@media (max-width: 980px) {
    .site-nav {
        position: absolute;
        top: 78px;
        left: 20px;
        right: 20px;
        padding: 18px;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 6px;
        border: 1px solid var(--line);
        border-radius: 18px;
        background: #fff;
        box-shadow: var(--shadow);
    }

    .site-nav.is-open { display: flex; }

    .site-nav a {
        padding: 11px 12px;
        border-radius: 10px;
    }

    .nav-toggle { display: block; }

    .hero {
        padding: 40px 0 64px;
    }

    .hero__grid {
        grid-template-columns: 1fr;
        gap: 42px;
    }

    .hero__content {
        display: flex;
        flex-direction: column;
    }

    .hero__title {
        font-size: clamp(40px, 9vw, 62px);
    }

    .hero__intro {
        grid-template-columns: 220px 1fr;
    }

    .hero__demo {
        width: 100%;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(calc(100% - 28px), var(--container));
    }

    .site-header__inner {
        min-height: 68px;
    }

    .site-nav {
        top: 68px;
        left: 14px;
        right: 14px;
    }

    .brand__text small { display: none; }

    .hero {
        padding-top: 26px;
    }

    .hero__eyebrow {
        font-size: 10px;
    }

    .hero__title {
        font-size: 42px;
        line-height: 1.02;
    }

    .hero__intro {
        display: flex;
        flex-direction: column;
        margin-top: 22px;
    }

    .avatar-wrap {
        width: 100%;
        min-height: 220px;
        padding-right: 118px;
        align-items: flex-end;
    }

    .hero-avatar {
        max-width: 220px;
        max-height: 250px;
    }

    .speech-bubble {
        top: 18px;
        right: 0;
        width: 150px;
        padding: 12px 14px;
        font-size: 12px;
    }

    .speech-bubble strong { font-size: 14px; }

    .hero__copy p {
        font-size: 16px;
        line-height: 1.65;
    }

    .feature-strip {
        grid-template-columns: repeat(2, 1fr);
    }

    .feature:nth-child(3) {
        border-left: 0;
        border-top: 1px solid var(--line);
    }

    .feature:nth-child(4) {
        border-top: 1px solid var(--line);
    }

    .deck-label {
        margin-bottom: 15px;
    }

    .flashcard {
        width: calc(100% - 10px);
        min-height: 430px;
    }

    .flashcard__body {
        min-height: 430px;
        padding: 34px 24px 24px;
        border-radius: 24px;
    }

    .flashcard__sheet {
        inset: 12px -10px -8px 14px;
        border-radius: 24px;
    }

    .flashcard h2 {
        font-size: 34px;
    }

    .flashcard p {
        font-size: 16px;
    }

    .click-coach {
        right: -15px;
        bottom: -16px;
    }

    .click-coach__hand {
        font-size: 48px;
    }

    .click-coach__text {
        display: none;
    }

    .site-footer__inner {
        flex-direction: column;
    }
}