* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans JP', sans-serif;
    background: #f5f7fb;
    color: #1f2937;
}

/* ─── Header ─── */
.header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: linear-gradient(90deg, #ffffff 0%, #f9fbff 100%);
    border-bottom: 1px solid #e5e7eb;
    padding: 12px 16px;
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: space-between;
}
.header h1 { margin: 0; font-size: 20px; white-space: nowrap; }
.meta { color: #6b7280; font-size: 13px; }

/* ─── Desktop: Two-column grid layout ─── */
.layout {
    display: grid;
    grid-template-columns: 360px 1fr;
    height: calc(100vh - 58px);
    overflow: hidden;
}
.sidebar {
    border-right: 1px solid #e5e7eb;
    background: #fff;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

/* ─── Search & Filters ─── */
.search {
    padding: 12px;
    border-bottom: 1px solid #eef2f7;
    position: sticky;
    top: 0;
    background: #fff;
    z-index: 5;
    flex-shrink: 0;
}
.search input[type="text"] {
    width: 100%;
    padding: 9px 10px;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 14px;
}
.search select {
    border: 1px solid #d1d5db;
    border-radius: 8px;
    background: #fff;
}
.search button[type="submit"] {
    margin-top: 8px;
    width: 100%;
    padding: 8px 10px;
    border: 1px solid #275ea3;
    background: #275ea3;
    color: #fff;
    border-radius: 8px;
    cursor: pointer;
}
.filter-block {
    margin-top: 8px;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    background: #fff;
    overflow: hidden;
}
.filter-title {
    font-size: 12px;
    font-weight: 700;
    color: #475569;
    padding: 8px 10px;
    background: #f8fafc;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}
.filter-count {
    font-size: 11px;
    color: #64748b;
    font-weight: 500;
}
.checkbox-grid {
    max-height: 180px;
    overflow-y: auto;
    padding: 6px 8px 10px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px 10px;
}
.checkbox-item {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 12px;
    line-height: 1.35;
    cursor: pointer;
    color: #1f2937;
    min-width: 0;
}
.checkbox-item input[type="checkbox"] {
    margin-top: 2px;
    width: 16px;
    height: 16px;
    flex: 0 0 16px;
}
.checkbox-item span {
    display: block;
    overflow-wrap: anywhere;
}

/* ─── List ─── */
.list { margin: 0; padding: 0; list-style: none; }
.list a {
    display: block;
    padding: 12px 12px;
    border-bottom: 1px solid #f1f5f9;
    text-decoration: none;
    color: inherit;
}
.list a:hover { background: #f8fafc; }
.list a.active { background: #e8f0fe; border-left: 3px solid #275ea3; }
.law-title {
    font-size: 14px;
    color: #0f172a;
    font-weight: 600;
    line-height: 1.35;
    display: -webkit-box;
    line-clamp: 2;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.file-name {
    margin-top: 6px;
    font-size: 12px;
    color: #64748b;
    word-break: break-all;
}
.file-meta { margin-top: 4px; font-size: 12px; color: #94a3b8; }
.reading-kana {
    margin-top: 4px;
    font-size: 12px;
    color: #475569;
    letter-spacing: 0.02em;
}

/* ─── Pager ─── */
.pager {
    display: flex;
    gap: 6px;
    padding: 10px 12px;
    border-top: 1px solid #eef2f7;
    position: sticky;
    bottom: 0;
    background: #fff;
    flex-shrink: 0;
    z-index: 5;
}
.pager a, .pager span {
    padding: 5px 8px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 12px;
    text-decoration: none;
    color: #334155;
    background: #fff;
}

/* ─── Content ─── */
.content {
    overflow: auto;
    padding: 16px;
}
.card {
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    padding: 16px;
    margin-bottom: 12px;
    box-shadow: 0 6px 16px rgba(15, 23, 42, 0.04);
}
.title { margin: 0 0 8px 0; font-size: 22px; }
.badge {
    display: inline-block;
    background: #eef2ff;
    color: #3730a3;
    border: 1px solid #c7d2fe;
    border-radius: 999px;
    font-size: 12px;
    padding: 3px 8px;
    margin-right: 6px;
    margin-bottom: 4px;
}
.kv {
    display: grid;
    grid-template-columns: 170px 1fr;
    gap: 6px 10px;
    font-size: 14px;
}
.kv dt { color: #475569; }
.kv dd { margin: 0; color: #0f172a; }

/* ─── Guide (Legend) ─── */
.guide h3 {
    margin: 16px 0 8px;
    font-size: 17px;
    color: #0f172a;
}
.guide p, .guide li {
    font-size: 14px;
    line-height: 1.8;
    color: #1f2937;
}
.guide ul {
    margin: 0;
    padding-left: 18px;
}
.guide .hint {
    margin-top: 8px;
    padding: 10px;
    border: 1px solid #dbeafe;
    border-radius: 8px;
    background: #eff6ff;
    color: #1e3a8a;
    font-size: 13px;
}

/* ─── Law Content ─── */
.law-content {
    font-size: 15px;
    line-height: 1.9;
    color: #111827;
}
.law-content h1, .law-content h2, .law-content h3, .law-content h4 {
    margin: 0.8em 0 0.4em;
    line-height: 1.4;
}
.law-content p, .law-content div, .law-content li {
    margin: 0.45em 0;
}
.law-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 10px 0;
    font-size: 14px;
}
.law-content th, .law-content td {
    border: 1px solid #dbe4ef;
    padding: 6px 8px;
    vertical-align: top;
}
.law-content th {
    background: #f8fafc;
    font-weight: 600;
}
.law-content a {
    color: #1d4ed8;
    text-decoration: underline;
    word-break: break-all;
}

/* ─── Empty Content Placeholder ─── */
.empty-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 60px 20px;
    color: #64748b;
}

/* ─── Mobile Back Button (hidden on desktop) ─── */
.mobile-back {
    display: none;
}

/* ─── Desktop Menu Toggle (hidden on desktop) ─── */
#menu-toggle {
    display: none;
}

/* ─── Feedback Section ─── */
.feedback-row {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}
.feedback-buttons {
    display: flex;
    gap: 8px;
    align-items: center;
}
.feedback-buttons button {
    padding: 6px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 4px;
}
#btn-good {
    border: 1px solid #86efac;
    background: #f0fdf4;
}
#btn-bad {
    border: 1px solid #fca5a5;
    background: #fef2f2;
}
#vote-status {
    font-size: 12px;
    color: #6b7280;
}
.view-count-label {
    margin-left: auto;
    font-size: 12px;
    color: #94a3b8;
    white-space: nowrap;
}
#comment-input {
    flex: 1;
    padding: 7px 10px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 13px;
    min-width: 0;
}

/* ═══════════════════════════════════════
   Tablet (≤1024px): single-column stack
   ═══════════════════════════════════════ */
@media (max-width: 1024px) {
    .layout {
        grid-template-columns: 1fr;
        height: auto;
        overflow: visible;
    }
    .sidebar {
        border-right: none;
        border-bottom: 1px solid #e5e7eb;
        max-height: 45vh;
    }
    .content {
        overflow: visible;
        height: auto;
    }
}

/* ═══════════════════════════════════════
   Mobile (≤768px): Master/Detail pattern
   No file selected → show search + list
   File selected    → show detail + back btn
   ═══════════════════════════════════════ */
@media (max-width: 768px) {
    .header { padding: 10px 12px; }
    .header h1 { font-size: 17px; }

    /* Stack layout, no fixed height, natural scroll */
    .layout {
        display: flex;
        flex-direction: column;
        height: auto;
        overflow: visible;
    }

    /* Sidebar: shown normally when no file selected */
    .sidebar {
        max-height: none;
        border-bottom: none;
        overflow-y: visible;
        order: 2;
    }

    /* Content area */
    .content {
        order: 3;
    }

    /* When a file is selected → hide sidebar, show detail */
    .layout.has-detail .sidebar {
        display: none;
    }

    /* When NO file selected and not landing → hide content on mobile; list is primary */
    .layout:not(.has-detail):not(.is-landing) .content {
        display: none;
    }

    /* Landing page: guide appears ABOVE sidebar */
    .layout.is-landing .content {
        order: 1;
    }
    .layout.is-landing .sidebar {
        order: 2;
        border-top: 1px solid #e5e7eb;
    }

    /* Mobile back button */
    .mobile-back {
        order: 0;
    }

    /* Guide: collapsible on mobile, closed by default */
    .guide-toggle {
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: space-between;
        -webkit-tap-highlight-color: rgba(39, 94, 163, 0.1);
    }
    .guide-arrow::after {
        content: '\25B6';
        font-size: 12px;
        color: #94a3b8;
        transition: transform 0.2s;
    }
    .guide.expanded .guide-arrow::after {
        transform: rotate(90deg);
    }
    .guide-body {
        display: none;
    }
    .guide.expanded .guide-body {
        display: block;
    }

    /* Mobile back button: visible when detail is open */
    .layout.has-detail .mobile-back {
        display: block;
        padding: 10px 12px;
        background: #fff;
        border-bottom: 1px solid #e5e7eb;
        position: sticky;
        top: 0;
        z-index: 15;
    }
    .mobile-back a {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        font-size: 14px;
        color: #275ea3;
        text-decoration: none;
        font-weight: 600;
        padding: 10px 14px;
        border: 1px solid #d1d5db;
        border-radius: 8px;
        background: #f8fafc;
        -webkit-tap-highlight-color: rgba(39, 94, 163, 0.15);
    }
    .mobile-back a:active {
        background: #e8f0fe;
    }

    /* Content adjustments */
    .content {
        padding: 10px;
    }

    /* Menu toggle: not needed in master/detail mode */
    #menu-toggle {
        display: none !important;
    }

    /* Prevent iOS zoom on inputs */
    .search input[type="text"],
    .search button[type="submit"],
    .search select {
        font-size: 16px !important;
    }
    .search input[type="text"] {
        padding: 12px;
    }
    .search button[type="submit"] {
        padding: 12px;
    }

    /* Filters: single column for easier touch, collapsed by default */
    .filter-block .checkbox-grid {
        display: none;
    }
    .filter-block.expanded .checkbox-grid {
        display: grid;
        grid-template-columns: 1fr;
        max-height: 200px;
    }
    .filter-title::after {
        content: '\25B6';
        font-size: 10px;
        color: #94a3b8;
        transition: transform 0.2s;
    }
    .filter-block.expanded .filter-title::after {
        transform: rotate(90deg);
    }
    .checkbox-item {
        font-size: 14px;
        padding: 4px 0;
        min-height: 36px;
        align-items: center;
    }
    .checkbox-item input[type="checkbox"] {
        width: 20px;
        height: 20px;
        flex: 0 0 20px;
    }

    /* List items: larger touch targets */
    .list a {
        padding: 14px 12px;
    }
    .law-title {
        font-size: 15px;
        line-clamp: 3;
        -webkit-line-clamp: 3;
    }

    /* Pager: larger tap area */
    .pager {
        justify-content: center;
    }
    .pager a, .pager span {
        padding: 10px 16px;
        font-size: 14px;
    }

    /* Cards */
    .card {
        padding: 14px;
        border-radius: 8px;
    }
    .title { font-size: 18px; line-height: 1.3; }

    /* KV: stack vertically */
    .kv {
        grid-template-columns: 1fr;
        gap: 4px;
    }
    .kv dt {
        margin-top: 10px;
        font-weight: 600;
        color: #334155;
        font-size: 13px;
    }
    .kv dd {
        padding-left: 10px;
        border-left: 2px solid #e2e8f0;
        font-size: 14px;
        line-height: 1.6;
    }

    /* Law content */
    .law-content table {
        display: block;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .law-content {
        font-size: 14px;
        line-height: 1.8;
    }

    /* Guide */
    .guide h3 { font-size: 16px; }
    .guide p, .guide li { font-size: 13px; line-height: 1.7; }

    /* Feedback: stack vertically for full-width buttons */
    .feedback-row {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    .feedback-buttons {
        justify-content: center;
        gap: 12px;
    }
    .feedback-buttons button {
        flex: 1;
        justify-content: center;
        padding: 12px 16px;
        font-size: 16px;
        min-height: 44px;
    }
    .view-count-label {
        margin-left: 0;
        text-align: center;
    }
    #vote-status {
        text-align: center;
        display: block;
    }
    #comment-input {
        font-size: 16px !important;
        padding: 12px;
        width: 100%;
    }

    /* Badge */
    .badge {
        font-size: 11px;
        padding: 2px 6px;
    }
}

/* ═══════════════════════════════════════
   Small phones (≤400px)
   ═══════════════════════════════════════ */
@media (max-width: 400px) {
    .header h1 { font-size: 15px; }
    .content { padding: 6px; }
    .card { padding: 10px; }
    .title { font-size: 16px; }
}