:root {
    --bg-main: #000000;
    --bg-secondary: #000000;
    --text-primary: #ffffff;
    --text-secondary: #ffffff;
    --accent: #4da3ff;
    --border-color: rgba(255, 255, 255, 0.3);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    padding-top: 80px; 
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: #7abfff;
}

/* Navbar */
.navbar {
    background-color: var(--bg-main) !important;
    padding: 1rem 0;
    transition: all 0.3s ease;
    border-bottom: 1px solid var(--border-color);
}

.navbar-brand, .nav-link {
    color: var(--text-primary) !important;
}

.nav-link {
    font-size: 0.95rem;
    letter-spacing: 0.05em;
    transition: opacity 0.2s ease;
}

.nav-link:hover, .nav-link.active {
    color: var(--accent) !important;
}

.navbar-toggler {
    border-color: var(--border-color);
}

.navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 1%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* Sections */
section {
    padding: 4rem 0;
    min-height: calc(100vh - 180px); 
}

.section-title {
    position: relative;
    display: inline-block;
    margin-bottom: 3rem;
    font-size: 2rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 40px;
    height: 2px;
    background-color: var(--accent);
}

/* Note Cards */
.note-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    margin-bottom: 1rem;
}

.note-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.1);
    border-color: #ffffff;
}

.note-card .fw-semibold {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.note-card .text-muted {
    color: var(--text-secondary) !important;
    font-size: 0.9rem;
}

/* Buttons & Icons */
.btn-custom {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--text-primary);
    border-radius: 4px;
    padding: 0.5rem 1.5rem;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.btn-custom:hover {
    background-color: var(--text-primary);
    color: var(--bg-main);
}

.btn-read {
    border-radius: 4px;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #ffffff;
    border-color: #ffffff;
}

.btn-read:hover {
    background-color: #ffffff;
    color: #000000;
}

.social-icon {
    font-size: 1.5rem;
    margin-right: 1.2rem;
    color: var(--text-secondary);
    transition: color 0.2s ease;
}

.social-icon:hover {
    color: var(--accent);
}

/* Footer */
footer {
    background-color: var(--bg-main);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 0;
}