@charset "UTF-8";

:root {
  --red: #e90000;
  --red-dark: #c80000;
  --black: #141414;
  --ink: #232323;
  --muted: #757575;
  --paper: #f4f4f4;
  --white: #ffffff;
  --line: #d9d9d9;
  --radius: 5px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  padding-top: 62px;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: 14px;
  line-height: 1.65;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
summary {
  font: inherit;
}

button,
a,
summary {
  -webkit-tap-highlight-color: transparent;
}

img {
  display: block;
  max-width: 100%;
}

.topbar {
  position: fixed;
  z-index: 50;
  top: 0;
  right: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 62px;
  padding: 0 18px;
  background: var(--red);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 18px;
  font-weight: 900;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: var(--radius);
  object-fit: contain;
}

.top-download {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 8px 15px;
  border-radius: var(--radius);
  color: #fff;
  background: var(--black);
  font-weight: 800;
  white-space: nowrap;
}

.hero-shell {
  position: relative;
  min-height: 650px;
  background: #1d1d1d;
}

.channel-rail {
  position: absolute;
  z-index: 6;
  top: 0;
  bottom: 0;
  left: 0;
  width: clamp(170px, 16vw, 260px);
  padding: 12px 10px;
  border-right: 1px solid #222;
  background: rgba(255, 255, 255, 0.97);
}

.channel-rail ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.channel-rail a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 54px;
  padding: 11px 12px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: #fff;
  font-size: 14px;
  font-weight: 900;
}

.channel-rail li:first-child a,
.channel-rail a:hover,
.channel-rail a:focus-visible {
  color: #fff;
  border-color: var(--red);
  background: var(--red);
}

.channel-rail small {
  font-size: 12px;
}

.rail-toggle {
  display: none;
}

.hero-stage {
  position: relative;
  min-height: 650px;
  margin-left: clamp(170px, 16vw, 260px);
  background-image: linear-gradient(90deg, rgba(0, 0, 0, 0.17), rgba(0, 0, 0, 0.04)), url("../images/bjt.jpg");
  background-position: center;
  background-size: cover;
}

.hero-stage::before {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.76) 0%, rgba(0, 0, 0, 0.58) 37%, rgba(0, 0, 0, 0.08) 72%);
  content: "";
}

.hero-copy {
  position: relative;
  z-index: 1;
  width: min(560px, 56vw);
  padding: clamp(110px, 14vw, 190px) clamp(34px, 5vw, 90px);
  color: #fff;
}

.hero-kicker,
.section-heading > p,
.download-section > div > p {
  margin: 0;
  color: var(--red);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.1em;
}

.hero-kicker {
  display: inline-block;
  padding: 5px 8px;
  color: #fff;
  background: var(--red);
  letter-spacing: 0.04em;
}

.hero-copy h1 {
  margin: 16px 0 0;
  font-size: clamp(48px, 7vw, 86px);
  line-height: 1;
  letter-spacing: -0.08em;
}

.hero-slogan {
  display: table;
  margin: 20px 0 0;
  padding: 2px 7px;
  background: var(--red);
  font-size: clamp(25px, 3vw, 38px);
  font-weight: 900;
  line-height: 1.4;
}

.hero-description {
  max-width: 500px;
  margin: 18px 0;
  color: #f4f4f4;
  font-size: 15px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 15px 0 22px;
}

.hero-tags span {
  padding: 5px 8px;
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 800;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  min-height: 48px;
  padding: 10px 18px;
  border-radius: var(--radius);
  font-weight: 900;
  transition: background 0.2s ease, transform 0.2s ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
}

.button b {
  font-size: 21px;
  line-height: 1;
}

.button-light {
  color: var(--ink);
  background: #fff;
}

.button-red {
  color: #fff;
  background: var(--red);
}

.age-label {
  display: block;
  margin-top: 16px;
  color: #dedede;
  font-size: 12px;
}

.content-wrap {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
}

.section-block {
  padding: 70px 0 0;
}

.section-heading {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 18px;
}

.section-heading h2 {
  margin: 0;
  padding-left: 12px;
  border-left: 5px solid var(--red);
  font-size: clamp(25px, 3vw, 34px);
  line-height: 1;
}

.section-heading > p {
  order: -1;
}

.section-heading > span {
  color: var(--muted);
  font-size: 13px;
}

.section-heading > a {
  margin-left: auto;
  font-size: 13px;
  font-weight: 800;
}

.schedule-table {
  border: 1px solid var(--black);
  background: #fff;
}

.schedule-row {
  display: grid;
  grid-template-columns: 100px 160px minmax(0, 1fr) 80px;
  min-height: 52px;
  border-top: 1px solid var(--black);
}

.schedule-row:first-child {
  border-top: 0;
}

.schedule-row > * {
  display: flex;
  align-items: center;
  padding: 8px 14px;
  border-left: 1px solid var(--black);
}

.schedule-row > *:first-child {
  border-left: 0;
}

.schedule-head {
  color: #fff;
  background: var(--black);
  font-size: 13px;
}

.schedule-row em {
  color: var(--red);
  font-style: normal;
  font-weight: 900;
}

.cover-strip {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
  margin-top: 26px;
}

.cover-strip figure,
.mosaic figure,
.discover-art {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--black);
  border-radius: var(--radius);
  background: #e8e8e8;
}

.cover-strip img {
  width: 100%;
  height: 150px;
  object-fit: contain;
  background: #e8e8e8;
}

.cover-strip figcaption,
.mosaic figcaption,
.discover-art figcaption {
  padding: 7px 9px;
  background: #fff;
  font-size: 12px;
  font-weight: 800;
}

.library-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.library-grid article {
  position: relative;
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 16px;
  min-height: 180px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.library-grid .number {
  position: absolute;
  top: 8px;
  right: 10px;
  color: #c8c8c8;
  font-size: 20px;
  font-weight: 900;
}

.library-grid img {
  width: 110px;
  height: 145px;
  object-fit: contain;
  background: #eee;
}

.library-grid h3,
.discover-copy h3,
.steps-grid h3 {
  margin: 7px 0;
  font-size: 16px;
}

.library-grid p,
.discover-copy p,
.steps-grid p,
.editorial > p,
.review-card p {
  margin: 0;
  color: #676767;
  font-size: 13px;
}

.library-grid a {
  display: inline-block;
  margin-top: 10px;
  color: var(--red);
  font-size: 13px;
  font-weight: 900;
}

.discover-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}

.discover-copy .section-heading {
  display: block;
}

.discover-copy .section-heading h2 {
  margin-top: 8px;
}

.discover-copy ol {
  display: grid;
  gap: 13px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.discover-copy li {
  display: flex;
  gap: 14px;
}

.discover-copy li > b {
  display: grid;
  flex: 0 0 34px;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--red);
  font-size: 13px;
}

.discover-copy h3 {
  margin: 0 0 3px;
}

.discover-art {
  min-height: 315px;
}

.discover-art img {
  width: 100%;
  height: 275px;
  object-fit: contain;
  background: #eee;
}

.discover-art figcaption {
  color: #fff;
  background: var(--black);
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.steps-grid article {
  padding: 17px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.steps-grid b {
  color: #bdbdbd;
  font-size: 26px;
  line-height: 1;
}

.faq-list {
  display: grid;
  gap: 8px;
}

.faq-list details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.faq-list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 52px;
  padding: 10px 15px;
  cursor: pointer;
  font-weight: 800;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary span {
  color: var(--red);
  font-size: 20px;
}

.faq-list details[open] summary span {
  transform: rotate(45deg);
}

.faq-list p {
  margin: 0;
  padding: 0 15px 15px;
  color: var(--muted);
  font-size: 13px;
}

.faq-list p a {
  color: var(--red);
  text-decoration: underline;
}

.mosaic {
  display: grid;
  grid-template-columns: 1.35fr 1fr 1fr;
  grid-template-rows: repeat(2, 160px);
  gap: 10px;
}

.mosaic-main {
  grid-row: span 2;
}

.mosaic img {
  width: 100%;
  height: calc(100% - 32px);
  object-fit: contain;
  background: #eee;
}

.mosaic-main img {
  height: calc(100% - 32px);
}

.ideas-section {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 30px;
  padding-bottom: 70px;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0;
}

.tag-cloud span {
  padding: 5px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  font-size: 12px;
}

.editorial {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.editorial .hero-kicker {
  color: var(--red);
  background: transparent;
  padding: 0;
}

.editorial h2 {
  margin: 9px 0;
  font-size: 22px;
}

.editorial > div {
  display: flex;
  align-items: center;
  gap: 13px;
  margin-top: 15px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-weight: 800;
}

.editorial img {
  width: 58px;
  height: 58px;
  border-radius: var(--radius);
  object-fit: contain;
  background: #eee;
}

.voices-section {
  padding: 54px 0;
  color: #fff;
  background: linear-gradient(rgba(15, 15, 15, 0.92), rgba(15, 15, 15, 0.92)), url("../images/bjt.jpg") center / cover;
}

.section-heading-dark h2,
.section-heading-dark > span {
  color: #fff;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.review-card {
  display: flex;
  gap: 12px;
  min-height: 150px;
  padding: 18px 18px 40px;
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  position: relative;
}

.review-card > img {
  width: 42px;
  height: 42px;
  border-radius: 50%;
}

.review-card > div {
  flex: 1;
  min-width: 0;
}

.review-card header {
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.rating {
  color: var(--red);
  font-size: 12px;
  white-space: nowrap;
}

.review-card time {
  position: absolute;
  right: 18px;
  bottom: 14px;
  color: #999;
  font-size: 12px;
}

.download-section {
  padding: 65px 20px;
  text-align: center;
  background: #fff;
}

.download-section > div {
  display: grid;
  justify-items: center;
  gap: 10px;
}

.download-section > div > p {
  color: var(--red);
}

.download-section h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 42px);
}

.download-section span {
  color: var(--muted);
}

.download-section .button {
  margin-top: 10px;
}

.site-footer {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 25px;
  padding: 28px max(24px, calc((100% - 1200px) / 2));
  border-top: 1px solid var(--line);
  background: #fff;
}

.footer-brand {
  color: var(--ink);
  font-size: 16px;
}

.footer-brand img {
  width: 30px;
  height: 30px;
}

.site-footer p,
.site-footer small {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.site-footer ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 15px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
}

.back-top {
  position: fixed;
  z-index: 20;
  right: 20px;
  bottom: 20px;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 50%;
  color: #fff;
  background: var(--black);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: 0.2s ease;
}

.back-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid #ff8b8b;
  outline-offset: 3px;
}

@media (max-width: 960px) {
  .content-wrap {
    width: min(1200px, calc(100% - 32px));
  }

  .hero-shell,
  .hero-stage {
    min-height: 610px;
  }

  .library-grid {
    grid-template-columns: 1fr;
  }

  .library-grid article {
    grid-template-columns: 130px 1fr;
  }

  .library-grid img {
    width: 130px;
    height: 145px;
  }

  .review-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 700px) {
  body {
    padding-top: 56px;
  }

  .topbar {
    height: 56px;
    padding: 0 12px;
  }

  .brand {
    gap: 7px;
    font-size: 16px;
  }

  .brand img {
    width: 30px;
    height: 30px;
  }

  .top-download {
    min-height: 34px;
    padding: 7px 10px;
    font-size: 12px;
  }

  .hero-shell {
    min-height: 660px;
  }

  .channel-rail {
    top: 0;
    right: 0;
    bottom: auto;
    width: auto;
    padding: 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .rail-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    min-height: 46px;
    padding: 10px 14px;
    border: 0;
    color: var(--ink);
    background: #fff;
    font-weight: 900;
  }

  .channel-rail ul {
    display: none;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
    padding: 8px 12px 12px;
    background: #fff;
  }

  .channel-rail.is-open ul {
    display: grid;
  }

  .channel-rail a {
    min-height: 42px;
    padding: 7px 9px;
    border-width: 1px;
    font-size: 12px;
  }

  .hero-stage {
    min-height: 660px;
    margin-left: 0;
    padding-top: 46px;
    background-position: 58% center;
  }

  .hero-stage::before {
    background: rgba(0, 0, 0, 0.66);
  }

  .hero-copy {
    width: 100%;
    padding: 150px 25px 60px;
    text-align: center;
  }

  .hero-copy h1 {
    font-size: 57px;
  }

  .hero-slogan {
    font-size: 27px;
  }

  .hero-tags {
    justify-content: center;
  }

  .age-label {
    text-align: center;
  }

  .section-block {
    padding-top: 50px;
  }

  .section-heading {
    display: block;
  }

  .section-heading > p {
    margin-bottom: 8px;
  }

  .section-heading > span,
  .section-heading > a {
    display: block;
    margin: 10px 0 0;
  }

  .schedule-table {
    overflow-x: auto;
  }

  .schedule-row {
    min-width: 680px;
  }

  .cover-strip {
    display: flex;
    width: calc(100% + 32px);
    margin: 26px -16px 0;
    padding: 0 16px 10px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
  }

  .cover-strip figure {
    flex: 0 0 180px;
    scroll-snap-align: start;
  }

  .discover-section,
  .ideas-section {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .steps-grid {
    grid-template-columns: 1fr 1fr;
  }

  .mosaic {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 250px 140px 140px;
  }

  .mosaic-main {
    grid-column: span 2;
    grid-row: auto;
  }

  .review-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    align-items: center;
    flex-direction: column;
    padding: 25px 16px;
    text-align: center;
  }

  .site-footer ul {
    gap: 12px;
  }

  .back-top {
    right: 14px;
    bottom: 14px;
  }
}

@media (max-width: 390px) {
  .hero-copy h1 {
    font-size: 50px;
  }

  .hero-slogan {
    font-size: 24px;
  }

  .steps-grid {
    grid-template-columns: 1fr;
  }

  .library-grid article {
    grid-template-columns: 100px 1fr;
    gap: 12px;
  }

  .library-grid img {
    width: 100px;
  }
}