* {
    box-sizing: border-box;
}

:root {
    --bg: #111827;
    --panel: #1f2937;
    --panel-2: #172033;
    --text: #f3f4f6;
    --muted: #9ca3af;
    --line: #374151;
    --accent: #60a5fa;
    --accent-strong: #2563eb;
    --danger: #b91c1c;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.container {
    max-width: 920px;
    margin: 0 auto;
    padding: 40px 20px 60px;
}

.app-header,
.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
}

h1 {
    margin: 0 0 6px;
}

h2 {
    margin-bottom: 4px;
}

.subtitle,
.section-heading p,
footer p {
    color: var(--muted);
}

.auth-controls,
.form-actions,
.card-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.auth-status {
    margin: 22px 0 32px;
    padding: 12px 14px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--panel-2);
    color: #d1d5db;
}

section {
    margin-top: 34px;
}

form {
    background: var(--panel);
    padding: 20px;
    border-radius: 10px;
    margin: 18px 0 24px;
    border: 1px solid var(--line);
}

label {
    display: block;
    margin-top: 15px;
    margin-bottom: 5px;
    font-weight: 600;
}

input,
select,
textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: var(--bg);
    color: white;
}

textarea {
    min-height: 100px;
    resize: vertical;
}

.button {
    margin-top: 0;
    padding: 10px 16px;
    border: 1px solid transparent;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
}

.primary {
    background: var(--accent-strong);
    color: white;
}

.secondary {
    background: transparent;
    border-color: #4b5563;
    color: var(--text);
}

.danger {
    background: var(--danger);
    color: white;
}

.topic-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 15px;
    margin-top: 18px;
}

.topic-card {
    background: var(--panel);
    padding: 18px;
    border-radius: 10px;
    border: 1px solid var(--line);
}

.topic-card h3 {
    margin-top: 0;
}

.topic-card p {
    color: #d1d5db;
    line-height: 1.5;
}

.status {
    color: var(--accent) !important;
    font-weight: bold;
}

.card-actions {
    margin-top: 16px;
}

.hidden {
    display: none !important;
}

footer {
    margin-top: 42px;
    border-top: 1px solid var(--line);
    padding-top: 18px;
    font-size: 13px;
}

@media (max-width: 700px) {
    .app-header,
    .section-heading {
        flex-direction: column;
    }

    .topic-list {
        grid-template-columns: 1fr;
    }
}