:root {
    --bg-color: #1a1a2e;
    --card-color: #16213e;
    --primary-color: #0f3460;
    --accent-color: #e94560;
    --text-color: #e0e0e0;
    --label-color: #c0c0c0;
    --border-color: #4a4a58;
    --input-bg-color: #2a2a3e;
    --success-color: #5cb85c;
    --error-color: #d9534f;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji",
    "Segoe UI Symbol";
}

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

body {
    font-family: var(--font-family);
    font-size: 18px;
    background-color: var(--bg-color);
    color: var(--text-color);
    padding: 20px;
}

h1 {
    text-align: center;
    color: var(--text-color);
    margin-bottom: .5rem;
    font-weight: 600;
}

.container {
    width: 90%;
    max-width: 680px;
    margin: 0 auto;
}

main > .container,
.output {
    margin: 20px auto;
}

form {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

label {
    font-weight: 500;
    color: var(--label-color);
    display: block;
}

legend {
    font-weight: 600;
    font-size: 1.25rem;
    color: var(--text-color);
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    min-height: 48px;
    padding: 10px;
    background-color: var(--input-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    box-sizing: border-box;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(233, 69, 96, 0.3);
}

::placeholder {
    color: var(--label-color);
    opacity: 0.7;
}

fieldset {
    border: none;
    background-color: var(--card-color);
    border-radius: 12px;
    padding: 16px;
}

.input-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--card-color);
    border-radius: 12px;
    padding: 16px;
}

.controls span {
    display: flex;
    flex-direction: column;
    width: 100%;
    gap: 15px;
}

button,
button[type="button"],
button[type="submit"] {
    cursor: pointer;
    text-decoration: none;
    border-radius: 8px;
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

#add-entry {
    background-color: var(--primary-color);
    color: var(--text-color);
    border: 1px solid var(--accent-color);
}

#add-entry:hover {
    background-color: #1a4a8a;
}

button[type="submit"] {
    background-color: var(--accent-color);
    color: white;
    width: 100%;
}

button[type="submit"]:hover {
    background-color: #d63c56;
}

#clear {
    background-color: transparent;
    color: var(--label-color);
    border: 1px solid var(--border-color);
    width: 100%;
}

#clear:hover {
    background-color: var(--input-bg-color);
    color: var(--text-color);
}

.buttons-container {
    display: flex;
    gap: 14px;
}

.buttons-container button[type="submit"] {
    flex: 5;
}

.buttons-container button[type="button"] {
    flex: 1;
}

.output {
    background-color: var(--card-color);
    border: 1px solid var(--border-color);
    padding: 25px;
    border-radius: 12px;
    text-align: center;
    line-height: 1.6;
}

.hide {
    display: none;
}

.output span {
    font-weight: bold;
    font-size: 2em;
    display: block;
    margin-bottom: 10px;
}

.output hr {
    border: 0;
    height: 1px;
    background-color: var(--border-color);
    margin: 20px 0;
}

.surplus {
    color: var(--error-color);
}

.deficit {
    color: var(--success-color);
}