:root {
    --bg: #f4f6fa;
    --card: #ffffff;
    --text: #222;
    --muted: #666;
    --accent: #1a73e8;
    --radius: 10px;
    --max-width: 900px;
}

html.dark {
    --bg: #0b1020;
    --card: #111827;
    --text: #e8edf5;
    --muted: #9aa7bf;
    --accent: #f6c84c;
}

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

.site-header {
    width: 100%;
    background: var(--card);
    padding: 16px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: solid 1px rgba(0,0,0,0.07);
    box-sizing: border-box;
}

.site-header h1 a {
    text-decoration: none;
    color: var(--text);
    font-size: 22px;
}

.theme-toggle {
    background: none;
    font-size: 22px;
    cursor: pointer;
    border: none;
    color: var(--text);
}

.container {
    width: min(95%, var(--max-width));
    margin: 25px auto;
}

.panel {
    background: var(--card);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: 0 2px 5px rgba(0,0,0,0.04);
}

input[type="text"],
textarea {
    width: 100%;
    padding: 12px;
    font-size: 16px;
    border-radius: var(--radius);
    border: 1px solid #ccc;
    background: var(--card);
    color: var(--text);
    margin-top: 10px;
    margin-bottom: 15px;
    box-sizing: border-box;
}

button {
    padding: 10px 16px;
    font-size: 16px;
    border-radius: var(--radius);
    background: var(--accent);
    color: #fff;
    border: none;
    cursor: pointer;
}

button:hover {
    opacity: 0.85;
}


@media (max-width: 600px) {
    .site-header {
        padding: 14px 16px;
    }

    .site-header h1 a {
        font-size: 20px;
    }

    .theme-toggle {
        font-size: 20px;
    }

    .container {
        margin: 18px auto;
        width: 92%;
    }

    .panel {
        padding: 16px;
    }

    input[type="text"],
    textarea {
        font-size: 15px;
        padding: 10px;
    }

    button {
        padding: 10px 14px;
        font-size: 15px;
    }

    .board-list a {
        font-size: 17px;
    }
}