* { box-sizing: border-box; }
html, body { height: 100%; }
body {
    margin: 0;
    background:
        radial-gradient(circle at 18% 20%, rgba(110,182,255,0.18), transparent 28%),
        radial-gradient(circle at 82% 26%, rgba(211,110,255,0.15), transparent 30%),
        radial-gradient(circle at 50% 75%, rgba(86,255,196,0.12), transparent 35%),
        var(--bg);
    color: var(--text);
    font-family: Arial, Helvetica, sans-serif;
}
.site-header, .site-footer { padding: 12px 18px; }
.site-header__inner, .site-footer__inner {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
}
.brand { font-size: 1.15rem; font-weight: 700; letter-spacing: 0.04em; }
.version { opacity: 0.75; }
.site-footer a { color: var(--accent); text-decoration: none; }
.footer-links { display: flex; gap: 12px; }
.app-shell {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 18px 18px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) 420px;
    gap: 18px;
}
.viewer-panel, .controls-panel, .page-simple {
    background: rgba(8,11,20,0.55);
    border: 1px solid var(--border);
    border-radius: 18px;
    box-shadow: 0 12px 40px rgba(0,0,0,0.28);
}
.viewer-panel { min-height: 76vh; overflow: hidden; }
.pulse-stage {
    position: relative;
    min-height: 76vh;
    overflow: hidden;
    background:
        linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.00));
    user-select: none;
    touch-action: none;
}
.bg-orb {
    position: absolute;
    width: 46vmin;
    height: 46vmin;
    border-radius: 50%;
    filter: blur(50px);
    opacity: 0.45;
    pointer-events: none;
}
.bg-orb--one { left: 2%; top: 10%; background: radial-gradient(circle, rgba(110,182,255,0.45), transparent 70%); }
.bg-orb--two { right: 4%; bottom: 6%; background: radial-gradient(circle, rgba(211,110,255,0.40), transparent 72%); }
.bg-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
    background-size: 34px 34px;
    mask-image: radial-gradient(circle at center, rgba(0,0,0,0.9), rgba(0,0,0,0.1) 65%, transparent 92%);
    opacity: 0.12;
    pointer-events: none;
}
.vignette {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, transparent 55%, rgba(0,0,0,0.55) 100%);
    pointer-events: none;
}
.pulse-frame {
    position: absolute;
    inset: 0;
    display: grid;
    place-items: center;
    perspective: 1200px;
}
.image-shell {
    position: absolute;
    width: min(76vw, 920px);
    height: min(68vh, 760px);
    display: grid;
    place-items: center;
    opacity: 0;
    transition: opacity 0.8s ease;
    will-change: transform, filter, opacity;
}
.image-shell img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 20px;
    box-shadow: 0 30px 60px rgba(0,0,0,0.48);
    background: rgba(255,255,255,0.03);
    backface-visibility: hidden;
}
.image-shell.is-visible { opacity: 1; }
.hud {
    position: absolute;
    left: 18px;
    right: 18px;
    bottom: 18px;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    padding: 12px 14px;
    background: rgba(10,14,24,0.55);
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 14px;
    backdrop-filter: blur(10px);
}
.hud__left { display: flex; flex-direction: column; gap: 4px; }
.hud__right { display: flex; gap: 10px; flex-wrap: wrap; }
button {
    background: var(--button-bg);
    color: var(--button-text);
    border: 1px solid var(--button-border);
    border-radius: 10px;
    padding: 10px 14px;
    cursor: pointer;
    font-size: 0.95rem;
}
button:hover { border-color: var(--accent); }
.controls-panel {
    background: var(--panel);
    padding: 18px;
    overflow: auto;
    max-height: 82vh;
}
.panel-header h1 { margin: 0 0 8px; }
.panel-header p { margin: 0 0 14px; opacity: 0.85; }
.controls-grid {
    display: grid;
    gap: 12px;
}
.control-item {
    padding: 12px;
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 12px;
    background: rgba(255,255,255,0.03);
}
.control-item__head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 8px;
}
.control-item label { font-weight: 700; }
.control-item .value { font-family: Consolas, monospace; opacity: 0.9; }
.control-item input[type="range"] {
    width: 100%;
    accent-color: var(--slider-accent);
}
.page-simple {
    max-width: 1000px;
    margin: 18px auto;
    padding: 24px;
}
.hidden-svg { position: absolute; }
@media (max-width: 1200px) {
    .app-shell { grid-template-columns: 1fr; }
    .controls-panel { max-height: none; }
}