/* General Styles */
:root {
    --primary-color: #007BFF; /* Bright Blue */
    --primary-dark: #0056b3;  /* Darker Blue */
    --primary-light: #f0f8ff; /* AliceBlue, for very light backgrounds */
    --dark-grey: #343a40;
    --light-grey: #f8f9fa;
    --text-color: #555;
    --white: #fff;

    /* New Accent Colors */
    --accent-coral: #ff6f61;
    --accent-mint: #68d388;
    --accent-yellow: #ffc107;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    margin: 0;
    line-height: 1.8;
    color: var(--text-color);
    /* New sky-like gradient background */
    background: linear-gradient(to bottom, #d3e9ff 0%, #ffffff 50%);
    background-attachment: fixed;
}

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

a:hover {
    color: var(--primary-dark);
}

/* Scroll Animation Base */
.scroll-animate {
    opacity: 0;
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

/* Animation Variations */
.scroll-animate.fade-in-up {
    transform: translateY(30px);
}
.scroll-animate.fade-in-left {
    transform: translateX(-40px);
}
.scroll-animate.fade-in-right {
    transform: translateX(40px);
}

/* Animation Triggered State */
.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0) translateX(0);
}


/* Header */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: background-color 0.3s ease-in-out, box-shadow 0.3s ease-in-out;
    background-color: var(--white);
}

#navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px 30px;
    transition: padding 0.3s ease-in-out;
}

#header.scrolled {
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

#header.scrolled #navbar {
    padding: 15px 30px;
}

.logo a {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--dark-grey);
}

#navbar ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
}

#navbar ul li {
    margin-left: 30px;
}

#navbar ul li a {
    color: var(--dark-grey);
    font-weight: 700;
    font-size: 1rem;
    position: relative;
    padding-bottom: 5px;
}

/* Underline effect for nav links */
#navbar ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease-in-out;
}
#navbar ul li a:hover::after {
    width: 100%;
}


/* Hero Section */
.hero {
    height: 90vh;
    background: url('https://images.unsplash.com/photo-1529333166437-77501bd49a94?q=80&w=1932&auto=format&fit=crop') no-repeat center center/cover;
    background-attachment: fixed; /* Parallax effect for hero */
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.hero-overlay {
    display: none;
}

.hero-content {
    position: relative;
    color: var(--dark-grey);
    padding: 20px;
    background-color: rgba(255, 255, 255, 0.8); /* Slightly more opaque background */
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--primary-dark);
}

.hero p {
    font-size: 1.3rem;
}

/* Content Sections */
.content-section {
    padding: 100px 30px;
    max-width: 1100px;
    margin: 0 auto;
    text-align: center;
    background-color: var(--white); /* Give sections a solid background */
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    margin-bottom: 40px;
}

.content-section-dark {
    background-color: var(--primary-light);
    padding: 100px 30px;
    text-align: center;
}

.content-section h2, .content-section-dark h2 {
    font-size: 2.5rem;
    color: var(--dark-grey);
    margin-bottom: 60px;
    position: relative;
    display: inline-block;
}

/* Decorative underline for headings */
.content-section h2::after, .content-section-dark h2::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    border-radius: 2px;
}

#intro h2::after { background-color: var(--accent-mint); }
#course h2::after { background-color: var(--accent-yellow); }
#video h2::after { background-color: var(--primary-color); }
#reviews h2::after { background-color: var(--accent-coral); }
#photo-gallery h2::after { background-color: var(--accent-mint); }
#apply h2::after { background-color: var(--accent-coral); }


/* Intro Section */
.intro-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    text-align: left;
}

.intro-item {
    background: var(--white);
    padding: 35px;
    border-radius: 8px;
    border-top: 5px solid var(--accent-mint);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
}
.intro-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.08);
}

/* Course Section */
.course-content {
    display: flex;
    align-items: center;
    gap: 60px;
    max-width: 1100px;
    margin: 0 auto;
    text-align: left;
}

.course-text {
    flex: 1;
}

.course-image {
    flex-shrink: 0;
}

.course-image img {
    max-width: 220px;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

/* Video Section */
.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    max-width: 100%;
    background: #000;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}
.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}


/* Review Section */
.review-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.review-card {
    background: var(--white);
    padding: 30px;
    border-radius: 8px;
    border-left: 5px solid var(--accent-coral);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    text-align: left;
}

.review-card p {
    font-style: italic;
    color: #444;
}

.review-card span {
    display: block;
    margin-top: 15px;
    font-weight: 700;
    text-align: right;
    color: var(--accent-coral);
}

/* CTA Section */
.cta p {
    font-size: 1.2rem;
    margin-bottom: 30px;
}

.cta-button {
    background-color: var(--accent-coral);
    color: var(--white);
    padding: 15px 40px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 700;
    transition: background-color 0.3s, transform 0.3s;
    box-shadow: 0 5px 15px rgba(255, 111, 97, 0.3);
}

.cta-button:hover {
    background-color: #e05a4f; /* Darker coral */
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(255, 111, 97, 0.4);
}

/* Photo Gallery Section */
.photo-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.gallery-item {
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.07);
    transition: transform 0.3s ease-in-out, box-shadow 0.3s;
}

.gallery-item:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Footer */
footer {
    background: var(--light-grey);
    color: #6c757d;
    text-align: center;
    padding: 40px 20px;
    border-top: 1px solid #e9ecef;
}

/* --- Mobile Optimization --- */
@media (max-width: 768px) {
    #navbar {
        flex-direction: column;
        padding: 15px;
    }

    #navbar ul {
        margin-top: 15px;
        flex-wrap: wrap;
        justify-content: center;
    }

    #navbar ul li {
        margin: 5px 10px;
    }

    .logo a {
        font-size: 1.5rem;
    }

    .hero {
        height: 70vh;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero p {
        font-size: 1.1rem;
    }

    .content-section, .content-section-dark {
        padding: 60px 20px;
    }

    .content-section h2, .content-section-dark h2 {
        font-size: 2rem;
        margin-bottom: 40px;
    }

    .course-content {
        flex-direction: column;
        gap: 40px;
    }

    .course-image img {
        max-width: 180px;
    }
}