:root {
    /* Colors */
    --dark-bg: #1e293b;      /* Slate 800 - Navy */
    --light-bg: #f8fafc;     /* Slate 50 */
    --white: #ffffff;
    --accent-color: #f59e0b; /* Amber 500 */
    --text-dark: #0f172a;    /* Slate 900 */
    --text-light: #f1f5f9;   /* Slate 100 */
    --text-muted: #64748b;   /* Slate 500 */
    --gray-color: #cbd5e1;   /* Slate 300 */
    --danger: #ef4444;       /* Red 500 */

    /* Typography */
    --font-heading: 'Inter', sans-serif;
    --font-body: 'Open Sans', sans-serif;
}

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

body {
    font-family: var(--font-body);
    color: var(--text-dark);
    background-color: var(--white);
    overflow: hidden; /* For scroll snap */
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 800;
    line-height: 1.2;
}

h1 { font-size: 3.5rem; margin-bottom: 1rem; }
h2 { font-size: 2.5rem; margin-bottom: 1.5rem; }
h3 { font-size: 1.75rem; margin-bottom: 1rem; }
h4 { font-size: 1.25rem; font-weight: 600; }

p {
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-accent { color: var(--accent-color); }
.text-dark { color: var(--text-dark); }
.text-light { color: var(--text-light); }
.text-muted { color: var(--text-muted); }
.text-gray { color: var(--gray-color); }
.font-bold { font-weight: bold; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }
.p-2 { padding: 0.5rem; }
.p-4 { padding: 1.5rem; }
.p-5 { padding: 3rem; }
.mx-auto { margin-left: auto; margin-right: auto; }
.d-flex { display: flex; }
.d-inline-block { display: inline-block; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-1 { flex: 1; }
.list-none { list-style: none; }
.border-bottom { border-bottom: 1px solid var(--gray-color); }
.rounded-full { border-radius: 9999px; }

.dark-bg { background-color: var(--dark-bg); color: var(--white); }
.light-bg { background-color: var(--light-bg); color: var(--text-dark); }
.accent-bg { background-color: var(--accent-color); color: var(--white); }

/* Layouts */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 10;
}

.content-centered {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.split-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.split-content.reverse {
    flex-direction: row-reverse;
}

.split-content .text-content, .split-content .image-content {
    flex: 1;
}

/* Scroll Snap Container */
.pitch-deck-container {
    height: 100vh;
    overflow-y: scroll;
    scroll-snap-type: y mandatory;
    scroll-behavior: smooth;
}

/* Slide Setup */
.slide {
    height: 100vh;
    width: 100%;
    scroll-snap-align: start;
    position: relative;
    display: flex;
    align-items: center;
    overflow: hidden;
}

/* Specific Slide Layouts */
.split-screen {
    display: flex;
    align-items: stretch;
}

.split-left, .split-right {
    flex: 1;
    position: relative;
}

.split-right.content-centered {
    padding: 50px;
    background: var(--light-bg);
}

.overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to right, rgba(30, 41, 59, 0.8), rgba(30, 41, 59, 0.2));
}

.overlay-light {
    position: absolute;
    inset: 0;
    background: linear-gradient(to left, rgba(248, 250, 252, 0.8), transparent);
}

/* UI Elements */
.btn-primary, .btn-dark {
    display: inline-block;
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
    font-family: var(--font-heading);
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
}

.btn-primary:hover {
    background-color: #d97706;
    transform: translateY(-2px);
}

.btn-dark {
    background-color: var(--dark-bg);
    color: var(--white);
}

.btn-dark:hover {
    background-color: #0f172a;
    transform: translateY(-2px);
}

.card {
    background: var(--white);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

.shadow-sm { box-shadow: 0 4px 6px rgba(0,0,0,0.05); }
.shadow-md { box-shadow: 0 10px 15px rgba(0,0,0,0.1); }
.shadow-lg { box-shadow: 0 20px 25px rgba(0,0,0,0.15); }
.shadow-xl { box-shadow: 0 25px 50px rgba(0,0,0,0.25); }

.image-rounded { border-radius: 12px; }
.image-full { width: 100%; height: auto; display: block; object-fit: cover; }

.badge {
    display: inline-block;
    padding: 5px 15px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 20px;
    margin: 0 5px;
    font-size: 0.9rem;
}
.badge-dark { background: var(--dark-bg); color: var(--white); padding: 5px 15px; border-radius: 20px; display: inline-block; }
.badge-accent { background: var(--accent-color); color: var(--white); padding: 5px 15px; border-radius: 20px; display: inline-block; }

/* Feature List */
.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    line-height: 1.5;
}

.feature-list .icon {
    font-size: 1.5rem;
    margin-right: 15px;
    margin-top: 2px;
}

/* Image Comparison */
.image-comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
}
.comp-img {
    position: relative;
    flex: 1;
    max-width: 400px;
}
.comp-img .label {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

/* Blockquote */
.massive-quote {
    font-size: 2rem;
    font-weight: 300;
    line-height: 1.4;
    max-width: 900px;
    margin: 0 auto;
    font-style: italic;
    position: relative;
}
.massive-quote::before {
    content: '"';
    position: absolute;
    top: -40px;
    left: -40px;
    font-size: 6rem;
    color: rgba(0,0,0,0.1);
    font-family: serif;
}

/* Animations (Intersection Observer targets) */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Navigation Dots */
.nav-dots {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.nav-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: rgba(100, 116, 139, 0.4);
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.nav-dot:hover {
    background-color: var(--accent-color);
}

.nav-dot.active {
    background-color: transparent;
    border-color: var(--accent-color);
    transform: scale(1.3);
}

/* Responsive */
@media (max-width: 992px) {
    .grid-3 { grid-template-columns: 1fr; }
    .split-content, .split-content.reverse { flex-direction: column; }
    .split-screen { flex-direction: column; }
    .split-left, .split-right { height: 50vh; overflow-y: auto; }
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    .image-comparison { flex-direction: column; }
    .comp-icon { transform: rotate(90deg); }
    .pricing-grid { flex-direction: column; align-items: center; }
}

@media (max-width: 768px) {
    h1 { font-size: 1.8rem; margin-bottom: 0.5rem; }
    h2 { font-size: 1.5rem; margin-bottom: 0.8rem; }
    h3 { font-size: 1.25rem; }
    p { font-size: 0.95rem; line-height: 1.5; margin-bottom: 0.8rem; }
    .split-right.content-centered { padding: 20px; }
    .p-5 { padding: 1.5rem; }
    .massive-quote { font-size: 1.2rem; }
    .massive-quote::before { font-size: 4rem; top: -25px; left: -20px; }
    .btn-primary, .btn-dark { padding: 10px 20px; font-size: 0.9rem; }
    .feature-list li { font-size: 0.95rem; margin-bottom: 1rem; }
    .badge { font-size: 0.8rem; padding: 4px 10px; }
    .nav-dots { display: none; } /* Hide dots on small mobile to save space */
    
    /* Thu nhỏ Header trên Mobile để không che mất nội dung */
    .main-header { padding: 8px 0; }
    .header-container { flex-wrap: wrap; justify-content: center; gap: 5px; }
    .main-header .logo { font-size: 1.1rem; }
    .main-header .nav-links { gap: 15px; }
    .main-header .nav-links a { font-size: 0.85rem; }
}

/* ====================================================
   HEADER & NAVIGATION
==================================================== */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 9999;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    padding: 15px 0;
    transition: all 0.3s ease;
}

.header-container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.main-header .logo {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--accent-color);
    text-decoration: none;
}

.main-header .nav-links {
    list-style: none;
    display: flex;
    gap: 30px;
    margin: 0;
    padding: 0;
}

.main-header .nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 600;
    font-size: 1rem;
    transition: color 0.3s;
}

.main-header .nav-links a:hover,
.main-header .nav-links a.active {
    color: var(--accent-color);
}

/* Fix overlap on Album page */
.album-page {
    overflow-y: auto; /* Standard scrolling for album */
    padding-top: 80px; /* Space for header */
}
.pt-5 { padding-top: 3rem; }
.pb-3 { padding-bottom: 1rem; }

/* ====================================================
   MASONRY GALLERY
==================================================== */
.masonry-grid {
    column-count: 3;
    column-gap: 20px;
    width: 90%;
    max-width: 1200px;
    margin: 0 auto 50px auto;
}

.masonry-item {
    break-inside: avoid;
    margin-bottom: 20px;
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.masonry-item img.gallery-img {
    width: 100%;
    display: block;
    border-radius: 12px;
    transition: transform 0.5s ease;
}

.masonry-item:hover img.gallery-img {
    transform: scale(1.05);
}

.masonry-item::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.5), transparent 50%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.masonry-item:hover::after {
    opacity: 1;
}

/* Delete Button in Admin Mode */
.btn-delete-img {
    position: absolute;
    top: 10px;
    right: 10px;
    background: #ef4444;
    color: white;
    border: none;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    font-size: 14px;
    font-weight: bold;
    cursor: pointer;
    z-index: 100;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    opacity: 0;
    transition: opacity 0.2s;
}

.masonry-item:hover .btn-delete-img {
    opacity: 1;
}

@media (max-width: 992px) {
    .masonry-grid { column-count: 2; }
}
@media (max-width: 576px) {
    .masonry-grid { column-count: 1; }
    .main-header .nav-links { gap: 15px; }
}

/* ====================================================
   LIGHTBOX
==================================================== */
.lightbox {
    display: none;
    position: fixed;
    z-index: 100000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.9);
    backdrop-filter: blur(5px);
}

.lightbox.active {
    display: flex;
    justify-content: center;
    align-items: center;
}

.lightbox-content {
    max-width: 90%;
    max-height: 90vh;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    animation: zoomIn 0.3s ease;
}

@keyframes zoomIn {
    from { transform: scale(0.9); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.lightbox-close:hover,
.lightbox-close:focus {
    color: var(--accent-color);
    text-decoration: none;
}