:root {
    --orange: #FF8C42;
    --blue: #0047AB;
    --bg-dark: #0a0a0a;
    --light: #f8f9fa;
    --text-dark: #333;
    --dark-bg: #1a1a1a;
    --footer-text: #cccccc;
    --font-main: 'Raleway', sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: var(--font-main); }
body { background-color: var(--light); color: var(--text-dark); overflow-x: hidden; scroll-behavior: smooth; }

/* --- NAVIGATION --- */
nav { 
    position: fixed; top: 0; left: 0; width: 100%; padding: 15px 8%; 
    display: flex; justify-content: space-between; align-items: center; 
    z-index: 9999; background: white; box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.nav-logo { display: flex; align-items: center; text-decoration: none; }
.logo-text-main { fill: var(--blue); }

.nav-links {
    display: flex; align-items: center; list-style: none; gap: 10px;
    position: relative; padding: 10px 25px;
}
.nav-item { position: relative; }
.nav-links li a { 
    display: flex;           
    align-items: center;     
    justify-content: center; 
    text-align: center;
    text-decoration: none; color: var(--blue); font-weight: 700; font-size: 13px; 
    text-transform: uppercase; padding: 10px 20px; display: inline-block;
    position: relative; z-index: 2; transition: color 0.3s ease;
}
.nav-marker {
    position: absolute; height: 38px; width: 0; top: 50%; transform: translateY(-50%);
    left: 0; background: var(--blue); border-radius: 20px; z-index: 1; opacity: 0;
    pointer-events: none; transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
}
.nav-links li:hover a { color: white !important; }
.nav-links:not(:hover) .nav-marker { opacity: 0 !important; width: 0 !important; }

/* SUB-MENU */
.sub-menu {
    position: absolute; top: 100%; left: 50%; transform: translateX(-50%) translateY(20px);
    background: rgba(10, 10, 10, 0.85); backdrop-filter: blur(25px);
    padding: 10px; border-radius: 12px; min-width: 240px;
    border: 1px solid rgba(255, 255, 255, 0.05); opacity: 0; visibility: hidden;
    transition: all 0.4s cubic-bezier(0.19, 1, 0.22, 1); z-index: 9990;
}
.nav-item:hover .sub-menu { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(10px); }
nav.scrolled .sub-menu { background: rgba(255, 255, 255, 0.98); border: 1px solid rgba(0, 0, 0, 0.05); box-shadow: 0 10px 30px rgba(0,0,0,0.08); }
.sub-menu ul { list-style: none; display: flex; flex-direction: column; gap: 5px; padding: 0 !important; }
.sub-menu ul li a {
    color: #fff !important; font-size: 13px !important; font-weight: 600 !important;
    text-transform: none !important; letter-spacing: 0.5px; padding: 10px 15px !important;
    border-radius: 8px; transition: all 0.3s ease !important; display: block; width: 100%; white-space: nowrap;
}
nav.scrolled .sub-menu ul li a { color: var(--text-dark) !important; }
.sub-menu ul li a:hover { color: var(--orange) !important; transform: translateX(8px); background: rgba(255, 140, 66, 0.1); }

/* --- HERO BANNER CAO CẤP --- */
.inverter-banner {
    margin-top: 130px;
    position: relative; width: 100%; height: 65vh; min-height: 500px;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; background: #000;
}
.inverter-banner img {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    object-fit: cover; object-position: center center; z-index: 1;
}
/* Đổi gradient banner Smarthome cho tối và sang hơn */
.smarthome-banner::after {
    content: ""; position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to right, rgba(0, 71, 171, 0.7) 0%, rgba(0,0,0,0.5) 100%);
    z-index: 2;
}
.page-header {
    position: relative; z-index: 3; text-align: center; padding: 0 10%; background: transparent !important;
}
.page-header h1 {
    font-size: clamp(35px, 5vw, 60px); font-weight: 900; color: #ffffff;
    text-transform: uppercase; letter-spacing: -1px; margin-bottom: 20px;
    text-shadow: 0 10px 30px rgba(0, 0, 0, 0.5); animation: fadeInUp 1s ease-out;
}
.page-header h1::after {
    content: ""; display: block; width: 80px; height: 6px;
    background: var(--orange); margin: 20px auto; border-radius: 10px;
}
.page-header p {
    font-size: clamp(14px, 2vw, 20px); font-weight: 700; color: var(--orange);
    letter-spacing: 4px; text-transform: uppercase;
    text-shadow: 0 5px 15px rgba(0, 0, 0, 0.4); animation: fadeInUp 1.2s ease-out;
}
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- MAIN LAYOUT --- */
.main-content-layout { display: flex; padding: 50px 8%; gap: 40px; background: #fcfcfc; }

/* SIDEBAR */
.sidebar { flex: 0 0 280px; }
.sidebar-sticky { position: sticky; top: 100px; }
.sidebar-section { margin-bottom: 35px; }
.sidebar-section h3 {
    font-size: 14px; text-transform: uppercase; letter-spacing: 2px;
    color: var(--blue); margin-bottom: 20px; border-left: 4px solid var(--orange); padding-left: 15px;
}
.group-title { font-size: 12px !important; color: #999 !important; margin: 20px 0 10px !important; display: flex; align-items: center; gap: 8px; }

.search-box { position: relative; }
.search-box input { width: 100%; padding: 15px 15px 15px 45px; border: 1px solid #eee; border-radius: 12px; outline: none; }
.search-box i { position: absolute; left: 15px; top: 50%; transform: translateY(-50%); color: var(--orange); }

.nav-link-item {
    display: block; padding: 12px 15px; color: #555; text-decoration: none;
    font-weight: 700; font-size: 14px; border-radius: 10px; transition: 0.3s;
}
.nav-link-item:hover { background: var(--blue); color: white !important; padding-left: 25px; }

/* PRODUCT DISPLAY */
.product-display { flex: 1; }
.featured-section {
    background: linear-gradient(135deg, #fff, #f0f7ff); padding: 30px;
    border-radius: 25px; margin-bottom: 50px; border: 1px solid #eef2f6;
}
.featured-header h2 { color: var(--blue); margin-bottom: 25px; font-size: 22px; }
.featured-header i { color: var(--orange); }

.brand-section { position: relative; padding: 40px 0 80px 0; overflow: hidden; border-bottom: 1px solid #eee; }
.bg-scroll-t {
    position: absolute; right: -5%; top: 50%; transform: translateY(-50%);
    font-size: 600px; font-weight: 900; color: rgba(0, 71, 171, 0.03); /* Chữ nền mờ xanh */
    z-index: 0; pointer-events: none; user-select: none;
}
.brand-header { position: relative; z-index: 2; margin-bottom: 40px; }
.brand-header h2 { font-size: 28px; color: var(--blue); text-transform: uppercase; border-left: 6px solid var(--orange); padding-left: 20px; }

.section-divider { border: 0; height: 1px; background: #eaeaea; margin: 40px 0; }

/* PRODUCT CARDS */
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 30px; position: relative; z-index: 2; }
.product-item {
    background: white; border-radius: 20px; padding: 30px; border: 1px solid rgba(0,0,0,0.03);
    transition: all 0.4s ease; display: flex; flex-direction: column; position: relative; cursor: pointer;
}
.product-item:hover { transform: translateY(-10px); box-shadow: 0 20px 40px rgba(0,71,171,0.1); border-color: var(--orange); }

.featured-item { border: 2px solid var(--orange) !important; }
.featured-item::before {
    content: "HOT"; position: absolute; top: 15px; left: 15px; background: var(--orange);
    color: white; padding: 4px 10px; font-size: 10px; font-weight: 900; border-radius: 5px; z-index: 3;
}

.img-box { height: 200px; display: flex; align-items: center; justify-content: center; margin-bottom: 20px; overflow: hidden; }
.img-box img { max-width: 90%; max-height: 90%; object-fit: contain; transition: 0.5s; }
.product-item:hover .img-box img { transform: scale(1.1); }

.product-name { font-size: 15px; font-weight: 800; color: var(--blue); margin-bottom: 20px; line-height: 1.5; min-height: 45px; }
.product-bottom { margin-top: auto; display: flex; align-items: center; justify-content: space-between; padding-top: 15px; border-top: 1px solid #f9f9f9; }
.price { color: var(--orange); font-weight: 900; font-size: 16px; }
.btn-mini { color: var(--blue); font-size: 22px; transition: 0.3s; }
.product-item:hover .btn-mini { color: var(--orange); transform: translateX(5px); }

/* FOOTER */
.main-footer { background-color: var(--dark-bg); color: #fff; padding: 60px 0 20px 0; }
.footer-container { max-width: 1200px; margin: 0 auto; padding: 0 20px; display: grid; grid-template-columns: 1.5fr 1fr 1.5fr; gap: 40px; }
.footer-col h4 { color: var(--orange); font-size: 1.2rem; margin-bottom: 25px; position: relative; text-transform: uppercase; font-weight: 700; }
.footer-col h4::after { content: ''; position: absolute; left: 0; bottom: -8px; width: 50px; height: 2px; background: var(--orange); }
.footer-slogan { font-size: 1rem; font-weight: 900; color: var(--orange); margin: 15px 0; letter-spacing: 1px; }
.footer-desc { color: var(--footer-text); line-height: 1.6; font-size: 0.9rem; margin-bottom: 20px; }
.footer-links { list-style: none; padding: 0; }
.footer-links li { margin-bottom: 12px; }
.footer-links a { color: var(--footer-text); text-decoration: none; transition: 0.3s; font-size: 0.95rem; }
.footer-links a:hover { color: var(--orange); padding-left: 5px; }
.footer-contact ul { list-style: none; padding: 0; }
.footer-contact li { display: flex; align-items: flex-start; gap: 15px; margin-bottom: 15px; color: var(--footer-text); font-size: 0.9rem; }
.footer-contact i { color: var(--orange); margin-top: 4px; width: 20px; text-align: center; }
.footer-social { display: flex; gap: 15px; }
.footer-social a { width: 35px; height: 35px; background: #333; color: white; display: flex; align-items: center; justify-content: center; border-radius: 50%; transition: 0.3s; text-decoration: none; }
.footer-social a:hover { background: var(--orange); transform: translateY(-3px); }
.footer-bottom { margin-top: 50px; padding-top: 20px; border-top: 1px solid #333; text-align: center; font-size: 0.85rem; color: #777; }
.footer-bottom a { color: var(--orange); text-decoration: none; }

/* REVEAL EFFECT */
.reveal { opacity: 0; transform: translateY(30px); transition: 0.8s ease-out; }
.reveal.active { opacity: 1; transform: translateY(0); }

/* =========================================
   RESPONSIVE - MOBILE & TABLET
   ========================================= */
.menu-toggle { display: none; color: #121212; font-size: 26px; cursor: pointer; z-index: 10000; }

@media (max-width: 992px) {
    .main-content-layout { flex-direction: column; }
    .sidebar { flex: none; width: 100%; }
    .sidebar-sticky { position: relative; top: 0; }
    .footer-container { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .menu-toggle { display: block !important; margin-right: 15px; }

    .nav-links {
        position: fixed !important;
        top: 0 !important; right: -100% !important;
        width: 75% !important; height: 100vh !important;
        background: rgba(15, 15, 15, 0.98) !important;
        backdrop-filter: blur(15px) !important;
        -webkit-backdrop-filter: blur(15px) !important;
        flex-direction: column !important;
        justify-content: flex-start !important;
        align-items: flex-start !important;
        padding: 90px 30px 30px 30px !important;
        transition: right 0.4s cubic-bezier(0.19, 1, 0.22, 1) !important;
        overflow-y: auto !important;
        z-index: 9998 !important;
        gap: 0 !important;
    }
    .nav-links.nav-active { right: 0 !important; }

    .nav-item { width: 100% !important; margin-bottom: 5px !important; }
    .nav-item > a {
        color: #fff !important;
        font-size: 15px !important;
        display: flex !important;
        justify-content: space-between !important;
        align-items: center !important;
        width: 100% !important;
        padding: 15px 0 !important;
        border-bottom: 1px solid rgba(255,255,255,0.05) !important;
    }
    .nav-marker { display: none !important; }

    .sub-menu {
        position: relative !important;
        top: 0 !important; left: 0 !important;
        transform: none !important;
        width: 100% !important;
        background: transparent !important;
        border: none !important;
        box-shadow: none !important;
        padding: 0 !important; margin: 0 !important;
        opacity: 1 !important;
        visibility: visible !important;
        display: none !important;
    }
    .sub-menu.mobile-active { display: block !important; margin-top: 5px !important; }
    .sub-menu ul { padding: 0 !important; margin: 0 !important; display: flex !important; flex-direction: column !important; align-items: center !important; width: 100% !important; }
    .sub-menu ul li { width: 100% !important; display: block !important; }
    .sub-menu ul li a {
        padding: 12px 0 !important;
        font-size: 14px !important;
        color: rgba(255,255,255,0.7) !important;
        width: 100% !important;
        display: flex !important;
        justify-content: center !important;
        align-items: center !important;
        text-align: center !important;
        white-space: normal !important;
        transform: none !important;
        background: transparent !important;
    }

    nav.scrolled .nav-links li a { color: #fff !important; }
    nav.scrolled .sub-menu { background: transparent !important; border: none !important; box-shadow: none !important; }
    nav.scrolled .sub-menu ul li a { color: rgba(255,255,255,0.7) !important; }

    .main-content-layout { flex-direction: column !important; padding: 20px 5% !important; gap: 20px !important; }
    .sidebar { width: 100% !important; flex: none !important; padding: 0 !important; }
    .sidebar-sticky { position: relative !important; top: 0 !important; }

    .inverter-banner { 
        height: 250px !important; 
        min-height: unset !important; 
        margin-top: 110px !important; /* Đẩy banner xuống vừa vặn với chiều cao của menu */
    }
    .inverter-banner img {
        height: 100% !important; /* Để ảnh tự co giãn tỷ lệ thuận với chiều rộng */
        object-fit: contain !important; /* Hiển thị trọn vẹn 100% bức ảnh */
        object-position: center center !important;
    }
    .page-header h1 { font-size: 28px !important; letter-spacing: 0 !important; }
    .page-header p { letter-spacing: 2px !important; font-size: 12px !important; }

    .product-grid { grid-template-columns: repeat(2, 1fr) !important; gap: 12px !important; }
    .product-item { padding: 15px !important; }
    .img-box { height: 150px !important; }
    .product-name { font-size: 13px !important; min-height: unset !important; }
    .brand-section { padding: 30px 0 50px 0 !important; }
    .brand-header h2 { font-size: 20px !important; }
    .featured-section { padding: 20px !important; margin-bottom: 30px !important; }
    .footer-container { grid-template-columns: 1fr !important; }
}
/* Giữ nguyên kích thước và định dạng cũ cho giao diện máy tính */
.nav-logo img {
    height: 110px;
    width: auto;
    transform: translateY(5px);
    transition: height 0.3s ease; /* Thêm hiệu ứng cho mượt mà khi thu nhỏ trang */
}

/* Tạo giao diện nhỏ hơn cho màn hình điện thoại (chiều rộng màn hình tối đa 768px) */
@media (max-width: 768px) {
    .nav-logo img {
        height: 80px; /* Bạn có thể thay đổi số 60px này cho phù hợp với ý muốn */
        transform: translateY(0); /* Đặt lại giá trị dịch chuyển về 0 để logo cân giữa thanh menu trên điện thoại */
    }
}