:root {
    --bg: #f5f7fb;
    --card: #ffffff;
    --ink: #1f2a44;
    --muted: #62718f;
    --accent: #1e6fff;
    --accent-dark: #0f4ecc;
    --border: #d9e1f2;
    --ok: #e8fff3;
    --danger: #ffecee;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    color: var(--ink);
    background: radial-gradient(circle at top right, #e8f0ff 0%, var(--bg) 45%);
}

.topbar {
    padding: 20px 28px;
    border-bottom: 1px solid var(--border);
    background: #fff;
    display: flex;
    justify-content: space-between;
    gap: 24px;
    align-items: center;
}

.topbar h1 {
    margin: 0;
    font-size: 1.4rem;
}

.topbar p {
    margin: 6px 0 0;
    color: var(--muted);
}

.topbar nav {
    display: flex;
    gap: 12px;
}

.topbar a,
.centered-card a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.grid {
    max-width: 1080px;
    margin: 22px auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.card,
.centered-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 18px;
    box-shadow: 0 8px 20px rgba(15, 35, 75, 0.07);
}

.wide {
    grid-column: 1 / -1;
}

h2,
h1 {
    margin-top: 0;
}

label {
    display: block;
    margin-bottom: 6px;
    font-size: 0.95rem;
}

input {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px;
    margin-bottom: 12px;
}

button {
    border: none;
    background: var(--accent);
    color: #fff;
    padding: 10px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
}

button:hover {
    background: var(--accent-dark);
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 12px;
}

.status-box {
    border-radius: 8px;
    background: var(--ok);
    border: 1px solid #b7ebcf;
    padding: 10px;
    margin-bottom: 8px;
}

.error-box {
    border-radius: 8px;
    background: var(--danger);
    border: 1px solid #ffc7ce;
    padding: 10px;
    margin-bottom: 12px;
}

.result {
    margin-top: 10px;
    color: #173869;
}

pre {
    margin: 0;
    white-space: pre-wrap;
    word-break: break-word;
    padding: 12px;
    border-radius: 8px;
    background: #101827;
    color: #d9f2ff;
}

.stats-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 8px;
}

.stats-table th,
.stats-table td {
    border: 1px solid var(--border);
    padding: 10px;
    text-align: left;
}

.stats-table th {
    background: #f0f4ff;
    font-size: 0.9rem;
}

.centered-card {
    max-width: 480px;
    margin: 48px auto;
}

@media (max-width: 900px) {
    .grid {
        grid-template-columns: 1fr;
    }

    .topbar {
        flex-direction: column;
        align-items: flex-start;
    }
}