* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    min-height: 100%;
}

body {
    min-height: 100vh;

    display: flex;
    flex-direction: column;

    background: #eef0f4;

    color: #24272c;

    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        sans-serif;

    font-size: 15px;
}


/* =========================
   TOP BAR
========================= */

.topbar {
    width: 100%;

    background: #ffffff;

    border-bottom: 1px solid #dfe2e7;

    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.topbar-inner {
    width: calc(100% - 60px);
    max-width: 1400px;

    height: 70px;

    margin: 0 auto;

    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    color: #3478e5;

    text-decoration: none;

    font-size: 25px;
    font-weight: 700;

    letter-spacing: -0.5px;
}

.return-button {
    padding: 9px 15px;

    background: #ffffff;

    border: 1px solid #d8dce2;
    border-radius: 18px;

    color: #555a61;

    text-decoration: none;

    font-size: 14px;
    font-weight: 600;
}

.return-button:hover {
    background: #f5f6f8;
    border-color: #c9ced6;
}


/* =========================
   PAGE
========================= */

.page {
    width: calc(100% - 40px);
    max-width: 760px;

    flex: 1;

    margin: 0 auto;

    padding: 55px 0 70px;
}


/* =========================
   DONATION CARD
========================= */

.donation-card {
    width: 100%;

    padding: 30px;

    background: #ffffff;

    border: 1px solid #dfe2e7;
    border-radius: 16px;

    box-shadow:
        0 4px 12px rgba(0, 0, 0, 0.06);
}

.donation-card h1 {
    margin: 0;

    color: #24272c;

    font-size: 27px;
    font-weight: 700;

    letter-spacing: -0.4px;
}

.intro {
    max-width: 620px;

    margin: 9px 0 0;

    color: #656a72;

    font-size: 15px;

    line-height: 1.6;
}

.divider {
    height: 1px;

    margin: 25px 0;

    background: #e3e5e9;
}


/* =========================
   AMOUNT BUTTONS
========================= */

.section-label,
.custom-amount label {
    display: block;

    margin-bottom: 9px;

    color: #454a52;

    font-size: 13px;
    font-weight: 650;
}

.amount-buttons {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 9px;
}

.amount-button {
    height: 46px;

    background: #ffffff;

    border: 1px solid #d7dbe1;
    border-radius: 8px;

    color: #555a61;

    font-size: 14px;
    font-weight: 650;

    cursor: pointer;
}

.amount-button:hover {
    background: #f5f7fa;

    border-color: #c7ccd4;
}

.amount-button.selected {
    background: #3478e5;

    border-color: #3478e5;

    color: #ffffff;
}


/* =========================
   CUSTOM AMOUNT
========================= */

.custom-amount {
    margin-top: 21px;
}

.amount-input {
    height: 46px;

    display: flex;
    align-items: center;

    padding: 0 13px;

    background: #f7f8fa;

    border: 1px solid #d7dbe1;
    border-radius: 8px;
}

.amount-input:focus-within {
    background: #ffffff;

    border-color: #3478e5;

    box-shadow:
        0 0 0 2px rgba(52, 120, 229, 0.10);
}

.amount-input span {
    margin-right: 8px;

    color: #737982;

    font-size: 14px;
}

.amount-input input {
    width: 100%;

    padding: 0;

    border: 0;
    outline: 0;

    background: transparent;

    color: #292d33;

    font-size: 14px;
}

.amount-input input::placeholder {
    color: #9a9fa7;
}


/* =========================
   DONATE BUTTON
========================= */

.donate-button {
    width: 100%;

    height: 46px;

    margin-top: 20px;

    background: #3478e5;

    border: 0;
    border-radius: 8px;

    color: #ffffff;

    font-size: 14px;
    font-weight: 650;

    cursor: pointer;
}

.donate-button:hover {
    background: #286fdc;
}

.donate-button:active {
    transform: translateY(1px);
}

.payment-note {
    margin: 11px 0 0;

    color: #858a92;

    text-align: center;

    font-size: 11px;
}


/* =========================
   ABOUT CARD
========================= */

.about-card {
    margin-top: 18px;

    padding: 24px 26px;

    background: #ffffff;

    border: 1px solid #dfe2e7;
    border-radius: 14px;

    box-shadow:
        0 3px 9px rgba(0, 0, 0, 0.045);
}

.about-card h2 {
    margin: 0;

    color: #292d33;

    font-size: 18px;
    font-weight: 650;
}

.about-card p {
    margin: 9px 0 0;

    color: #686d75;

    font-size: 14px;

    line-height: 1.65;
}


/* =========================
   FOOTER
========================= */

.footer {
    min-height: 65px;

    padding: 0 30px;

    display: flex;
    align-items: center;
    justify-content: space-between;

    background: #ffffff;

    border-top: 1px solid #dfe2e7;

    color: #858a92;

    font-size: 12px;
}


/* =========================
   MOBILE
========================= */

@media (max-width: 600px) {

    .topbar-inner {
        width: calc(100% - 24px);

        height: 64px;
    }

    .logo {
        font-size: 23px;
    }

    .return-button {
        padding: 8px 11px;

        font-size: 12px;
    }

    .page {
        width: calc(100% - 24px);

        padding: 30px 0 45px;
    }

    .donation-card {
        padding: 22px;
    }

    .donation-card h1 {
        font-size: 24px;
    }

    .amount-buttons {
        grid-template-columns:
            repeat(2, 1fr);
    }

    .footer {
        padding: 15px 20px;

        flex-direction: column;

        gap: 5px;
    }
}