:root {
  --accent: #e91e63;
  --text: #222;
  --muted: #666;
  --bg: #f8f8f8;
}

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fff;
  padding: 16px 32px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.logo { font-size: 22px; font-weight: 700; color: var(--accent); }
.navbar a { text-decoration: none; margin-left: 16px; color: var(--text); }
.navbar a:hover { color: var(--accent); }

.container {
  max-width: 1200px;
  margin: 30px auto;
  padding: 0 16px;
}

/* --- Sản phẩm --- */
.product {
  display: grid;
  grid-template-columns: 2fr 1.2fr;
  gap: 40px;
  margin-bottom: 40px;
}
.gallery {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
}
.main-img {
  width: 100%;
  border-radius: 12px;
  transition: 0.3s;
}
.main-img:hover { transform: scale(1.04); }
.thumbs {
  margin-top: 10px;
  display: flex;
  gap: 10px;
  justify-content: center;
}
.thumb {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  border: 1px solid #ddd;
  cursor: pointer;
  object-fit: cover;
  transition: 0.3s;
}
.thumb:hover { border-color: var(--accent); transform: scale(1.05); }

.details {
  background: #fff;
  padding: 24px;
  border-radius: 12px;
}
.details h1 { font-size: 22px; margin-bottom: 10px; }
.price { font-size: 28px; color: var(--accent); font-weight: bold; }

.option { margin-top: 10px; }
.option-btn {
  border: 1px solid #ccc;
  background: #fff;
  padding: 8px 12px;
  border-radius: 6px;
  margin-right: 8px;
  cursor: pointer;
}
.option-btn.active, .option-btn:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.actions {
  margin: 16px 0;
}
.btn {
  padding: 12px 20px;
  border: none;
  border-radius: 8px;
  font-weight: bold;
  cursor: pointer;
}
.buy {
  background: var(--accent);
  color: #fff;
  margin-right: 8px;
}
.add {
  background: #fff;
  border: 1px solid #ddd;
}
.btn:hover { transform: translateY(-2px); }

.specs-short {
  margin-top: 16px;
  color: var(--muted);
  list-style: disc;
  padding-left: 20px;
}

/* --- Tabs --- */
.info-tabs {
  background: #fff;
  border-radius: 12px;
  padding: 20px;
}
.tab-buttons {
  display: flex;
  gap: 10px;
  margin-bottom: 16px;
}
.tab-buttons button {
  border: 1px solid #ddd;
  padding: 8px 16px;
  border-radius: 6px;
  background: #fff;
  cursor: pointer;
}
.tab-buttons button.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.tab-content {
  display: none;
  animation: fadeIn 0.4s ease;
}
.tab-content.active { display: block; }

table {
  width: 100%;
  border-collapse: collapse;
}
td {
  padding: 10px;
  border-bottom: 1px solid #eee;
}
td:first-child { color: var(--muted); width: 40%; }

footer {
  text-align: center;
  padding: 20px;
  font-size: 13px;
  color: var(--muted);
}

@keyframes fadeIn {
  from {opacity: 0; transform: translateY(5px);}
  to {opacity: 1; transform: translateY(0);}
}
.price {
  font-size: 28px;
  color: var(--accent);
  font-weight: bold;
  transition: opacity 0.3s ease;
}
/* Nền galaxy với hiệu ứng động */
body, html {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    color: white;
    overflow-x: hidden;
    height: 100%;
}

.galaxy-bg {
    position: fixed;
    width: 100%;
    height: 100%;
    background: radial-gradient(ellipse at center, rgba(20,10,40,1) 0%, rgba(0,0,0,1) 100%);
    background-image: url('img/ChatGPT\ Image\ 01_23_56\ 16\ thg\ 10\,\ 2025.png');
    background-size: cover;
    background-position: center;
    animation: galaxyMove 20s ease-in-out infinite alternate;
    z-index: -1;
    filter: brightness(0.8) blur(1px);
}

/* Hiệu ứng chuyển động ánh sáng */
@keyframes galaxyMove {
    0% {
        transform: scale(1) translate(0, 0);
        filter: hue-rotate(0deg);
    }

    50% {
        transform: scale(1.05) translate(10px, -10px);
        filter: hue-rotate(30deg);
    }

    100% {
        transform: scale(1) translate(0, 0);
        filter: hue-rotate(0deg);
    }
}

header {
    text-align: center;
    padding: 30px;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(8px);
}

    header h1 {
        font-size: 2.5rem;
        color: #a4bfff;
        text-shadow: 0 0 20px #69f;
    }

#searchInput {
    margin-top: 10px;
    padding: 10px;
    width: 50%;
    border: none;
    border-radius: 20px;
    outline: none;
    text-align: center;
    background-color: rgba(255,255,255,0.15);
    color: white;
}

.event-banner {
    text-align: center;
    background: linear-gradient(90deg, #1e1e3f, #3f1e5f);
    padding: 15px;
    border-radius: 10px;
    margin: 10px auto;
    width: 90%;
}

.product-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    padding: 30px;
}

.product-card {
    background: rgba(0, 0, 0, 0.65);
    border-radius: 15px;
    padding: 20px;
    text-align: center;
    box-shadow: 0 0 25px rgba(80, 120, 255, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

    .product-card:hover {
        transform: translateY(-10px) scale(1.05);
        box-shadow: 0 0 40px rgba(120, 180, 255, 0.8);
    }

    .product-card img {
        width: 100%;
        height: 230px;
        object-fit: cover;
        border-radius: 10px;
    }

/* Popup */
.popup {
    display: none;
    position: fixed;
    z-index: 10;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.8);
    backdrop-filter: blur(6px);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    box-shadow: 0 0 20px rgba(0,0,0,0.5);
    border-radius: 15px;
}
    .popup img {
        width: 100%;
        height: 100%;
        object-fit: contain; /* hoặc cover tùy bạn muốn hiển thị */
        display: block;
        border-radius: 10px;
    }

.popup-content {
    background-color: rgba(25, 25, 35, 0.95);
    margin: 10% auto;
    padding: 20px;
    border-radius: 20px;
    width: 350px;
    text-align: center;
    box-shadow: 0 0 25px rgba(120, 180, 255, 0.8);
    animation: popupIn 0.4s ease;
}

@keyframes popupIn {
    from {
        transform: scale(0.8);
        opacity: 0;
    }

    to {
        transform: scale(1);
        opacity: 1;
    }
}

.close {
    float: right;
    font-size: 28px;
    cursor: pointer;
}

.add-cart {
    background: linear-gradient(90deg, #2a9df4, #8a2be2);
    border: none;
    padding: 10px 20px;
    color: white;
    border-radius: 20px;
    cursor: pointer;
    transition: 0.3s;
}

    .add-cart:hover {
        background: linear-gradient(90deg, #8a2be2, #2a9df4);
    }
/* 🌌 HIỆU ỨNG SAO TÍM HỒNG NEON */
.stars {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
    pointer-events: none;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: radial-gradient(circle, #ff66ff, #ff00ff);
    border-radius: 50%;
    opacity: 0.8;
    animation: twinkle 3s infinite ease-in-out;
}

@keyframes twinkle {
    0%, 100% {
        opacity: 0.2;
        transform: scale(1);
    }

    50% {
        opacity: 1;
        transform: scale(1.8);
    }
}

/* Làm nền galaxy đậm và tím hồng hơn */
.galaxy-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  filter: brightness(0.9) saturate(1.5) blur(1px);
  background: radial-gradient(circle at center, #2a003f 0%, #000010 100%);
  background-image: url('img/ChatGPT Image 01_23_56 16 thg 10, 2025.png');
  background-size: cover;
  background-position: center;
  animation: galaxyMove 20s ease-in-out infinite alternate;
  z-index: -1; /* Đặt sau nội dung */
}


/* Popup thêm ánh sáng neon tím */
.popup-content {
    border: 1px solid rgba(255, 0, 255, 0.3);
    box-shadow: 0 0 35px rgba(255, 0, 255, 0.6);
}
/* ===== THANH MENU ===== */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(0, 0, 40, 0.6);
  padding: 15px 50px;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.navbar h1 {
  font-size: 2rem;
  color: #aee4ff;
  text-shadow: 0 0 10px #39f;
}

.navbar ul {
  list-style: none;
  display: flex;
  gap: 30px;
  margin: 0;
}

.navbar ul li a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  transition: color 0.3s, text-shadow 0.3s;
}

.navbar ul li a:hover {
  color: #00c8ff;
  text-shadow: 0 0 10px #00c8ff;
}

/* ===== SẢN PHẨM CĂN GIỮA ===== */
.product-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 40px;
  padding: 40px 0;
}

.product-card {
  background: rgba(0, 0, 0, 0.7);
  border-radius: 20px;
  padding: 25px;
  width: 280px;
  text-align: center;
  box-shadow: 0 0 30px rgba(120, 180, 255, 0.4);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.product-card:hover {
  transform: translateY(-10px) scale(1.05);
  box-shadow: 0 0 40px rgba(120, 180, 255, 0.9);
}

.product-card img {
  width: 100%;
  height: 260px;
  object-fit: contain;
  border-radius: 12px;
}

/* ===== NÚT “CHI TIẾT” XANH BIỂN ===== */
.detail-btn {
  background: linear-gradient(90deg, #007bff, #00c6ff);
  border: none;
  padding: 12px 25px;
  font-size: 1.1rem;
  color: white;
  border-radius: 30px;
  cursor: pointer;
  transition: 0.3s;
}

.detail-btn:hover {
  transform: scale(1.08);
  background: linear-gradient(90deg, #00c6ff, #007bff);
}

/* ===== BỐ CỤC CHÍNH ===== */
.main-container {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 30px;
    margin: 30px auto;
    width: 90%;
}
/* === Hiệu ứng hover cho giá sản phẩm === */
.price:hover {
  opacity: 0.8;
  text-shadow: 0 0 10px var(--accent);
}

/* === Hiệu ứng cho nút “Mua ngay” và “Thêm vào giỏ” === */
.buy:hover {
  background: linear-gradient(90deg, #ff4081, #e91e63);
  box-shadow: 0 0 12px rgba(233, 30, 99, 0.5);
}

.add:hover {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 8px rgba(233, 30, 99, 0.3);
}

/* === Hiệu ứng hover cho tab nội dung === */
.tab-buttons button:hover {
  background: rgba(233, 30, 99, 0.1);
  border-color: var(--accent);
}

/* === Responsive cho sản phẩm === */
@media (max-width: 768px) {
  .product {
    grid-template-columns: 1fr;
  }

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

  .product-card {
    width: 90%;
  }
}

/* === Hiệu ứng cho thumbnail khi được chọn === */
.thumb.active {
  border-color: var(--accent);
  box-shadow: 0 0 8px rgba(233, 30, 99, 0.4);
}
.tab-content,
.details,
.specs-short {
  color: black;
}
.nav-bar {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin: 20px 0;
}

.nav-item {
  padding: 10px 20px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  background-color: #ffffff;
  color: #333;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}

.nav-item:hover {
  background-color: #ffe4ec;
  border-color: #e91e63;
  color: #e91e63;
}

.nav-item.active {
  background-color: #e91e63;
  color: #fff;
  border-color: #e91e63;
}
.gallery {
  position: relative;
  background: rgba(255, 255, 255, 0.05);
  padding: 20px;
  border-radius: 12px;
}

.main-img {
  width: 100%;
  max-height: 400px;
  object-fit: contain;
  border-radius: 12px;
  margin-bottom: 16px;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
}

/* Thanh cuộn ảnh phụ */
.thumb-scroll {
  display: flex;
  overflow-x: auto;
  gap: 12px;
  padding-bottom: 8px;
  scrollbar-width: thin;
}

.thumb-scroll::-webkit-scrollbar {
  height: 6px;
}

.thumb-scroll::-webkit-scrollbar-thumb {
  background: #e91e63;
  border-radius: 3px;
}

.thumb {
  width: 80px;
  height: 80px;
  object-fit: cover;
  border-radius: 8px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.3s, border-color 0.3s;
}

.thumb:hover,
.thumb.active {
  border-color: #e91e63;
  transform: scale(1.05);
}
/* === KHUNG BANNER QUẢNG CÁO === */
.promo-banner {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 30px;
  color: white;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
  text-align: center;
}

.promo-banner h2 {
  font-size: 1.4rem;
  margin-bottom: 10px;
  color: #ff99cc;
}

.promo-banner p {
  font-size: 1rem;
  color: #eee;
}

/* === TAB THÔNG TIN SẢN PHẨM === */
.info-tabs {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 24px;
  color: white;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
}

.tab-buttons {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.tab-buttons button {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.3s ease, border-color 0.3s ease;
}

.tab-buttons button.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.tab-buttons button:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent);
}

.tab-content {
  display: none;
  animation: fadeIn 0.4s ease;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: translateY(0); }
}

.tab-content h2 {
  font-size: 1.2rem;
  color: #ff99cc;
  margin-bottom: 10px;
}

.tab-content p {
  font-size: 1rem;
  color: #eee;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}

td {
  padding: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: #ddd;
}

td:first-child {
  color: #aaa;
  width: 40%;
}
.details,
.promo-banner {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 30px;
  color: white;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
}

/* Tiêu đề và giá */
.details h1,
.promo-banner h2 {
  font-size: 1.4rem;
  margin-bottom: 10px;
  color: #ff99cc;
}

.price {
  font-size: 1.2rem;
  font-weight: bold;
  color: #fff;
  margin-bottom: 16px;
}

/* Tùy chọn dung lượng */
.option {
  margin-bottom: 16px;
}

.option p {
  margin-bottom: 8px;
  color: #ccc;
}

.option-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  margin-right: 8px;
  transition: background 0.3s ease, border-color 0.3s ease;
}

.option-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.option-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent);
}

/* Nút hành động */
.actions,
.promo-banner button {
  display: inline-block;
  margin-right: 12px;
  margin-top: 12px;
}

.btn,
.promo-banner button {
  background: linear-gradient(90deg, #007bff, #00c6ff);
  border: none;
  padding: 10px 20px;
  color: white;
  border-radius: 30px;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.3s ease;
}

.btn:hover,
.promo-banner button:hover {
  background: linear-gradient(90deg, #00c6ff, #007bff);
}

/* Danh sách thông số */
.specs-short {
  list-style: none;
  padding: 0;
  margin-top: 16px;
}

.specs-short li {
  padding: 6px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: #eee;
}
.color-gallery {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 30px;
  color: white;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
  text-align: center;
}

.color-gallery .main-img {
  width: 100%;
  max-height: 400px;
  object-fit: contain;
  border-radius: 12px;
  margin-bottom: 16px;
}

.color-options p {
  margin-bottom: 8px;
  color: #ccc;
}

.color-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  margin: 6px;
  transition: background 0.3s ease, border-color 0.3s ease;
}

.color-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.color-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent);
}
.feature-box.ipad {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 30px;
  color: white;
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.1);
  animation: fadeIn 0.6s ease;
}

.feature-box.ipad h2 {
  font-size: 1.4rem;
  margin-bottom: 16px;
  color: #ff99cc;
  text-align: center;
}

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.feature-list li {
  margin-bottom: 12px;
  padding-left: 28px;
  position: relative;
  font-size: 1rem;
  color: #eee;
}

.feature-list li::before {
  content: "🎥";
  position: absolute;
  left: 0;
  font-size: 1.2rem;
  color: var(--accent);
}

/* Hiệu ứng xuất hiện */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
/* Khung sản phẩm sẫm, nổi bật nội dung */
.details,
.product-card,
.promo-banner,
.info-tabs,
.feature-box.ipad {
  background: rgba(15, 10, 25, 0.8);
  border: 1px solid rgba(255, 100, 255, 0.2);
  box-shadow: 0 0 25px rgba(100, 0, 150, 0.3);
}

/* Nút và hiệu ứng neon dịu hơn */
.btn, .promo-banner button, .buy {
  background: linear-gradient(90deg, #b000ff, #ff00aa);
  box-shadow: 0 0 10px rgba(255, 0, 200, 0.4);
}
.btn:hover, .promo-banner button:hover, .buy:hover {
  background: linear-gradient(90deg, #ff00aa, #b000ff);
  box-shadow: 0 0 20px rgba(255, 0, 255, 0.6);
}

/* Chữ giá – sáng tím nhẹ */
.price {
  color: #ff77dd;
  text-shadow: 0 0 12px rgba(255, 0, 200, 0.6);
}

/* Màu chữ mô tả dịu hơn */
.specs-short li, .tab-content p, .feature-list li {
  color: #ccc;
}
.product {
  background: rgba(20, 10, 40, 0.85); /* nền tím đậm, hơi trong suốt */
  border: 1px solid rgba(255, 100, 255, 0.2); /* viền tím nhẹ */
  box-shadow: 0 0 25px rgba(150, 0, 255, 0.3); /* hiệu ứng phát sáng tím */
  border-radius: 15px;
  padding: 20px;
}
/* Logo trong header */
.logo {
  display: flex;
  align-items: center;
  font-size: 1.5em;
  font-weight: bold;
  color: #fff;
}

.logo img {
  height: 45px;
  width: auto;
  margin-right: 10px;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.3);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(20, 15, 30, 0.9);
  padding: 10px 40px;
  box-shadow: 0 0 20px rgba(255, 100, 255, 0.2);
  position: sticky;
  top: 0;
  z-index: 100;
}
/* ===== Khung Chat ===== */
#chatbot-container {
  position: fixed;
  bottom: 80px;
  right: 25px;
  width: 320px;
  font-family: Arial, sans-serif;
  z-index: 9999;
  display: none; /* Ẩn mặc định */
}

#chatbot-body {
  background: #fff;
  border: 2px solid #0078ff;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.25);
  display: flex;
  flex-direction: column;
  height: 400px;
}

#chatbot-header {
  background: linear-gradient(45deg, #0078ff, #00c3ff);
  color: white;
  padding: 10px;
  text-align: center;
  border-radius: 10px 10px 0 0;
  font-weight: bold;
}

#chatbot-messages {
  flex: 1;
  overflow-y: auto;
  padding: 10px;
  border-top: 1px solid #eee;
  border-bottom: 1px solid #eee;
}

#chatbot-input-area {
  display: flex;
  padding: 8px;
  border-top: 1px solid #ddd;
}

#chatbot-input {
  flex: 1;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 5px;
}

#chatbot-input:focus {
  outline: none;
  border-color: #0078ff;
}

#chatbot-input-area button {
  margin-left: 5px;
  padding: 8px 12px;
  border: none;
  background: #0078ff;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}

#chatbot-input-area button:hover {
  background: #005fcc;
}

.user-msg {
  text-align: right;
  color: #333;
  margin: 5px 0;
}

.bot-msg {
  text-align: left;
  color: #0078ff;
  margin: 5px 0;
}

/* ===== Icon Chat ===== */
#chatbot-icon {
  position: fixed;
  bottom: 20px;
  right: 25px;
  width: 55px;
  height: 55px;
  background: linear-gradient(45deg, #0078ff, #00c3ff);
  color: white;
  border-radius: 50%;
  font-size: 26px;
  text-align: center;
  line-height: 55px;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
  transition: transform 0.2s, box-shadow 0.2s;
  z-index: 10000;
}