* {
  padding: 0;
  margin: 0;
  border: none;
  text-decoration: none;
  font-family: "Fredoka", sans-serif;
  letter-spacing: 1px;
}

body {
  background-color: grey;
}

#about {
  /* background-image: url(img/UU语音.jpg); */
  background: linear-gradient(135deg, #FFB6C1 10%, #b16cff 50%, #DC143C 90%);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

#about::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 0;
}



#study {
  /* background-image: url(img/UU语音.jpg); */
  background: linear-gradient(135deg, #FFB6C1 10%, #b16cff 50%, #DC143C 90%);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

#study::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 0;
}

#download {
  /* background-image: url(img/UU语音.jpg);
  background: linear-gradient(135deg, #f9d465 10%, #f9a5dd 50%, #61caff 90%); */
  background: linear-gradient(135deg, #0e0e0e 10%, #b16cff 50%, #000000 90%);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

#download::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 0;
}



#social {
  /* background-image: url(img/UU语音.jpg); */
  background: linear-gradient(135deg, #FFB6C1 10%, #b16cff 50%, #DC143C 90%);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

#social::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 0;
}



#question {
  /* background-image: url(img/UU语音.jpg); */
 background: linear-gradient(135deg, #0e0e0e 10%, #b16cff 50%, #000000 90%);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

#question::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 0;
}



.hero-section-container {
  background-color: rgba(255, 255, 255, 0.1);
  height: 85vh;
  width: 85%;
  border-radius: 30px;
  border: 2px solid rgba(211, 211, 211, 0.2);
  backdrop-filter: blur(8px);
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 15px;
  margin: 10px;
  z-index: 1;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: white;
  position: relative;
}

.logo span {
  color: rgb(93, 0, 255);
}

nav {
  display: flex;
  align-items: center;
  gap: 30px;
}

nav a {
  color: white;
  font-size: 18px;
  font-weight: 500;
  position: relative;
  display:flex;
  justify-content: center;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -10px;
  height: 2px;
  width: 80%;
  box-shadow: 0 0 5px white;
  transform: scaleX(0) translateY(-100%);
  background-color: white;
  transition: 0.3s;
}
nav a:hover::after {
  transform: scaleX(0.5) translateY(0);

}

.active {
  color: rgb(93, 0, 255);
}

.active::after {
  background-color: rgb(0, 225, 225);
}

header button {
  font-size: 18px;
  font-weight: bold;
  padding: 7px 25px;
  background-color: transparent;
  border: 1px solid white;
  border-radius: 20px;
  color: white;
  transition: 0.3s;
  cursor: pointer;
}

header button:hover {
  background-color: rgb(93, 0, 255);
  color: rgba(0, 0, 0, 0.6);
  border-color: rgb(93, 0, 255);
}

/* Hero Content */
.hero-content {
  padding: 15px 25px 0 25px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
}

/* Right Section */
.hero-content img {
  width: 35%;
  filter: drop-shadow(0 0 10px rgb(255, 186, 225));
  position: absolute;
  top: 50px;
  transition: transform 0.2s ease-in-out, filter 0.3s ease-in-out;
}

/* 鼠标悬停时的样式 */
.hero-content img:hover {
  filter: drop-shadow(0 0 20px rgb(244, 86, 176));
}

.right-section {
  display: flex;
  justify-content: center;
  align-items: center;
  align-self: start;
}

/* Right Section Animation */
@keyframes rotatePlanet {
  from{
    transform: rotate(0deg);
  }
  to{
    transform: rotate(360deg);
  }
}

.image-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

/* ──────────────── 环绕旋转特效字 ──────────────── */
.circle-text-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: min(550px, 90vw);
  height: min(550px, 90vw);
}

.circle-text-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.outer-ring {
  animation: ringSpinCW 20s linear infinite;
}

.inner-ring {
  animation: ringSpinCCW 26s linear infinite;
}

@keyframes ringSpinCW {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

@keyframes ringSpinCCW {
  from { transform: rotate(0deg); }
  to   { transform: rotate(-360deg); }
}

.circle-text-wrap img {
  position: relative !important;
  z-index: 2;
  width: 85%;
  filter: drop-shadow(0 0 30px rgba(255, 110, 199, 0.5)) drop-shadow(0 0 60px rgba(192, 132, 252, 0.3));
  animation: girlFloat 4s ease-in-out infinite alternate;
}

@keyframes girlFloat {
  from { transform: translateY(0) rotate(-1deg); }
  to   { transform: translateY(-10px) rotate(1deg); }
}



/* left Section */
.left-section {
  display:flex;
  align-items: center;
  z-index: 1;
  /* position: relative; */
  
}

.left-section h3 {
  font-size: 4rem;
  letter-spacing: 20px;
  color: white;
  position: absolute;
  top: 17%;
  left: 5%;
}

.left-section h2 {
  font-size: 9rem;
  font-weight: 800;
  color: white;
  margin: -20px 0 0 0;
  position: absolute;
  left: 2%;
  top: 33%;
}

h2 .color-change {
  color: rgb(93, 0, 255);
}

.left-section p {
  font-size: 18px;
  letter-spacing: 1px;
  line-height: 1.5;
  color: rgb(230, 230, 230);
  width: 100%;
  /* margin-bottom: 50px; */
  position: absolute;
  top: 55%;
  left: 2%;
}

p span {
  color: white;
  font-weight: 600;
}

.big-cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: bold;
  letter-spacing: 2px;
  width: 250px;
  height: 55px;
  border-radius: 50px;
  background-color: rgb(93, 0, 255);
  color: white;
  text-transform: uppercase;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: all 0.35s ease;
  position: absolute;
  top: 75%;
  left: 5%;
}

.big-cta-btn:hover {
  background: linear-gradient(135deg, rgb(130, 50, 255), rgb(255, 110, 199));
  transform: scale(1.08);
  box-shadow: 0 0 30px rgba(192, 132, 252, 0.6), 0 0 60px rgba(255, 110, 199, 0.3);
}

.big-cta-btn:active {
  transform: scale(0.96);
}.btn-study {
  display: inline-block;
  font-size: 18px;
  font-weight: bold;
  letter-spacing: 1px;
  color: white;
  background-color: rgb(93, 0, 255);
  padding: 12px 28px;
  border-radius: 30px;
  text-decoration: none;
  transition: all 0.3s;
}

.btn-study:hover {
  background-color: rgb(120, 50, 255);
  transform: scale(1.05);
}

/* ──────────────── social.html 链接样式 ──────────────── */
#social .left-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  text-align: center;
}

.social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-width: 340px;
  padding: 16px 36px;
  font-family: "Kaiti", "STKaiti", serif;
  font-size: 28px;
  color: #fff;
  text-decoration: none;
  background: linear-gradient(135deg, rgba(130, 100, 255, 0.35), rgba(255, 110, 199, 0.25));
  border: 1px solid rgba(192, 132, 252, 0.4);
  border-radius: 50px;
  backdrop-filter: blur(6px);
  transition: all 0.35s ease;
  cursor: pointer;
}

.social-link:hover {
  background: linear-gradient(135deg, rgba(130, 100, 255, 0.55), rgba(255, 110, 199, 0.45));
  border-color: rgba(192, 132, 252, 0.7);
  transform: scale(1.06);
  box-shadow: 0 0 25px rgba(192, 132, 252, 0.35);
}

.social-link:active {
  transform: scale(0.97);
}

/* ──────────────── 移动端响应式适配 ──────────────── */
/* 平板端适配 */
@media (max-width: 1024px) {
  .hero-section-container {
    width: 92%;
    height: auto;
    min-height: 85vh;
    padding-bottom: 30px;
  }

  .hero-content {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 20px;
  }

  .left-section {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .left-section h3 {
    font-size: 2.8rem;
    position: relative;
    top: auto;
    left: auto;
    margin-bottom: 10px;
  }

  .left-section h2 {
    font-size: 5rem;
    position: relative;
    top: auto;
    left: auto;
    margin-bottom: 15px;
  }

  .left-section p {
    font-size: 16px;
    position: relative;
    top: auto;
    left: auto;
    margin-bottom: 25px;
    width: 100%;
  }

  .big-cta-btn {
    position: relative;
    top: auto;
    left: auto;
    width: 220px;
    height: 50px;
    font-size: 18px;
  }

  .right-section {
    order: -1;
  }

  .circle-text-wrap {
    width: min(480px, 85vw);
    height: min(480px, 85vw);
  }

  .social-icons {
    position: relative;
    top: auto;
    right: auto;
    margin-top: 30px;
  }
}

/* 手机端适配 */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    gap: 15px;
    padding: 10px;
  }

  .logo {
    font-size: 20px;
  }

  nav {
    gap: 15px;
    flex-wrap: wrap;
    justify-content: center;
  }

  nav a {
    font-size: 15px;
  }

  header button,
  .cta-btn {
    font-size: 15px;
    padding: 6px 18px;
  }

  .hero-section-container {
    width: 95%;
    border-radius: 20px;
    margin: 5px auto;
    height: auto;
    min-height: 100vh;
  }

  .hero-content {
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 15px;
  }

  .left-section {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .left-section h3 {
    font-size: 1.8rem;
    letter-spacing: 10px;
    position: relative;
    top: auto;
    left: auto;
  }

  .left-section h2 {
    font-size: 3.2rem;
    position: relative;
    top: auto;
    left: auto;
  }

  .left-section p {
    font-size: 14px;
    position: relative;
    top: auto;
    left: auto;
    width: 100%;
    padding: 0 10px;
  }

  .big-cta-btn {
    position: relative;
    top: auto;
    left: auto;
    width: 200px;
    height: 48px;
    font-size: 16px;
  }

  .right-section {
    order: -1;
  }

  .circle-text-wrap {
    width: min(380px, 90vw);
    height: min(380px, 90vw);
  }

  .circle-text-wrap img {
    width: 75%;
  }

  .btn-study {
    font-size: 16px;
    padding: 10px 20px;
  }

  .social-icons {
    position: relative;
    top: auto;
    right: auto;
    bottom: auto;
    justify-content: center;
    margin-top: 25px;
    gap: 25px;
  }

  .social-icons i {
    font-size: 16px;
    padding: 12px;
    width: 18px;
    height: 18px;
  }

  .hero-content img {
    position: relative;
    top: auto;
    width: 60%;
  }

  /* study.html & social.html 中左侧内容居中 */
  #study .left-section,
  #social .left-section {
    text-align: center;
  }

  #study .left-section iframe,
  #social .left-section a {
    margin: 0 auto;
  }

  #study iframe {
    width: 100% !important;
    height: auto !important;
    aspect-ratio: 850 / 450;
    max-width: 850px;
  }

  #social .left-section span {
    font-size: 28px !important;
  }

  .social-link {
    min-width: auto;
    width: 90%;
    max-width: 340px;
    padding: 12px 24px;
    font-size: 20px;
  }
}

/* 小屏手机端适配 */
@media (max-width: 480px) {
  .hero-section-container {
    width: 98%;
    border-radius: 16px;
  }

  .left-section h3 {
    font-size: 1.4rem;
    letter-spacing: 6px;
  }

  .left-section h2 {
    font-size: 2.5rem;
  }

  .left-section p {
    font-size: 13px;
  }

  .big-cta-btn {
    width: 180px;
    height: 44px;
    font-size: 15px;
    letter-spacing: 1px;
  }

  .circle-text-wrap {
    width: min(320px, 92vw);
    height: min(320px, 92vw);
  }

  nav {
    gap: 10px;
  }

  nav a {
    font-size: 13px;
  }

  .social-icons {
    gap: 20px;
  }

  .social-icons i {
    font-size: 14px;
    padding: 10px;
    width: 16px;
    height: 16px;
  }

  .btn-study {
    font-size: 14px;
    padding: 8px 16px;
  }

  #study iframe {
    width: 100% !important;
    height: auto !important;
    aspect-ratio: 16 / 9;
    max-width: 100%;
  }

  #social .left-section span {
    font-size: 20px !important;
  }
}

/* 减少动画偏好设置 */

  .social-link {
    padding: 10px 18px;
    font-size: 16px;
    min-width: auto;
    width: 92%;
    max-width: 300px;
  }

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