:root {
    --bg: #0b0f19;
    --accent: #3b82f6;
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    --glass: rgba(255, 255, 255, 0.03);
    --border: rgba(255, 255, 255, 0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }
body { background: var(--bg); color: var(--text-main); overflow-y: auto; }

.container { max-width: 1240px; margin: 0 auto; padding: 0 25px; }

/* Bài 1: Sticky Header & UI */
.main-header {
    position: fixed; top: 0; width: 100%; z-index: 1000;
    padding: 20px 0; border-bottom: 1px solid var(--border);
    background: rgba(11, 15, 25, 0.8); backdrop-filter: blur(15px);
}
.nav-wrapper { display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 1.5rem; font-weight: 800; color: #fff; text-decoration: none; }
.logo span { color: var(--accent); }
.nav-links { display: flex; list-style: none; gap: 40px; }
.nav-links a { color: var(--text-dim); text-decoration: none; transition: 0.3s; font-size: 0.9rem; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); }

/* Bài 2: Hero UI */
.hero { padding: 180px 0 100px; }
.hero-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; align-items: center; gap: 50px; }
.reveal-text { font-size: 5rem; line-height: 1; margin-bottom: 25px; }
.reveal-text span { color: var(--accent); }
.hero-desc { color: var(--text-dim); font-size: 1.1rem; max-width: 500px; margin-bottom: 35px; }

.blob {
    width: 400px; height: 400px;
    background: linear-gradient(45deg, var(--accent), #8b5cf6);
    filter: blur(80px); opacity: 0.3; border-radius: 50%;
}

/* Bài 5: Masonry Layout */
.masonry-layout { column-count: 3; column-gap: 20px; padding: 50px 0; }
.masonry-item { break-inside: avoid; margin-bottom: 20px; border-radius: 20px; overflow: hidden; border: 1px solid var(--border); }
.masonry-item img { width: 100%; transition: 0.5s cubic-bezier(0.4, 0, 0.2, 1); }
.masonry-item:hover img { transform: scale(1.1); filter: brightness(1.2); }

/* Responsive */
@media (max-width: 992px) {
    .hero-grid { grid-template-columns: 1fr; text-align: center; }
    .hero-desc { margin: 0 auto 30px; }
    .masonry-layout { column-count: 2; }
    .nav-links { display: none; }
}
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 100px;
    background: var(--glass);
    padding: 50px;
    border-radius: 30px;
    border: 1px solid var(--border);
    backdrop-filter: blur(20px);
}

.contact-info h1 span { color: var(--accent); }
.info-details { margin-top: 40px; }
.info-item { display: flex; gap: 15px; margin-bottom: 25px; }

/* Bài 4: Floating Label UI */
.input-group {
    position: relative;
    margin-bottom: 35px;
}

.input-group input, .input-group textarea {
    width: 100%;
    padding: 10px 0;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--border);
    color: white;
    font-size: 1rem;
    outline: none;
    transition: 0.3s;
}

.input-group label {
    position: absolute;
    top: 10px;
    left: 0;
    color: var(--text-dim);
    transition: 0.3s ease all;
    pointer-events: none;
}

.input-group input:focus ~ label,
.input-group input:valid ~ label,
.input-group textarea:focus ~ label,
.input-group textarea:valid ~ label {
    top: -20px;
    font-size: 0.8rem;
    color: var(--accent);
}

.input-group .bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 0;
    background: var(--accent);
    transition: 0.4s;
}

.input-group input:focus ~ .bar, .input-group textarea:focus ~ .bar {
    width: 100%;
}

.btn-send {
    width: 100%;
    padding: 15px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    position: relative;
    overflow: hidden;
    transition: 0.3s;
}

.btn-send:hover { transform: translateY(-3px); box-shadow: 0 10px 20px rgba(59, 130, 246, 0.3); }

#toast {
    position: fixed;
    top: 25px;
    right: 30px;
    border-radius: 12px;
    background: #fff;
    padding: 20px 35px 20px 25px;
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
    border-left: 6px solid var(--accent);
    overflow: hidden;
    transform: translateX(calc(100% + 30px));
    transition: all 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    z-index: 9999;
}

#toast.active {
    transform: translateX(0%);
}

.toast-content {
    display: flex;
    align-items: center;
}

.toast-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 35px;
    width: 35px;
    background-color: var(--accent);
    color: #fff;
    font-size: 20px;
    border-radius: 50%;
}

.toast-message {
    display: flex;
    flex-direction: column;
    margin: 0 20px;
}

.text-1 {
    font-weight: 600;
    color: #333;
}

.text-2 {
    font-size: 14px;
    color: #666;
}

.progress {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    width: 100%;
    background: #ddd;
}

.progress:before {
    content: '';
    position: absolute;
    bottom: 0;
    right: 0;
    height: 100%;
    width: 100%;
    background-color: var(--accent);
}

#toast.active .progress:before {
    animation: progress 3s linear forwards;
}

@keyframes progress {
    100% { right: 100%; }
}
:root {
    --padding-section: 80px 0;
    --gap: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

.section-padding { padding: var(--padding-section); }

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--gap);
    margin-top: 50px;
}

.service-card {
    background: var(--glass);
    padding: 30px;
    border-radius: 20px;
    border: 1px solid var(--border);
    transition: 0.3s ease;
}

.masonry-wrapper {
    column-count: 3;
    column-gap: var(--gap);
    width: 100%;
}

.portfolio-item {
    break-inside: avoid; 
    margin-bottom: var(--gap);
    position: relative;
    border-radius: 15px;
    overflow: hidden;
}

.portfolio-item img {
    width: 100%; 
    display: block;
    height: auto;
}

@media (max-width: 992px) {
    .masonry-wrapper { column-count: 2; }
    .display-title { font-size: 2.5rem; }
}

@media (max-width: 600px) {
    .masonry-wrapper { column-count: 1; } 
    .services-grid {
        grid-template-columns: 1fr; 
    }
    .section-padding { padding: 50px 0; }
    .filter-container {
        display: flex;
        overflow-x: auto; 
        padding-bottom: 10px;
        white-space: nowrap;
    }
}

html, body {
    max-width: 100vw;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

.masonry-wrapper {
    column-count: 3;
    column-gap: 20px;
    width: 100%;
}

.portfolio-item {
    break-inside: avoid;
    margin-bottom: 20px;
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition-smooth);
}

/* Hiệu ứng kính mờ khi hover vào ảnh */
.work-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(11, 15, 25, 0.9), transparent);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 25px;
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition-smooth);
}

.portfolio-item:hover .work-overlay {
    opacity: 1;
    transform: translateY(0);
}

.portfolio-item:hover img {
    transform: scale(1.1);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.service-card {
    background: var(--glass);
    padding: 40px 30px;
    border-radius: 24px;
    border: 1px solid var(--border);
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: radial-gradient(circle at top right, rgba(59, 130, 246, 0.1), transparent);
    opacity: 0;
    transition: 0.5s;
}

.service-card:hover {
    border-color: var(--accent);
    transform: translateY(-10px);
}

.service-card:hover::before { opacity: 1; }

.acc-header {
    width: 100%;
    background: none;
    border: none;
    color: var(--accent);
    display: flex;
    justify-content: space-between;
    padding: 15px 0 0;
    cursor: pointer;
    font-weight: 600;
}

.acc-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    color: var(--text-dim);
    font-size: 0.95rem;
    line-height: 1.6;
}

.accordion-item.active .acc-content {
    max-height: 150px;
    margin-top: 10px;
}

@media (max-width: 992px) {
    .masonry-wrapper { column-count: 2; }
    .reveal-text { font-size: 3.5rem; }
}

@media (max-width: 600px) {
    .masonry-wrapper { column-count: 1; }
    .container { padding: 0 15px; }
    .contact-wrapper {
        grid-template-columns: 1fr;
        padding: 30px 20px;
    }
}
.main-footer {
    background: rgba(11, 15, 25, 0.98);
    border-top: 1px solid var(--border);
    padding: 80px 0 0;
    margin-top: 100px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 60px;
    padding-bottom: 60px;
}

.footer-brand .logo { font-size: 2rem; }
.footer-brand p { color: var(--text-dim); margin: 20px 0; line-height: 1.6; }

.footer-links h4, .footer-contact h4 {
    color: white;
    margin-bottom: 25px;
    font-size: 1.2rem;
}

.footer-links ul { list-style: none; }
.footer-links ul li { margin-bottom: 12px; }
.footer-links ul li a { color: var(--text-dim); text-decoration: none; transition: 0.3s; }
.footer-links ul li a:hover { color: var(--accent); padding-left: 5px; }

.footer-contact p { color: var(--text-dim); margin-bottom: 15px; }

.footer-bottom {
    border-top: 1px solid var(--border);
    padding: 30px 0;
    background: #060910;
}

.bottom-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.bottom-flex p { color: var(--text-dim); font-size: 0.9rem; }

.btn-top {
    background: var(--accent);
    color: white;
    border: none;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    cursor: pointer;
    transition: 0.4s;
    font-size: 1.2rem;
}

.btn-top:hover { transform: translateY(-5px); box-shadow: 0 5px 15px rgba(59, 130, 246, 0.4); }

/* Responsive Footer */
@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    .footer-links ul li a:hover { padding-left: 0; }
    .bottom-flex { flex-direction: column; gap: 20px; }
}
.filter-btn :hover{
    animation: scales 3s ease-in forwards;

}
.filter-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 40px 0;
    flex-wrap: wrap;
}

.filter-btn {
    position: relative;
    padding: 12px 28px;
    border-radius: 50px;
    background: var(--glass);
    border: 1px solid var(--border);
    color: var(--text-dim);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); 
    overflow: hidden;
    z-index: 1;
}

.filter-btn:hover {
    color: white;
    transform: scale(1.1); 
    border-color: var(--accent);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.4);
}

.filter-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
    box-shadow: 0 10px 25px rgba(59, 130, 246, 0.5);
    transform: scale(1.05);
}

.filter-btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
    z-index: -1;
}

.filter-btn:active::after {
    width: 200px;
    height: 200px;
    opacity: 0;
}