:root {
    --bg: #f4f4f9;
    --card: #ffffff;
    --text: #333333;
    --muted: #666666;
    --accent: #2c5d63;
    --border: #dddddd;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Georgia, "Times New Roman", serif;
    background: var(--bg);
    color: var(--text);
}

.page {
    width: min(1080px, calc(100% - 32px));
    margin: 0 auto;
    padding: 40px 0 60px;
}

.hero {
    margin-bottom: 32px;
}

.eyebrow {
    margin: 0 0 8px;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.85rem;
}

.hero h1 {
    margin: 0 0 12px;
    font-size: clamp(2.3rem, 5vw, 3.8rem);
}

.intro {
    margin: 0;
    max-width: 720px;
    color: var(--muted);
    font-size: 1.05rem;
    line-height: 1.7;
}

.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.card,
.notes {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 24px;
}

.card h2,
.notes h2 {
    margin: 0 0 16px;
    font-size: 1.4rem;
}

.equation {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.equation span {
    color: var(--muted);
}

input {
    width: 100%;
    min-width: 100px;
    flex: 1 1 100px;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 1rem;
}

button {
    border: 0;
    border-radius: 6px;
    padding: 12px 18px;
    background: var(--accent);
    color: #ffffff;
    font-size: 1rem;
    cursor: pointer;
}

button:hover,
button:focus-visible {
    background: #234b50;
    outline: none;
}

.result {
    margin: 16px 0 0;
    min-height: 48px;
    color: var(--text);
    line-height: 1.6;
}

.result-line {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.copy-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    padding: 0;
    border-radius: 6px;
    background: #e3e5e8;
    color: #5f6770;
    border: 1px solid #cfd4da;
    line-height: 1;
}

.copy-button:hover,
.copy-button:focus-visible {
    background: #d7dbe0;
}

.copy-icon {
    width: 14px;
    height: 14px;
    object-fit: contain;
    opacity: 0.8;
}

.copy-button.copied {
    background: #dbe9de;
    border-color: #bdd3c1;
    color: #3f6b48;
}

.notes {
    margin-top: 24px;
}

.notes ul {
    margin: 0;
    padding-left: 20px;
    color: var(--muted);
}

.notes li {
    margin-bottom: 12px;
    line-height: 1.6;
}

code {
    color: var(--text);
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

@media (max-width: 640px) {
    .page {
        width: min(100% - 24px, 1080px);
        padding-top: 28px;
    }

    .card,
    .notes {
        padding: 20px;
    }
}