/* --- Global Styles & Dark Theme --- */
:root {
    --primary-color: #1a1a1a;
    --secondary-color: #2d2d2d;
    --accent-color: #00a8ff;
    --text-color: #f0f0f0;
    --text-muted: #a0a0a0;
    --border-color: #444;
    --success-color: #28a745;
    --error-color: #dc3545;
}

body {
    background-color: var(--primary-color);
    color: var(--text-color);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    line-height: 1.6;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #fff;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* --- Header & Navigation --- */
.main-header {
    background-color: var(--secondary-color);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
}

.main-nav a {
    margin-left: 1.5rem;
    font-size: 1rem;
    font-weight: 500;
}

.main-nav a.btn {
    background-color: var(--accent-color);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.main-nav a.btn:hover {
    background-color: #fff;
    color: var(--primary-color);
}

/* --- Main Container & Layout --- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* --- Hero Section --- */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background-color: var(--secondary-color);
    border-radius: 8px;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

/* --- Video Grid --- */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.video-card {
    background-color: var(--secondary-color);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--border-color);
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 168, 255, 0.2);
}

.video-card img {
    width: 100%;
    height: 180px;
    object-fit: cover;
}

.video-card-content {
    padding: 1rem;
}

.video-card-content h3 {
    margin-top: 0;
    font-size: 1.2rem;
}

.video-card-content p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* --- Forms --- */
.form-container {
    max-width: 450px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: var(--secondary-color);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    color: var(--text-color);
    font-size: 1rem;
    box-sizing: border-box;
}

.btn {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: 5px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    text-align: center;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #fff;
    color: var(--primary-color);
}

.btn-block {
    display: block;
    width: 100%;
}

/* --- Alerts --- */
.alert {
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 5px;
    border: 1px solid transparent;
}

.alert-success {
    background-color: var(--success-color);
    color: #fff;
}

.alert-error {
    background-color: var(--error-color);
    color: #fff;
}

/* --- Footer --- */
.main-footer {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}