body {
    margin: 0;
    font-family: 'Merriweather', serif;
    background-color: #0f0f0f;
    color: #f0f0f0;
    line-height: 1.6;
    scroll-behavior: smooth;
}

header {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: #1a1a1a;
    padding: 1rem 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    z-index: 1000;
}

header h1 {
    margin: 0;
    font-family: 'Inter', sans-serif;
    font-size: 1.8rem;
    color: #b67d4c;
}

.subtitle {
    margin-top: 4px;
    font-size: 1rem;
    color: #999;
}

nav {
    margin-top: 120px;
    background-color: #1a1a1a;
    padding: 1rem 2rem;
}

nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

nav a {
    text-decoration: none;
    color: #5e5eff;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #b67d4c;
}

main {
    padding: 2rem;
    padding-top: 10px;
    max-width: 800px;
    margin: auto;
}

section.intro p {
    font-style: italic;
    color: #ccc;
    text-align: justify;
}

section.concept {
    margin: 2rem 0;
    border-left: 4px solid #5e5eff;
    padding-left: 1rem;
}

section.concept h2 {
    cursor: pointer;
    color: #b67d4c;
    margin-bottom: 0.5rem;
    transition: color 0.3s ease;
}

section.concept h2:hover {
    color: #5e5eff;
}

section .content {
    display: none;
    margin-top: 0.5rem;
    padding-left: 0.5rem;
    border-left: 2px solid #333;
    animation: fadeIn 0.5s ease-in-out;
}

.controls {
    margin: 2rem 0;
    text-align: center;
}

.controls button {
    padding: 0.6rem 1.2rem;
    background-color: #5e5eff;
    color: #fff;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.3s;
}

.controls button:hover {
    background-color: #4a4ae0;
}

.comment-box {
    margin-top: 3rem;
}

.comment-box h3 {
    margin-bottom: 0.5rem;
}

.comment-box {
    margin-top: 2rem;
    text-align: center;
    padding: 1rem;
}

.comment-box textarea {
    width: 100%;
    max-width: 600px;
    min-height: 120px;
    padding: 1rem;
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    background: #1a1a1a;
    border: 1px solid #444;
    color: #eee;
    border-radius: 8px;
    resize: vertical;
    box-sizing: border-box;
    margin: 0 auto;
    display: block;
}


footer {
    margin-top: 4rem;
    padding: 2rem;
    text-align: center;
    color: #666;
    font-style: italic;
    border-top: 1px solid #333;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}