/* ================= Global Styles & Fonts ================= */
body {
    font-family: 'Roboto', sans-serif;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}

/* Language Toggle Logic */
:lang(en) .lang-cn { display: none !important; }
:lang(zh-CN) .lang-en { display: none !important; }
#lang-switch-btn span { display: inline-block; }

/* ================= Home Carousel ================= */
#home { padding: 0 !important; }
#homeCarousel .carousel-item {
    height: 65vh; 
    background-size: cover;
    background-position: center;
    position: relative;
}
#homeCarousel .carousel-item::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)); z-index: 1;
}
#homeCarousel .hero-content-wrapper {
    position: relative; z-index: 2; height: 90vh;
}

/* ================= Floating Contact Bar ================= */
#floating-contact {
    position: fixed; top: 50%; right: 0; transform: translateY(-50%);
    z-index: 1050; display: flex; flex-direction: column;
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}
.contact-item {
    display: flex; align-items: center; justify-content: flex-end; 
    padding: 10px 15px; margin-bottom: 5px; color: #fff; text-decoration: none;
    font-weight: 500; border-radius: 5px 0 0 5px; transition: all 0.3s;
}
.contact-item:hover {
    box-shadow: 0 0 15px rgba(0,0,0,0.3);
    transform: translateX(-5px);
}
.contact-item i { margin-left: 10px; font-size: 1.2rem; }
.phone-call { background-color: #007bff; }
.whatsapp { background-color: #25d366; }

/* ================= Client Logo Slider ================= */
#clients { padding: 40px 0; background-color: #fff; }
.logo-slider-wrapper {
    display: flex; overflow: hidden; padding: 0px 0; cursor: default;
    width: 100vw; position: relative; left: 50%; right: 50%; margin-left: -50vw; margin-right: -50vw;
}
.logo-slide-container {
    display: flex; white-space: nowrap; animation: slide-left 25s linear infinite; 
}
.logo-slide-container:hover { animation-play-state: paused; }
.logo-slide {
    flex-shrink: 0; padding: 0 30px; opacity: 1; transition: opacity 0.3s; display: flex; align-items: center;
}
.logo-slide img {
    height: 85px; width: auto; max-width: none;  transition: filter 0.3s;
}
.logo-slide:hover img { filter: grayscale(0%); }
@keyframes slide-left {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); } 
}

/* ================= Why Choose Us Module ================= */
#why-us {
    background: url('../images/bg-why-us.jpg') no-repeat center center;
    background-size: cover; min-height: auto; position: relative; padding: 80px 0;
}
#why-us::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0, 0, 0, 0.8); z-index: 1;
}
#why-us .container { position: relative; z-index: 2; color: #fff; }
.advantage-card {
    background: rgba(255, 255, 255, 0.95); color: #333; padding: 30px;
    border-radius: 8px; box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    height: 100%; text-align: center; transition: all 0.3s ease;
}
.advantage-card:hover {
    transform: translateY(-5px); box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}
.advantage-card i { font-size: 3rem; color: #000; margin-bottom: 15px; }

/* ================= Project Carousel Styles ================= */
#projects .carousel-item { padding: 20px 0; }
.project-card {
    background: #fff; box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05); transition: box-shadow 0.3s;
}
.project-card:hover { box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1); }
#projectCarousel .carousel-control-prev, #projectCarousel .carousel-control-next { width: 5%; opacity: 0.8; }
#projectCarousel .row { margin-bottom: 0 !important; }

/* ================= Buttons & Navbar ================= */
.btn-dark-custom {
    background-color: #000; color: #fff; border: 2px solid #000;
    border-radius: 0; padding: 10px 25px; font-weight: 500; transition: all 0.3s;
}
.btn-dark-custom:hover { background-color: #333; border-color: #333; color: #fff; }
.navbar { background-color: #fff; box-shadow: 0 2px 10px rgba(0,0,0,0.1); padding: 15px 0; transition: all 0.3s; }
.navbar-brand { font-weight: 700; font-size: 1.5rem; color: #000; }
.nav-link { color: #000 !important; font-weight: 500; margin: 0 10px; transition: color 0.3s; }
.btn-consult { background-color: #000; color: #fff; border-radius: 0; padding: 10px 25px; font-weight: 500; transition: all 0.3s; }
#lang-switch-btn { border: 1px solid #000; padding: 5px 15px; margin-left: 15px; font-size: 0.9rem; cursor: pointer; }

/* ================= Common Sections ================= */
section { padding: 40px 0; }
.section-title { text-align: center; margin-bottom: 20px; }
.feature-banner {
    position: relative; width: 100%; min-height: 380px; background-size: cover; 
    background-position: center; display: flex; align-items: center; justify-content: center; margin-bottom: 60px;
}
.feature-overlay-box {
    background-color: rgba(255, 255, 255, 0.95); padding: 40px; max-width: 550px; margin: 0;
    box-shadow: 0 15px 30px rgba(0,0,0,0.15); border-left: 5px solid #000; text-align: center;
}
.process-icon {
    font-size: 3.5rem; color: #000; background: #f4f4f4; width: 100px; height: 100px;
    line-height: 100px; border-radius: 50%; margin: 0 auto 25px; transition: all 0.3s;
}
.testimonial-author { font-weight: 700; margin-top: 20px; color: #000; }
footer { background-color: #1a1a1a; color: #ccc; padding: 60px 0 20px; font-size: 0.9rem; }
footer ul { padding: 0; list-style: none; }
footer ul a { color: #ccc; text-decoration: none; display: block; padding: 5px 0; transition: color 0.3s; }
.social-icons a { display: inline-block; color: #fff; font-size: 1.2rem; margin-right: 15px; transition: color 0.3s; }
.copyright { text-align: center; border-top: 1px solid #333; padding-top: 20px; margin-top: 40px; color: #666; }

/* ================= Custom Cards & Interactions ================= */
.card-custom { 
    border: none; margin-bottom: 30px; transition: transform 0.3s ease, box-shadow 0.3s ease; height: 100%; will-change: transform, box-shadow;
}
.card-custom:hover, .card-custom:focus {
    transform: translateY(-5px) scale(1.02); box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15); z-index: 1;
}
.card-body { padding: 25px; background: #fff; border: 1px solid #eee; border-top: none; }
.testimonial-item { 
    background: #f4f4f4; padding: 30px; border-radius: 5px; margin-bottom: 20px; 
    position: relative; height: 100%; transition: transform 0.3s ease, box-shadow 0.3s ease; will-change: transform, box-shadow;
}
.testimonial-item:hover, .testimonial-item:focus {
    transform: translateY(-3px); box-shadow: 0 8px 15px rgba(0,0,0,0.1);
}

/* ================= Responsive ================= */
@media (max-width: 991px) {
    #homeCarousel .carousel-item, #homeCarousel .hero-content-wrapper { height: 40vh; }
    #homeCarousel h1 { font-size: 2.0rem; }
    #homeCarousel p.lead { font-size: 1rem; }
    #floating-contact {
        position: fixed; bottom: 0; left: 0; right: 0; top: auto; transform: none;
        flex-direction: row; width: 100%; margin-bottom: 0; box-shadow: 0 -2px 10px rgba(0,0,0,0.1); border-radius: 0;
    }
    .contact-item { flex: 1; justify-content: center; margin: 0; border-radius: 0; padding: 15px 10px; }
    .contact-item span { display: none; }
    .contact-item i { margin: 0; }
    .installation-process-row { display: none !important; }
    #why-us { padding: 30px 0; min-height: auto; }
}
@media (max-width: 576px) {
    .card-title { font-size: 1rem; font-weight: 700; }
    .card-text { font-size: 0.85rem; }
    .card-body { padding: 15px; }
    .col-6 { padding-left: 5px; padding-right: 5px; }
}