:root {
    color-scheme: light dark;
    --bg: #f5f6f8;
    --card: #ffffff;
    --text: #1c1e21;
    --muted: #65676b;
    --border: #d0d3d8;
    --accent: #0d6efd;
    --accent-hover: #0b5ed7;
    --error-bg: #fdecea;
    --error-text: #b02a37;
    --success-bg: #e7f5ec;
    --success-text: #1e7b41;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1b1d21;
        --card: #26282d;
        --text: #e4e6eb;
        --muted: #9a9da3;
        --border: #3d4046;
        --accent: #3d8bfd;
        --accent-hover: #5c9dfd;
        --error-bg: #3a2325;
        --error-text: #f1959e;
        --success-bg: #1f3327;
        --success-text: #7fd39d;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: "Segoe UI", system-ui, sans-serif;
    font-size: 15px;
}

main {
    max-width: 900px;
    margin: 0 auto;
    padding: 24px 16px 48px;
}

h1 { font-size: 1.5rem; margin: 0 0 8px; }

.muted { color: var(--muted); }

a { color: var(--accent); }

.live-preview {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    margin: 16px 0 24px;
}

.live-preview h2 {
    font-size: 1.05rem;
    margin: 0 0 12px;
}

.live-preview h2 .muted { font-weight: 400; font-size: 0.85rem; }

.live-preview-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

@media (max-width: 700px) {
    .live-preview-columns { grid-template-columns: 1fr; }
}

.live-preview-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--muted);
    margin-bottom: 6px;
}

.banner-preview-frame {
    width: 100%;
    height: 120px;
    border: 1px dashed var(--border);
    border-radius: 6px;
    display: block;
    overflow: hidden;
    background: var(--bg);
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 8px;
}

.banner-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

@media (max-width: 700px) {
    .banner-columns { grid-template-columns: 1fr; }
}

fieldset {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
}

legend { font-weight: 600; padding: 0 6px; }

label {
    display: block;
    margin: 14px 0 4px;
    font-weight: 600;
    font-size: 0.9rem;
}

input[type="url"],
input[type="password"] {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg);
    color: var(--text);
}

input[type="file"] { width: 100%; color: var(--muted); }

.preview {
    display: block;
    width: 100%;
    max-width: 320px;
    border: 1px solid var(--border);
    border-radius: 6px;
    margin-bottom: 6px;
}

.no-image {
    border: 1px dashed var(--border);
    border-radius: 6px;
    padding: 20px;
    text-align: center;
    color: var(--muted);
    margin-bottom: 6px;
}

button {
    margin-top: 16px;
    padding: 9px 22px;
    border: 0;
    border-radius: 6px;
    background: var(--accent);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
}

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

button.secondary {
    margin-top: 0;
    background: transparent;
    color: var(--muted);
    border: 1px solid var(--border);
    font-weight: 400;
}

.error {
    background: var(--error-bg);
    color: var(--error-text);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 12px 0;
}

.error ul { margin: 0; padding-left: 18px; }

.success {
    background: var(--success-bg);
    color: var(--success-text);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 12px 0;
}

.login-box {
    max-width: 360px;
    margin: 10vh auto 0;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 28px;
    text-align: center;
}

.login-box input { margin-bottom: 12px; }
.login-box button { width: 100%; margin-top: 4px; }