/* Auth cube: лицевая грань — вход; правая грань — регистрация. */
.auth-cube-overlay {
    perspective: none;
    overflow: hidden;
    padding: 16px;
    box-sizing: border-box;
}
.auth-cube-scene {
    width: min(440px, 100%);
    height: 410px;
    --auth-cube-depth: 220px;
    position: relative;
    perspective: 1400px;
    transition: height 620ms cubic-bezier(.2,.7,.2,1);
}
.auth-cube {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transform: translateZ(calc(-1 * var(--auth-cube-depth))) rotateY(0deg);
    transition: transform 620ms cubic-bezier(.2,.7,.2,1);
}
.auth-cube.is-rotated {
    transform: translateZ(calc(-1 * var(--auth-cube-depth))) rotateY(-90deg);
}
.auth-face {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    transform-style: preserve-3d;
}
.auth-face-login { transform: rotateY(0deg) translateZ(var(--auth-cube-depth)); }
.auth-face-register { transform: rotateY(90deg) translateZ(var(--auth-cube-depth)); }
.auth-face .modal-content {
    width: 100%;
    max-width: none;
    height: 100%;
    box-sizing: border-box;
    margin: 0;
    animation: none;
    overflow-y: auto;
    scrollbar-width: thin;
}
.auth-face-login .modal-content { padding: 32px 28px; }
.auth-no-motion, .auth-no-motion .auth-cube { transition: none !important; }
@media (prefers-reduced-motion: reduce) {
    .auth-cube-scene, .auth-cube { transition: none !important; }
}

.auth-face-register .registration-card {
    max-width: 440px;
    padding: 36px 32px 26px;
    overflow-y: auto;
}
.registration-close {
    position: absolute;
    right: 18px;
    top: 18px;
    display: grid;
    place-items: center;
    width: 34px;
    height: 34px;
    padding: 0;
    border: 1px solid var(--border);
    border-radius: 11px;
    color: var(--text-secondary);
    background: var(--surface-hover);
    cursor: pointer;
}
.registration-close:hover { color: var(--text); }
.registration-emblem {
    display: grid;
    place-items: center;
    width: 68px;
    height: 68px;
    margin: 0 auto 18px;
    border-radius: 20px;
    color: var(--text);
    background: var(--surface-hover);
    border: 1px solid var(--border);
}
.registration-title {
    color: var(--text);
    margin: 0;
    font-size: 25px;
    font-weight: 700;
    text-align: center;
    line-height: 1.25;
}
.registration-description {
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.5;
    margin: 10px 0 28px;
}
.registration-field { margin-top: 16px; }
.registration-error,
.registration-success {
    font-size: 13px;
    line-height: 1.4;
    margin: 12px 0 0;
    text-align: left;
}
.registration-error { color: var(--danger, #dc2626); }
.registration-success { color: var(--success-text, #15803d); }
.auth-face-register [hidden] { display: none !important; }
.registration-submit {
    display: block;
    width: 100%;
    min-height: 48px;
    border: none;
    border-radius: 13px;
    margin-top: 24px;
    padding: 12px 18px;
    background: var(--primary, #303038);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: opacity .2s ease, transform .2s ease;
}
.registration-submit:hover:not(:disabled) { opacity: .9; transform: translateY(-1px); }
.registration-submit:disabled { opacity: .55; cursor: progress; }
.registration-login-link {
    color: var(--text-secondary);
    font-size: 13px;
    text-align: center;
    margin: 22px 0 0;
}
.registration-login-link button {
    color: var(--text);
    border: none;
    background: transparent;
    padding: 2px;
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 3px;
    cursor: pointer;
}
@media (max-width: 480px) {
    .auth-face-register .registration-card { padding: 34px 20px 22px; width: calc(100% - 28px); }
    .registration-title { font-size: 23px; }
}