/* ============================================================
   CyberStudy 4E — Layout: хедер, mega-menu, drawer, модалка,
   футер
   ============================================================ */

/* ── Хедер ── */
.cs-header {
    position: sticky;
    top: 0;
    z-index: 60;
    background: rgba(18, 28, 49, .94);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--cs-line-strong);
}
.cs-header__inner {
    position: relative;
    max-width: var(--cs-container);
    margin: 0 auto;
    padding: 0 var(--cs-pad-x);
    height: var(--cs-header-h);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.cs-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    font-size: 20px;
    letter-spacing: -.02em;
    color: var(--cs-white);
    flex: 0 0 auto;
}
.cs-logo:hover { color: var(--cs-white); }
.cs-logo__badge {
    background: var(--cs-accent-grad);
    color: var(--cs-on-accent);
    padding: 2px 8px;
    border-radius: var(--cs-r-xs);
}

/* ── Навігація ── */
.cs-nav {
    flex: 1 1 auto;
    min-width: 0;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 14px;
    font-size: 13px;
    font-weight: 600;
}
.cs-nav__item { position: static; }
.cs-nav__link {
    display: block;
    cursor: pointer;
    padding: 26px 0;
    border-bottom: 2px solid transparent;
    color: #93A3BF;
    white-space: nowrap;
    transition: color .18s ease-out, border-color .18s ease-out;
}
.cs-nav__item:hover > .cs-nav__link,
.cs-nav__item.is-open > .cs-nav__link { color: var(--cs-white); border-color: var(--cs-accent); }
.cs-nav__item.is-active > .cs-nav__link { color: var(--cs-white); }
.cs-header__cta { flex: 0 0 auto; }

.cs-burger {
    display: none;
    width: 42px;
    height: 42px;
    align-items: center;
    justify-content: center;
    background: none;
    border: 1px solid var(--cs-line);
    border-radius: var(--cs-r-sm);
    color: var(--cs-text);
    cursor: pointer;
}
.cs-burger span, .cs-burger span::before, .cs-burger span::after {
    content: "";
    display: block;
    width: 18px;
    height: 2px;
    background: currentColor;
    position: relative;
    transition: transform .2s ease-out, opacity .2s ease-out;
}
.cs-burger span::before { position: absolute; top: -6px; left: 0; }
.cs-burger span::after { position: absolute; top: 6px; left: 0; }

/* ── Mega-панель ── */
.cs-mega {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 70;
    border-top: 1px solid var(--cs-line-strong);
    background: linear-gradient(180deg, var(--cs-panel), var(--cs-panel-2));
    box-shadow: var(--cs-shadow-lg);
    animation: csPanel .2s ease-out both;
    display: none;
}
.cs-mega.is-visible { display: block; }
@keyframes csPanel { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: none; } }

.cs-mega__inner {
    max-width: var(--cs-container);
    margin: 0 auto;
    padding: 30px var(--cs-pad-x);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 28px;
}
.cs-mega__group-title {
    font-family: var(--cs-mono);
    font-size: 11px;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: var(--cs-accent);
    padding-bottom: 10px;
    border-bottom: 1px solid var(--cs-line);
    margin-bottom: 12px;
}
.cs-mega__group-title--link {
    display: block;
    text-decoration: none;
    transition: color .16s ease-out;
}
.cs-mega__group-title--link:hover { color: var(--cs-white); }
.cs-mega__links { display: grid; gap: 2px; }
.cs-mega__link {
    display: flex;
    align-items: baseline;
    gap: 8px;
    padding: 7px 0;
    font-size: 14px;
    line-height: 1.45;
    color: var(--cs-text-item);
    transition: color .16s ease-out, padding-left .16s ease-out;
}
.cs-mega__link:hover { color: var(--cs-white); padding-left: 6px; }
.cs-mega__tag {
    font-family: var(--cs-mono);
    font-size: 11px;
    letter-spacing: .08em;
    color: #9DB0CC;
    white-space: nowrap;
}

/* ── Таби службових сторінок ── */
.cs-tabs {
    border-top: 1px solid #1B2740;
    background: rgba(10, 17, 32, .55);
}
.cs-tabs__inner {
    max-width: var(--cs-container);
    margin: 0 auto;
    padding: 0 var(--cs-pad-x);
    display: flex;
    align-items: center;
    gap: 26px;
    height: 46px;
    font-family: var(--cs-mono);
    font-size: 11px;
    letter-spacing: .16em;
    text-transform: uppercase;
    overflow-x: auto;
    scrollbar-width: none;
}
.cs-tabs__inner::-webkit-scrollbar { display: none; }
.cs-tabs__tab {
    color: #7A8CAA;
    border-bottom: 1px solid transparent;
    padding: 4px 0;
    white-space: nowrap;
    transition: color .16s ease-out, border-color .16s ease-out;
}
.cs-tabs__tab:hover { color: var(--cs-white); }
.cs-tabs__tab.is-active { color: var(--cs-accent); border-color: var(--cs-accent); }
.cs-tabs__note { margin-left: auto; color: #3E4F6E; white-space: nowrap; }
@media (max-width: 720px) {
    .cs-tabs__inner { gap: 18px; height: auto; padding-top: 10px; padding-bottom: 10px; }
}

/* ── Мобільний drawer ── */
.cs-drawer {
    position: fixed;
    inset: 0;
    z-index: 90;
    background: linear-gradient(180deg, #101C31, #070E1B);
    transform: translateX(100%);
    transition: transform .3s ease-out;
    overflow-y: auto;
    padding: 24px var(--cs-pad-x) 48px;
}
.cs-drawer.is-open { transform: translateX(0); }
.cs-drawer__head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
}
.cs-drawer__close {
    width: 40px; height: 40px;
    background: none;
    border: 1px solid var(--cs-line);
    border-radius: var(--cs-r-sm);
    color: var(--cs-text);
    font-size: 18px;
    cursor: pointer;
}
.cs-drawer nav a { display: block; padding: 12px 0; font-size: 17px; font-weight: 700; color: var(--cs-text); border-bottom: 1px solid rgba(34, 49, 79, .6); }
.cs-drawer nav a:hover { color: var(--cs-accent); }
.cs-drawer__sub { padding-left: 14px; }
.cs-drawer__sub a { font-size: 14px; font-weight: 500; color: var(--cs-text-body); }
.cs-drawer__foot { margin-top: 32px; display: grid; gap: 12px; font-family: var(--cs-mono); font-size: 13px; color: var(--cs-text-body); }
.cs-drawer__foot a { color: var(--cs-text-body); border: 0 !important; padding: 2px 0 !important; font-weight: 400 !important; }
.cs-drawer__foot a:hover { color: var(--cs-white); }

@media (max-width: 960px) {
    .cs-nav, .cs-header__cta { display: none; }
    .cs-burger { display: inline-flex; }
}

/* ── Модальне вікно консультації ── */
.cs-modal {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 16px;
}
.cs-modal.is-open { display: flex; }
.cs-modal__overlay { position: absolute; inset: 0; background: rgba(7, 14, 27, .75); backdrop-filter: blur(4px); }
.cs-modal__panel {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 520px;
    max-height: 92vh;
    overflow-y: auto;
    background: linear-gradient(180deg, var(--cs-panel), #101A2E);
    border: 1px solid var(--cs-line);
    border-radius: var(--cs-r-lg);
    box-shadow: var(--cs-shadow-lg);
}
.cs-modal__head {
    position: sticky;
    top: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 22px;
    background: inherit;
    border-bottom: 1px solid var(--cs-line-strong);
}
.cs-modal__title { font-size: 18px; font-weight: 800; color: var(--cs-white); margin: 0; }
.cs-modal__close {
    width: 34px; height: 34px;
    display: flex; align-items: center; justify-content: center;
    background: none;
    border: 1px solid var(--cs-line);
    border-radius: var(--cs-r-sm);
    color: var(--cs-text-body);
    font-size: 16px;
    cursor: pointer;
    transition: color .15s ease-out, border-color .15s ease-out;
}
.cs-modal__close:hover { color: var(--cs-white); border-color: var(--cs-accent); }
.cs-modal__body { padding: 22px; }

/* Стан успіху/помилки в модалці */
.cs-modal__state { text-align: center; padding: 32px 8px; display: none; }
.cs-modal__state.is-visible { display: block; }
.cs-modal__state-icon { font-size: 44px; line-height: 1; margin-bottom: 12px; }
.cs-modal__state h4 { color: var(--cs-white); font-size: 18px; margin: 0 0 8px; }
.cs-modal__state p { color: var(--cs-text-body); font-size: 14px; margin: 0; }

/* ── Футер ── */
.cs-footer {
    background: var(--cs-footer-grad);
    color: var(--cs-text-dim);
    padding: 60px 0 28px;
    font-size: 14px;
    border-top: 1px solid var(--cs-line-strong);
}
.cs-footer__grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr 1fr;
    gap: 44px;
    padding-bottom: 44px;
    border-bottom: 1px solid var(--cs-line-strong);
}
.cs-footer__brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; color: var(--cs-white); margin-bottom: 14px; }
.cs-footer__about { line-height: 1.65; max-width: 330px; }
.cs-footer__col-title {
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .08em;
    color: var(--cs-white);
    text-transform: uppercase;
    margin-bottom: 14px;
}
.cs-footer__links { display: grid; gap: 9px; }
.cs-footer__links a { color: var(--cs-text-dim); transition: color .16s ease-out; }
.cs-footer__links a:hover { color: var(--cs-white); }
.cs-footer__bottom {
    display: flex;
    justify-content: space-between;
    gap: 24px;
    padding-top: 22px;
    font-size: 13px;
    flex-wrap: wrap;
}
.cs-footer__legal { display: flex; gap: 24px; }
@media (max-width: 900px) {
    .cs-footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 560px) {
    .cs-footer__grid { grid-template-columns: 1fr; }
}