/* ========================================
   Lesson Page Styles - すごいAI道場
   レッスンページ共通スタイル
   ======================================== */

/* Lesson Page Container */
.lesson-page {
    max-width: 900px;
    margin: 120px auto 40px;
    padding: 40px;
    background: white;
    border: 3px solid #625147;
    border-radius: 8px;
    width: 100%;
    box-sizing: border-box;
}

/* Lesson Header */
.lesson-header {
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 3px solid var(--category-color, #625147);
}

.lesson-title-row {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 15px;
}

.lesson-number-badge {
    display: inline-block;
    background: var(--category-color, #625147);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.lesson-title {
    font-size: 2.5rem;
    color: #000814;
    margin: 0;
}

.lesson-description {
    font-size: 1.2rem;
    color: #625147;
    line-height: 1.8;
}

/* Video Container */
.video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    margin: 30px 0;
    background: #f5f5f5;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.video-container iframe,
.video-container #player {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Content Sections */
.content-section {
    margin: 40px 0;
}

.content-section h2 {
    font-size: 1.8rem;
    color: #000814;
    margin-bottom: 20px;
    padding-left: 15px;
    border-left: 5px solid var(--category-color, #625147);
}

.content-section h3 {
    font-size: 1.4rem;
    color: #000814;
    margin: 25px 0 15px;
}

.content-section p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #625147;
    margin-bottom: 15px;
}

.content-section ul {
    margin: 15px 0;
    padding-left: 30px;
}

.content-section li {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #625147;
    margin-bottom: 10px;
}

.content-section ol {
    margin: 15px 0;
    padding-left: 30px;
}

.content-section ol li {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #625147;
    margin-bottom: 10px;
}

/* Reference Links */
.reference-links {
    background: #f8f8f8;
    padding: 25px;
    border-radius: 8px;
    border-left: 5px solid var(--category-color, #625147);
    margin: 30px 0;
}

.reference-links h3 {
    font-size: 1.3rem;
    color: #000814;
    margin-bottom: 15px;
}

.reference-links a {
    display: inline-block;
    color: #4a90e2;
    text-decoration: none;
    font-weight: 600;
    padding: 10px 20px;
    background: white;
    border: 2px solid #4a90e2;
    border-radius: 6px;
    margin: 5px 10px 5px 0;
    transition: all 0.3s ease;
}

.reference-links a:hover {
    background: #4a90e2;
    color: white;
    transform: translateY(-2px);
}

/* Navigation Buttons */
.navigation-buttons {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    margin-top: 50px;
    padding-top: 30px;
    border-top: 2px solid #e0e0e0;
}

.nav-btn {
    flex: 1;
    padding: 15px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.nav-btn.prev {
    background: #e0e0e0;
    color: #000814;
}

.nav-btn.prev:hover {
    background: #c0c0c0;
    transform: translateX(-5px);
}

.nav-btn.next {
    background: var(--category-color, #625147);
    color: white;
}

.nav-btn.next:hover {
    background: var(--category-color-dark, #4a403a);
    transform: translateX(5px);
}

.nav-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.nav-btn.disabled:hover {
    transform: none;
}

/* Highlight Box */
.highlight-box {
    background: var(--category-bg-light, #f8f8f8);
    padding: 20px;
    border-radius: 8px;
    border-left: 5px solid var(--category-color, #625147);
    margin: 20px 0;
}

.highlight-box strong {
    color: var(--category-color, #625147);
}

/* Accordion Styles */
.accordion-container {
    margin: 30px 0;
    width: 100%;
}

.accordion-toggle {
    width: 100%;
    background: linear-gradient(135deg, var(--category-color, #625147) 0%, var(--category-color-light, #736860) 100%);
    color: white;
    border: none;
    padding: 20px 30px;
    font-size: 1.2rem;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.accordion-toggle:hover {
    background: linear-gradient(135deg, var(--category-color-dark, #4a403a) 0%, var(--category-color, #625147) 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

.accordion-toggle:active {
    transform: translateY(0);
}

.accordion-icon {
    font-size: 1rem;
    transition: transform 0.3s ease;
    display: inline-block;
}

.accordion-toggle.active .accordion-icon {
    transform: rotate(90deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-out;
    background: #f8f8f8;
    border-radius: 0 0 8px 8px;
    margin-top: -5px;
    width: 100%;
}

.accordion-content.active {
    max-height: 5000px;
    transition: max-height 0.8s ease-in;
    padding: 30px;
    border: 2px solid #e0e0e0;
    overflow-y: auto;
}

.accordion-content .content-section {
    margin: 0;
    width: 100%;
}

.accordion-content .content-section h2:first-child {
    margin-top: 0;
}

/* Discord Community Button (for community page) */
.discord-join-button {
    display: inline-block;
    background: linear-gradient(135deg, #9b59b6 0%, #7d3c98 100%);
    color: white;
    padding: 20px 40px;
    font-size: 1.3rem;
    font-weight: 700;
    text-decoration: none;
    border-radius: 12px;
    transition: all 0.3s ease;
    box-shadow: 0 6px 20px rgba(155, 89, 182, 0.4);
    border: none;
    cursor: pointer;
}

.discord-join-button:hover {
    background: linear-gradient(135deg, #8e44ad 0%, #6c2c7c 100%);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(155, 89, 182, 0.6);
}

/* ========================================
   Responsive Design - Lesson Pages
   ======================================== */

@media (max-width: 768px) {
    .lesson-page {
        margin: 100px 15px 40px;
        padding: 20px 15px;
    }

    .lesson-title-row {
        gap: 15px;
    }

    .lesson-number-badge {
        font-size: 0.9rem;
        padding: 8px 16px;
    }

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

    .lesson-description {
        font-size: 1rem;
    }

    .content-section h2 {
        font-size: 1.5rem;
    }

    .content-section h3 {
        font-size: 1.2rem;
    }

    .content-section p,
    .content-section li {
        font-size: 1rem;
    }

    .navigation-buttons {
        flex-direction: column;
    }

    .nav-btn {
        width: 100%;
    }

    .reference-links {
        padding: 20px;
    }

    .reference-links a {
        display: block;
        margin: 8px 0;
    }

    .accordion-toggle {
        padding: 15px 20px;
        font-size: 1.1rem;
    }

    .accordion-content.active {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .lesson-page {
        margin: 90px 10px 30px;
        padding: 15px 10px;
    }

    .lesson-title-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .lesson-number-badge {
        font-size: 0.85rem;
        padding: 6px 14px;
    }

    .lesson-title {
        font-size: 1.5rem;
    }

    .lesson-description {
        font-size: 0.95rem;
    }

    .content-section h2 {
        font-size: 1.3rem;
        padding-left: 10px;
    }

    .content-section h3 {
        font-size: 1.1rem;
    }

    .content-section p,
    .content-section li {
        font-size: 0.95rem;
    }

    .highlight-box {
        padding: 15px;
    }

    .reference-links {
        padding: 15px;
    }

    .nav-btn {
        padding: 12px 20px;
        font-size: 1rem;
    }

    .accordion-toggle {
        padding: 12px 15px;
        font-size: 1rem;
        gap: 10px;
    }

    .accordion-content.active {
        padding: 15px;
    }
}