:root{
    --bg:#0b1020;
    --panel:#0f1724;
    --muted:#9aa6b2;
    --accent:#1a73e8;
    --accent-2:#1284f7;
    --card-border:#172233;
    --success:#3ed598;
    --danger:#ff5c5c;
    --glass: rgba(255,255,255,0.03);
}

html,body{
    background: linear-gradient(180deg,#051026 0%, #071428 100%);
    color:var(--muted);
    margin:28px;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    -webkit-font-smoothing:antialiased;
    -moz-osx-font-smoothing:grayscale;
}

/* Animated neural network background (top of page only) */
.neural-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 80vh;
    max-height: 800px;
    overflow: hidden;
    pointer-events: none;
    z-index: 0;
    -webkit-mask-image: linear-gradient(to bottom, black 40%, transparent 100%);
    mask-image: linear-gradient(to bottom, black 40%, transparent 100%);
}

.neural-bg object {
    width: 100%;
    height: 100%;
    display: block;
}

.wrap {
    position: relative;
    z-index: 1;
    max-width:980px;
    margin:0 auto;
}

header {
    display:flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content:space-between;
    gap:16px;
    margin-bottom:18px;
    position: sticky;
    top: 0;
    z-index: 100;
    background: transparent;
    backdrop-filter: none;
    /* background: linear-gradient(180deg, #051026 0%, #071428 100%); */
    padding: 8px 0 12px;
    transition: transform 0.35s ease, opacity 0.35s ease, background 0.3s ease, backdrop-filter 0.3s ease;
}

header.header-scrolled {
    background: rgba(11, 16, 32, 0.7);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
}

header.header-hidden {
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
}

h1{
    color:#fff;
    font-weight:600;
    margin-bottom:12px;
    letter-spacing:0.2px;
    font-size:20px;
    flex: 1;
}

#languageSelect {
    margin-left: auto;
}

/* Second header row: site-wide nav links */
.header-nav {
    width: 100%;
    display: flex;
    gap: 24px;
    padding-top: 8px;
    /* border-top: 1px solid var(--card-border); */
    justify-content: center;
}

.header-nav a {
    color: var(--accent);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.3px;
    transition: color 0.15s ease;
}

.header-nav a:hover {
    color: #fff;
}

.title-block {
    text-align: center;
    padding: 0 15% 0 15%;
    font-weight: 500;
    font-size: 23px;
    margin-bottom: 4rem;
}

/* Content layout for side navbar on wide screens */
.content-layout {
    display: flex;
    flex-direction: column;
}

.content-main {
    flex: 1;
    min-width: 0;
}

.controls {
    display:flex;
    align-items:center;
    gap:12px;
}

#container{
    position:relative;
    display:block;
    background:linear-gradient(180deg, rgba(255,255,255,0.02), transparent);
    padding:12px;
    border:1px solid var(--card-border);
    border-radius:10px;
    box-shadow: 0 10px 30px rgba(2,6,23,0.6);
}

#preview-wrap{
    display:flex;
    align-items:center;
    justify-content:center;
    min-height:320px;
    background:var(--glass);
    border-radius:8px;
    overflow:hidden;
    position:relative;
}

#image-preview{
    max-width:100%;
    max-height:640px;
    display:none;
    border-radius:6px;
    background:#000;
    object-fit:contain;
}

#canvas{ position:absolute; pointer-events:none; left:0; top:0; }

.btn{
    padding:10px 14px;
    font-size:14px;        
    line-height:1;   
    background:linear-gradient(180deg,var(--accent), var(--accent-2));
    color:#fff;
    border:none;
    border-radius:8px;
    cursor:pointer;
    font-weight:600;
    box-shadow:0 8px 28px rgba(26,115,232,0.18);
    display:inline-flex;
    align-items:center;
    gap:8px;
    transition:transform .08s ease, box-shadow .12s ease, opacity .12s ease;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}
.btn:hover{ transform:translateY(-2px); }
.btn:active{ transform:translateY(0); }
.btn[disabled]{
    opacity:0.55;
    cursor:not-allowed;
    box-shadow:none;
    transform:none;
}

input[type="file"]{
    position:absolute!important;
    width:1px!important;
    height:1px!important;
    padding:0!important;
    margin:-1px!important;
    overflow:hidden!important;
    clip:rect(0,0,0,0)!important;
    white-space:nowrap!important;
    border:0!important;
}

#file-label{
    cursor:pointer;
    user-select:none;
}

#submit-btn{
    min-width:120px;
}

.lang-select {
    border-radius: 4px;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    background-color: var(--card-border);
    color: white;
}

.meta {
    margin-top:14px;
    display:flex;
    gap:16px;
    align-items:flex-start;
    flex-wrap:wrap;
}

#result{
    padding:10px 12px;
    border-radius:8px;
    background:linear-gradient(90deg, rgba(255,255,255,0.02), transparent);
    color:#bfe9ff;
    font-weight:600;
    min-width:220px;
    box-shadow: inset 0 -1px 0 rgba(255,255,255,0.02);
}

#details, #std-models-results {
    color:var(--muted);
    margin-top:12px;
    padding-bottom:12px;
    line-height:1.5;
    max-width:760px;
}

#details ul { padding-left:18px; color:var(--muted); margin:8px 0; }
#std-models-results ul { padding-left:18px; color:var(--muted); margin:8px 0; }

/* small screens */
@media (max-width:767px){
    html, body {
        margin: 12px;
    }
    .plain-text-centered {
        padding: 0;
    }
    #image-preview{ max-width:100%; height:auto; }
    /* header{flex-direction:column; align-items:flex-start; gap:8px;} */
    .controls{width:100%}
}

.collapsible-container {
    margin: 10px 0;
}

.collapsible-header {
    display: flex;
    align-items: center;
    cursor: pointer;
    user-select: none;
    border: none;
    width: 100%;
    text-align: left;
}

.arrow {
    display: inline-block;
    margin-right: 10px;
    transition: transform 0.2s ease;
    font-size: 14px;
}

.collapsible-content {
    max-height: 1000px;
    overflow: hidden;
    transition: max-height 0.2s ease, padding 0.2s ease;
}

.collapsible-container.collapsed .collapsible-content {
    max-height: 0;
    padding: 0 16px;
    visibility: hidden;
}

.collapsible-container.collapsed .arrow {
    transform: rotate(-90deg);
}

.svg-label-list {
    list-style: none;
    padding-left: 0;
    margin: 0;
}

.svg-label-list li {
    position: relative;
    padding-left: 2.2em;
    line-height: 1.4;
    display: flex;
    align-items: flex-start;
}

/* Псевдоэлемент, показывающий SVG как маркер */
.svg-label-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 2em;
    height: 1.4em;
    background-image: url('images/Ultralytics.svg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: contain;
    pointer-events: none;
}

.svg-label-list.small li  { padding-left: 22px; }
.svg-label-list.small li::before { width: 14px; height: 14px; }

.svg-label-list.large li  { padding-left: 36px; }
.svg-label-list.large li::before { width: 24px; height: 24px; }

.svg-label-list.vigil li::before {
        background-image: url('images/Vigil.svg');
}

/* Smooth scroll for nav anchors */
html {
    scroll-behavior: smooth;
}

/* Page navigation bar */
.page-nav {
    display: flex;
    flex-wrap: wrap;
    padding: 16px 0;
    margin-bottom: 32px;
}

.page-nav a {
    flex: 1;
    text-align: center;
    align-content: center;
    color: var(--muted);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 600;
    padding: 4px 0;
    border-bottom: 2px solid var(--card-border);
    transition: color 0.2s ease, border-color 0.2s ease, border-left-color 0.2s ease;
}

.page-nav a.active {
    color: #fff;
    border-bottom-color: var(--accent);
}

@media (hover: hover) {
    .page-nav a:hover {
        color: #fff;
    }
}

@media (hover: none) {
    .page-nav a:active {
        color: #fff;
        border-bottom-color: var(--accent);
    }
}

/* Side navbar layout on wider screens */
@media (min-width: 768px) {
    .content-layout {
        flex-direction: row;
        gap: 20px;
    }

    .page-nav {
        order: 1;
        position: sticky;
        top: 76px;
        align-self: flex-start;
        flex-direction: column;
        flex-wrap: nowrap;
        width: 170px;
        flex-shrink: 0;
        padding: 16px 0;
        gap: 4px;
        margin-bottom: 0;
        border-left: 1px solid var(--card-border);
        transition: top 0.35s ease;
    }

    header.header-hidden ~ .title-block ~ .content-layout .page-nav,
    header.header-hidden ~ .content-layout .page-nav {
        top: 20px;
    }

    .page-nav a {
        flex: none;
        text-align: left;
        padding: 10px 16px;
        font-size: 1rem;
        border-bottom: none;
        border-left: 2px solid transparent;
        margin-left: -1px;
        line-height: 1.4;
    }

    .page-nav a:hover {
        border-bottom-color: transparent;
    }

    .page-nav a.active {
        border-bottom-color: transparent;
        border-left-color: var(--accent);
    }
}

/* Wider screens: more room for sidebar */
@media (min-width: 1080px) {
    .wrap {
        max-width: 1000px;
    }

    .content-layout {
        gap: 32px;
    }

    .page-nav {
        width: 200px;
    }

    .page-nav a {
        font-size: 1rem;
    }
}

/* Content section spacing */
.content-section {
    display:flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    margin-bottom: 48px;
    scroll-margin-top: 80px;
}

.content-section ul {
    text-align: center;
    list-style-position: inside;
    padding: 0px;
    margin: 0.5em 0;
}

.content-section li {
    text-align: center;
}

.try-it-section {
    display:flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap:16px;
    margin-top: 18px;
    margin-bottom:18px;
}

/* Task and Usage Sections */
.description-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
    width: 100%;
}

.task-section, .usage-section, .problem-section, .solution-section {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.section-title {
    font-weight: 700;
    color: #fff;
    font-size: 15px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    opacity: 0.9;
}

.task-section .section-title {
    color: var(--accent);
}

.usage-section .section-title,
.problem-section .section-title {
    color: var(--accent-2);
}

.solution-section .section-title {
    color: var(--success);
}

.section-content {
    color: var(--muted);
    line-height: 1.6;
    margin: 0.5em 0;
}

/* Go to top button */
.go-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    z-index: 90;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease, border-color 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.go-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.go-to-top:hover {
    border-color: var(--accent);
    background: rgba(26, 115, 232, 0.15);
    color: #fff;
}

.go-to-top svg {
    width: 22px;
    height: 22px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}