@import url('https://fonts.googleapis.com/css2?family=Inter:wght@200;300;400;500;600;900&display=swap');

/* ===== БАЗОВЫЕ СТИЛИ ===== */

body {
    font-family: 'Inter', sans-serif;
    overflow-x: hidden;
    background-color: #000;
}

::-webkit-scrollbar {
    width: 0;
}

html {
    scrollbar-width: none;
}

/* ===== ЭФФЕКТЫ ===== */

.shimmer-text {
    background: linear-gradient(
        110deg,
        #ffffff 45%,
        #555555 50%,
        #ffffff 55%
    );
    background-size: 250% 100%;
    color: #000;
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: shine 5s linear infinite;
}

@keyframes shine {
    0% { background-position: 100% 0; }
    100% { background-position: -100% 0; }
}

.fade-in-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== СЕКЦИИ (STICKY CARD-STACK) ===== */

.sticky-section {
    position: sticky;
    top: 0;
    min-height: 100vh;
    width: 100%;
    overflow-y: hidden;
    overflow-x: visible;
    box-shadow: 0 -20px 50px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
}

/* Секции с большим контентом — не sticky, скроллятся нормально */
.sticky-section.scrollable {
    position: relative;
    min-height: auto;
    overflow: visible;
}

.sticky-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* ===== ТЕМЫ ===== */

.theme-black {
    background-color: #050505;
    color: #ffffff;
}

.theme-white {
    background-color: #f2f2f2;
    color: #000000;
}

/* ===== ДЕКОРАТИВНЫЕ ЛИНИИ ===== */

.grid-line-x {
    position: absolute;
    left: 0;
    width: 100%;
    height: 1px;
    background: rgba(255,255,255,0.08);
    pointer-events: none;
}

.grid-line-y {
    position: absolute;
    top: 0;
    height: 100%;
    width: 1px;
    background: rgba(255,255,255,0.08);
    pointer-events: none;
}

.theme-white .grid-line-x,
.theme-white .grid-line-y {
    background: rgba(0,0,0,0.08);
}

/* ===== ТИПОГРАФИКА ===== */

.hero-title {
    font-size: 11vw;
    line-height: 0.85;
    letter-spacing: -0.04em;
    font-weight: 800;
    text-transform: uppercase;
}

.section-title {
    font-weight: 200;
    letter-spacing: -0.02em;
}

/* ===== ХЕДЕР ===== */

.glass-header {
    background: rgba(0, 0, 0, 0.01);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: background 0.3s ease, border-color 0.3s ease;
}

.glass-header.header-light {
    background: rgba(255, 255, 255, 0.01);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.glass-header.header-light .nav-content {
    mix-blend-mode: normal !important;
    color: #000 !important;
}

.glass-header.header-light .nav-content a {
    color: #000 !important;
}

.glass-header.header-light .header-btn {
    border-color: rgba(0, 0, 0, 0.3) !important;
    color: #000 !important;
}

.glass-header.header-light .header-btn:hover {
    background: #000;
    color: #fff;
}

.nav-content {
    mix-blend-mode: difference;
    color: white;
}

/* ===== ТАБЫ ===== */

.tab-btn.active {
    background-color: #000;
    color: #fff;
    border-color: #000;
}

/* ===== МОБИЛЬНЫЕ СТИЛИ (до 768px) ===== */

@media (max-width: 768px) {
    html {
        scroll-snap-type: y proximity;
    }

    .sticky-section {
        position: relative;
        height: calc(var(--app-height, 100svh) + 40px);
        min-height: 0;
        overflow: hidden;
        scroll-snap-align: start;
        display: flex;
        flex-direction: column;
        justify-content: center;
        padding-bottom: 80px;
    }

    /* Наложение секций — тень сверху, без скруглений */
    .sticky-section + .sticky-section {
        margin-top: -40px;
        box-shadow: 0 -15px 40px rgba(0,0,0,0.35);
    }

    .sticky-section + .sticky-section.theme-white {
        box-shadow: 0 -15px 40px rgba(0,0,0,0.1);
    }

    /* Длинные секции — растут по контенту, не зажаты в 1 экран */
    .sticky-section.scrollable {
        height: auto;
        min-height: 0;
        overflow: visible;
        justify-content: flex-start;
    }

    .sticky-content {
        justify-content: flex-start;
        padding-top: 80px;
        padding-bottom: 50px;
    }

    .hero-title {
        font-size: 13vw;
        line-height: 0.88;
        letter-spacing: -0.03em;
    }
}

/* ===== МАЛЕНЬКИЕ ЭКРАНЫ (до 480px) — iPhone SE ===== */

@media (max-width: 480px) {
    .sticky-section + .sticky-section {
        margin-top: -24px;
        box-shadow: 0 -10px 30px rgba(0,0,0,0.3);
    }

    .sticky-content {
        padding-top: 72px;
        padding-bottom: 40px;
    }

    .hero-title {
        font-size: 14vw;
        line-height: 0.88;
    }

    .section-title {
        font-size: clamp(1.8rem, 8vw, 2.5rem);
        line-height: 1.1;
        letter-spacing: -0.01em;
    }

    .tab-btn {
        flex: 1 1 calc(50% - 0.5rem);
        text-align: center;
        padding: 0.5rem 0.75rem;
        font-size: 9px;
    }
}

/* ===== КРОШЕЧНЫЕ ЭКРАНЫ (до 360px) ===== */

@media (max-width: 360px) {
    .hero-title {
        font-size: 13vw;
    }

    .section-title {
        font-size: clamp(1.5rem, 7.5vw, 2rem);
    }
}

/* ===== НИЗКИЕ ЭКРАНЫ (ноутбуки) ===== */

@media (min-width: 769px) and (max-height: 900px) {
    .sticky-content {
        padding-top: 80px;
        padding-bottom: 40px;
    }
}