@charset "UTF-8";
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;700&family=Roboto:wght@300;400;500;700&display=swap');

:root {
    --primary-color: #E1306C;
    /* Instagram Pink/Red */
    --secondary-color: #833AB4;
    /* Instagram Purple */
    --accent-color: #FCAF45;
    /* Instagram Orange/Yellow */
    --text-color: #262626;
    --bg-color: #FAFAFA;
    --card-bg: #FFFFFF;
    --sidebar-width: 280px;
    --nav-height: 60px;
}

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

body {
    font-family: 'Noto Sans KR', 'Roboto', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    font-size: 16px;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    background: linear-gradient(45deg, #405DE6, #5851DB, #833AB4, #C13584, #E1306C, #FD1D1D);
    color: white;
    padding: 60px 0;
    text-align: center;
    border-radius: 0 0 20px 20px;
    margin-bottom: 40px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Back Nav */
.back-nav {
    margin-bottom: 20px;
}

.back-nav a {
    display: inline-flex;
    align-items: center;
    color: #666;
    font-weight: 500;
    transition: color 0.3s;
}

.back-nav a:hover {
    color: var(--primary-color);
}

.back-nav i {
    margin-right: 8px;
}

/* Grid Layout for Lessons */
.lesson-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    padding: 20px 0;
}

/* Lesson Card */
.lesson-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid #eee;
    display: flex;
    flex-direction: column;
}

.lesson-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
}

.card-header {
    background: #f8f8f8;
    padding: 15px 20px;
    font-weight: 700;
    color: #666;
    font-size: 0.9rem;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-body {
    padding: 20px;
    flex-grow: 1;
}

.card-body h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: #333;
    line-height: 1.4;
}

.card-body p {
    font-size: 0.95rem;
    color: #666;
    margin-bottom: 15px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-footer {
    padding: 15px 20px;
    border-top: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: #888;
}

.read-btn {
    display: inline-block;
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border-radius: 20px;
    font-weight: 500;
    transition: background 0.3s;
}

.read-btn:hover {
    background: #C13584;
}

/* Badges */
.badge {
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-setup {
    background: #e3f2fd;
    color: #1565c0;
}

.badge-creative {
    background: #fce4ec;
    color: #c2185b;
}

.badge-execution {
    background: #e8f5e9;
    color: #2e7d32;
}

.badge-optimization {
    background: #fff3e0;
    color: #ef6c00;
}

/* Lesson Detail Page Styles */
.lesson-container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    padding: 50px;
    border-radius: 20px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.lesson-header {
    text-align: center;
    margin-bottom: 40px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 30px;
}

.lesson-meta {
    color: #888;
    font-size: 0.9rem;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.lesson-title {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: #222;
}

.lesson-content h2 {
    font-size: 1.6rem;
    margin: 40px 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary-color);
    color: #333;
    display: inline-block;
}

.lesson-content h3 {
    font-size: 1.3rem;
    margin: 30px 0 15px;
    color: #444;
}

.lesson-content p {
    margin-bottom: 20px;
    font-size: 1.05rem;
    color: #444;
    text-align: justify;
}

.highlight-box {
    background: #f8f9fa;
    border-left: 4px solid var(--secondary-color);
    padding: 20px;
    margin: 25px 0;
    border-radius: 0 8px 8px 0;
}

.action-plan {
    background: #e8f5e9;
    border: 1px solid #c8e6c9;
    padding: 25px;
    border-radius: 12px;
    margin-top: 50px;
}

.action-plan h3 {
    color: #2e7d32;
    margin-top: 0;
}

ul,
ol {
    margin-bottom: 20px;
    padding-left: 25px;
}

li {
    margin-bottom: 10px;
}

blockquote {
    font-size: 1.2rem;
    font-style: italic;
    color: #555;
    padding: 20px;
    border-left: 5px solid #ddd;
    margin: 30px 0;
    background: #fafafa;
}

.faq-section {
    margin-top: 50px;
    border-top: 1px solid #eee;
    padding-top: 30px;
}

.faq-item {
    margin-bottom: 20px;
}

.faq-question {
    font-weight: 700;
    color: #333;
    margin-bottom: 5px;
}

.faq-answer {
    color: #666;
}

/* Interactive Elements */
/* Calculator */
.interactive-box {
    background: #f1f8e9;
    border: 1px solid #c5e1a5;
    padding: 25px;
    border-radius: 12px;
    margin: 30px 0;
}

.calc-input-group {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
    align-items: center;
}

.calc-input-group label {
    flex: 1;
    font-weight: 500;
}

.calc-input-group input {
    flex: 1;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.calc-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
    width: 100%;
    transition: background 0.3s;
}

.calc-btn:hover {
    background: #C13584;
}

.calc-result {
    margin-top: 15px;
    font-weight: bold;
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-color);
}

/* Quiz */
.quiz-container {
    background: #e3f2fd;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid #bbdefb;
    margin: 30px 0;
}

.quiz-option {
    display: block;
    background: white;
    padding: 12px;
    margin: 8px 0;
    border-radius: 6px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.2s;
}

.quiz-option:hover {
    border-color: #2196f3;
}

.quiz-option.correct {
    background: #d4edda;
    border-color: #28a745;
    color: #155724;
}

.quiz-option.wrong {
    background: #f8d7da;
    border-color: #dc3545;
    color: #721c24;
}

.quiz-feedback {
    display: none;
    margin-top: 10px;
    font-weight: 500;
}

/* Accordion */
.accordion {
    margin: 20px 0;
}

.accordion-item {
    border: 1px solid #ddd;
    border-radius: 8px;
    margin-bottom: 10px;
    overflow: hidden;
}

.accordion-header {
    background: #fafafa;
    padding: 15px;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.accordion-header:hover {
    background: #f0f0f0;
}

.accordion-content {
    display: none;
    padding: 15px;
    border-top: 1px solid #ddd;
    background: white;
}

.accordion-content.active {
    display: block;
}

/* Responsive */
@media (max-width: 768px) {
    .lesson-container {
        padding: 30px 20px;
    }

    .lesson-title {
        font-size: 1.8rem;
    }

    header h1 {
        font-size: 1.8rem;
    }
}