/* ========================================
   반응형 웹사이트 - 메인 CSS
   ======================================== */

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

body {
    font-family: 'Segoe UI', 'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
}

/* ========== 헤더 스타일 ========== */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 20px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 28px;
    font-weight: bold;
    color: #667eea;
    text-decoration: none;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #667eea;
}

/* ========== 네비게이션 ========== */
nav {
    display: flex;
    gap: 30px;
}

nav a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

nav a:hover {
    color: #667eea;
}

nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #667eea;
    transition: width 0.3s ease;
}

nav a:hover::after {
    width: 100%;
}

/* ========== 히어로 섹션 ========== */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 80px 20px;
}

.hero-content h1 {
    font-size: 48px;
    margin-bottom: 20px;
    animation: slideDown 0.6s ease;
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.9;
    animation: slideUp 0.6s ease 0.2s both;
}

/* ========== 도구 그리드 ========== */
.tools-section {
    max-width: 1200px;
    margin: 60px auto;
    padding: 0 20px;
}

.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: white;
    animation: fadeIn 0.8s ease;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.tool-card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    cursor: pointer;
}

.tool-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.tool-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.tool-card h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: #333;
}

.tool-card p {
    color: #666;
    font-size: 14px;
    margin-bottom: 20px;
}

.tool-card a {
    display: inline-block;
    padding: 10px 25px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    transition: all 0.3s ease;
    font-weight: 500;
}

.tool-card a:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

/* ========== 푸터 ========== */
footer {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
    padding: 40px 20px;
    margin-top: 80px;
}

footer p {
    margin-bottom: 10px;
}

/* ========== 애니메이션 ========== */
@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ========== 홈 버튼 스타일 (모든 페이지) ========== */
.home-btn {
    position: fixed;
    top: 20px;
    left: 20px;
    padding: 12px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    font-weight: 600;
    z-index: 999;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.home-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* ========== 반응형 디자인 ========== */
@media (max-width: 768px) {
    .header-container {
        justify-content: space-between;
    }

    .nav-toggle {
        display: block;
    }

    nav {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: 20px 0;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    }

    nav.active {
        display: flex;
    }

    nav a {
        padding: 15px 20px;
        border-bottom: 1px solid #eee;
    }

    .hero-content h1 {
        font-size: 36px;
    }

    .hero-content p {
        font-size: 16px;
    }

    .section-title {
        font-size: 28px;
    }

    .tools-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .tool-card {
        padding: 20px;
    }

    .home-btn {
        padding: 10px 15px;
        font-size: 14px;
        top: 10px;
        left: 10px;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 28px;
    }

    .hero-content p {
        font-size: 14px;
    }

    .section-title {
        font-size: 24px;
        margin-bottom: 30px;
    }

    .tool-card {
        padding: 15px;
    }

    .tool-icon {
        font-size: 36px;
    }
}