:root {
    --blue: #123f66;
    --accent: #e59b22;
    --ink: #1f2b35;
    --soft: #f3f7f9;
    --line: #d7e1e7;
}

* {
    box-sizing: border-box;
}


main {
    padding: 10px 0 60px;
}

.wrap {
    width: min(100% - 40px, 1220px);
    margin: auto;
    padding: 20px 20px;
}

h1 {
    margin: 0;
    font-size: clamp(2rem, 5vw, 3rem);
    line-height: 1.15;
}


.grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.calculator {
    padding: 22px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--soft);
}

h2 {
    margin: 0 0 7px;
    color: var(--blue);
    font-size: 1.3rem;
    line-height: 1.25;
}

.intro {
    min-height: 54px;
    margin: 0 0 18px;
    color: #52636d;
    font-size: .93rem;
}

label {
    display: block;
    margin: 13px 0 5px;
    font-weight: bold;
    font-size: .93rem;
}

input, select {
    width: 100%;
    padding: 11px;
    border: 1px solid #aebfc9;
    border-radius: 4px;
    background: #fff;
    color: var(--ink);
    font: inherit;
}

    input:focus {
        outline: 3px solid rgba(18, 63, 102, .2);
        border-color: var(--blue);
    }

button {
    width: 100%;
    margin-top: 18px;
    padding: 11px;
    border: 0;
    border-radius: 4px;
    background: var(--accent);
    color: #172b3a;
    font: inherit;
    font-weight: bold;
    cursor: pointer;
}

    button:hover {
        background: #cc8413;
    }

.answer {
    min-height: 68px;
    margin-top: 18px;
    padding: 14px;
    border-left: 4px solid var(--blue);
    background: #fff;
}

    .answer strong {
        display: block;
        color: var(--blue);
        font-size: 1.35rem;
    }

.error {
    color: #a32323;
}

.data-entry {
    width: 100%;
    min-height: 130px;
    padding: 12px;
    resize: vertical;
    border: 1px solid #aebfc9;
    border-radius: 4px;
    color: var(--ink);
    font: inherit;
}

.data-entry:focus {
    outline: 3px solid rgba(18, 63, 102, .2);
    border-color: var(--blue);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
    margin: 22px 0;
}

.stat {
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: var(--soft);
}

.stat span {
    display: block;
    color: #52636d;
    font-size: .87rem;
}

.stat strong {
    display: block;
    margin-top: 3px;
    color: var(--blue);
    font-size: 1.25rem;
    overflow-wrap: anywhere;
}

.formula {
    margin: 18px 0;
    padding: 17px 20px;
    border-left: 4px solid var(--accent);
    background: #fff8e9;
}

.guide {
    max-width: 760px;
    margin: 46px 0 0 0;
}

    .guide section {
        margin-bottom: 34px;
    }

    .guide h2 {
        font-size: 1.5rem;
    }

footer {
    padding: 21px 20px;
    color: #fff;
    background: var(--blue);
}

footer p {
    margin: 0;
}

.tools,
.categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 25px;
}

.tool,
.category {
    display: flex;
    flex-direction: column;
    min-height: 220px;
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--soft);
}

.tool h3,
.category h3 {
    margin: 10px 0 9px 0;
    color: var(--blue);
    font-size: 1.25rem;
}

.tool p,
.category p {
    margin: 0;
}

.button,
.link {
    display: inline-block;
    margin-top: auto;
    padding-top: 18px;
    color: #124f78;
    font-weight: bold;
    text-decoration: none;
}

.button:hover,
.link:hover {
    color: #8e5606;
    text-decoration: underline;
}

.about,
.content {
    max-width: 760px;
    margin:0;
}

.about section,
.content section {
    margin-bottom: 34px;
}

.about h2,
.content h2 {
    margin-bottom: 10px;
    font-size: 1.55rem;
}

ul {
    padding-left: 24px;
}

.compact-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
}

.ratio-sign {
    display: grid;
    place-items: end center;
    padding-bottom: 9px;
    color: var(--blue);
    font-size: 1.25rem;
    font-weight: bold;
}

.ratio-row {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 8px;
    align-items: end;
}

.proportion-layout {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 18px;
    align-items: center;
    max-width: 620px;
    margin: 22px auto;
}

.fraction-fields {
    display: grid;
    gap: 10px;
}

.fraction-fields input:first-child {
    border-bottom: 3px solid var(--blue);
}

.equals-sign {
    color: var(--blue);
    font-size: 1.6rem;
    font-weight: bold;
}

.fraction-calculation {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 18px;
    align-items: end;
    max-width: 820px;
    margin: 22px auto;
}

.mixed-number-inputs {
    display: grid;
    grid-template-columns: .8fr 1fr 1fr;
    gap: 8px;
}

.operator-select {
    width: auto;
    min-width: 70px;
    font-weight: bold;
}

@media (max-width: 780px) {
    .grid {
        grid-template-columns: 1fr;
    }

    .intro {
        min-height: 0;
    }

    .compact-grid {
        grid-template-columns: 1fr;
    }

    .proportion-layout {
        gap: 10px;
    }

    .fraction-calculation {
        gap: 10px;
    }

    .mixed-number-inputs {
        grid-template-columns: 1fr;
    }
}