body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #fff5f5;
}

/* ===== NAVBAR ===== */
.navbar {
    background: linear-gradient(45deg, #d40000, #ff2d2d);
    color: white;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
    /* ✨ thêm */
    position: sticky;
    top: 0;
    z-index: 999;
}

.logo {
    font-size: 24px;
    font-weight: bold;
}

.navbar ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 20px;
}

.navbar a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}

.navbar a:hover {
    color: yellow;
}

/* ===== HERO ===== */
.hero {
    height: 500px;
    background: url("landmark.jpg") center/cover no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    position: relative;
}

.hero-content {
    background: rgba(0,0,0,0.45);
    padding: 30px;
    border-radius: 12px;
    position: relative;
    z-index: 2;
}

.subtitle {
    font-size: 18px;
}

.hero h1 {
    font-size: 48px;
    margin: 10px 0;
}

.desc {
    max-width: 600px;
    margin: auto;
}

/* ===== BUTTON ===== */
.btn {
    display: inline-block;
    margin-top: 15px;
    padding: 12px 25px;
    background: #ffcc00;
    color: black;
    font-weight: bold;
    text-decoration: none;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(255, 204, 0, 0.5);
    transition: all 0.25s ease;
}

.btn:hover {
    background: #ffd633;
    transform: translateY(-2px);
}

/* ===== CONTENT ĐỒNG BỘ HERO ===== */
.content {
    padding: 80px 20px;
    text-align: center;

    /* nền gradient cùng tone banner */
    background: linear-gradient(
        135deg,
        rgba(212, 0, 0, 0.95),
        rgba(255, 140, 0, 0.9)
    );

    color: white;
    position: relative;
    overflow: hidden;
}

/* overlay mềm giống hero */
.content::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(
        circle at center,
        rgba(255,255,255,0.15),
        transparent 60%
    );
    pointer-events: none;
}

/* tiêu đề */
.content h2 {
    font-size: 36px;
    margin-bottom: 20px;
    font-weight: 700;
    letter-spacing: 1px;
}

/* đoạn văn */
.content p {
    max-width: 850px;
    margin: auto;
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.95;
}

/* hiệu ứng xuất hiện nhẹ */
.content h2,
.content p {
    animation: fadeUp 0.8s ease forwards;
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
/* ===== NỀN SECTION ===== */
.gioithieu-section {
  padding: 60px 20px;
  background: linear-gradient(135deg, #fff5f5, #fff9e6);
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ===== CARD NỔI ===== */
.gioithieu-card {
  max-width: 900px;
  width: 100%;
  background: #ffffff;
  border-radius: 20px;
  padding: 40px 50px;
  text-align: center;

  /* hiệu ứng nổi */
  box-shadow: 0 15px 40px rgba(255, 0, 0, 0.15);
  border: 2px solid #ffe066;

  transition: all 0.3s ease;
}

.gioithieu-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 25px 60px rgba(255, 0, 0, 0.25);
}

/* ===== TIÊU ĐỀ ===== */
.gioithieu-title {
  font-size: 32px;
  font-weight: bold;
  color: #d62828;
  margin-bottom: 8px;
}

.gioithieu-sub {
  color: #e63946;
  font-size: 18px;
  margin-bottom: 25px;
}

/* ===== NỘI DUNG ===== */
.gioithieu-content {
  text-align: justify;
  color: #444;
  line-height: 1.7;
  font-size: 16px;
}

.gioithieu-content h3 {
  text-align: center;
  color: #d62828;
  margin-bottom: 15px;
}
/* ===== ẢNH GIỚI THIỆU ===== */
.gt-img {
  width: 100%;
  max-width: 650px;
  border-radius: 12px;
  margin: 10px auto 25px;
  display: block;
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
  transition: 0.3s;
}

.gt-img:hover {
  transform: scale(1.03);
}

/* ===== VIDEO TẾT ===== */
.video-box {
  max-width: 800px;
  margin: 25px auto 40px;
  text-align: center;
}

.video-box video {
  width: 100%;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

/* ===== HOA ANH ĐÀO RƠI NHIỀU ===== */
.sakura {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
}

/* mỗi cánh hoa */
.sakura span {
  position: absolute;
  top: -10vh;
  font-size: 20px;
  animation: sakuraFall linear infinite;
}

/* dùng emoji hoa */
.sakura span::before {
  content: "🌸";
}

/* random vị trí & tốc độ */
.sakura span:nth-child(1)  { left: 5%;  animation-duration: 8s; }
.sakura span:nth-child(2)  { left: 15%; animation-duration: 10s; }
.sakura span:nth-child(3)  { left: 25%; animation-duration: 7s; }
.sakura span:nth-child(4)  { left: 35%; animation-duration: 9s; }
.sakura span:nth-child(5)  { left: 45%; animation-duration: 11s; }
.sakura span:nth-child(6)  { left: 55%; animation-duration: 8s; }
.sakura span:nth-child(7)  { left: 65%; animation-duration: 12s; }
.sakura span:nth-child(8)  { left: 75%; animation-duration: 9s; }
.sakura span:nth-child(9)  { left: 85%; animation-duration: 10s; }
.sakura span:nth-child(10) { left: 95%; animation-duration: 7s; }
.sakura span:nth-child(11) { left: 12%; animation-duration: 13s; }
.sakura span:nth-child(12) { left: 28%; animation-duration: 9s; }
.sakura span:nth-child(13) { left: 52%; animation-duration: 8s; }
.sakura span:nth-child(14) { left: 68%; animation-duration: 11s; }
.sakura span:nth-child(15) { left: 82%; animation-duration: 10s; }

/* animation rơi */
@keyframes sakuraFall {
  0% {
    transform: translateY(-10vh) rotate(0deg);
    opacity: 0;
  }
  10% { opacity: 1; }
  100% {
    transform: translateY(110vh) rotate(360deg);
    opacity: 0;
  }
}