* { margin: 0; box-sizing: border-box; }

body {
    background-color: whitesmoke;
    font-family: "Roboto Mono", monospace;
    min-height: 100vh;
}

/* subtle dot grid */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: radial-gradient(circle, #d4c5bc 1px, transparent 1px);
    background-size: 28px 28px;
    opacity: 0.45;
    pointer-events: none;
    z-index: 0;
}

main {
    position: relative;
    z-index: 1;
}

.header {
    text-align: center;
    padding-top: 64px;
    margin-bottom: 52px;
}

.eyebrow {
    font-size: 10px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: #bbb;
    margin-bottom: 14px;
}

h1 {
    font-weight: 700;
    font-size: 2.4rem;
    letter-spacing: -0.03em;
    line-height: 1.1;
    color: #111;
}

h1 em {
    font-style: normal;
    color: #e07060;
}

.subtitle {
    font-size: 11px;
    color: #aaa;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    margin-top: 10px;
}

.equations {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 460px;
    margin: 0 auto;
    padding: 0 24px 80px;
}

.row {
    display: flex;
    align-items: center;
    width: 100%;
    gap: 16px;
    padding: 14px 0;
    border-bottom: 1px solid #e8ddd6;
    transition: background 0.2s;
}

.row:first-child { border-top: 1px solid #e8ddd6; }

label {
    font-size: 10px;
    color: #bbb;
    min-width: 110px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

button {
    align-items: center;
    background-color: #fee6e3;
    border: 2px solid #111;
    border-radius: 4px;
    color: #111;
    cursor: pointer;
    display: flex;
    font-family: "Roboto Mono", monospace;
    font-size: 13px;
    font-weight: 700;
    height: 44px;
    justify-content: center;
    padding: 0 20px;
    position: relative;
    user-select: none;
    touch-action: manipulation;
    flex: 1;
    transition: background-color 0.15s;
}

button:after {
    background-color: #111;
    border-radius: 4px;
    content: "";
    display: block;
    height: 44px;
    left: 0;
    width: 100%;
    position: absolute;
    top: -2px;
    transform: translate(6px, 6px);
    transition: transform .2s ease-out;
    z-index: -1;
}

button:hover:after { transform: translate(0, 0); }
button:active { background-color: #ffdeda; outline: 0; }
button:hover { outline: 0; background-color: #fdd5d0; }

a { text-decoration: none; color: inherit; }