:root {
    --point: #00f2ff;
    --bg: #000000;
    --card: #111;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg);
    color: #fff;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    line-height: 1.8;
    word-break: keep-all;
}

/* ===== HEADER ===== */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 5%;
    background: rgba(0, 0, 0, 0.98);
    border-bottom: 1px solid #222;
    position: sticky;
    top: 0;
    z-index: 10000;
    gap: 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.3rem;
    font-weight: 900;
    color: #fff;
    text-decoration: none;
    letter-spacing: -1px;
    white-space: nowrap;
    transition: color 0.3s;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
}

.logo:hover {
    color: var(--point);
}

.logo-img {
    width: 45px;
    height: 45px;
    object-fit: contain;
}

.nav-container {
    display: flex;
    align-items: center;
    gap: 20px;
    flex: 1;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 25px;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
}

.nav-links a {
    color: #fff;
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 700;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--point);
}

/* ===== DROPDOWN ===== */
.dropdown {
    position: relative;
    display: inline-block;
}

.btn-box {
    border: 2px solid var(--point);
    border-radius: 25px;
    padding: 8px 20px;
    cursor: pointer;
    color: var(--point);
    font-weight: 800;
    font-size: 0.85rem;
    background: transparent;
    transition: all 0.3s;
    white-space: nowrap;
}

.btn-box:hover {
    background: var(--point);
    color: #000;
}

.btn-filled {
    background: var(--point);
    color: #000;
}

.dropdown-content {
    display: none;
    position: absolute;
    background: #111;
    min-width: 240px;
    border: 2px solid var(--point);
    border-radius: 12px;
    top: 40px;
    right: 0;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.9);
    z-index: 10001;
    padding: 0;
    overflow: hidden;
}

.dropdown.active .dropdown-content {
    display: block !important;
}

.dropdown-content a {
    padding: 12px 18px;
    display: block;
    color: #fff;
    text-decoration: none;
    font-size: 0.9rem;
    border-bottom: 1px solid #333;
    transition: all 0.2s;
}

.dropdown-content a:last-child {
    border-bottom: none;
}

.dropdown-content a:hover {
    background: var(--point);
    color: #000;
    font-weight: 800;
}

/* ===== HERO ===== */
.hero {
    text-align: center;
    padding: 180px 5%;
    background: #000;
}

.hero h1 {
    font-size: clamp(2.2rem, 8vw, 4rem);
    font-weight: 900;
    margin-bottom: 15px;
    letter-spacing: -1px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
}

.hero p {
    color: var(--point);
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
}

/* ===== SECTION ===== */
section {
    padding: 80px 5% 50px;
    max-width: 1100px;
    margin: 0 auto;
    background: #000;
}

/* About 섹션 위에 큰 여백 추가 */
#about {
    margin-top: 150px;
    padding-top: 150px;
}

h2 {
    color: var(--point);
    font-size: 2.2rem;
    margin-bottom: 30px;
    border-bottom: 2px solid var(--point);
    display: inline-block;
    padding-bottom: 8px;
}

h3 {
    color: #fff;
    font-size: 1.5rem;
    margin-top: 45px;
    margin-bottom: 20px;
    font-weight: 700;
}

h4 {
    color: var(--point);
    font-size: 1.3rem;
    margin: 0 0 15px 0;
    font-weight: 700;
}

p {
    color: #ddd;
    margin-bottom: 15px;
    line-height: 1.9;
}

.highlight {
    color: var(--point);
    font-weight: bold;
}

.main-copy {
    font-size: 1.4rem;
    font-weight: bold;
    color: #fff;
    border-left: 5px solid var(--point);
    padding-left: 20px;
    margin: 40px 0 30px 0;
}

/* ===== LIST ===== */
ul {
    list-style: none;
    padding-left: 0;
    margin: 15px 0 25px 0;
}

li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 25px;
    color: #ccc;
    font-size: 1rem;
    line-height: 1.6;
}

li::before {
    content: "●";
    color: var(--point);
    position: absolute;
    left: 0;
    font-size: 0.8rem;
}

/* ===== AI TRINITY ===== */
.ai-trinity {
    background: #0a0a0a;
    border: 1px solid var(--point);
    border-radius: 20px;
    padding: 35px;
    margin: 50px 0;
    box-shadow: 0 0 30px rgba(0, 242, 255, 0.08);
}

.ai-trinity h4 {
    text-align: center;
    margin-bottom: 25px;
}

/* ===== CAMP BOX ===== */
.camp-box {
    background: var(--card);
    padding: 30px;
    border-radius: 15px;
    border: 1px solid #333;
    margin-top: 25px;
    transition: all 0.3s;
}

.camp-box:hover {
    border-color: var(--point);
    transform: translateY(-3px);
    background: #1a1a1a;
}

/* ===== GRAMMAR GRID ===== */
.stage-title {
    margin: 70px 0 25px;
    border-left: 5px solid var(--point);
    padding-left: 20px;
}

.stage-title h3 {
    margin: 0;
}

.grammar-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
    gap: 18px;
    margin-bottom: 30px;
}

.g-link {
    background: #111;
    padding: 22px;
    border-radius: 12px;
    text-decoration: none;
    color: #fff;
    border: 1px solid #333;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.g-link:hover {
    transform: translateY(-4px);
    border-color: var(--point);
    background: #1a1a1a;
    box-shadow: 0 8px 25px rgba(0, 242, 255, 0.1);
}

.g-num {
    color: var(--point);
    font-size: 0.8rem;
    font-weight: 900;
    letter-spacing: 1px;
}

.g-title {
    font-size: 1rem;
    font-weight: 700;
    line-height: 1.4;
}

/* ===== FOOTER ===== */
.notice-footer {
    text-align: center;
    padding: 70px 5%;
    border-top: 1px solid #222;
    margin-top: 80px;
}

.notice-footer p {
    color: #888;
    font-size: 0.95rem;
    margin-bottom: 25px;
}

.btn-reg {
    background: var(--point);
    color: #000;
    padding: 18px 60px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 900;
    font-size: 1.1rem;
    display: inline-block;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn-reg:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px var(--point);
}

.footer-info {
    text-align: center;
    padding: 40px 5%;
    color: #444;
    font-size: 0.85rem;
    border-top: 1px solid #222;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    header {
        flex-wrap: wrap;
        padding: 12px 5%;
    }

    .logo {
        font-size: 1.3rem;
    }

    .nav-container {
        width: 100%;
        gap: 15px;
    }

    .nav-links {
        gap: 15px;
    }

    .grammar-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }

    section {
        padding: 60px 5% 40px;
    }

    #about {
        margin-top: 100px;
        padding-top: 100px;
    }

    h2 {
        font-size: 1.9rem;
    }
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: flex-start;
        padding: 10px 5%;
        gap: 12px;
    }

    .logo {
        font-size: 1.2rem;
    }

    .logo-img {
        width: 40px;
        height: 40px;
    }

    .nav-container {
        width: 100%;
        flex-direction: column;
        gap: 10px;
    }

    .nav-links {
        gap: 12px;
        flex-wrap: wrap;
        font-size: 0.9rem;
    }

    .btn-box {
        padding: 6px 16px;
        font-size: 0.8rem;
    }

    .hero {
        padding: 120px 5%;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

    .hero p {
        font-size: 1rem;
    }

    section {
        padding: 50px 5% 30px;
    }

    #about {
        margin-top: 50px;
        padding-top: 50px;
    }

    h2 {
        font-size: 1.6rem;
    }

    h3 {
        font-size: 1.2rem;
        margin-top: 30px;
    }

    .grammar-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 12px;
    }

    .g-link {
        padding: 16px;
    }

    .g-title {
        font-size: 0.9rem;
    }

    .camp-box {
        padding: 20px;
    }

    .ai-trinity {
        padding: 20px;
    }

    .btn-reg {
        padding: 14px 45px;
        font-size: 1rem;
    }
}