/* ===== Module 1: Nav ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--header-height);
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.2s;
}

.site-header.is-sticky { box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  max-width: 1920px;
  margin: 0 auto;
  width: var(--container-width);
}

.header-brand { display: flex; align-items: center; gap: 48px; }
.login-dropdown .btn-primary--sm{
  width: 96px;
}
.logo img { height: 31px; width: auto; }

.site-nav { display: flex; align-items: center; gap: 48px; }
.site-nav a { font-size: 16px; line-height: 22px; }
.site-nav a:hover { color: var(--color-primary); }

.site-nav a.is-active {
  position: relative;
  color: var(--color-primary-text);
  font-weight: 900;
}

.site-nav a.is-active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -21px;
  transform: translateX(-50%);
  width: 32px;
  height: 4px;
  border-radius: 2px;
  background: var(--color-primary-text);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px; height: 32px;
  background: none; border: none; cursor: pointer; padding: 4px;
}

.menu-toggle span {
  display: block; width: 100%; height: 2px;
  background: var(--color-text-1); border-radius: 1px;
}

/* Login dropdown popover */
.login-dropdown {
  position: relative;
}

.login-dropdown__menu {
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  z-index: 200;
  width: 96px;
  padding: 4px;
  background: var(--color-white);
  border-radius: 8px;
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08), 0 3px 6px rgba(0, 0, 0, 0.12);
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity 0.16s ease 0.18s, transform 0.16s ease 0.18s, visibility 0s linear 0.34s;
}

.login-dropdown__menu::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  right: 0;
  height: 8px;
}

.login-dropdown:hover .login-dropdown__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition-delay: 0s;
}

.login-dropdown__item {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 32px;
  font-size: 14px;
  line-height: 22px;
  color: rgba(0, 0, 0, 0.88);
  border-radius: 4px;
  transition: background 0.15s, color 0.15s;
}

.login-dropdown__item:hover {
  background: #fff1f0;
  color: var(--color-primary-text);
}

/* ===== Module 2: Banner ===== */
.mod-banner {
  position: relative;
  margin-top: var(--header-height);
  height: 480px;
  background: linear-gradient(270deg, #e0e4fa 0%, #dee3ff 100%);
  overflow: hidden;
}

.mod-banner__bg {
  position: absolute;
  inset: 0;
  background: url("../assets/images/banner-bg.png") center / cover no-repeat;
  pointer-events: none;
}

.mod-banner__inner {
  position: relative;
  z-index: 4;
  display: grid;
  grid-template-columns: 360px 1fr;
  height: 480px;
  max-width: 1920px;
  margin: 0 auto;
  padding: 0 clamp(24px, 16vw, 320px);
  gap: 40px;
}
.mod-banner__content{
  box-sizing: border-box;
  padding-top: 128px;
}

.mod-banner__title {
  font-size: 40px;
  font-weight: 500;
  line-height: 64px;
  letter-spacing: 0.01em;
}

.mod-banner__title .hl { color: var(--color-blue); }

.mod-banner__subtitle {
  margin-top: 32px;
  font-size: 20px;
  line-height: 30px;
  color: var(--color-text-4);
}

.mod-banner__actions {
  display: flex;
  gap: 18px;
  margin-top: 63px;
  flex-wrap: wrap;
}

.mod-banner__scene {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 900px;
  height: 480px;
}

.mod-banner__scene-base {
  position: absolute;
  bottom: 0;
  width: 100%;
  z-index: 1;
}

.mod-banner__sphere {
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translateX(-51%);
  width: 168px;
  z-index: 3;
  animation: bannerSphereFloat 3s linear infinite;
}

.mod-banner__sphere-mask {
  position: absolute;
  top: 73px;
  left: 50%;
  transform: translateX(-51%);
  width: 168px;
  z-index: 2;
}

@keyframes bannerSphereFloat {
  0%, 100% {
    transform: translate(-51%, 0);
  }
  50% {
    transform: translate(-51%, -12px);
  }
}

@media (min-width: 1660px) {
  .mod-banner__scene {
    right: 170px;
  }
}

/* ===== Module 3: School ===== */
.mod-school {
  position: relative;
  padding: 80px 0;
  background: var(--color-bg-light);
  overflow: hidden;
}

.mod-school__blur {
  position: absolute;
  top: -88px;
  left: 50%;
  transform: translateX(-50%);
  width: 1440px;
  height: 288px;
  background: #fff;
  border-radius: 50%;
  filter: blur(209px);
  pointer-events: none;
}

.mod-school__header { position: relative; text-align: center; margin-bottom: 48px; }

.mod-school__cards {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.school-card {
  background: #fff;
  border-radius: 16px;
  padding: 32px;
  min-height: 360px;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.school-card__icon {
  width: 64px;
  height: 64px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
}

.school-card__icon--blue { background: rgba(27, 102, 242, 0.1); }
.school-card__icon--green { background: rgba(36, 186, 138, 0.1); }
.school-card__icon--red { background: rgba(255, 110, 102, 0.1); }
.school-card__icon--purple { background: rgba(137, 77, 248, 0.1); }

.school-card__title { font-size: 24px; font-weight: 700; line-height: 36px; }

.school-card__list {
  font-size: 18px;
  line-height: 36px;
  color: var(--color-text-2);
  white-space: pre-line;
}

/* ===== Module 4/6/8: CTA bars ===== */
.mod-cta {
  position: relative;
  height: 144px;
  overflow: hidden;
}

.mod-cta__bg {
  position: absolute;
  inset: 0;
}

.mod-cta__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.mod-cta__overlay {
  position: absolute;
  inset: 0;
}


.mod-cta__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 144px;
  max-width: 1920px;
  margin: 0 auto;
  gap: 24px;
  width: var(--container-width);
}

.mod-cta__title {
  font-size: 28px;
  font-weight: 700;
  line-height: 32px;
  letter-spacing: 1px;
}

.mod-cta__desc {
  margin-top: 8px;
  font-size: 20px;
  color: var(--color-text-2);
}

.mod-cta__desc .em,
.mod-cta__title .em { color: var(--color-primary); font-weight: 900; }

/* ===== Module 5: Student ===== */
.mod-student {
  padding: 80px 0;
  background: #fff;
}

.mod-student__header { text-align: center; margin-bottom: 48px; }

.mod-student__cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.student-card {
  border-radius: 16px;
  overflow: hidden;
  /* min-height: 440px; */
  display: flex;
  flex-direction: column;
}

.student-card__body { padding: 40px 40px 0; }

.student-card__title {
  font-size: 24px;
  font-weight: 700;
  line-height: 36px;
  margin-bottom: 8px;
}

.student-card__desc {
  font-size: 16px;
  line-height: 32px;
  color: var(--color-text-2);
}

.student-card__mock {
  /* flex: 1; */
  /* margin-top: 21px; */
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 0 16px 0;
  overflow: hidden;
}

.student-card__mock img {
  width: 100%;
  max-width: 260px;
  object-fit: contain;
  object-position: bottom center;
}

.student-card--blue { background: linear-gradient(180deg, #f9fdff 0%, #d1e7ff 100%); }
.student-card--red { background: linear-gradient(180deg, #fff6f6 0%, #ffd4d2 100%); }
.student-card--purple { background: linear-gradient(180deg, #f9faff 0%, #d7e2ff 100%); }
.student-card--green { background: linear-gradient(180deg, #effffa 0%, #d9f6f1 100%); }

/* ===== Module 7: Enterprise ===== */
.mod-enterprise {
  padding: 80px 0;
  background: #fff;
}

.mod-enterprise__header { text-align: center; margin-bottom: 48px; }

.mod-enterprise__cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.ent-card {
  display: flex;
  flex-direction: column;
}

.ent-card__mock {
  border-radius: 16px;
  overflow: hidden;
  line-height: 0;
}

.ent-card__mock img {
  width: 100%;
  height: auto;
  display: block;
}

.ent-card__body {
  margin-top: 24px;
}

.ent-card__title {
  font-size: 32px;
  font-weight: 700;
  line-height: 36px;
  color: var(--color-text-1);
  margin-bottom: 8px;
}

.ent-card__desc {
  font-size: 20px;
  line-height: 30px;
  color: var(--color-text-2);
}

/* ===== Module 9: FAQ ===== */
.mod-faq {
  position: relative;
  padding: 80px 0;
  background: var(--color-bg-light);
  overflow: hidden;
}

.mod-faq__blur {
  position: absolute;
  top: -87px;
  left: 50%;
  transform: translateX(-50%);
  width: 1440px;
  height: 285px;
  background: #fff;
  border-radius: 50%;
  filter: blur(209px);
  pointer-events: none;
}

.mod-faq__header { position: relative; text-align: center; margin-bottom: 48px; }

.mod-faq__grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 394px);
  justify-content: center;
  gap: 25px;
  margin-bottom: 32px;
}

.faq-item {
  background: #fff;
  border: 1px solid #d9d9d9;
  border-radius: 16px;
  padding: 24px;
  width: 394px;
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 20px;
  line-height: 32px;
  cursor: pointer;
  overflow: hidden;
}

.faq-item:hover,.faq-item:active {
  background: #fff3f3;
  border-color: var(--color-primary);
  color: var(--color-primary-text);
}

.faq-item__title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.faq-item__arrow { color: #888; font-size: 32px; flex-shrink: 0; }
.faq-item:hover .faq-item__arrow { color: var(--color-primary); }

.mod-faq__more { position: relative; display: flex; justify-content: center; }

.mod-faq__more .faq-item { width: 240px; }

a.faq-item { text-decoration: none; color: inherit; }

.faq-item--loading { cursor: default; pointer-events: none; color: #888; }

/* ===== Module 10: Footer ===== */
.site-footer { background: var(--color-footer-bg); color: #b8b9cc; }

.footer-main { padding: 56px 0; }

.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 48px;
  align-items: start;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-col h3 {
  font-size: 18px;
  font-weight: 500;
  color: #b8b9cc;
  margin-bottom: 13px;
}

.footer-col a {
  font-size: 14px;
  line-height: 40px;
  color: #b8b9cc;
  transition: color 0.2s;
}

.footer-col ul li { margin-bottom: 0; }

.footer-col a:hover,
.footer-col a.is-highlight { color: #ff453a; }

.footer-contact address { font-style: normal; font-size: 14px; line-height: 40px; }

.footer-qr { display: flex; gap: 36px; }

.footer-qr__item { text-align: center; }

.footer-qr__item img {
  width: 120px;
  height: 120px;
  border-radius: 8px;
  margin: 0 auto 12px;
}

.footer-qr__item p { font-size: 14px; color: #848799; }

.footer-bottom {
  padding: 16px 0;
  text-align: center;
  font-size: 12px;
  line-height: 30px;
  color: #848799;
}

.footer-bottom img {
  display: inline-block;
  vertical-align: middle;
  width: 13px;
  height: 13px;
  margin: 0 4px;
}

/* ===== Responsive ===== */
@media (max-width: 1279px) {
  .mod-banner__inner { grid-template-columns: 1fr; text-align: center; }
  .mod-banner__actions { justify-content: center; }
  .mod-banner__visual { height: 300px; margin-top: 24px; }
  .mod-school__cards,
  .mod-student__cards { grid-template-columns: repeat(2, 1fr); }
  .mod-enterprise__cards { grid-template-columns: repeat(2, 1fr); }
  .mod-faq__grid { grid-template-columns: repeat(2, 394px); }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 767px) {
  .menu-toggle { display: flex; }
  .header-inner .login-dropdown { display: none; }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 16px 24px;
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s, opacity 0.25s;
  }

  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .site-nav a { padding: 14px 0; border-bottom: 1px solid #f5f5f5; }
  .site-nav a.is-active::after { display: none; }
  .header-brand { gap: 16px; }

  .mod-banner { min-height: auto; }
  .mod-banner__inner { padding: 48px 24px; min-height: auto; }
  .mod-banner__title { font-size: 28px; line-height: 1.4; }
  .mod-banner__subtitle { margin-top: 16px; }
  .mod-banner__actions { margin-top: 32px; }
  .mod-banner__visual { height: 220px; }
  .mod-banner__scene { width: 320px; height: 220px; transform: translateX(-50%); }
  .mod-banner__scene-base { width: 300px; }
  .mod-banner__sphere { width: 126px; }
  .mod-banner__sphere-mask { top: 40px; width: 150px; }

  .mod-school, .mod-student, .mod-enterprise, .mod-faq { padding: 48px 0; }
  .mod-school__cards,
  .mod-student__cards,
  .mod-enterprise__cards,
  .mod-faq__grid { grid-template-columns: 1fr; }

  .mod-faq__grid .faq-item { width: 100%; }

  .ent-card__title { font-size: 24px; line-height: 32px; }
  .ent-card__desc { font-size: 16px; line-height: 28px; }

  .mod-cta { height: auto; }
  .mod-cta__inner {
    flex-direction: column;
    height: auto;
    padding: 32px 24px;
    text-align: center;
  }

  .mod-cta__title { font-size: 22px; }
  .footer-links { grid-template-columns: 1fr; }
  .footer-qr { justify-content: center; }
}