:root {
    --browser-top: rgb(28, 28, 32);
    --browser-bottom: rgb(18, 18, 22);
    --section-bg: rgb(22, 22, 24);
    --separator-color: rgba(45, 45, 50, 1);
    --separator-width: 1px;
    --text-primary: #ffffff;
    --text-secondary: #9ca3af;
    --text-muted: #4b5563;
    --accent: #3b82f6;
    --hover-bg: rgba(255, 255, 255, 0.05);
    --active-bg: rgba(255, 255, 255, 0.1);
    
    /* Palette Sémantique */
    --pix-accent: rgb(46, 95, 204);
    --pix-info: rgb(109, 96, 75);
    --pix-primary: rgb(255, 255, 255);
    --pix-secondary: rgb(156, 163, 175);
}

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

body {
    font-family: 'Avenir', Helvetica, Arial, sans-serif;
    background-color: #121212;
    color: var(--text-secondary);
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
}

.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Browser (Left Column) */
.browser {
    width: 25%;
    height: 100%;
    background: linear-gradient(to bottom, var(--browser-top), var(--browser-bottom));
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.browser::-webkit-scrollbar {
    display: none;
}

.logo-container {
    padding: 3rem;
    display: flex;
    justify-content: center;
}

.logo {
    width: 4rem;
    height: 4rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.logo img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.menu {
    flex: 1;
    padding: 0 0.5rem;
}

.section-menu {
    margin-bottom: 0.25rem;
}

.section-header {
    display: flex;
    align-items: center;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-radius: 0.375rem;
    transition: all 0.2s;
    margin: 0 0.5rem;
}

.section-header:hover {
    background-color: var(--hover-bg);
    color: var(--text-primary);
}

.section-header.active {
    background-color: var(--active-bg);
    color: var(--text-primary);
}

.disclosure-icon {
    margin-right: 0.5rem;
    transition: transform 0.2s;
    display: flex;
    align-items: center;
}

.disclosure-icon.expanded {
    transform: rotate(90deg);
}

.section-title {
    font-weight: 700;
    font-size: 0.875rem;
}

.subsections-container {
    margin-left: 2rem;
    margin-top: 0.25rem;
    border-left: 1px solid #1f2937;
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.3s ease-out, opacity 0.3s;
    opacity: 0;
}

.subsections-container.expanded {
    max-height: 500px;
    opacity: 1;
}

.sub-btn {
    display: block;
    width: 100%;
    text-align: left;
    padding: 0.375rem 1rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    background: none;
    border: none;
    cursor: pointer;
    transition: color 0.2s;
}

.sub-btn:hover {
    color: var(--text-secondary);
}

.lang-switcher {
    padding: 1.5rem;
    margin-top: auto;
    display: flex;
    gap: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    background: rgba(0, 0, 0, 0.2);
}

.lang-btn {
    background: none;
    border: none;
    font-size: 0.625rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}

.lang-btn.active {
    color: white;
    transform: scale(1.1);
}

/* Separator */
.separator {
    width: var(--separator-width);
    background-color: var(--separator-color);
    height: 100%;
}

/* Content Area (Right Column) */
.content-area {
    width: 75%;
    height: 100%;
    background-color: var(--section-bg);
    overflow-y: auto;
    scroll-behavior: smooth;
}

.content {
    max-width: 56rem;
    margin: 0 auto;
    padding: 5rem;
}

.section-content {
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s, transform 0.3s;
}

.section-content.visible {
    opacity: 1;
    transform: translateY(0);
}

.content-header {
    margin-bottom: 5rem;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-weight: 500;
}

.content-title {
    font-size: 3.75rem;
    font-weight: 700;
    color: white;
    margin-bottom: 2rem;
    letter-spacing: -0.025em;
}

.content-desc {
    font-size: 1.25rem;
    line-height: 1.625;
    color: var(--text-secondary);
    max-width: 42rem;
}

.content-header {
    margin-bottom: 1.5rem;
}

.subsections-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.subsection-item {
    scroll-margin-top: 5rem;
}

.subsection-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.subsection-title::before {
    content: '';
    width: 0.25rem;
    height: 1.5rem;
    background-color: var(--accent);
    border-radius: 9999px;
}

.subsection-text {
    font-size: 1.125rem;
    line-height: 1.625;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.subsection-text p {
    margin-bottom: 1rem;
}

.subsection-text p:last-child {
    margin-bottom: 0;
}

.subsection-text ul, .subsection-text ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.subsection-text li {
    margin-bottom: 0.5rem;
}

.subsection-text h3 {
    color: white;
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.subsection-image {
    border-radius: 1rem;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    background: rgba(0, 0, 0, 0.4);
}

.subsection-image img {
    width: 100%;
    height: auto;
    display: block;
    opacity: 0.8;
    transition: opacity 0.7s;
}

.subsection-image img:hover {
    opacity: 1;
}

footer {
    margin-top: 10rem;
    padding-top: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-muted);
    font-size: 0.75rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s;
}

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

/* Custom Scrollbar */
.content-area::-webkit-scrollbar {
    width: 6px;
}

.content-area::-webkit-scrollbar-track {
    background: transparent;
}

.content-area::-webkit-scrollbar-thumb {
    background: #2d2d32;
    border-radius: 10px;
}

.content-area::-webkit-scrollbar-thumb:hover {
    background: #3f3f46;
}