:root {
    --ink: #17202a;
    --muted: #637083;
    --line: #dfe5eb;
    --surface: #f5f7f8;
    --brand: #067a6f;
    --accent: #e9a23b;
}

html {
    min-height: 100%;
}

body {
    background: #fff;
    color: var(--ink);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
    letter-spacing: 0;
    min-height: 100%;
}

.site-header {
    border-bottom: 1px solid var(--line);
}

.navbar {
    min-height: 72px;
}

.navbar-brand {
    align-items: center;
    color: var(--ink);
    display: inline-flex;
    font-size: 1.15rem;
    font-weight: 750;
    gap: .65rem;
}

.brand-symbol {
    align-items: center;
    background: var(--brand);
    border-radius: 7px;
    color: #fff;
    display: inline-flex;
    font-size: .8rem;
    height: 36px;
    justify-content: center;
    width: 36px;
}

.support-label {
    color: var(--muted);
    font-size: .88rem;
}

.page-intro {
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    padding: 64px 0 58px;
}

.eyebrow {
    color: var(--brand);
    display: block;
    font-size: .75rem;
    font-weight: 800;
    margin-bottom: .7rem;
}

.page-intro h1 {
    font-size: clamp(2rem, 4vw, 3.25rem);
    font-weight: 800;
    line-height: 1.2;
    margin: 0 0 1rem;
}

.page-intro p,
.section-heading p,
.support-band p {
    color: var(--muted);
    margin: 0;
}

.tutorial-section {
    padding: 64px 0 80px;
}

.section-heading {
    align-items: end;
    display: flex;
    justify-content: space-between;
    margin-bottom: 28px;
}

.section-heading h2,
.support-band h2 {
    font-size: 1.45rem;
    font-weight: 750;
    margin: 0 0 .5rem;
}

.tutorial-count {
    color: var(--brand);
    font-size: .9rem;
    font-weight: 700;
}

.tutorial-list {
    display: grid;
    gap: 1.5rem;
    margin: 0 auto;
    max-width: 960px;
}

.tutorial-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    overflow: hidden;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.tutorial-card:hover {
    border-color: #b8c5d0;
    box-shadow: 0 14px 34px rgba(23, 32, 42, .09);
    transform: translateY(-3px);
}

.video-frame {
    background: #111;
}

.tutorial-card-header {
    align-items: flex-start;
    display: flex;
    gap: 1rem;
    min-width: 0;
    padding: 1.2rem 1.4rem;
}

.tutorial-number {
    color: var(--accent);
    flex: 0 0 auto;
    font-size: .8rem;
    font-weight: 800;
    padding-top: .18rem;
}

.tutorial-card-header h3 {
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.55;
    margin: 0;
    overflow-wrap: anywhere;
}

.support-band {
    background: #eef7f5;
    border-top: 1px solid #d8ebe7;
    padding: 42px 0;
}

.site-footer {
    background: var(--ink);
    color: #cbd2d9;
    font-size: .85rem;
    padding: 24px 0;
}

@media (max-width: 767.98px) {
    .navbar {
        min-height: 64px;
    }

    .page-intro {
        padding: 44px 0 40px;
    }

    .tutorial-section {
        padding: 44px 0 56px;
    }

    .section-heading {
        align-items: flex-start;
        flex-direction: column;
        gap: .75rem;
    }

    .tutorial-list {
        gap: 1rem;
    }

    .tutorial-card-header {
        padding: 1rem;
    }

    .tutorial-card-header h3 {
        font-size: 1rem;
    }
}