/* Base Styles */
body { font-family: "Helvetica Neue", Arial, sans-serif; line-height: 1.8; color: #333; background-color: #f4f6f8; margin: 0; padding: 0; font-size: 15px; }
a { color: #3498db; text-decoration: none; transition: 0.3s; }
a:hover { color: #2980b9; text-decoration: underline; }

.container { max-width: 900px; margin: 40px auto; background: #fff; padding: 60px 40px; border-radius: 12px; box-shadow: 0 4px 20px rgba(0,0,0,0.08); }

/* Headings */
h1 { font-size: 26px; text-align: center; margin-bottom: 40px; color: #2c3e50; border-bottom: none; }
h1 span { display: block; font-size: 14px; color: #7f8c8d; font-weight: normal; margin-top: 10px; }

h2 { font-size: 20px; border-bottom: 2px solid #3498db; padding-bottom: 10px; margin: 50px 0 20px; color: #2c3e50; font-weight: bold; background: none; border-left: none; }
h3 { font-size: 18px; border-left: 5px solid #3498db; padding-left: 15px; margin: 30px 0 15px; background: #f9f9f9; padding-top: 5px; padding-bottom: 5px; color: #444; }

p { margin-bottom: 1.5em; text-align: justify; }
ul { margin-bottom: 1.5em; padding-left: 20px; }
li { margin-bottom: 8px; }

/* Table of Contents */
.toc { background: #f9f9f9; padding: 25px; border: 1px solid #e1e1e1; border-radius: 8px; margin-bottom: 50px; }
.toc-title { font-weight: bold; text-align: center; margin-bottom: 15px; display: block; color: #2c3e50; font-size: 16px; }
.toc ul { list-style: none; padding: 0; margin: 0; }
.toc li { margin-bottom: 8px; border-bottom: 1px dashed #eee; padding-bottom: 5px; }
.toc li:last-child { border-bottom: none; }
.toc a { color: #555; font-weight: 500; display: block; font-size: 14px; }
.toc a:hover { color: #3498db; padding-left: 5px; }

/* Date Info */
.date-info { text-align: right; font-size: 13px; color: #777; margin-top: 60px; border-top: 1px solid #eee; padding-top: 20px; }

/* Button */
.back-link { display: block; text-align: center; margin-top: 60px; color: #fff; background: #3498db; text-decoration: none; font-weight: bold; padding: 15px 30px; border-radius: 50px; transition: 0.3s; width: fit-content; margin-left: auto; margin-right: auto; box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3); }
.back-link:hover { background: #2980b9; color: #fff; transform: translateY(-2px); text-decoration: none; }

p.copyright { text-align: center; margin-bottom: 0; }

/* Responsive */
@media (max-width: 768px) {
    .container { padding: 30px 20px; margin: 20px auto; }
    h1 { font-size: 22px; }
    h2 { font-size: 18px; }
}