/* ===== Brand: B = #3B59FF (logo blue) ===== */
:root {
  --color-brand: #3B59FF;
  --color-brand-dark: #2948E8;
  --color-brand-soft: rgba(59, 89, 255, 0.08);

  --color-hero-bg: #3B59FF;
  --color-page-bg: #FFFFFF;

  --color-text-dark: #222222;
  --color-text-body: #4A4A4A;
  --color-text-muted: #737373;
  --color-border-light: #E8E8E8;

  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Typography scale */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-md: 1.125rem;
  --text-lg: 1.25rem;
  --text-section: clamp(1.5rem, 2.5vw, 2rem);
  --text-hero: clamp(2rem, 5vw, 3rem);

  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;

  --leading-tight: 1.35;
  --leading-snug: 1.55;
  --leading-normal: 1.75;
  --leading-relaxed: 1.85;

  --tracking-en: 0.18em;

  --header-height: 72px;
  --container-max: 1200px;
  --section-padding: 100px;
  --transition: 0.3s ease;
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--color-text-body);
  background-color: var(--color-page-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 10000;
  padding: 10px 18px;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: #FFFFFF;
  background: var(--color-brand);
  border-radius: 6px;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 16px;
  outline: 2px solid #FFFFFF;
  outline-offset: 2px;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}

strong {
  color: var(--color-text-dark);
  font-weight: var(--font-semibold);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: var(--section-padding) 0;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  letter-spacing: 0;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
}

/* Hero buttons — follow hero blue bg */
.hero .btn--primary {
  background: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.5);
}

.hero .btn--primary:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: #FFFFFF;
}

.hero .btn--outline {
  background: transparent;
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.5);
}

.hero .btn--outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: #FFFFFF;
}

/* Content area buttons — B color fill */
.btn--primary {
  background: var(--color-brand);
  color: #FFFFFF;
  border-color: var(--color-brand);
}

.btn--primary:hover {
  background: var(--color-brand-dark);
  border-color: var(--color-brand-dark);
}

.btn--full {
  width: 100%;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: transparent;
  transition: background var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.header--past-hero {
  background: #FFFFFF;
  border-bottom: 1px solid var(--color-border-light);
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.nav__logo-img {
  height: 36px;
  width: auto;
  object-fit: contain;
  border-radius: 6px;
  flex-shrink: 0;
}

.nav__logo-text {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  letter-spacing: 0;
  color: #FFFFFF;
  white-space: nowrap;
}

.header--past-hero .nav__logo-text {
  color: var(--color-text-dark);
}

.nav__end {
  display: flex;
  align-items: center;
  gap: 40px;
}

.nav__tools {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

button.nav__lang {
  font-family: inherit;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
}

.nav__lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 32px;
  padding: 0 12px;
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.38);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.06);
  transition: background var(--transition), border-color var(--transition), color var(--transition);
  flex-shrink: 0;
}

.nav__lang:hover {
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.65);
  background: rgba(255, 255, 255, 0.12);
}

.header--past-hero .nav__lang {
  color: var(--color-text-body);
  border-color: var(--color-border-light);
  background: var(--color-page-bg);
}

.header--past-hero .nav__lang:hover {
  color: var(--color-brand);
  border-color: rgba(59, 89, 255, 0.35);
  background: var(--color-brand-soft);
}

html[lang="en"] body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: 40px;
  list-style: none;
}

.nav__link {
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  letter-spacing: 0;
  color: rgba(255, 255, 255, 0.88);
  position: relative;
}

.header--past-hero .nav__link {
  color: var(--color-text-muted);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: #FFFFFF;
  transition: width var(--transition);
}

.header--past-hero .nav__link::after {
  background: var(--color-brand);
}

.nav__link:hover,
.nav__link.active {
  color: #FFFFFF;
  font-weight: var(--font-medium);
}

.header--past-hero .nav__link:hover,
.header--past-hero .nav__link.active {
  color: var(--color-brand);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 100%;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #FFFFFF;
  transition: all var(--transition);
}

.header--past-hero .nav__toggle span {
  background: var(--color-text-dark);
}

.nav__toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav__toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav__toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero — B color fill ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: #FFFFFF;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: var(--color-hero-bg);
}

.hero__bg-img {
  display: none;
}

.hero__overlay {
  display: none;
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
}

.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: calc(var(--header-height) + 56px) 24px 96px;
}

.hero__tag {
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  letter-spacing: var(--tracking-en);
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 28px;
}

.hero__title {
  font-size: var(--text-hero);
  font-weight: var(--font-semibold);
  letter-spacing: 0.02em;
  line-height: var(--leading-tight);
  margin-bottom: 28px;
  color: #FFFFFF;
}

.hero__slogan {
  font-size: 1.3125rem;
  font-weight: var(--font-normal);
  color: rgba(255, 255, 255, 0.85);
  letter-spacing: 0.04em;
  line-height: 1.95;
  margin-bottom: 52px;
  max-width: 32em;
  margin-left: auto;
  margin-right: auto;
}

.hero__actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero__scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.55);
  font-size: var(--text-xs);
  font-weight: var(--font-normal);
  letter-spacing: 0;
  animation: bounce 2s infinite;
}

.hero__scroll:hover {
  color: #FFFFFF;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ===== Section Header (white area — B color accents) ===== */
.section__header {
  text-align: center;
  margin-bottom: 56px;
}

.section__label {
  display: block;
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  letter-spacing: var(--tracking-en);
  text-transform: uppercase;
  color: var(--color-brand);
  margin-bottom: 12px;
}

.section__title {
  font-size: var(--text-section);
  font-weight: var(--font-semibold);
  letter-spacing: 0;
  line-height: var(--leading-tight);
  margin-bottom: 16px;
  color: var(--color-text-dark);
}

.section__divider {
  width: 48px;
  height: 2px;
  background: var(--color-brand);
  margin: 0 auto;
}

/* ===== Content sections — soft blue tint ===== */
.about,
.vision,
.contact {
  position: relative;
  background: linear-gradient(180deg, #F8FAFF 0%, #FFFFFF 100%);
  overflow: hidden;
}

.about::before,
.vision::before,
.contact::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -80px;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle, rgba(59, 89, 255, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.about::after,
.vision::after,
.contact::after {
  content: '';
  position: absolute;
  bottom: -100px;
  left: -60px;
  width: 320px;
  height: 320px;
  background: radial-gradient(circle, rgba(59, 89, 255, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.about .container,
.vision .container,
.contact .container {
  position: relative;
  z-index: 1;
}

.vision,
.contact {
  border-top: 1px solid var(--color-border-light);
}

/* Shared panel — vision intro, about block, contact intro */
.section-panel {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(59, 89, 255, 0.12);
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(59, 89, 255, 0.06);
}

.section-intro {
  max-width: 720px;
  margin: 0 auto 32px;
  padding: 20px 32px;
  text-align: center;
}

.section-intro__text {
  font-size: var(--text-md);
  font-weight: var(--font-medium);
  line-height: var(--leading-relaxed);
  color: var(--color-text-dark);
  margin: 0;
}

/* ===== About ===== */
.about__panel {
  padding: 40px 48px;
}

.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px 56px;
  align-items: center;
}

.about__visual {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  background: var(--color-page-bg);
  box-shadow: 0 2px 12px rgba(59, 89, 255, 0.04);
}

.about__image {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
}

.about__text {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.about__text p {
  color: var(--color-text-body);
  margin-bottom: 16px;
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-relaxed);
}

.about__text-last {
  margin-bottom: 0 !important;
}

.about__lead {
  font-size: var(--text-md);
  line-height: var(--leading-relaxed);
  color: var(--color-text-dark) !important;
  margin-bottom: 18px !important;
  font-weight: var(--font-medium);
  padding-bottom: 18px;
  border-bottom: 1px solid var(--color-border-light);
}

/* ===== Vision ===== */
.vision.section {
  padding-top: 48px;
  padding-bottom: 48px;
}

.vision .section__header {
  margin-bottom: 32px;
}

.vision__grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.vision-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 28px 24px 24px;
  background: var(--color-page-bg);
  border-radius: 16px;
  border: 1px solid var(--color-border-light);
  overflow: hidden;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.vision-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-brand) 0%, rgba(59, 89, 255, 0.3) 100%);
  opacity: 0;
  transition: opacity var(--transition);
}

.vision-card:hover {
  transform: translateY(-4px);
  border-color: rgba(59, 89, 255, 0.25);
  box-shadow: 0 12px 32px rgba(59, 89, 255, 0.1);
}

.vision-card:hover::before {
  opacity: 1;
}

.vision-card__num {
  position: absolute;
  top: 12px;
  right: 16px;
  font-size: 3.5rem;
  font-weight: var(--font-semibold);
  line-height: 1;
  color: var(--color-brand);
  opacity: 0.1;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
  user-select: none;
}

.vision-card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  background: linear-gradient(135deg, rgba(59, 89, 255, 0.12) 0%, rgba(59, 89, 255, 0.04) 100%);
  border-radius: 14px;
  color: var(--color-brand);
}

.vision-card__title {
  font-size: var(--text-md);
  font-weight: var(--font-semibold);
  color: var(--color-text-dark);
  margin-bottom: 8px;
  line-height: var(--leading-snug);
}

.vision-card__tagline {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  color: var(--color-brand);
  background: var(--color-brand-soft);
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 12px;
  line-height: 1.4;
}

.vision-card__desc {
  font-size: var(--text-sm);
  font-weight: var(--font-normal);
  color: var(--color-text-body);
  line-height: var(--leading-relaxed);
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--color-border-light);
}

/* ===== Contact ===== */
.contact__intro.section-intro {
  max-width: none;
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}

.contact__intro .section-intro__text {
  white-space: nowrap;
}

html[lang="en"] .contact__intro .section-intro__text {
  white-space: normal;
}

.contact__cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  max-width: 880px;
  margin: 0 auto;
}

.contact-card {
  padding: 36px 32px;
  background: var(--color-page-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 16px;
  text-align: center;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.contact-card:hover {
  transform: translateY(-4px);
  border-color: rgba(59, 89, 255, 0.25);
  box-shadow: 0 12px 32px rgba(59, 89, 255, 0.1);
}

.contact-card__icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(59, 89, 255, 0.12) 0%, rgba(59, 89, 255, 0.04) 100%);
  border-radius: 14px;
  color: var(--color-brand);
}

.contact-card__title {
  font-size: var(--text-md);
  font-weight: var(--font-semibold);
  color: var(--color-text-dark);
  margin-bottom: 12px;
}

.contact-card__text {
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  color: var(--color-text-body);
  line-height: var(--leading-relaxed);
  margin: 0;
}

.contact-card__text a {
  color: var(--color-brand);
}

.contact-card__text a:hover {
  color: var(--color-brand-dark);
}

/* ===== Footer ===== */
.footer {
  padding: 40px 0;
  border-top: 1px solid var(--color-border-light);
  background: var(--color-page-bg);
}

.footer__inner {
  text-align: center;
}

.footer__links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 12px;
}

.footer__links a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.footer__links a:hover {
  color: var(--color-brand);
}

.footer__sep {
  color: var(--color-border-light);
  font-size: var(--text-sm);
}

.footer__copyright {
  font-size: var(--text-sm);
  font-weight: var(--font-normal);
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

.footer__legal {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: var(--text-xs);
  font-weight: var(--font-normal);
  color: #BBBBBB;
}

.footer__legal a {
  color: #BBBBBB;
  transition: color var(--transition);
}

.footer__legal a:hover {
  color: var(--color-text-muted);
}

/* ===== Error page ===== */
.error-page {
  min-height: calc(100vh - var(--header-height));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: calc(var(--header-height) + 48px) 0 80px;
}

.error-page__content {
  text-align: center;
  max-width: 480px;
}

.error-page__code {
  font-size: clamp(4rem, 12vw, 6rem);
  font-weight: var(--font-semibold);
  line-height: 1;
  color: var(--color-brand);
  opacity: 0.15;
  margin-bottom: 16px;
}

.error-page__title {
  font-size: var(--text-section);
  font-weight: var(--font-semibold);
  color: var(--color-text-dark);
  margin-bottom: 16px;
}

.error-page__desc {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-text-body);
  margin-bottom: 32px;
}

/* ===== Legal pages ===== */
.legal-page-body {
  background: var(--color-page-bg);
}

.legal {
  padding-top: calc(var(--header-height) + 48px);
  padding-bottom: 80px;
}

.legal__content {
  max-width: 760px;
  margin: 0 auto;
}

.legal__title {
  font-size: var(--text-section);
  font-weight: var(--font-semibold);
  color: var(--color-text-dark);
  margin-bottom: 12px;
  text-align: center;
}

.legal__meta {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: 32px;
}

.legal__intro {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-text-body);
  margin-bottom: 40px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border-light);
}

.legal__section {
  margin-bottom: 32px;
}

.legal__section h2 {
  font-size: var(--text-md);
  font-weight: var(--font-semibold);
  color: var(--color-text-dark);
  margin-bottom: 12px;
}

.legal__section p {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-body);
  margin-bottom: 12px;
}

.legal__section ul {
  margin: 8px 0 12px 1.25em;
  padding: 0;
}

.legal__section li {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-body);
  margin-bottom: 8px;
}

.legal__section a {
  color: var(--color-brand);
}

.legal__section a:hover {
  color: var(--color-brand-dark);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  :root {
    --section-padding: 80px;
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 40px;
    align-items: start;
  }

  .about__text {
    justify-content: flex-start;
  }

  .about__panel {
    padding: 28px 24px;
  }

  .vision.section {
    padding-top: 40px;
    padding-bottom: 40px;
  }

  .vision .section__header {
    margin-bottom: 24px;
  }

  .vision__grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .section-intro {
    margin-bottom: 24px;
    padding: 18px 24px;
  }

  .contact__intro .section-intro__text {
    white-space: normal;
  }

  .contact__cards {
    grid-template-columns: 1fr;
    max-width: 480px;
  }

  .about__visual {
    max-width: 560px;
    margin: 0 auto;
    width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: 64px;
    --header-height: 64px;
  }

  .nav__end {
    gap: 0;
  }

  .nav__tools {
    gap: 10px;
  }

  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: #FFFFFF;
    padding: 16px 0;
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }

  .nav__menu.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav__menu li {
    width: 100%;
  }

  .nav__link {
    display: block;
    padding: 16px 24px;
    text-align: center;
    color: var(--color-text-body);
  }

  .nav__link::after {
    display: none;
  }

  .nav__logo-text {
    font-size: var(--text-xs);
  }

  .hero__title {
    letter-spacing: 0.02em;
  }

  .hero__slogan {
    font-size: var(--text-base);
    letter-spacing: 0.02em;
    line-height: 1.95;
  }

  .hero__actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }
}