px 0 40px; }
  .catalog-intro h1 { font-size: clamp(36px, 10vw, 48px); }
  .catalog-intro p { font-size: 15px; }
  .catalog-section-heading { align-items: flex-start; flex-direction: column; gap: 13px; }
  .catalog-grade-tabs { max-width: 100%; overflow-x: auto; }
  .catalog-library { padding-top: 36px; padding-bottom: 70px; }
  .catalog-book-card { padding: 17px; border-radius: 21px; }
  .catalog-book-header { grid-template-columns: 88px 1fr; gap: 16px; min-height: 137px; }
  .catalog-book-header img { width: 82px; height: 114px; }
  .catalog-book-header h3 { font-size: 18px; }
  .catalog-unit { grid-template-columns: auto minmax(0,1fr); }
  .catalog-unit > b { display: none; }
  .catalog-unit-copy strong { font-size: 13px; }
  .catalog-unit-public { grid-template-columns: 1fr; align-items: start; gap: 7px; }
  .catalog-unit-public .catalog-unit-status { justify-self: start; }
  .catalog-custom { padding: 48px 23px; border-radius: 24px; }
  .catalog-video-section { padding: 78px 0; }
  .catalog-video-play strong { font-size: 14px; }
  .catalog-video-play span { width: 50px; height: 50px; }
  .catalog-final-cta { margin-bottom: 55px; padding: 33px 24px; }
  .catalog-footer { grid-template-columns: 1fr auto; }
  .catalog-footer p { display: none; }
  .catalog-footer > span { font-size: 10px; }
  .catalog-dialog { padding: 34px 24px 27px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}