@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600;700&display=swap');

* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    font-family: "Poppins", sans-serif; 
}

:root {
    --primary-color: #007bff;
    --secondary-color: #4953a0;
    --accent-color: #FFD700;
    --text-dark: #333;
    --text-light: #f8f8f8;
    --bg-light: #f4f7f6;
    --shadow: 0 10px 20px rgba(0,0,0,0.08);
    --transition: all 0.3s ease;
}

body { 
    background: var(--bg-light); 
    scroll-behavior: smooth; 
    padding-top: 80px; 
    color: var(--text-dark);
}

/* --- NAVBAR --- */
.navbar {
    position: fixed; top: 0; left: 0; width: 100%; 
    background: var(--primary-color);
    display: flex; justify-content: space-between; align-items: center;
    padding: 15px 5%; z-index: 1000; 
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.navbar .logo { 
    color: #fff; font-size: 22px; font-weight: 700; 
    letter-spacing: 0.5px; text-transform: uppercase;
}

.navbar ul { list-style: none; display: flex; gap: 25px; margin: 0; padding: 0; }

.navbar ul li a { 
    color: white; font-size: 16px; text-decoration: none; 
    font-weight: 500; transition: var(--transition); 
}

.navbar ul li a:hover { color: var(--accent-color); }

/* --- CONTAINER & LAYOUT --- */
.container { 
    display: flex; flex-wrap: wrap; gap: 30px; 
    padding: 40px 20px; justify-content: center; 
    max-width: 1200px; margin: 0 auto;
}

.update-box { 
    width: 100%; text-align: center; background: var(--secondary-color); 
    padding: 12px; font-size: 14px; font-weight: 600; 
    color: #fff; border-radius: 8px; margin-bottom: 20px;
    box-shadow: var(--shadow);
}

/* --- CARDS --- */
.card, .price-box {
    width: 100%; max-width: 360px; border-radius: 15px; 
    overflow: hidden; background: #fff; border: none;
    box-shadow: var(--shadow); transition: var(--transition); 
    padding: 0; /* Để header sát mép */
}

.card:hover, .price-box:hover { 
    transform: translateY(-10px); 
    box-shadow: 0 15px 30px rgba(0,0,0,0.15); 
}

.card-header { 
    background: var(--primary-color); color: #fff; 
    padding: 20px; font-size: 20px; font-weight: 600; 
    position: relative; 
}

.card-header span { 
    position: absolute; right: 15px; top: 18px; 
    background: rgba(255,255,255,0.2); color: #fff; 
    padding: 4px 12px; border-radius: 20px; 
    font-size: 12px; backdrop-filter: blur(5px);
    border: 1px solid rgba(255,255,255,0.3);
}

.card-body { padding: 25px; }

/* --- INFO SECTION --- */
.info { 
    display: flex; justify-content: space-between; 
    margin-bottom: 25px; border-bottom: 1px solid #eee; padding-bottom: 15px;
}

.info div img { width: 35px; height: 35px; margin-bottom: 8px; filter: grayscale(0.2); }

.info div span { font-size: 13px; font-weight: 600; color: #555; }

/* --- DETAILS LIST --- */
.details { text-align: left; margin-bottom: 20px; }

.details ul li { 
    margin-bottom: 10px; font-size: 14px; 
    display: flex; align-items: center; color: #444;
}

.details ul li::before { 
    content: "✓"; color: #28a745; font-weight: bold; 
    margin-right: 10px; background: #e8f5e9;
    width: 20px; height: 20px; display: flex;
    justify-content: center; align-items: center;
    border-radius: 50%; font-size: 10px;
}

/* --- PRICE SECTION --- */
.price-box { padding: 30px 20px; }

.price-box h3 { color: var(--primary-color); margin-bottom: 15px; font-size: 18px; }

.price { margin: 15px 0; }

.original-price { color: #999; text-decoration: line-through; font-size: 16px; }

.discounted-price { 
    color: #e63946; font-size: 28px; font-weight: 700; display: block;
}

.out-of-stock { 
    background: #ffebee; color: #c62828; padding: 2px 8px;
    border-radius: 4px; font-size: 12px; vertical-align: middle;
}

/* --- FOOTER --- */
footer { 
    text-align: center; background: #222; color: #bbb; 
    padding: 40px 20px; font-size: 14px; margin-top: 50px;
}

footer a { color: var(--primary-color); text-decoration: none; font-weight: 600; }

/* --- STAR RATING --- */
.stars { display: flex; flex-direction: row-reverse; justify-content: center; }

input.star { display: none; }

label.star { 
    padding: 5px; font-size: 24px; color: #ddd; 
    cursor: pointer; transition: var(--transition); 
}

input.star:checked ~ label.star { color: #ffca08; }

label.star:hover { transform: scale(1.2); color: #ffca08; }

label.star:before { content: '\f005'; font-family: FontAwesome; }

/* --- RESPONSIVE --- */
@media (max-width: 768px) {
    .navbar { padding: 10px 15px; }
    .navbar .logo { font-size: 18px; }
    .navbar ul { gap: 15px; }
    .navbar ul li a { font-size: 14px; }
    .container { padding: 20px 10px; }
}
/* --- PRICE BOX (Phần giá sim) --- */
.price-box { 
    text-align: center; 
    background: #ffffff; /* Nền trắng sạch sẽ */
    border: 2px solid #eef2f7; /* Thêm khung viền nhẹ */
    border-radius: 12px; 
    padding: 25px; 
    margin-top: 15px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05); /* Đổ bóng nhẹ tạo chiều sâu */
    transition: all 0.3s ease;
}

.price-box:hover {
    border-color: #1e90ff; /* Đổi màu khung khi di chuột vào */
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(30, 144, 255, 0.15);
}

.price-box h3 { 
    color: #1e90ff; 
    margin-bottom: 12px; 
    font-size: 19px; 
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.price { 
    display: flex;
    flex-direction: column; /* Đẩy giá gốc lên trên giá mới */
    gap: 5px;
    align-items: center;
}

.original-price { 
    color: #999; 
    text-decoration: line-through; 
    font-size: 15px; 
}

.discounted-price { 
    color: #ff4d4f; /* Màu đỏ hiện đại */
    font-size: 26px; 
    font-weight: 700; 
}

.out-of-stock { 
    background: #fff1f0;
    color: #f5222d; 
    font-size: 12px; 
    font-weight: bold; 
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid #ffa39e;
    margin-top: 5px;
    display: inline-block;
}

/* Đường kẻ phân cách */
.separator { 
    width: 80%; 
    height: 1px; 
    background: linear-gradient(to right, transparent, #ddd, transparent); 
    margin: 20px auto; 
}
/* --- BUY NOW BUTTON --- */
.buy-now-btn {
    display: inline-block;
    background: linear-gradient(45deg, #1e90ff, #0056b3); /* Gradient màu xanh cuốn hút */
    color: white;
    padding: 12px 30px;
    border-radius: 50px; /* Bo tròn hoàn toàn */
    text-decoration: none;
    font-size: 18px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    box-shadow: 0 8px 15px rgba(0, 123, 255, 0.3); /* Bóng đổ ấn tượng */
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden; /* Quan trọng cho hiệu ứng lấp lánh */
    margin-top: 25px; /* Khoảng cách với nội dung phía trên */
}

.buy-now-btn:hover {
    transform: translateY(-3px) scale(1.02); /* Nút nhích lên và to ra nhẹ */
    box-shadow: 0 12px 20px rgba(0, 123, 255, 0.45);
    background: linear-gradient(45deg, #0056b3, #1e90ff); /* Đảo ngược gradient */
}

/* Hiệu ứng lấp lánh (pulsating glow) */
.buy-now-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.6); /* Ánh sáng trắng mờ */
    border-radius: 50%;
    opacity: 0;
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease, opacity 0.4s ease;
    z-index: 1;
}

.buy-now-btn:hover::before {
    width: 200%;
    height: 200%;
    opacity: 1;
}

/* Đảm bảo chữ trên nút luôn nằm trên hiệu ứng lấp lánh */
.buy-now-btn span {
    position: relative;
    z-index: 2;
}

/* Thêm hiệu ứng lắc nhẹ khi hover để tăng sự chú ý */
.buy-now-btn:hover {
    animation: shake 0.3s cubic-bezier(.36,.07,.19,.97) both;
    transform: translateY(-3px) scale(1.02);
}

@keyframes shake {
    10%, 90% { transform: translate3d(-1px, -3px, 0) scale(1.02); }
    20%, 80% { transform: translate3d(2px, -3px, 0) scale(1.02); }
    30%, 50%, 70% { transform: translate3d(-4px, -3px, 0) scale(1.02); }
    40%, 60% { transform: translate3d(4px, -3px, 0) scale(1.02); }
}