/* ====================== RESET ====================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Bỏ gạch chân cho tất cả các link */
a {
  text-decoration: none;
  color: inherit;
}

/* ====================== BODY ====================== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: #ffffff;
  color: #2c2c2c;
  line-height: 1.6;
}

/* ====================== HEADER ====================== */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    position: sticky;
    top: 0;
    background: #fff;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    z-index: 999;
    /* Không wrap trên màn hình lớn */
    flex-wrap: nowrap;
  }
  
  /* Khi kích thước màn hình rất nhỏ, cho phép header wrap */
  @media (max-width: 600px) {
    .header {
      flex-wrap: wrap;
      justify-content: center;
    }
    .header-left,
    .header-nav {
      width: 100%;
      text-align: center;
      margin-bottom: 0.5rem;
    }
    .header-right {
      width: 100%;
      text-align: center;
      margin-top: 0.5rem;
    }
  }
  
  .header-left .logo img {
    width: 48px;
    height: auto;
  }
  
  .header-nav ul {
    list-style: none;
    display: flex;
    flex-wrap: nowrap;
    gap: 1rem;
    overflow-x: auto;  /* Cho phép cuộn ngang nếu cần */
    scrollbar-width: none; /* Ẩn scrollbar trên Firefox */
  }
  .header-nav ul::-webkit-scrollbar {
    display: none; /* Ẩn scrollbar trên Chrome */
  }
  
  .header-nav ul li a {
    font-weight: 500;
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    transition: background-color 0.3s;
    white-space: nowrap;
    font-size: 0.9rem; /* Giảm font-size cho phù hợp trên màn hình nhỏ */
  }
  
  .header-nav ul li a:hover {
    background-color: #eaeaea;
  }
  
  .header-right .btn-primary {
    background-color: #0072ff;
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 500;
    transition: background-color 0.3s;
    white-space: nowrap;
    font-size: 0.9rem;
  }
  
  .header-right .btn-primary:hover {
    background-color: #005adb;
  }
  

/* ====================== HERO SECTION: App Intro ====================== */
.app-hero {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, #0072ff, #80deea);
  color: #fff;
  text-align: center;
  position: relative;
}

.app-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* Bạn có thể mở dòng dưới nếu dùng background image */
  /* background: url('../img/app-bg.jpg') center/cover no-repeat; */
  opacity: 0.2;
  z-index: 0;
}

.app-hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  width: 100%;
}

.app-hero-img {
  width: 220px; /* Kích thước logo lớn */
  margin-bottom: 1rem;
  border-radius: 10px;
  object-fit: contain;
}

.app-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #fff;
}

.app-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: #f0f0f0;
}

.btn-secondary {
  background-color: #fff;
  color: #0072ff;
  padding: 0.5rem 1rem;
  border: 2px solid #0072ff;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s, color 0.3s;
}

.btn-secondary:hover {
  background-color: #0072ff;
  color: #fff;
}

/* ====================== MAIN CONTENT: Feature Sections ====================== */
main {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
}

/* Tạo khoảng cách rõ ràng giữa các section (thêm padding/margin-bottom) */
.feature-section {
  display: flex;
  align-items: center;
  margin-bottom: 4rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #eaeaea;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.feature-section.active {
  opacity: 1;
  transform: translateY(0);
}

/* Với section không dual, đảo ngược thứ tự cho các section chẵn */
.feature-section:not(.dual):nth-of-type(even) {
  flex-direction: row-reverse;
}

/* Nếu section chỉ có 1 ảnh (thêm class "single") giảm kích thước ảnh để cân đối */
.feature-image.single img {
  max-width: 70%;
}

/* Dành cho section dual: 3 cột (2 ảnh bên ngoài, nội dung ở giữa) */
.feature-section.dual {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.feature-section.dual .feature-image.left,
.feature-section.dual .feature-image.right {
  flex: 1 1 30%;
  max-width: 30%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-section.dual .feature-content {
  flex: 1 1 40%;
  max-width: 40%;
  padding: 1rem 2rem;
}

/* Ảnh trong các section chung (nếu không áp dụng cho single đã được set riêng) */
.feature-image img {
  width: 100%;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.feature-content {
  flex: 1;
  padding: 1rem 2rem;
}

.feature-content h2 {
  font-size: 2rem;
  color: #0072ff;
  margin-bottom: 1rem;
}

.feature-content p {
  font-size: 1.125rem;
  color: #555;
  line-height: 1.8;
}

/* ====================== HOẠT ẢNH: Fade-in ====================== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 1.5s forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* ====================== FOOTER ====================== */
.footer {
  background-color: #f9f9f9;
  border-top: 1px solid #eaeaea;
  padding: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-logo img {
  width: 48px;
  height: auto;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.footer-links li a {
  color: #0072ff;
  font-weight: 500;
  transition: color 0.3s;
}

.footer-links li a:hover {
  color: #005adb;
}

/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  .feature-section,
  .feature-section.dual {
    flex-direction: column;
    text-align: center;
    border: none;
    padding-bottom: 1rem;
  }
  .feature-section.dual .feature-image.left,
  .feature-section.dual .feature-image.right,
  .feature-section.dual .feature-content {
    max-width: 100%;
    flex: unset;
    padding: 1rem 0;
  }
  .header-nav ul {
    gap: 1rem;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
  .app-hero-img {
    width: 180px;
  }
}
/* ====================== RESET ====================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Bỏ gạch chân cho tất cả các link */
a {
  text-decoration: none;
  color: inherit;
}

/* ====================== BODY ====================== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: #ffffff;
  color: #2c2c2c;
  line-height: 1.6;
}

/* ====================== HEADER ====================== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  background: #fff;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  z-index: 999;
}

.header-left .logo img {
  width: 48px;
  height: auto;
}

.header-nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.header-nav ul li a {
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  transition: background-color 0.3s;
}

.header-nav ul li a:hover {
  background-color: #eaeaea;
}

.header-right .btn-primary {
  background-color: #0072ff;
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s;
}

.header-right .btn-primary:hover {
  background-color: #005adb;
}

/* ====================== HERO SECTION: App Intro ====================== */
.app-hero {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, #0072ff, #80deea);
  color: #fff;
  text-align: center;
  position: relative;
}

.app-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* Nếu có background image thì mở dòng dưới */
  /* background: url('../img/app-bg.jpg') center/cover no-repeat; */
  opacity: 0.2;
  z-index: 0;
}

.app-hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  width: 100%;
}

.app-hero-img {
  width: 220px; /* Tăng kích thước logo */
  margin-bottom: 1rem;
  border-radius: 10px;
  object-fit: contain;
}

.app-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #fff;
}

.app-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: #f0f0f0;
}

.btn-secondary {
  background-color: #fff;
  color: #0072ff;
  padding: 0.5rem 1rem;
  border: 2px solid #0072ff;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s, color 0.3s;
}

.btn-secondary:hover {
  background-color: #0072ff;
  color: #fff;
}

/* ====================== MAIN CONTENT: Feature Sections ====================== */
main {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
}

/* --- Các section cơ bản: hình và nội dung xen kẽ --- */
.feature-section {
  display: flex;
  align-items: center;
  margin-bottom: 4rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* Khi cuộn vào view */
.feature-section.active {
  opacity: 1;
  transform: translateY(0);
}

/* Đối với những section không thuộc dạng dual, đảo ngược thứ tự cho các section chẵn */
.feature-section:not(.dual):nth-of-type(even) {
  flex-direction: row-reverse;
}

.feature-image {
  flex: 1;
  padding: 1rem;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-image img {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.feature-content {
  flex: 1;
  padding: 1rem 2rem;
}

.feature-content h2 {
  font-size: 2rem;
  color: #0072ff;
  margin-bottom: 1rem;
}

.feature-content p {
  font-size: 1.125rem;
  color: #555;
  line-height: 1.8;
}

/* --- Các section dual (2 ảnh bên trái và bên phải với nội dung ở giữa) --- */
.feature-section.dual {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.feature-section.dual .feature-image.left,
.feature-section.dual .feature-image.right {
  flex: 1 1 30%;
  max-width: 30%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-section.dual .feature-content {
  flex: 1 1 40%;
  max-width: 40%;
  padding: 1rem 2rem;
}

/* ====================== HOẠT ẢNH: Fade-in ====================== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 1.5s forwards;
}
@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* ====================== FOOTER ====================== */
.footer {
  background-color: #f9f9f9;
  border-top: 1px solid #eaeaea;
  padding: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-logo img {
  width: 48px;
  height: auto;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.footer-links li a {
  color: #0072ff;
  font-weight: 500;
  transition: color 0.3s;
}

.footer-links li a:hover {
  color: #005adb;
}

/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  .feature-section,
  .feature-section.dual {
    flex-direction: column;
    text-align: center;
  }
  .feature-section.dual .feature-image.left,
  .feature-section.dual .feature-image.right,
  .feature-section.dual .feature-content {
    max-width: 100%;
    flex: unset;
    padding: 1rem 0;
  }
  .header-nav ul {
    gap: 1rem;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
  .app-hero-img {
    width: 180px;
  }
}
/* ====================== RESET ====================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Bỏ gạch chân cho tất cả các link */
a {
  text-decoration: none;
  color: inherit;
}

/* ====================== BODY ====================== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: #ffffff;
  color: #2c2c2c;
  line-height: 1.6;
}

/* ====================== HEADER ====================== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  background: #fff;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  z-index: 999;
}

.header-left .logo img {
  width: 48px;
  height: auto;
}

.header-nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.header-nav ul li a {
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  transition: background-color 0.3s;
}

.header-nav ul li a:hover {
  background-color: #eaeaea;
}

.header-right .btn-primary {
  background-color: #0072ff;
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s;
}

.header-right .btn-primary:hover {
  background-color: #005adb;
}

/* ====================== HERO SECTION: App Intro ====================== */
.app-hero {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, #0072ff, #80deea);
  color: #fff;
  text-align: center;
  position: relative;
}

.app-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* Nếu có background image thì mở dòng dưới */
  /* background: url('../img/app-bg.jpg') center/cover no-repeat; */
  opacity: 0.2;
  z-index: 0;
}

.app-hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  width: 100%;
}

.app-hero-img {
  width: 220px; /* Tăng kích thước logo */
  margin-bottom: 1rem;
  border-radius: 10px;
  object-fit: contain;
}

.app-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #fff;
}

.app-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: #f0f0f0;
}

.btn-secondary {
  background-color: #fff;
  color: #0072ff;
  padding: 0.5rem 1rem;
  border: 2px solid #0072ff;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s, color 0.3s;
}

.btn-secondary:hover {
  background-color: #0072ff;
  color: #fff;
}

/* ====================== MAIN CONTENT: Feature Sections ====================== */
main {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
}

/* --- Các section đơn: hình và nội dung xen kẽ --- */
.feature-section {
  display: flex;
  align-items: center;
  margin-bottom: 4rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* Khi cuộn vào view */
.feature-section.active {
  opacity: 1;
  transform: translateY(0);
}

/* Đối với những section không có class dual:
   nếu section nằm xen kẽ, đảo ngược theo thứ tự */
.feature-section:not(.dual):nth-of-type(even) {
  flex-direction: row-reverse;
}

.feature-image {
  flex: 1;
  padding: 1rem;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-image img {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.feature-content {
  flex: 1;
  padding: 1rem 2rem;
}

.feature-content h2 {
  font-size: 2rem;
  color: #0072ff;
  margin-bottom: 1rem;
}

.feature-content p {
  font-size: 1.125rem;
  color: #555;
  line-height: 1.8;
}

/* --- Các section dual (3 cột: 2 ảnh bên trái & phải, nội dung ở giữa) --- */
.feature-section.dual {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.feature-section.dual .feature-image.left,
.feature-section.dual .feature-image.right {
  flex: 1 1 30%;
  max-width: 30%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-section.dual .feature-content {
  flex: 1 1 40%;
  max-width: 40%;
  padding: 1rem 2rem;
}

/* ====================== HOẠT ẢNH: Fade-in ====================== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 1.5s forwards;
}
@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* ====================== FOOTER ====================== */
.footer {
  background-color: #f9f9f9;
  border-top: 1px solid #eaeaea;
  padding: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-logo img {
  width: 48px;
  height: auto;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.footer-links li a {
  color: #0072ff;
  font-weight: 500;
  transition: color 0.3s;
}

.footer-links li a:hover {
  color: #005adb;
}

/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  .feature-section,
  .feature-section.dual {
    flex-direction: column;
    text-align: center;
  }
  .feature-section.dual .feature-image.left,
  .feature-section.dual .feature-image.right,
  .feature-section.dual .feature-content {
    max-width: 100%;
    flex: unset;
    padding: 1rem 0;
  }
  .header-nav ul {
    gap: 1rem;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
  .app-hero-img {
    width: 180px;
  }
}
/* ====================== RESET ====================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Bỏ gạch chân cho tất cả các link */
a {
  text-decoration: none;
  color: inherit;
}

/* ====================== BODY ====================== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: #ffffff;
  color: #2c2c2c;
  line-height: 1.6;
}

/* ====================== HEADER ====================== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  background: #fff;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  z-index: 999;
}

.header-left .logo img {
  width: 48px;
  height: auto;
}

.header-nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.header-nav ul li a {
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  transition: background-color 0.3s;
}

.header-nav ul li a:hover {
  background-color: #eaeaea;
}

.header-right .btn-primary {
  background-color: #0072ff;
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s;
}

.header-right .btn-primary:hover {
  background-color: #005adb;
}

/* ====================== HERO SECTION: App Intro ====================== */
.app-hero {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, #0072ff, #80deea);
  color: #fff;
  text-align: center;
  position: relative;
}

.app-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* Nếu có background image thì mở dòng dưới */
  /* background: url('../img/app-bg.jpg') center/cover no-repeat; */
  opacity: 0.2;
  z-index: 0;
}

.app-hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  width: 100%;
}

.app-hero-img {
  width: 220px; /* Tăng kích thước logo */
  margin-bottom: 1rem;
  border-radius: 10px;
  object-fit: contain;
}

.app-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #fff;
}

.app-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: #f0f0f0;
}

.btn-secondary {
  background-color: #fff;
  color: #0072ff;
  padding: 0.5rem 1rem;
  border: 2px solid #0072ff;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s, color 0.3s;
}

.btn-secondary:hover {
  background-color: #0072ff;
  color: #fff;
}

/* ====================== MAIN CONTENT: Feature Sections ====================== */
main {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
}

/* --- Các section đơn: hình và nội dung xen kẽ --- */
.feature-section {
  display: flex;
  align-items: center;
  margin-bottom: 4rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* Khi cuộn vào view */
.feature-section.active {
  opacity: 1;
  transform: translateY(0);
}

/* Đối với những section không có 3 cột: nếu section nằm xen kẽ, đảo ngược theo thứ tự */
.feature-section:not(.dual):nth-of-type(even) {
  flex-direction: row-reverse;
}

.feature-image {
  flex: 1;
  padding: 1rem;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-image img {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.feature-content {
  flex: 1;
  padding: 1rem 2rem;
}

.feature-content h2 {
  font-size: 2rem;
  color: #0072ff;
  margin-bottom: 1rem;
}

.feature-content p {
  font-size: 1.125rem;
  color: #555;
  line-height: 1.8;
}

/* --- Các section dual (2 ảnh xung quanh nội dung): Light/Dark Mode, Thông báo & Lịch sử --- */
.feature-section.dual {
  display: flex;
  align-items: center;
  justify-content: space-between;
  /* Có thể bắt buộc chiều rộng tối đa cho từng cột */
}

.feature-section.dual .feature-image.left,
.feature-section.dual .feature-image.right {
  flex: 1 1 30%;
  max-width: 30%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-section.dual .feature-content {
  flex: 1 1 40%;
  max-width: 40%;
  padding: 1rem 2rem;
}

/* ====================== HOẠT ẢNH: Fade-in ====================== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 1.5s forwards;
}
@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* ====================== FOOTER ====================== */
.footer {
  background-color: #f9f9f9;
  border-top: 1px solid #eaeaea;
  padding: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-logo img {
  width: 48px;
  height: auto;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.footer-links li a {
  color: #0072ff;
  font-weight: 500;
  transition: color 0.3s;
}

.footer-links li a:hover {
  color: #005adb;
}

/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  .feature-section,
  .feature-section.dual {
    flex-direction: column;
    text-align: center;
  }
  .feature-section.dual .feature-image.left,
  .feature-section.dual .feature-image.right,
  .feature-section.dual .feature-content {
    max-width: 100%;
    flex: unset;
    padding: 1rem 0;
  }
  .header-nav ul {
    gap: 1rem;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
  .app-hero-img {
    width: 180px;
  }
}
/* ====================== RESET ====================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ====================== BODY ====================== */
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: #ffffff;
  color: #2c2c2c;
  line-height: 1.6;
}

/* ====================== HEADER (giống index.css) ====================== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  background: #fff;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  z-index: 999;
}

.header-left .logo img {
  width: 48px;
  height: auto;
}

.header-nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.header-nav ul li a {
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  transition: background-color 0.3s;
}

.header-nav ul li a:hover {
  background-color: #eaeaea;
}

.header-right .btn-primary {
  background-color: #0072ff;
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s;
}

.header-right .btn-primary:hover {
  background-color: #005adb;
}

/* ====================== HERO SECTION: App Intro ====================== */
.app-hero {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, #0072ff, #80deea);
  color: #fff;
  text-align: center;
  position: relative;
}

.app-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('../img/app-bg.jpg') center/cover no-repeat;
  opacity: 0.2;
  z-index: 0;
}

.app-hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  width: 100%;
}

.app-hero-img {
  width: 200px;
  margin-bottom: 1rem;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.app-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #fff;
}

.app-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: #f0f0f0;
}

.btn-secondary {
  background-color: #fff;
  color: #0072ff;
  padding: 0.5rem 1rem;
  border: 2px solid #0072ff;
  border-radius: 6px;
  font-weight: 500;
  transition: background-color 0.3s, color 0.3s;
}

.btn-secondary:hover {
  background-color: #0072ff;
  color: #fff;
}

/* ====================== MAIN CONTENT: Feature Sections ====================== */
main {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
}

/* Mỗi section hiển thị tính năng: bố cục xen kẽ giữa ảnh và nội dung */
.feature-section {
  display: flex;
  align-items: center;
  margin-bottom: 4rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* Khi phần tử có class active (thêm qua JS khi cuộn vào view) */
.feature-section.active {
  opacity: 1;
  transform: translateY(0);
}

.feature-section:nth-of-type(even) {
  flex-direction: row-reverse;
}

.feature-image {
  flex: 1;
  padding: 1rem;
}

.feature-image img {
  width: 100%;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.feature-content {
  flex: 1;
  padding: 1rem 2rem;
}

.feature-content h2 {
  font-size: 2rem;
  color: #0072ff;
  margin-bottom: 1rem;
}

.feature-content p {
  font-size: 1.125rem;
  color: #555;
  line-height: 1.8;
}

/* ====================== HOẠT ẢNH: Fade-in ====================== */
.animate-fade-in {
  opacity: 0;
  animation: fadeIn 1.5s forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* ====================== FOOTER ====================== */
.footer {
  background-color: #f9f9f9;
  border-top: 1px solid #eaeaea;
  padding: 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-logo img {
  width: 48px;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.footer-links li a {
  color: #0072ff;
  font-weight: 500;
  transition: color 0.3s;
}

.footer-links li a:hover {
  color: #005adb;
}

/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  /* Ở màn hình nhỏ, các section chuyển sang bố cục cột và header được giữ không wrap */
  .header-nav ul {
    gap: 0.5rem;
  }
  .feature-section,
  .feature-section.dual {
    flex-direction: column;
    text-align: center;
    border: none;
    padding-bottom: 1rem;
  }
  .feature-section.dual .feature-image.left,
  .feature-section.dual .feature-image.right,
  .feature-section.dual .feature-content {
    max-width: 100%;
    flex: unset;
    padding: 1rem 0;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
  .app-hero-img {
    width: 180px;
  }
}
/* ====================== RESPONSIVE ====================== */
@media (max-width: 768px) {
  .feature-section {
    flex-direction: column;
  }
  .feature-content {
    padding: 1rem 0;
  }
  .header-nav ul {
    gap: 1rem;
  }
  .app-title {
    font-size: 2rem;
  }
  .app-subtitle {
    font-size: 1.2rem;
  }
}