:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-main: #333333;
    --text-sub: #666666;
    --border-color: #e2e8f0;
    --nav-height: 70px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Pretendard', sans-serif;
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
}

/* Header & Navigation */
header {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    height: var(--nav-height);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    font-weight: 800;
    font-size: 1.4rem;
    color: var(--primary-color);
    letter-spacing: -1px;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

/* Main Layout */
.app-container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

.section {
    margin-bottom: 60px;
}

.card {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

/* Generator Styling */
.header { text-align: center; margin-bottom: 30px; }
.header h1 { font-size: 2.5rem; color: var(--primary-color); margin-bottom: 10px; }
.header p { color: var(--text-sub); }

.input-section { text-align: center; margin: 30px 0; }
input {
    width: 100%;
    max-width: 450px;
    padding: 20px 25px;
    border: 2px solid var(--border-color);
    border-radius: 15px;
    font-size: 1.1rem;
    outline: none;
    transition: all 0.3s;
}
input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.1);
}

.btn-group { display: flex; justify-content: center; gap: 15px; flex-wrap: wrap; }
button { padding: 16px 35px; border: none; border-radius: 12px; font-size: 1rem; font-weight: 700; cursor: pointer; transition: all 0.2s; }
.btn-primary { background-color: var(--accent-color); color: white; }
.btn-primary:hover { background-color: #2980b9; transform: translateY(-2px); }
.btn-copy { background-color: #ecf0f1; color: #2c3e50; display: none; }

/* Poem Result */
.poem-card { margin-top: 40px; padding: 35px; background: #f8fafc; border-radius: 16px; border-left: 6px solid var(--accent-color); animation: slideUp 0.5s ease-out; }
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.poem-line { display: flex; margin-bottom: 20px; align-items: flex-start; }
.initial-box { width: 45px; height: 45px; background: var(--primary-color); color: white; display: flex; align-items: center; justify-content: center; border-radius: 10px; font-weight: 900; margin-right: 20px; flex-shrink: 0; font-size: 1.2rem; }
.content-text { font-size: 1.15rem; color: #334155; padding-top: 8px; font-weight: 500; }

/* Content Sections */
.info-content { background: white; padding: 50px; border-radius: 20px; box-shadow: 0 4px 15px rgba(0,0,0,0.02); }
.info-content h2 { margin-bottom: 25px; color: var(--primary-color); font-size: 1.8rem; border-bottom: 3px solid var(--accent-color); display: inline-block; padding-bottom: 5px; }
.info-content p { margin-bottom: 20px; font-size: 1.05rem; color: #444; text-align: justify; }

/* Tips Grid */
.tips-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 30px; margin-top: 20px; }
.tip-item { background: #fdfdfd; padding: 25px; border-radius: 15px; border: 1px solid #f0f0f0; }
.tip-item h3 { color: var(--accent-color); margin-bottom: 12px; font-size: 1.2rem; }
.tip-item p { font-size: 0.95rem; margin-bottom: 0; }

/* FAQ Section */
.faq-list details { background: #f9fbff; padding: 15px 20px; border-radius: 12px; margin-bottom: 15px; border: 1px solid #eef2f8; }
.faq-list summary { font-weight: 700; cursor: pointer; color: var(--primary-color); list-style: none; position: relative; padding-right: 30px; }
.faq-list summary::after { content: '▼'; position: absolute; right: 0; font-size: 0.8rem; transition: transform 0.3s; }
.faq-list details[open] summary::after { transform: rotate(180deg); }
.faq-list p { margin-top: 15px; padding-top: 15px; border-top: 1px solid #e2e8f0; font-size: 0.95rem; margin-bottom: 0; }

/* Ad Placeholder */
.ad-placeholder { background: #f1f3f5; border: 2px dashed #dee2e6; padding: 40px; text-align: center; margin-bottom: 60px; border-radius: 15px; color: #adb5bd; }
.ad-placeholder p { font-size: 0.8rem; letter-spacing: 2px; margin-bottom: 10px; }

/* Contact Form */
.contact-box { text-align: center; }
.contact-form { margin-top: 35px; text-align: left; }
.form-row { display: flex; gap: 15px; margin-bottom: 15px; }
.form-row input { flex: 1; max-width: none; }
.contact-form input, .contact-form textarea { width: 100%; padding: 15px; border: 1px solid var(--border-color); border-radius: 12px; outline: none; font-size: 1rem; }
.contact-form textarea { height: 150px; margin-bottom: 20px; resize: none; }
.contact-box .btn-primary { width: 100%; }

/* Footer */
.footer { padding: 60px 20px; background: white; border-top: 1px solid var(--border-color); text-align: center; }
.footer-links { margin-bottom: 25px; }
.footer-links a { margin: 0 15px; text-decoration: none; color: var(--text-sub); font-size: 0.95rem; font-weight: 500; }
.footer-links a:hover { color: var(--accent-color); }

#toast { position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%); background: rgba(0,0,0,0.85); color: white; padding: 12px 30px; border-radius: 50px; display: none; z-index: 2000; font-weight: 600; box-shadow: 0 5px 15px rgba(0,0,0,0.2); }

@media (max-width: 600px) {
    .nav-links { display: none; }
    .info-content { padding: 30px 20px; }
    .form-row { flex-direction: column; }
    .header h1 { font-size: 2rem; }
}