/* ----- GLOBAL RESET & BASE ----- */
        *,
        *::before,
        *::after { box-sizing: border-box; margin: 0; padding: 0; }
        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background: #f0f6fe;
            color: #0b2b44;
            line-height: 1.6;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }
        a { color: #1a5d9e; text-decoration: none; }
        a:hover { text-decoration: underline; }

        .site-header {
            background: #0b2b44;
            color: #fff;
            padding: 1rem 2rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 0.75rem;
            box-shadow: 0 2px 8px rgba(11, 43, 68, 0.15);
        }
        .site-header .logo { font-weight: 700; font-size: 1.4rem; letter-spacing: -0.5px; }
        .site-header .logo span { color: #7bbaff; }
        .site-header nav { display: flex; gap: 1.25rem; font-size: 0.95rem; }
        .site-header nav a { color: #cde0f5; transition: color 0.2s; }
        .site-header nav a:hover { color: #fff; text-decoration: none; }

        .page-wrapper {
            display: flex;
            flex: 1 0 auto;
            max-width: 1440px;
            width: 100%;
            margin: 0 auto;
            background: #fff;
            box-shadow: 0 4px 24px rgba(11, 43, 68, 0.06);
            border-radius: 0 0 16px 16px;
            overflow: hidden;
        }

        .sidebar {
            width: 280px;
            min-width: 280px;
            background: #e8f0fe;
            padding: 2rem 1.25rem;
            border-right: 1px solid #d0e2f5;
            position: sticky;
            top: 0;
            align-self: flex-start;
            max-height: 100vh;
            overflow-y: auto;
        }
        .sidebar h3 {
            font-size: 0.8rem;
            text-transform: uppercase;
            letter-spacing: 0.5px;
            color: #2b6a9e;
            margin-bottom: 1.25rem;
            border-bottom: 2px solid #b8d4f0;
            padding-bottom: 0.5rem;
        }
        .sidebar nav ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
        .sidebar nav ul li a {
            display: block;
            padding: 0.5rem 0.75rem;
            border-radius: 8px;
            font-size: 0.92rem;
            font-weight: 500;
            color: #1a4a70;
            transition: background 0.2s, color 0.2s;
        }
        .sidebar nav ul li a:hover { background: #c9ddf5; color: #0b2b44; text-decoration: none; }
        .sidebar nav ul li a .icon { margin-right: 0.5rem; opacity: 0.7; }
        .sidebar .song-id-badge {
            margin-top: 1.5rem;
            padding: 0.5rem 0.75rem;
            background: #d4e4f7;
            border-radius: 20px;
            font-size: 0.75rem;
            color: #1a5d9e;
            text-align: center;
            font-weight: 600;
        }

        .main-content {
            flex: 1;
            padding: 2.5rem 2.5rem 3rem;
            background: #ffffff;
            min-width: 0;
        }

        .song-info { margin-bottom: 2.5rem; }
        .song-info h1 { font-size: 2.2rem; font-weight: 700; color: #0b2b44; margin-bottom: 0.3rem; letter-spacing: -0.5px; }
        .song-info .subtitle { font-size: 1rem; color: #3d6e9e; margin-bottom: 1.25rem; border-left: 4px solid #3d8bd9; padding-left: 1rem; background: #f0f7fe; border-radius: 0 8px 8px 0; padding: 0.75rem 1rem; }
        .song-info .general-meaning {
            background: #f5faff;
            padding: 1.25rem 1.5rem;
            border-radius: 12px;
            border-left: 5px solid #1a6ec4;
            margin-bottom: 1.25rem;
            font-size: 1.05rem;
            color: #1a3f5c;
        }
        .theme-keywords { display: flex; flex-wrap: wrap; gap: 0.5rem; }
        .theme-keywords .badge {
            background: #d4e4f7;
            color: #0b3d66;
            padding: 0.3rem 1rem;
            border-radius: 30px;
            font-size: 0.8rem;
            font-weight: 600;
            letter-spacing: 0.3px;
            border: 1px solid #b8d4f0;
        }

        .section { margin-bottom: 2.75rem; }
        .section h2 {
            font-size: 1.5rem;
            font-weight: 600;
            color: #0b2b44;
            border-bottom: 3px solid #b8d4f0;
            padding-bottom: 0.4rem;
            margin-bottom: 1.25rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        .section h2 small { font-size: 0.75rem; font-weight: 400; color: #4d7aa8; margin-left: 0.5rem; }

        .segment-card {
            background: #f8fbff;
            border-radius: 12px;
            padding: 1.25rem 1.5rem;
            margin-bottom: 1.25rem;
            border: 1px solid #e3effa;
            box-shadow: 0 2px 6px rgba(11, 43, 68, 0.03);
        }
        .segment-card:hover { box-shadow: 0 4px 12px rgba(11, 43, 68, 0.06); }
        .segment-card .line-ids {
            font-size: 0.8rem;
            font-weight: 600;
            color: #2b6a9e;
            background: #dcebf9;
            display: inline-block;
            padding: 0.15rem 0.9rem;
            border-radius: 30px;
            margin-bottom: 0.5rem;
        }
        .segment-card .seg-meaning { font-weight: 500; color: #0b2b44; margin-bottom: 0.6rem; }
        .segment-card .seg-grammar {
            font-size: 0.93rem;
            color: #1f4a6e;
            background: #edf5fc;
            padding: 0.6rem 1rem;
            border-radius: 8px;
            margin-top: 0.3rem;
            border-left: 3px solid #6aa7e0;
        }
        .segment-card .seg-grammar strong { color: #0b3d66; }

        .situation-card {
            background: #f5faff;
            border-radius: 12px;
            padding: 1.25rem 1.5rem;
            margin-bottom: 1.25rem;
            border-left: 5px solid #3d8bd9;
            box-shadow: 0 2px 6px rgba(11, 43, 68, 0.03);
        }
        .situation-card .sit-title { font-weight: 700; color: #0b2b44; font-size: 1.05rem; }
        .situation-card .sit-when { font-size: 0.92rem; color: #2a5e88; margin: 0.2rem 0 0.5rem; }
        .situation-card .sit-expressions { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.5rem; }
        .situation-card .sit-expressions .expr {
            background: #e3effa;
            color: #0b3d66;
            padding: 0.2rem 0.9rem;
            border-radius: 30px;
            font-size: 0.85rem;
            font-weight: 500;
            border: 1px solid #c5dbf2;
        }

        .vocab-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
        .vocab-block {
            background: #f8fbff;
            border-radius: 12px;
            padding: 1.25rem 1.5rem;
            border: 1px solid #e3effa;
        }
        .vocab-block h3 { font-size: 1rem; font-weight: 600; color: #0b3d66; border-bottom: 2px solid #d4e4f7; padding-bottom: 0.4rem; margin-bottom: 0.75rem; }
        .vocab-item { padding: 0.4rem 0; border-bottom: 1px solid #edf5fc; font-size: 0.95rem; }
        .vocab-item:last-child { border-bottom: none; }
        .vocab-item .term { font-weight: 600; color: #0b2b44; }
        .vocab-item .def { display: block; color: #2a5e88; font-size: 0.88rem; margin-top: 0.1rem; }
        .vocab-item .use { display: block; color: #4d7aa8; font-size: 0.82rem; font-style: italic; margin-top: 0.05rem; }
        .vocab-block .meta-label { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.4px; color: #5a85b0; margin-top: 0.3rem; }

        .illustrative-text {
            background: #f5faff;
            border-radius: 12px;
            padding: 1.25rem 1.5rem;
            margin-bottom: 1rem;
            border-left: 5px solid #6aa7e0;
            font-size: 1rem;
            line-height: 1.7;
        }
        .illustrative-text .hl {
            background: #fcee8f;
            padding: 0.1rem 0.3rem;
            border-radius: 4px;
            font-weight: 600;
            color: #0b2b44;
            border-bottom: 2px solid #e8c84a;
        }

        .dialogue-box {
            background: #f8fbff;
            border-radius: 12px;
            padding: 1.25rem 1.5rem;
            margin-bottom: 1.25rem;
            border: 1px solid #dcebf9;
        }
        .dialogue-box .dialog-explain {
            font-size: 0.9rem;
            font-weight: 500;
            color: #1a4a70;
            margin-bottom: 0.75rem;
            background: #e3effa;
            padding: 0.3rem 1rem;
            border-radius: 30px;
            display: inline-block;
        }
        .dialogue-line { display: flex; gap: 0.75rem; padding: 0.4rem 0; border-bottom: 1px solid #edf5fc; }
        .dialogue-line:last-child { border-bottom: none; }
        .dialogue-line .speaker { font-weight: 700; color: #0b3d66; min-width: 70px; }
        .dialogue-line .text { color: #1a3f5c; }
        .dialogue-line .text .hl {
            background: #fcee8f;
            padding: 0.1rem 0.3rem;
            border-radius: 4px;
            font-weight: 600;
            color: #0b2b44;
            border-bottom: 2px solid #e8c84a;
        }

        .site-footer {
            background: #0b2b44;
            color: #aac4dd;
            padding: 1.25rem 2rem;
            text-align: center;
            font-size: 0.85rem;
            margin-top: auto;
            border-top: 1px solid #1a4a70;
        }
        .site-footer a { color: #7bbaff; }

        @media (max-width: 1024px) {
            .vocab-grid { grid-template-columns: 1fr; }
            .sidebar { width: 220px; min-width: 220px; padding: 1.5rem 1rem; }
            .main-content { padding: 1.75rem 1.5rem 2rem; }
        }
        @media (max-width: 820px) {
            .page-wrapper { flex-direction: column; border-radius: 0; }
            .sidebar {
                width: 100%; min-width: unset; border-right: none; border-bottom: 1px solid #d0e2f5;
                position: relative; max-height: none; padding: 1rem 1.25rem; background: #eef5fc;
            }
            .sidebar nav ul { flex-direction: row; flex-wrap: wrap; gap: 0.25rem; }
            .sidebar nav ul li a { padding: 0.3rem 0.7rem; font-size: 0.82rem; }
            .sidebar h3 { margin-bottom: 0.6rem; }
            .main-content { padding: 1.25rem 1rem 2rem; }
            .song-info h1 { font-size: 1.7rem; }
            .site-header { padding: 0.75rem 1rem; flex-direction: column; align-items: stretch; gap: 0.5rem; }
            .site-header nav { flex-wrap: wrap; gap: 0.75rem; font-size: 0.85rem; }
            .segment-card { padding: 1rem; }
            .situation-card { padding: 1rem; }
            .vocab-block { padding: 1rem; }
            .illustrative-text { padding: 1rem; }
            .dialogue-box { padding: 1rem; }
        }
        @media (max-width: 480px) {
            .song-info h1 { font-size: 1.4rem; }
            .main-content { padding: 0.75rem 0.75rem 1.5rem; }
            .sidebar { padding: 0.75rem; }
            .sidebar nav ul li a { font-size: 0.75rem; padding: 0.2rem 0.5rem; }
            .theme-keywords .badge { font-size: 0.7rem; padding: 0.15rem 0.6rem; }
            .dialogue-line { flex-direction: column; gap: 0.1rem; padding: 0.5rem 0; }
            .dialogue-line .speaker { min-width: unset; font-size: 0.85rem; }
            .section h2 { font-size: 1.2rem; }
        }
        .section-anchor { scroll-margin-top: 1.5rem; }