:root {
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --color-bg: #ffffff;
    --color-surface: #ffffff;
    --color-surface-subtle: #f9fafb;
    --color-text: #111827;
    --color-text-muted: #6b7280;
    --color-accent-photo: rgba(251, 113, 133, 0.08);
    --color-accent-video: rgba(56, 189, 248, 0.08);
    --shadow-soft: 0 10px 40px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 20px 45px rgba(0, 0, 0, 0.12);
    --transition-smooth: 0.45s cubic-bezier(0.2, 0.8, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ==========================================
   MINIMALIST HEADER (tamvu.io.vn style)
   ========================================== */
header {
    padding: 24px 48px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

header.fixed-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
}

.logo {
    display: flex;
    flex-direction: column;
    text-decoration: none;
}

.logo .name {
    font-size: 20px;
    font-weight: 900;
    color: var(--color-text);
    letter-spacing: -0.5px;
    text-transform: uppercase;
}

.logo .role {
    font-size: 11px;
    font-weight: 500;
    color: var(--color-text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-top: 2px;
}

.nav-links {
    display: flex;
    gap: 32px;
    align-items: center;
}

.nav-item {
    text-decoration: none;
    color: var(--color-text);
    font-size: 13px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color 0.3s;
    position: relative;
}

.nav-item::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-text);
    transition: width 0.3s;
}

.nav-item:hover::after,
.nav-item.active::after {
    width: 100%;
}

.btn-pill {
    padding: 10px 24px;
    text-decoration: none;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    border-radius: 50px;
    background: var(--color-text);
    color: #fff;
    transition: all 0.3s;
}

.btn-pill:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12);
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 22px;
    color: var(--color-text);
    cursor: pointer;
}

/* ==========================================
   HOME SPLIT SCREEN (tamvu.io.vn/home/)
   ========================================== */
.split-container {
    display: flex;
    width: 100vw;
    min-height: 100vh;
}

.split {
    position: relative;
    width: 50%;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    transition: width 0.6s cubic-bezier(0.2, 0.8, 0.2, 1), opacity 0.6s ease;
    background: var(--color-bg);
    border-right: 1px solid rgba(0, 0, 0, 0.05);
    text-decoration: none;
    color: inherit;
}

.split:last-child {
    border-right: none;
}

.bg-block {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    transition: opacity 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
    opacity: 0;
}

.split-left .bg-block {
    background: var(--color-accent-photo);
}

.split-right .bg-block {
    background: var(--color-accent-video);
}

.split-content {
    position: relative;
    z-index: 10;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.split-title {
    font-size: 3.5vw;
    font-weight: 300;
    line-height: 1.05;
    margin-bottom: 24px;
    text-transform: uppercase;
    letter-spacing: -1px;
    color: var(--color-text);
}

.split-title b {
    font-weight: 700;
}

.explore-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: var(--color-text);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s;
}

.explore-btn .arrow {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 1px solid rgba(0, 0, 0, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.explore-btn:hover .arrow,
.split:hover .explore-btn .arrow {
    background: var(--color-text);
    color: #fff;
    transform: translateX(5px);
    border-color: var(--color-text);
}

@media (hover: hover) {
    .split-container:has(.split-left:hover) .split-left {
        width: 55%;
    }
    .split-container:has(.split-left:hover) .split-right {
        width: 45%;
        opacity: 0.5;
    }
    .split-container:has(.split-left:hover) .split-left .bg-block {
        opacity: 1;
    }

    .split-container:has(.split-right:hover) .split-right {
        width: 55%;
    }
    .split-container:has(.split-right:hover) .split-left {
        width: 45%;
        opacity: 0.5;
    }
    .split-container:has(.split-right:hover) .split-right .bg-block {
        opacity: 1;
    }
}

/* ==========================================
   CONTAINER & MINIMALIST FILTER TABS
   ========================================== */
.container {
    padding: 40px 48px 64px;
    max-width: 1600px;
    margin: 0 auto;
}

.filter-bar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 44px;
}

.filter-btn {
    background: transparent;
    border: 1px solid rgba(0, 0, 0, 0.08);
    color: var(--color-text-muted);
    padding: 8px 20px;
    border-radius: 50px;
    font-family: var(--font-primary);
    font-size: 12px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    cursor: pointer;
    transition: all 0.25s ease;
}

.filter-btn:hover {
    color: var(--color-text);
    border-color: var(--color-text);
}

.filter-btn.active {
    background: var(--color-text);
    color: #ffffff;
    border-color: var(--color-text);
}

/* ==========================================
   PHOTO MASONRY GRID & ALBUM CARDS
   ========================================== */
.masonry-grid {
    column-count: 3;
    column-gap: 48px;
}

.album-card,
.bts-card {
    break-inside: avoid;
    margin-bottom: 48px;
    background: var(--color-surface);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    cursor: pointer;
    position: relative;
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.album-card:hover,
.bts-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.album-card img,
.bts-card img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.album-card:hover img,
.bts-card:hover img {
    transform: scale(1.02);
}

.album-info,
.bts-info {
    padding: 22px 24px;
    text-align: center;
}

.album-meta {
    font-size: 10px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 600;
    margin-bottom: 6px;
}

.album-title,
.bts-title {
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--color-text);
}

/* ==========================================
   VIDEO DENSE GRID (16:9 & 9:16 VERTICAL)
   ========================================== */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: 48px;
    grid-auto-flow: dense;
}

.video-item {
    background: var(--color-surface);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
    cursor: pointer;
    position: relative;
    display: flex;
    flex-direction: column;
}

.video-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.video-item:hover .img-container img {
    transform: scale(1.05);
}

.img-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    background: #000;
    overflow: hidden;
}

.img-container img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
    opacity: 0.88;
}

.play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(6px);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid rgba(255, 255, 255, 0.85);
    z-index: 10;
    transition: all 0.3s ease;
}

.play-btn::after {
    content: '';
    border-left: 16px solid white;
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    margin-left: 5px;
}

.video-item:hover .play-btn {
    background: var(--color-text);
    border-color: var(--color-text);
    transform: translate(-50%, -50%) scale(1.1);
}

.video-item.vertical {
    grid-row: span 2;
}

.video-item.vertical .img-container {
    padding-bottom: 177.77%;
}

.video-info {
    padding: 22px 24px;
    text-align: center;
}

.video-meta {
    font-size: 11px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 600;
    margin-bottom: 6px;
}

.video-title {
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--color-text);
}

/* ==========================================
   LIGHTBOX 1: ALBUM MASONRY MODAL
   ========================================== */
.lightbox-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(12px);
    z-index: 1000;
    overflow-y: auto;
    opacity: 0;
    transition: opacity 0.3s ease;
    padding-bottom: 64px;
}

.lightbox-modal.active {
    display: block;
    opacity: 1;
}

.lightbox-header {
    padding: 24px 48px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1010;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.lightbox-title {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.close-btn {
    background: none;
    border: none;
    font-size: 28px;
    font-weight: 300;
    color: var(--color-text);
    cursor: pointer;
    transition: opacity 0.2s;
}

.close-btn:hover {
    opacity: 0.5;
}

.album-images-grid {
    column-count: 3;
    column-gap: 32px;
    padding: 48px;
    max-width: 1600px;
    margin: 0 auto;
}

.album-images-grid img {
    width: 100%;
    break-inside: avoid;
    margin-bottom: 32px;
    border-radius: 8px;
    box-shadow: var(--shadow-soft);
    cursor: zoom-in;
    transition: transform 0.4s ease, box-shadow 0.4s ease;
}

.album-images-grid img:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

/* ==========================================
   LIGHTBOX 2: FULLSCREEN SLIDER + SLIDESHOW
   ========================================== */
.fullscreen-viewer {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.96);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.fullscreen-viewer.active {
    display: flex;
    opacity: 1;
}

.fs-img-container {
    position: relative;
    max-width: 90%;
    max-height: 88vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.fs-img-container img {
    max-width: 100%;
    max-height: 88vh;
    object-fit: contain;
    border-radius: 4px;
}

.fs-controls {
    position: absolute;
    top: 32px;
    right: 48px;
    display: flex;
    gap: 24px;
    z-index: 2010;
}

.fs-btn {
    background: transparent;
    border: none;
    color: #fff;
    opacity: 0.7;
    font-size: 13px;
    font-family: var(--font-primary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    cursor: pointer;
    transition: opacity 0.2s;
}

.fs-btn:hover {
    opacity: 1;
}

.fs-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    color: #fff;
    opacity: 0.45;
    font-size: 40px;
    font-weight: 300;
    cursor: pointer;
    z-index: 2010;
    transition: opacity 0.2s;
    padding: 16px;
}

.fs-arrow:hover {
    opacity: 1;
}

.fs-prev {
    left: 32px;
}

.fs-next {
    right: 32px;
}

/* ==========================================
   VIDEO LIGHTBOX (YouTube Plyr + Google Drive)
   ========================================== */
.video-lightbox {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 3000;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
}

.video-lightbox.active {
    display: flex;
    opacity: 1;
}

.vl-container {
    width: 90%;
    max-width: 1160px;
    position: relative;
}

.vl-container.vertical {
    max-width: 460px;
}

.vl-iframe-wrap {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    background: #000;
    border-radius: 8px;
    overflow: hidden;
}

.vl-container.vertical .vl-iframe-wrap {
    padding-bottom: 177.77%;
}

.vl-iframe-wrap iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.close-vl {
    position: fixed;
    top: 32px;
    right: 48px;
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: 50%;
    color: white;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    z-index: 3010;
}

.close-vl:hover {
    background: rgba(255, 255, 255, 0.28);
    transform: scale(1.08);
}

/* ==========================================
   BTS MODAL DETAILS
   ========================================== */
.modal-content {
    max-width: 1280px;
    margin: 0 auto;
    padding: 32px 48px;
}

.section-title {
    font-size: 16px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin: 40px 0 24px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    padding-bottom: 12px;
}

.bts-images-grid {
    column-count: 3;
    column-gap: 24px;
}

.bts-images-grid img {
    width: 100%;
    break-inside: avoid;
    margin-bottom: 24px;
    border-radius: 8px;
    box-shadow: var(--shadow-soft);
    cursor: zoom-in;
    transition: transform 0.4s;
}

.bts-images-grid img:hover {
    transform: translateY(-4px);
}

.bts-videos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 32px;
}

.vid-thumb-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    background: #000;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    cursor: pointer;
}

.vid-thumb-container img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.85;
    transition: transform 0.4s;
}

.vid-thumb-container:hover img {
    transform: scale(1.05);
}

/* ==========================================
   CONTACT SECTION (tamvu.io.vn/home/contact.html)
   ========================================== */
.contact-container {
    max-width: 1200px;
    margin: 72px auto;
    padding: 0 48px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.contact-info h1 {
    font-size: 48px;
    font-weight: 900;
    letter-spacing: -1.5px;
    text-transform: uppercase;
    line-height: 1.08;
    margin-bottom: 24px;
}

.contact-info p {
    font-size: 17px;
    color: var(--color-text-muted);
    line-height: 1.65;
    margin-bottom: 40px;
    font-weight: 300;
}

.info-list {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.info-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.info-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--color-text-muted);
}

.info-value {
    font-size: 20px;
    font-weight: 500;
    color: var(--color-text);
    text-decoration: none;
    transition: color 0.3s;
}

.info-value:hover {
    color: #fb7185;
}

.btn-company {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-text);
    color: var(--color-surface);
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 16px 32px;
    border-radius: 50px;
    margin-top: 36px;
    cursor: pointer;
    transition: all 0.3s;
    border: none;
    outline: none;
}

.btn-company:hover {
    background: #000;
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12);
}

.contact-image {
    width: 100%;
    height: 580px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    position: relative;
}

.contact-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: filter 0.5s, transform 0.6s;
}

.contact-image:hover img {
    transform: scale(1.02);
}

.popup-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.popup-modal.active {
    display: flex;
}

.popup-content {
    background: var(--color-surface);
    max-width: 560px;
    width: 90%;
    padding: 44px;
    border-radius: 24px;
    box-shadow: var(--shadow-soft);
    position: relative;
}

.close-popup {
    position: absolute;
    top: 24px;
    right: 24px;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
}

.popup-title {
    font-size: 20px;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.copy-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 14px;
    padding: 16px;
    border: 1px solid rgba(0, 0, 0, 0.06);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.copy-item:hover {
    background: #f9fafb;
    border-color: rgba(0, 0, 0, 0.15);
}

.copy-item-content {
    flex: 1;
}

.copy-item-content strong {
    display: block;
    font-size: 11px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 4px;
}

.copy-item-content span {
    font-size: 15px;
    font-weight: 500;
}

.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--color-text);
    color: white;
    padding: 12px 24px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
    opacity: 0;
    transition: all 0.3s;
    z-index: 4000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* ==========================================
   RESPONSIVE BREAKPOINTS
   ========================================== */
@media (max-width: 1024px) {
    .masonry-grid,
    .album-images-grid,
    .bts-images-grid {
        column-count: 2;
    }
}

@media (max-width: 900px) {
    header {
        padding: 16px 24px;
    }
    .mobile-menu-btn {
        display: block;
    }
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: rgba(255, 255, 255, 0.98);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid rgba(0, 0, 0, 0.06);
        box-shadow: var(--shadow-soft);
    }
    .nav-links.open {
        display: flex;
    }
    .split-title {
        font-size: 8vw;
    }
    .contact-container {
        grid-template-columns: 1fr;
        gap: 48px;
        margin: 40px auto;
    }
    .contact-image {
        height: 420px;
    }
}

@media (max-width: 768px) {
    .split-container {
        flex-direction: column;
    }
    .split {
        width: 100% !important;
        height: 50vh;
        border-right: none;
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    }
    .masonry-grid,
    .album-images-grid,
    .bts-images-grid {
        column-count: 1;
    }
    .video-grid,
    .bts-videos-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    .container,
    .album-images-grid,
    .modal-content {
        padding: 24px;
    }
    .lightbox-header {
        padding: 16px 24px;
    }
    .contact-container {
        padding: 0 24px;
    }
    .fs-arrow {
        font-size: 28px;
    }
    .fs-prev {
        left: 12px;
    }
    .fs-next {
        right: 12px;
    }
    .close-vl {
        top: 16px;
        right: 16px;
        width: 40px;
        height: 40px;
    }
}