:root {
    --white: #f2f4f7;
    --silver: #d9dde2;
    --line: rgba(217, 221, 226, 0.5);
}

* {
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    min-height: 100%;
    margin: 0;
    background: #030303;
}

body {
    overflow: hidden;
    color: var(--white);
    font-family: Arial, Helvetica, sans-serif;
    -webkit-font-smoothing: antialiased;
    text-rendering: geometricPrecision;
}

button,
img {
    -webkit-tap-highlight-color: transparent;
}

.scene {
    position: relative;
    width: 100%;
    min-height: 100svh;
    overflow: hidden;
    isolation: isolate;
    background:
        radial-gradient(circle at 50% 14%, rgba(255,255,255,0.085) 0%, rgba(255,255,255,0.036) 12%, transparent 34%),
        radial-gradient(circle at 50% 42%, rgba(255,255,255,0.02) 0%, transparent 42%),
        linear-gradient(180deg, #060606 0%, #101010 44%, #080808 100%);
}

.night-base,
.starfield,
.shooting-stars,
.atmosphere,
.veil,
.center-glow {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.night-base {
    z-index: 0;
    background:
        radial-gradient(circle at 50% 10%, rgba(255,255,255,0.055), transparent 24%),
        radial-gradient(circle at 20% 14%, rgba(255,255,255,0.022), transparent 26%),
        radial-gradient(circle at 80% 16%, rgba(255,255,255,0.022), transparent 26%),
        radial-gradient(circle at 50% 32%, rgba(255,255,255,0.018), transparent 36%),
        #060606;
}

.starfield,
.shooting-stars {
    z-index: 1;
}

.star {
    position: absolute;
    width: var(--size, 1px);
    height: var(--size, 1px);
    border-radius: 999px;
    background: rgba(255,255,255,var(--alpha,0.72));
    box-shadow: 0 0 9px rgba(255,255,255,0.26);
    animation: twinkle var(--speed, 6s) ease-in-out var(--delay, 0s) infinite;
}

@keyframes twinkle {
    0%, 100% { opacity: .46; transform: scale(.92); }
    50% { opacity: 1; transform: scale(1.22); }
}

.shooting-star {
    position: absolute;
    width: clamp(130px, 14vw, 220px);
    height: 1px;
    border-radius: 999px;
    opacity: 0;
    background: linear-gradient(90deg, rgba(255,255,255,0), rgba(255,255,255,0.96) 72%, rgba(255,255,255,0.82) 100%);
    box-shadow:
        0 0 8px rgba(255,255,255,0.12),
        0 0 16px rgba(255,255,255,0.08);
    transform: rotate(-27deg);
    transform-origin: right center;
    animation: meteor 2.8s cubic-bezier(.2,.62,.18,1) forwards;
}

.shooting-star::after {
    content: "";
    position: absolute;
    right: -2px;
    top: 50%;
    width: 3px;
    height: 3px;
    translate: 0 -50%;
    border-radius: 50%;
    background: rgba(255,255,255,0.92);
    box-shadow: 0 0 12px rgba(255,255,255,0.18);
}

@keyframes meteor {
    0% {
        opacity: 0;
        translate: 0 0;
    }
    10% { opacity: .32; }
    28% { opacity: .48; }
    62% { opacity: .34; }
    100% {
        opacity: 0;
        translate: 46vw 25vh;
    }
}

.atmosphere {
    z-index: 2;
    background:
        radial-gradient(circle at 50% 20%, rgba(255,255,255,0.056), transparent 22%),
        radial-gradient(circle at 50% 52%, rgba(255,255,255,0.034), transparent 24%);
    mix-blend-mode: screen;
    opacity: .82;
}

.mountain-wrap {
    position: absolute;
    z-index: 3;
    left: 50%;
    bottom: 0;
    top: auto;
    right: auto;
    width: 118%;
    height: min(42vh, 420px);
    translate: -50% 0;
    overflow: hidden;
    pointer-events: none;
    opacity: .98;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,.12) 12%, rgba(0,0,0,.7) 38%, #000 100%);
    -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,.12) 12%, rgba(0,0,0,.7) 38%, #000 100%);
}

.mountain-wrap img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center bottom;
    filter: grayscale(1) brightness(1.04) contrast(1.08) saturate(0);
    transform: scale(1.03);
    animation: driftMountain 20s ease-in-out infinite alternate;
}

@keyframes driftMountain {
    from { transform: scale(1.02) translateY(2px); }
    to   { transform: scale(1.045) translateY(-2px); }
}

.veil {
    z-index: 4;
}

.veil-top {
    background: linear-gradient(180deg, rgba(0,0,0,0.08) 0%, rgba(0,0,0,0.02) 30%, transparent 100%);
}

.veil-bottom {
    background: linear-gradient(0deg, rgba(0,0,0,0.14) 0%, rgba(0,0,0,0.04) 16%, transparent 40%);
}

.center-glow {
    z-index: 5;
    background: radial-gradient(circle at 50% 41%, rgba(255,255,255,0.12), transparent 18%);
}

.brand-box {
    position: absolute;
    z-index: 6;
    left: 50%;
    top: 40%;
    translate: -50% -50%;
    width: min(420px, 46vw);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: clamp(18px, 3vh, 26px);
    text-align: center;
}

.brand-logo {
    display: block;
    width: 100%;
    height: auto;
    pointer-events: none;
    user-select: none;
    filter: drop-shadow(0 0 18px rgba(255,255,255,0.1));
    animation: logoFade 1.15s cubic-bezier(.2,.72,.18,1) both;
}

@keyframes logoFade {
    from {
        opacity: 0;
        transform: translateY(8px) scale(.985);
        filter: blur(4px);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
        filter: drop-shadow(0 0 18px rgba(255,255,255,0.1));
    }
}

.welcome-btn {
    appearance: none;
    min-width: 188px;
    height: 46px;
    padding: 0 32px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(0, 0, 0, 0.16);
    color: var(--white);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: .28em;
    text-indent: .28em;
    cursor: pointer;
    box-shadow:
        inset 0 0 0 1px rgba(255,255,255,0.05),
        0 0 22px rgba(255,255,255,0.08);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: transform .28s ease, border-color .28s ease, background .28s ease, box-shadow .28s ease;
    animation: buttonFade .95s .3s ease both;
}

@keyframes buttonFade {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.welcome-btn:hover {
    transform: translateY(-2px);
    border-color: rgba(255,255,255,0.84);
    background: rgba(255,255,255,0.055);
    box-shadow: 0 0 24px rgba(255,255,255,0.12);
}

.welcome-btn:focus-visible {
    outline: 2px solid rgba(255,255,255,0.74);
    outline-offset: 4px;
}

@media (max-width: 960px) {
    .brand-box {
        width: min(360px, 58vw);
        top: 39%;
    }

    .mountain-wrap {
        width: 132%;
        height: min(38vh, 360px);
    }

    .mountain-wrap img {
        filter: grayscale(1) brightness(1) contrast(1.06) saturate(0);
    }
}

@media (max-width: 700px) {
    .brand-box {
        width: min(300px, 74vw);
        top: 37%;
        gap: 18px;
    }

    .mountain-wrap {
        width: 170%;
        height: 34vh;
        opacity: .96;
    }

    .mountain-wrap img {
        object-position: center bottom;
        filter: grayscale(1) brightness(.94) contrast(1.05) saturate(0);
    }

    .welcome-btn {
        min-width: 176px;
        height: 44px;
    }
}