:root {
    color-scheme: light;
    --background: #f4f7fb;
    --surface: #ffffff;
    --text: #1f2937;
    --muted: #64748b;
    --accent: #0f766e;
    --accent-dark: #115e59;
    --border: #d9e2ec;
    --shadow: 0 18px 45px rgba(15, 23, 42, 0.10);
}

* {
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.5;
    color: var(--text);
    background:
        linear-gradient(135deg, rgba(15, 118, 110, 0.12), transparent 34%),
        linear-gradient(315deg, rgba(37, 99, 235, 0.10), transparent 30%),
        var(--background);
}

.site-header {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 56px 0 28px;
}

.eyebrow {
    margin: 0 0 10px;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent-dark);
}

h1,
h2,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 12px;
    font-size: clamp(2rem, 5vw, 3.7rem);
    line-height: 1.05;
}

.intro {
    max-width: 620px;
    margin-bottom: 0;
    color: var(--muted);
    font-size: 1.08rem;
}

.exercise-grid {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 8px 0 56px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
}

.exercise-card {
    display: flex;
    flex-direction: column;
    min-height: 100%;
    padding: 22px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    box-shadow: var(--shadow);
}

.card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border);
}

h2 {
    margin-bottom: 0;
    font-size: 1.2rem;
}

.card-header span {
    flex: 0 0 auto;
    padding: 4px 9px;
    border-radius: 999px;
    background: #e6fffb;
    color: var(--accent-dark);
    font-size: 0.78rem;
    font-weight: 700;
}

ol {
    display: grid;
    gap: 10px;
    margin: 18px 0 0;
    padding-left: 22px;
}

li::marker {
    color: var(--accent);
    font-weight: 700;
}

a {
    display: inline-flex;
    width: 100%;
    min-height: 42px;
    align-items: center;
    padding: 8px 10px;
    border-radius: 7px;
    color: var(--text);
    text-decoration: none;
    transition: background-color 160ms ease, color 160ms ease, transform 160ms ease;
}

a:hover,
a:focus-visible {
    color: #ffffff;
    background: var(--accent);
    transform: translateX(3px);
    outline: none;
}

@media (max-width: 560px) {
    .site-header {
        padding-top: 38px;
    }

    .exercise-card {
        padding: 18px;
    }

    .card-header {
        align-items: flex-start;
        flex-direction: column;
        gap: 8px;
    }
}