body {
    font-family: Arial, sans-serif;
    background: #19191c;
    color: #fff;
    margin: 0;
    padding: 30px;
}

* {
    box-sizing: border-box;
}

.container {
    max-width: 800px;
    margin: auto;
    background: #25252a;
    padding: 25px;
    border-radius: 8px;
}

h1,
h2 {
    text-align: center;
}

h1 {
    margin-top: 0;
}

.top-summary {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin: 20px 0;
}

.top-summary div {
    background: #303038;
    border: 1px solid #444;
    border-radius: 8px;
    padding: 14px;
}

.top-summary span {
    display: block;
    color: #cfcfd4;
    font-size: 14px;
    margin-bottom: 6px;
}

.top-summary strong {
    display: block;
    font-size: 22px;
}

.form {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

input,
select {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
}

select {
    min-width: 170px;
}

button {
    padding: 12px 16px;
    border: none;
    border-radius: 8px;
    background: #4caf50;
    color: white;
    font-size: 16px;
    cursor: pointer;
}

button:hover {
    opacity: 0.9;
}

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

.toolbar label {
    color: #cfcfd4;
}

.secondary {
    background: #3f7fd6;
}

.delete {
    background: #d9534f;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
}

th,
td {
    padding: 12px;
    border-bottom: 1px solid #444;
    text-align: center;
}

td:first-child,
th:first-child {
    text-align: left;
}

.amount-input {
    max-width: 180px;
    text-align: right;
}

.empty {
    color: #cfcfd4;
    text-align: center;
}

.summary,
.result {
    background: #303038;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
}

.pay {
    color: #ffb347;
}

.receive {
    color: #7CFF7C;
}

.neutral {
    color: #ccc;
}

@media (max-width: 640px) {
    body {
        padding: 16px;
    }

    .container {
        padding: 18px;
    }

    .top-summary {
        grid-template-columns: 1fr;
    }

    .form input,
    .form button,
    .toolbar select,
    .toolbar button {
        width: 100%;
    }

    .toolbar label {
        width: 100%;
    }

    th,
    td {
        padding: 10px 6px;
    }

    .amount-input {
        max-width: 130px;
    }
}