/* Единый задник терминала: пласты, инженерная сетка, медные источники света и
   затемнение. Раньше эти слои копировались в Main.cshtml, GtmAltS.cshtml и
   sn-theme.css по отдельности — копии разъезжались, а на экране паузы задник
   накладывался сам на себя. Теперь он один и живёт здесь.
   Подключается <link>'ом во всех трёх layout'ах. */
.sn-geo-backdrop {
    background:
    linear-gradient(rgba(20, 16, 12, 0.58), rgba(20, 16, 12, 0.58)),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='1200' height='800' viewBox='0 0 1200 800' preserveAspectRatio='xMidYMid slice'><defs><pattern id='congl' x='0' y='0' width='40' height='40' patternUnits='userSpaceOnUse'><circle cx='8' cy='10' r='3' fill='none' stroke='%23f0a755' stroke-width='0.8' opacity='0.30'/><circle cx='25' cy='15' r='2' fill='none' stroke='%23f0a755' stroke-width='0.8' opacity='0.30'/><circle cx='35' cy='8' r='1.4' fill='%23f0a755' opacity='0.25'/><circle cx='15' cy='28' r='2.5' fill='none' stroke='%23ffb86b' stroke-width='0.8' opacity='0.28'/><circle cx='32' cy='32' r='3.5' fill='none' stroke='%23f0a755' stroke-width='0.8' opacity='0.30'/><circle cx='5' cy='35' r='1.2' fill='%23ffb86b' opacity='0.25'/></pattern><pattern id='shale' x='0' y='0' width='42' height='12' patternUnits='userSpaceOnUse'><line x1='2' y1='4' x2='16' y2='4' stroke='%23f0a755' stroke-width='1' opacity='0.28'/><line x1='24' y1='8' x2='38' y2='8' stroke='%23f0a755' stroke-width='1' opacity='0.28'/></pattern><pattern id='sand' x='0' y='0' width='28' height='28' patternUnits='userSpaceOnUse'><circle cx='7' cy='7' r='1.2' fill='%23f0a755' opacity='0.28'/><circle cx='21' cy='21' r='1.2' fill='%23f0a755' opacity='0.28'/><circle cx='14' cy='14' r='0.6' fill='%23ffb86b' opacity='0.22'/></pattern><pattern id='lime' x='0' y='0' width='44' height='22' patternUnits='userSpaceOnUse'><path d='M0 11 L44 11 M0 22 L44 22 M22 0 L22 11 M11 11 L11 22 M33 11 L33 22' stroke='%23ffb86b' stroke-width='0.8' fill='none' opacity='0.24'/></pattern><pattern id='dolo' x='0' y='0' width='44' height='22' patternUnits='userSpaceOnUse' patternTransform='skewX(-22)'><path d='M0 11 L44 11 M0 22 L44 22 M22 0 L22 11 M11 11 L11 22 M33 11 L33 22' stroke='%23ffb86b' stroke-width='0.8' fill='none' opacity='0.28'/></pattern><pattern id='coal' x='0' y='0' width='10' height='10' patternUnits='userSpaceOnUse'><rect width='10' height='10' fill='%23000' opacity='0.10'/><line x1='0' y1='5' x2='10' y2='5' stroke='%23c8843a' stroke-width='0.6' opacity='0.22'/></pattern><pattern id='base' x='0' y='0' width='32' height='32' patternUnits='userSpaceOnUse'><path d='M5 5 L11 11 M11 5 L5 11' stroke='%23f0a755' stroke-width='0.9' fill='none' opacity='0.32'/><path d='M22 22 L28 28 M28 22 L22 28' stroke='%23f0a755' stroke-width='0.9' fill='none' opacity='0.32'/><path d='M22 8 L26 12 M26 8 L22 12' stroke='%23ffb86b' stroke-width='0.7' fill='none' opacity='0.26'/><path d='M5 22 L9 26 M9 22 L5 26' stroke='%23ffb86b' stroke-width='0.7' fill='none' opacity='0.26'/></pattern></defs><path d='M0,0 L1200,0 L1200,100 Q900,-10 600,100 Q300,210 0,100 Z' fill='url(%23dolo)'/><path d='M0,100 Q300,210 600,100 Q900,-10 1200,100 L1200,200 Q900,90 600,200 Q300,310 0,200 Z' fill='url(%23shale)'/><path d='M0,200 Q300,310 600,200 Q900,90 1200,200 L1200,380 Q900,270 600,380 Q300,490 0,380 Z' fill='url(%23sand)'/><path d='M0,380 Q300,490 600,380 Q900,270 1200,380 L1200,490 Q900,380 600,490 Q300,600 0,490 Z' fill='url(%23lime)'/><path d='M0,490 Q300,600 600,490 Q900,380 1200,490 L1200,590 Q900,480 600,590 Q300,700 0,590 Z' fill='url(%23congl)'/><path d='M0,590 Q300,700 600,590 Q900,480 1200,590 L1200,700 Q900,590 600,700 Q300,810 0,700 Z' fill='url(%23coal)'/><path d='M0,700 Q300,810 600,700 Q900,590 1200,700 L1200,800 L0,800 Z' fill='url(%23base)'/><g fill='none' stroke='%23f0a755' stroke-width='1.2' opacity='0.40'><path d='M0,100 Q300,210 600,100 Q900,-10 1200,100'/><path d='M0,200 Q300,310 600,200 Q900,90 1200,200'/><path d='M0,380 Q300,490 600,380 Q900,270 1200,380'/><path d='M0,490 Q300,600 600,490 Q900,380 1200,490'/><path d='M0,590 Q300,700 600,590 Q900,480 1200,590'/><path d='M0,700 Q300,810 600,700 Q900,590 1200,700'/></g></svg>"),
    /* Engineer-grid hairlines (copper) */
    repeating-linear-gradient(to right,
    transparent 0, transparent 79px,
    rgba(240, 167, 85, 0.07) 79px, rgba(240, 167, 85, 0.07) 80px),
    repeating-linear-gradient(to bottom,
    transparent 0, transparent 79px,
    rgba(240, 167, 85, 0.07) 79px, rgba(240, 167, 85, 0.07) 80px),
    /* Warm copper light sources */
    radial-gradient(ellipse 60% 50% at 78% 8%, rgba(240, 167, 85, 0.32), transparent 65%),
    radial-gradient(ellipse 50% 60% at 12% 92%, rgba(200, 132, 58, 0.26), transparent 60%),
    /* Vertical depth gradient */
    linear-gradient(180deg, #1d1813 0%, #161310 45%, #0d0a08 100%);
    background-size: auto, cover, auto, auto, auto, auto, auto;
    background-position: center;
    background-repeat: no-repeat, no-repeat, repeat, repeat, no-repeat, no-repeat, no-repeat;
    background-attachment: fixed;
}