.mode-btn, .sidebar-toggle {
    /* clearer, more readable buttons */
    background: rgba(255,255,255,0.06);
    color: var(--white);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 8px;
    padding: 8px 14px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: box-shadow 0.14s ease, transform 0.08s ease, background 0.12s ease, color 0.12s ease;
}
.mode-btn:hover, .sidebar-toggle:hover {
    transform: translateY(-1px);
    background: rgba(255,255,255,0.12);
    box-shadow: 0 10px 22px rgba(0,0,0,0.10);
}
.mode-btn.active {
    /* active: stronger translucent fill with dark text */
    background: rgba(255,255,255,0.18);
    color: #111;
    border-color: rgba(255,255,255,0.22);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}
.sidebar-toggle {
    font-size: 1.1rem;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    transform: rotate(0deg);
}
.sidebar-toggle.collapsed {
    transform: rotate(180deg);
}
:root {
        --viewer-light: #f3f4f6; /* light gray viewer background */
    --black: #000000;
    --main-font: 'Montserrat', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Arial, sans-serif;
    --dark-gray: #121212;
    --gray: #1E1E1E;
    --light-gray: #2E2E2E;
    --lighter-gray: #3E3E3E;
    --white: #FFFFFF;
    --off-white: #F0F0F0;
    --accent: rgba(255, 255, 255, 0.1);
    --accent-hover: rgba(255, 255, 255, 0.15);
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --glow: 0 0 10px rgba(255, 255, 255, 0.1), 0 0 20px rgba(110, 231, 183, 0.05);
    --fs-base: clamp(0.95rem, 0.9rem + 0.2vw, 1.05rem);
    --fs-h1: clamp(2rem, 4.5vw, 3rem);
    --fs-h2: clamp(1.4rem, 3.2vw, 2.2rem);
    --accent-gradient: linear-gradient(90deg, #6EE7B7 0%, #3B82F6 100%);
    --viewer-bg: linear-gradient(180deg, var(--dark-gray), var(--black));
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: var(--main-font);
}

body {
    background-color: var(--black);
    color: var(--white);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
    scroll-behavior: smooth;
    min-height: 100vh;
    font-family: var(--main-font);
    background: url('background2025.png') center center / cover no-repeat fixed, var(--black);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: rgba(0, 0, 0, 0.8);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
    box-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo img {
    height: 40px;
    width: 40px;
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.logo:hover img {
    transform: rotate(15deg) scale(1.05);
    box-shadow: 0 0 15px rgba(255,255,255,0.2);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--white);
    letter-spacing: -0.5px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
}

nav a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-weight: 400;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
    font-size: 0.95rem;
}

nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--white);
    transition: var(--transition);
}

nav a:hover::after {
    width: 100%;
}

nav a:hover {
    color: var(--white);
}

nav a.active {
    color: var(--white);
    font-weight: 500;
}

nav a.active::after {
    width: 100%;
}

/* Layout */
.app {
    display: grid;
    grid-template-columns: 320px 1fr 320px;
    gap: 24px;
    align-items: start;
}

.sidebar {
    /* более прозрачный фон для боковых панелей */
    background: rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(20px);
    padding: 20px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    max-height: calc(100vh - 120px);
    overflow: auto;
    position: sticky;
    top: 100px;
    transition: min-width 0.3s ease-in-out, width 0.3s ease-in-out;
}

.sidebar.left {
    min-width: 280px;
    /* align left sidebar padding with other sidebars (match 20px) */
    padding-left: 20px;
    padding-right: 20px;
}

.sidebar.right {
    min-width: 360px;
    max-width: 420px;
}

.sidebar.collapsed {
    min-width: 56px;
    width: 56px;
    overflow: hidden;
    padding-left: 0;
    padding-right: 0;
}

.sidebar.collapsed > *:not(.sidebar-header) {
    display: none;
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 14px;
    padding: 0 20px; /* Padding for header content when collapsed */
}

/* Left sidebar spacing and layout improvements */
.sidebar.left .sidebar-header {
    /* make sure header content has breathing room */
    gap: 12px;
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 10px; /* spacing between reload button and filter input */
    margin: 10px 0 14px 0;
}

.controls .btn {
    align-self: flex-start; /* don't stretch primary button */
}

/* Основные кнопки — белый текст по умолчанию */
.btn,
.mode-btn,
.sidebar-toggle,
button.model-item {
    color: var(--white) !important;
}

.models-list {
    display: flex;
    flex-direction: column;
    gap: 12px; /* space between model items */
    margin-top: 12px;
    padding-left: 0; /* align items with header */
}

/* make filter input easier to use in sidebar */
.sidebar.left .input {
    width: 100%;
}

/* small vertical spacing for model items to avoid visual crowding */
button.model-item {
    margin-bottom: 4px;
}

.sidebar.collapsed .sidebar-header {
    padding: 0 12px;
}


.sidebar.collapsed .sidebar-header > div {
    display: none;
}

.sidebar-toggle {
    transition: transform 0.3s ease-in-out;
}

.sidebar.collapsed .sidebar-toggle {
    transform: rotate(180deg);
}

.viewer-wrap {
    min-height: calc(100vh - 120px);
}

/* toolbar above the canvas: more breathing room and clearer vertical spacing */
.viewer-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 6px 0 6px;
    margin-bottom: 18px; /* increase space between toolbar and canvas */
    gap: 12px;
}

.viewer-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

#fullscreenBtn {
    /* make fullscreen button visually separated from the canvas */
    margin-top: 2px;
    padding: 8px 10px;
}

.canvas-container {
    width: 100%;
    height: 60vh;
    min-height: 380px;
    border-radius: 12px;
    overflow: hidden;
}

/* Ensure model list buttons always look correct */
button.model-item {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    display: block;
    width: 100%;
    padding: 12px 16px;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 8px;
    color: var(--white);
    text-align: left;
    cursor: pointer;
    font-weight: 600;
}

button.model-item:focus { outline: 2px solid rgba(59,130,246,0.25); }

button.model-item:hover {
    background: rgba(255,255,255,0.14);
    transform: translateY(-2px);
    color: var(--white);
}

/* selected model in the list */
button.model-item.selected {
    background: rgba(255,255,255,0.22);
    color: #111;
    border-color: rgba(255,255,255,0.24);
    box-shadow: 0 8px 22px rgba(0,0,0,0.10);
}

.info-section {
    padding: 12px 0;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.info-section:last-child {
    border-bottom: none;
}

.controls-group {
    display: flex;
    gap: 8px;
    margin-top: 8px;
}

.site-header, .site-footer {
    display: block; /* Make sure they are visible */
}

@media (max-width: 1100px) {
    .app {
        grid-template-columns: 1fr;
    }
    .sidebar {
        position: relative;
        top: 0;
        max-height: none;
    }
    .sidebar.right { order: 3; }
    .sidebar.left { order: 1; }
    .viewer-wrap { order: 2; }
}

.loading {
    color: var(--white);
    background: var(--accent);
    padding: 6px 12px;
    border-radius: 8px;
    border: 1px solid var(--accent-hover);
    font-size: 0.9rem;
    font-weight: 500;
    display: none;
}

.btn {
    /* primary action button — transparent Frutiger style */
    background: rgba(255,255,255,0.03);
    color: var(--white);
    padding: 10px 16px;
    border-radius: 6px;
    border: 1px solid rgba(255,255,255,0.14);
    cursor: pointer;
    font-weight: 700;
    font-size: 0.95rem;
    transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease, color 0.12s ease;
}

.btn:hover {
    transform: translateY(-2px);
    background: rgba(255,255,255,0.06);
    color: var(--white);
    box-shadow: 0 10px 24px rgba(0,0,0,0.10);
}

.input {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    padding: 9px 12px;
    border-radius: 8px;
    color: var(--white);
    width: 160px;
    font-size: 0.95rem;
    transition: var(--transition);
}

.input:focus {
    border-color: rgba(255,255,255,0.15);
    background: rgba(255,255,255,0.05);
    outline: none;
}

/* Make the filter input placeholder more visible (whiter) */
.input::placeholder {
    color: rgba(228, 228, 228, 0.9);
    opacity: 1; /* ensure strong color in all browsers */
}
.input::-webkit-input-placeholder { color: rgba(255,255,255,0.9); }
.input:-ms-input-placeholder { color: rgba(255,255,255,0.9); }
.input::-ms-input-placeholder { color: rgba(255,255,255,0.9); }
.input:-moz-placeholder { color: rgba(255,255,255,0.9); opacity:1; }
.input::-moz-placeholder { color: rgba(255,255,255,0.9); opacity:1; }

.note {
    color: rgba(255,255,255,0.5);
    font-size: 0.9rem;
    padding: 8px 0;
    border-top: 1px solid rgba(255,255,255,0.05);
    margin-top: 12px;
}

#errorBox {
    background: rgba(255,59,48,0.1);
    border: 1px solid rgba(255,59,48,0.2);
    color: #ff8d85;
    padding: 12px;
    border-radius: 8px;
    font-size: 0.9rem;
    margin-top: 12px;
    white-space: pre-wrap;
}

.app { display: grid; grid-template-columns: 320px 1fr 320px; gap: 24px; align-items: start; }
/* ensure sidebar width uses the new grid */
.sidebar { min-width: 320px; max-width: 360px; }
.viewer-wrap { min-height: calc(100vh - 120px); }
.canvas-container {
    width: 100%;
    height: 60vh;
    min-height: 380px;
    border-radius: 12px;
    overflow: hidden;
    position: relative; /* required for pseudo background layer */
    /* subtle framed look */
    border: 1px solid rgba(255,255,255,0.06);
    box-shadow: 0 12px 40px rgba(0,0,0,0.45);
    background: transparent;
    /* blur the page background that sits behind the viewer */
    -webkit-backdrop-filter: blur(6px) saturate(110%);
    backdrop-filter: blur(6px) saturate(110%);
}

/* decorative semi-transparent dark overlay behind the WebGL canvas */
.canvas-container::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(0,0,0,0.22), rgba(0,0,0,0.42));
    z-index: 0;
    pointer-events: none;
}

/* ensure the renderer canvas sits above the decorative background */
.canvas-container > canvas {
    position: relative;
    z-index: 1;
    display: block;
}
.info-panel { display:flex; flex-direction:column; gap:12px; padding: 12px; }

@media (max-width: 1000px) {
    .app { grid-template-columns: 1fr; }
    .sidebar { width: 100%; max-width: none; }
    .viewer-main { height: 60vh; }
    .info-panel { flex-direction: column; gap: 16px; }
}

.site-footer {
    text-align: center;
    padding: 20px;
    color: rgba(255,255,255,0.4);
    font-size: 0.85rem;
    border-top: 1px solid rgba(255,255,255,0.05);
    margin-top: 40px;
}

@media (max-width: 900px) {
    .layout { 
        flex-direction: column;
        padding: 80px 16px;
    }
    .sidebar {
        position: relative;
        width: 100%;
        top: 0;
        max-height: none;
    }
    .canvas-container {
        height: 60vh;
    }
}

@media (max-width: 480px) {
    .header-content {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    nav ul {
        justify-content: center;
    }
}