/* styles.css */
:root {
    --bg-main: #f8fafc; --bg-accent: #f1f5f9; --player-area-dark: #1e293b;
    --text-dark: #0f172a; --text-muted: #64748b; --text-light: #f1f5f9;
    --primary-accent: #0284c7; --completed-accent: #10b981; --border-color: #e2e8f0;
}
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; background-color: var(--bg-main); color: var(--text-dark); margin: 0; line-height: 1.6; }

/* 로그인 & 팝업 오버레이 */
.overlay-container {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    background: rgba(15, 23, 42, 0.95); z-index: 9999;
    display: flex; flex-direction: column; justify-content: center; align-items: center;
}
.login-box {
    background: #ffffff; padding: 40px; border-radius: 12px; width: 350px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5); text-align: center;
}
.login-box h2 { margin-top: 0; color: var(--text-dark); font-weight: 800;}
.login-box p { color: var(--text-muted); font-size: 0.85rem; margin-bottom: 25px;}
.login-input {
    width: 100%; padding: 12px; margin-bottom: 15px; border: 1px solid var(--border-color);
    border-radius: 6px; box-sizing: border-box; font-size: 0.95rem;
}
.login-btn {
    width: 100%; padding: 12px; background: var(--primary-accent); color: white;
    border: none; border-radius: 6px; font-weight: bold; cursor: pointer; font-size: 1rem; transition: 0.2s;
}
.login-btn:hover { background: #0369a1; }
.error-msg { color: #ef4444; font-size: 0.85rem; margin-top: 10px; display: none; }

/* 메인 UI 스타일 */
.top-nav { background-color: #ffffff; padding: 15px 50px; border-bottom: 1px solid var(--border-color); display: flex; align-items: center; justify-content: space-between; }
.breadcrumb { font-size: 0.85rem; color: var(--text-muted); }
.breadcrumb strong { color: var(--text-dark); }
.brand-name { font-weight: 800; font-size: 1rem; letter-spacing: -0.5px;}
.logout-btn { background: transparent; border: 1px solid var(--border-color); color: var(--text-dark); padding: 5px 15px; border-radius: 6px; cursor: pointer; font-size: 0.8rem; font-weight: 700; margin-left: 20px;}
.logout-btn:hover { background: var(--bg-accent); }

.main-player-section { display: flex; flex-direction: column; background-color: var(--player-area-dark); margin: 30px; border-radius: 16px; overflow: hidden; box-shadow: 0 20px 40px rgba(0,0,0,0.15); }
.language-tabs { display: flex; background-color: #0f172a; padding: 10px 20px; gap: 10px; border-bottom: 1px solid #334155; }
.lang-btn { background: transparent; color: #94a3b8; border: 1px solid transparent; padding: 6px 15px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; cursor: pointer; transition: 0.2s; }
.lang-btn.active { background: var(--primary-accent); color: #fff; border-color: var(--primary-accent); }

.player-body { display: flex; width: 100%; }
.video-wrapper { flex: 2.2; position: relative; padding-bottom: 39.375%; background-color: #000; overflow: hidden; }
.video-content { position: absolute; top: 0; left: 0; width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; flex-direction: column; color: var(--text-muted); text-align: center; }
.video-content h3 { color: #fff; margin-bottom: 10px; font-weight: 700; font-size: 1.5rem;}
.popout-blocker { position: absolute; top: 0; right: 0; width: 70px; height: 60px; background-color: #000; z-index: 50; }

.lesson-playlist { flex: 1; border-left: 1px solid #334155; display: flex; flex-direction: column; max-height: calc(100vh - 200px); background: transparent;}
.playlist-header { padding: 25px; border-bottom: 1px solid #334155; color: #fff; }
.playlist-header h4 { margin: 0; font-size: 1rem; }
.module-meta { font-size: 0.8rem; color: #888; }
.lesson-items { list-style: none; padding: 0; margin: 0; overflow-y: auto; flex-grow: 1; }

.part-header { padding: 15px 25px 10px 25px; font-size: 0.8rem; font-weight: 700; color: #94a3b8; text-transform: uppercase; letter-spacing: 1px; background: #1e293b; border-bottom: 1px solid #334155; margin-top: 10px; }
.part-header:first-child { margin-top: 0; }
.lesson-link { display: flex; align-items: center; justify-content: space-between; padding: 15px 25px; color: #cbd5e1; text-decoration: none; border-bottom: 1px solid #334155; cursor: pointer; transition: 0.3s; position: relative; }
.lesson-link.current { color: #fff; background-color: rgba(2, 132, 199, 0.15); }
.lesson-link.current::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 4px; background-color: var(--primary-accent); }
.item-left { 
    display: flex; 
    align-items: center; 
    gap: 15px; /* 💡 Ch.번호와 제목 사이의 숨통(간격)을 틔워줍니다 */
}

.lesson-index { 
    width: 45px; /* 너비를 살짝 늘렸습니다 */
    flex-shrink: 0; /* 💡 텍스트가 두 줄 세 줄이 되어도 이 45px 영역이 절대 찌그러지지 않게 방어합니다 */
    font-weight: bold; 
    color: #64748b; 
    font-size: 0.85rem;
}

/* 💡 이 부분은 기존에 없었다면 맨 아래에 추가해 주세요 */
.lesson-item-title {
    line-height: 1.4; /* 두 줄로 넘어갔을 때 줄 간격을 더 자연스럽게 만듭니다 */
    word-break: keep-all; /* 단어 중간에서 텍스트가 흉하게 잘리는 것을 방지합니다 */
}
.current .lesson-index { color: var(--primary-accent); }
.check-mark { color: var(--completed-accent); font-weight: bold; margin-left: 10px; display: none; }
.is-completed .check-mark { display: inline; }

.content-container { max-width: 900px; margin: 0 auto; padding: 20px 30px 60px 30px; }
.status-and-content { background-color: #ffffff; padding: 40px; border-radius: 16px; box-shadow: 0 4px 12px rgba(0,0,0,0.03); border: 1px solid var(--border-color); }
.main-content h1 { margin-top: 0; font-size: 2.2rem; font-weight: 800; }
.main-content h3 { margin-top: 40px; margin-bottom: 15px; font-size: 1.3rem; font-weight: 700;}
.audio-section { background: #ffffff; border: 1px solid var(--border-color); border-radius: 12px; padding: 25px; margin-top: 20px; box-shadow: 0 2px 5px rgba(0,0,0,0.02); }
.audio-section h4 { margin-top: 0; }
audio { width: 100%; height: 35px; }

@media (max-width: 1100px) {
    .player-body { flex-direction: column; }
    .lesson-playlist { border-left: none; border-top: 1px solid #334155; }
}