/* Copyright (c) Meta Platforms, Inc. and affiliates.*/
/* This source code is licensed under the CC BY-NC 4.0 license found in the*/
/* LICENSE file in the root directory of this source tree.*/

/* ===== CSS Variables ===== */
:root {
    --color-bg-black: #000000;
    --color-bg-primary: #0c0c0f;
    --color-bg-secondary: #10101a;
    --color-bg-tertiary: #1a1a25;
    --color-bg-card: #16161f;
    --color-text-primary: #ffffff;
    --color-text-secondary: #a0a0b0;
    --color-text-muted: #6b6b7b;
    --color-accent: #4f46e5;
    --color-accent-hover: #6366f1;
    --color-accent-light: rgba(79, 70, 229, 0.1);
    --color-border: #2a2a3a;
    --color-success: #10b981;
    --color-warning: #f59e0b;

    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;

    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;

    --border-radius-sm: 0.375rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    --border-radius-full: 9999px;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);

    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    --container-max-width: 1200px;
    --header-height: 70px;
}

/* ===== Reset & Base Styles ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    min-height: 100vh;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input {
    font-family: inherit;
}

/* ===== Utility Classes ===== */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-text-primary);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-bg-tertiary);
    border-color: var(--color-text-muted);
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
}

.header-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo a {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-xl);
    font-weight: 600;
}

.logo-icon {
    color: var(--color-accent);
    font-size: var(--font-size-2xl);
}

.main-nav {
    display: none;
}

@media (min-width: 1024px) {
    .main-nav {
        display: block;
    }
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.nav-links a {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text-primary);
}

.dropdown {
    position: relative;
}

.dropdown-arrow {
    font-size: var(--font-size-xs);
    margin-left: var(--spacing-xs);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 180px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-sm);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-fast);
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li {
    margin: 0;
}

.dropdown-menu a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-sm);
}

.dropdown-menu a:hover {
    background: var(--color-bg-tertiary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.language-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.language-selector:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-tertiary);
}

.mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-sm);
}

@media (min-width: 1024px) {
    .mobile-menu-toggle {
        display: none;
    }
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: all var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    padding-top: var(--spacing-4xl);
    padding-bottom: var(--spacing-4xl);
    background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
}

.hero-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: grid;
    gap: var(--spacing-3xl);
    align-items: center;
    grid-template-columns: 1.25fr 1fr;
}

@media (max-width: 1023px) {
    .hero-container {
        grid-template-columns: 1fr;
    }
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: var(--font-size-5xl);
    }
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 1200px;
}

.hero-authors {
    margin-bottom: var(--spacing-xl);
    max-width: 1200px;
}

.author-list {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-xs);
}

.author-list sup {
    color: var(--color-accent);
    font-weight: 600;
}

.author-affiliation {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    font-style: italic;
}

.author-affiliation sup {
    color: var(--color-accent);
    font-style: normal;
    font-weight: 600;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.hero-media {
    position: relative;
    display: flex;
    justify-content: right;
}

@media (max-width: 1023px) {
    .hero-media {
        justify-content: center;
    }
}

.video-container {
    position: relative;
    border-radius: 1.5rem;
    overflow: hidden;
    border: 1px solid var(--color-border);
    display: inline-block;
    width: 80%;
}

.video-container video,
.video-container img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 1.5rem;
}

.video-placeholder {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-card) 100%);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-xl);
}

.play-button {
    width: 80px;
    height: 80px;
    background: var(--color-accent);
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.play-button:hover {
    background: var(--color-accent-hover);
    transform: scale(1.05);
}

.play-button svg {
    width: 32px;
    height: 32px;
    margin-left: 4px;
}

.video-label {
    margin-top: var(--spacing-lg);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

/* ===== Section Styles ===== */
.section-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-4xl) var(--spacing-lg);
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-5xl);
}

/* ===== Purpose Section ===== */
.purpose-section {
    background: var(--color-bg-primary);
}

.purpose-section .section-title {
    text-align: left;
}

.purpose-section .section-description {
    text-align: left;
    margin: 0 0 var(--spacing-3xl);
    max-width: none;
}

.purpose-grid {
    display: grid;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .purpose-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.video-card {
    background: var(--color-bg-card);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    overflow: hidden;
}

.video-card-media {
    width: 100%;
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.video-card-media video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.video-card-caption {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    text-align: center;
}

/* ===== Technical Section ===== */
.technical-section {
    background: var(--color-bg-secondary);
}

.technical-section .section-title {
    text-align: left;
}

.technical-section .section-description {
    text-align: left;
    margin: 0 0 var(--spacing-3xl);
    max-width: none;
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

@media (min-width: 1024px) {
    .process-steps {
        flex-direction: row;
        align-items: flex-start;
        gap: var(--spacing-xl);
    }
}

.step {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--color-bg-card);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    overflow: visible;
    position: relative;
    z-index: 1;
}

.step:hover {
    z-index: 10;
}

.step-image {
    width: 100%;
    aspect-ratio: 4 / 3;
    overflow: visible;
    background: #000000;
    position: relative;
}

.step-image img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    z-index: 1;
}

@media (min-width: 1024px) {
    .step-image {
        cursor: pointer;
    }

    .step-image img {
        transition: transform var(--transition-base), box-shadow var(--transition-base);
    }

    .step-image:hover img {
        transform: scale(1.4);
        box-shadow: var(--shadow-xl);
        z-index: 100;
    }
}

.step-content {
    padding: var(--spacing-lg);
}

.step-content h3 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.step-content p {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.youtube-section {
    margin-top: var(--spacing-3xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

@media (min-width: 768px) {
    .youtube-section {
        flex-direction: row;
        align-items: center;
        gap: var(--spacing-xl);
    }
}

.youtube-text {
    flex: 1;
}

.youtube-label {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.youtube-subtext {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
}

.youtube-subtext a {
    color: var(--color-accent);
    text-decoration: underline;
}

.youtube-subtext a:hover {
    color: var(--color-accent-hover);
}

.youtube-container {
    flex: 2;
    position: relative;
    width: 100%;
    max-width: 720px;
    aspect-ratio: 16 / 9;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.youtube-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    aspect-ratio: 16 / 9;
}

/* ===== Dataset Section ===== */
.dataset-section {
    background: var(--color-bg-primary);
}

.dataset-section .section-title {
    text-align: left;
}

.dataset-section .section-description {
    text-align: left;
    margin: 0 0 var(--spacing-3xl);
    max-width: none;
}

.dataset-images {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.dataset-figure {
    margin: 0;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: #000000;
    border: 1px solid var(--color-border);
}

.dataset-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.dataset-figure figcaption {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    text-align: center;
    background: var(--color-bg-card);
}

/* ===== Comparison Section ===== */
.comparison-section {
    background: var(--color-bg-black);
}

.comparison-section .section-title {
    text-align: left;
    margin-bottom: var(--spacing-xl);
}

.comparison-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.comparison-text {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.comparison-text p {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.comparison-figure {
    margin: 0;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: #000000;
}

.comparison-figure img {
    width: 100%;
    height: auto;
    display: block;
}

/* ===== Performance Section ===== */
.performance-section {
    background: var(--color-bg-primary);
}

.performance-section .section-title {
    text-align: left;
}

.performance-section .section-description {
    text-align: left;
    margin: 0 0 var(--spacing-3xl);
    max-width: none;
}

.performance-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .performance-grid {
        flex-direction: row;
        align-items: flex-start;
    }
}

.performance-figure {
    margin: 0;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: #000000;
}

.performance-figure img {
    width: 100%;
    height: auto;
    display: block;
}

.performance-figure figcaption {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    text-align: center;
    background: var(--color-bg-card);
}

/* Proportional widths based on aspect ratios: 1.44 : 2.26 */
@media (min-width: 768px) {
    .performance-figure--scannet {
        flex: 1.44;
    }

    .performance-figure--mapanything {
        flex: 2.26;
    }
}

/* ===== Download Section ===== */
.download-section {
    background: var(--color-bg-primary);
}

.download-card {
    background: linear-gradient(135deg, var(--color-accent) 0%, #7c3aed 100%);
    padding: var(--spacing-3xl);
    border-radius: var(--border-radius-xl);
    display: grid;
    gap: var(--spacing-xl);
    align-items: center;
}

@media (min-width: 768px) {
    .download-card {
        grid-template-columns: 1fr 1fr;
    }
}

.download-content h2 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.download-content p {
    opacity: 0.9;
}

.download-form .form-group {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.download-form input {
    flex: 1;
    min-width: 200px;
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-md);
    color: var(--color-text-primary);
    font-size: var(--font-size-base);
}

.download-form input::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

.download-form input:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.5);
    background: rgba(255, 255, 255, 0.15);
}

.download-form .btn-primary {
    background: var(--color-text-primary);
    color: var(--color-accent);
}

.download-form .btn-primary:hover {
    background: rgba(255, 255, 255, 0.9);
}

/* ===== Resources Section ===== */
.resources-section {
    background: var(--color-bg-secondary);
}

.resources-grid {
    display: grid;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .resources-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.resource-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: var(--spacing-2xl);
    background: var(--color-bg-card);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-fast);
}

.resource-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
}

.resource-icon {
    width: 64px;
    height: 64px;
    background: var(--color-accent-light);
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.resource-icon svg {
    width: 32px;
    height: 32px;
    color: var(--color-accent);
}

.resource-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.resource-card p {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

/* ===== Footer ===== */
.footer {
    background: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--spacing-lg);
}

.footer-grid {
    display: grid;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-3xl);
}

@media (min-width: 768px) {
    .footer-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.footer-column h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column a {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.footer-column a:hover {
    color: var(--color-text-primary);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    width: 40px;
    height: 40px;
    background: var(--color-bg-tertiary);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--color-accent);
}

.social-links svg {
    width: 20px;
    height: 20px;
}

.footer-bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    align-items: center;
    text-align: center;
}

@media (min-width: 768px) {
    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
}

.footer-legal {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    justify-content: center;
}

.footer-legal a {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.footer-legal a:hover {
    color: var(--color-text-secondary);
}

.copyright {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content,
.hero-media {
    animation: fadeInUp 0.6s ease-out;
}

.hero-media {
    animation-delay: 0.2s;
}

/* ===== Scrollbar Styling ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-bg-tertiary);
    border-radius: var(--border-radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

/* ===== Selection Styling ===== */
::selection {
    background: var(--color-accent);
    color: var(--color-text-primary);
}

/* ===== Citation Section ===== */
.citation-section {
    background: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
}

.citation-section .section-title {
    text-align: left;
}

.citation-section .section-description {
    text-align: left;
    margin: 0 0 var(--spacing-xl);
    max-width: none;
}

.citation-box {
    position: relative;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    overflow: hidden;
}

.citation-box pre {
    margin: 0;
    overflow-x: auto;
}

.citation-box code {
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    white-space: pre;
}

.citation-box .copy-btn {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-accent);
    color: var(--color-text-primary);
    font-size: var(--font-size-sm);
    font-weight: 500;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
}

.citation-box .copy-btn:hover {
    background: var(--color-accent-hover);
}