/* Basic reset */
html, body {
    margin: 0;
    padding: 0;
}

/* Layout and typography */
body {
    font-family: "Roboto", "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f4f8;
    color: #333333;
    padding: 0 20px 50px 20px;
    max-width: 850px;
    margin-left: auto;
    margin-right: auto;
    position: relative;
    scroll-behavior: smooth;
}

/* Back button */
.back-button {
    position: fixed;
    top: 16px;
    left: 16px;
    background-color: #e53333;
    color: #ffffff;
    border: none;
    padding: 10px 16px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    z-index: 1000;
    box-shadow: 0 4px 15px rgba(229, 51, 51, 0.3);
    transition: background-color 0.3s ease;
}

.back-button:hover {
    background-color: #b22828;
}

/* Page header */
.page-header {
    text-align: center;
    margin-top: 70px; /* account for fixed back button */
    color: #003b77;
    margin-bottom: 12px;
}

.page-header h1 {
    font-size: 2.6rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1rem;
    margin: 0 0 6px 0;
    color: #444444;
}

/* Author and date */
.author-date {
    font-size: 0.95rem;
    color: #666666;
    font-style: italic;
    text-align: right;
}

/* Article content */
.article-content p {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: 2.5rem;
    color: #444444;
}

/* Tips list */
.tips-list {
    list-style-type: decimal;
    padding-left: 18px;
    margin: 0;
}

.tips-list li {
    background: #ffffff;
    border-left: 6px solid #e53333;
    margin: 16px 0;
    padding: 18px 20px;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(229, 51, 51, 0.1);
}

/* Tip title button */
.tip-title {
    width: 100%;
    background: none;
    border: none;
    text-align: left;
    font-weight: 700;
    color: #e53333;
    font-size: 1.3rem;
    cursor: pointer;
    padding: 8px 0;
    display: block;
    transition: color 0.3s ease;
    outline-offset: 3px;
}

.tip-title:hover,
.tip-title:focus {
    color: #b22d2d;
    text-decoration: underline;
}

/* Strong keyboard focus */
.tip-title:focus {
    outline: 2px solid #003b77;
}

/* Tip details */
.tip-details {
    font-size: 1rem;
    line-height: 1.55;
    margin-top: 10px;
    color: #222222;
    padding-left: 10px;
    border-left: 3px solid #e8a0a0;
}

/* Footer */
.page-footer {
    text-align: center;
    font-size: 0.92rem;
    color: #777777;
    margin-top: 60px;
}

/* Responsive */
@media (max-width: 640px) {
    body {
        padding: 0 12px 50px 12px;
        max-width: 100%;
    }

    .page-header h1 {
        font-size: 1.8rem;
    }

    .tip-title {
        font-size: 1.1rem;
    }

    .tip-details {
        font-size: 0.95rem;
    }

    .back-button {
        padding: 8px 14px;
        font-size: 0.95rem;
    }
}