/* =============================================
           Whole-Spec v3 — Claude-inspired Dark Theme
           Design: Warm gray palette, clean hierarchy
           ============================================= */

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

        :root {
            /* 라이트 모드 (기본) — 눈 편한 웜 화이트 */
            --bg-base: #f5f3f0;
            --bg-sidebar: #edeae6;
            --bg-surface: #ffffff;
            --bg-elevated: #f0ede9;
            --bg-hover: #e8e5e0;
            --bg-active: #ddd9d3;

            --text-primary: #2c2c2c;
            --text-secondary: #5a5a5a;
            --text-tertiary: #8a8a8a;
            --text-inverse: #ffffff;

            --accent: #c4854c;
            --accent-hover: #b37540;
            --accent-subtle: rgba(196,133,76,0.08);
            --accent-muted: rgba(196,133,76,0.2);

            --border: #ddd9d3;
            --border-light: #e8e5e0;
            --border-strong: #c5c0b8;

            --success: #4a9e55;
            --info: #4a8fb0;
            --warning: #c4854c;

            --sidebar-w: 260px;
            --topbar-h: 52px;
            --radius: 8px;
            --radius-sm: 5px;
            --transition: 150ms ease;

            --font-sans: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
            --font-mono: 'IBM Plex Mono', 'Consolas', monospace;
        }

        [data-theme="dark"] {
            --bg-base: #1a1a1a;
            --bg-sidebar: #141414;
            --bg-surface: #212121;
            --bg-elevated: #2a2a2a;
            --bg-hover: #333333;
            --bg-active: #3a3a3a;

            --text-primary: #ececec;
            --text-secondary: #a0a0a0;
            --text-tertiary: #6b6b6b;
            --text-inverse: #1a1a1a;

            --accent: #d4a574;
            --accent-hover: #e0b68a;
            --accent-subtle: rgba(212,165,116,0.1);
            --accent-muted: rgba(212,165,116,0.25);

            --border: #2e2e2e;
            --border-light: #252525;
            --border-strong: #404040;

            --success: #6bba75;
            --info: #7aadcc;
            --warning: #d4a574;
        }

        html { font-size: 14px; }
        body {
            font-family: var(--font-sans);
            background: var(--bg-base);
            color: var(--text-primary);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        /* ── 레이아웃 ── */
        .layout {
            display: flex;
            min-height: 100vh;
        }

        /* ── 사이드바 ── */
        .sidebar {
            width: var(--sidebar-w);
            background: var(--bg-sidebar);
            border-right: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            position: fixed;
            top: 0;
            left: 0;
            bottom: 0;
            z-index: 100;
            overflow: hidden;
        }

        .sidebar-header {
            padding: 16px 18px;
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            gap: 10px;
            flex-shrink: 0;
        }
        .sidebar-logo {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--text-primary);
            letter-spacing: -0.3px;
            text-decoration: none;
        }
        .sidebar-logo span { color: var(--accent); }
        .sidebar-version {
            font-size: 0.7rem;
            color: var(--text-tertiary);
            background: var(--bg-elevated);
            padding: 2px 6px;
            border-radius: 3px;
            font-family: var(--font-mono);
        }

        /* 사이드바 검색 */
        .sidebar-search {
            padding: 10px 14px;
            flex-shrink: 0;
        }
        .sidebar-search input {
            width: 100%;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            color: var(--text-primary);
            padding: 7px 10px;
            border-radius: var(--radius-sm);
            font-size: 0.85rem;
            font-family: var(--font-sans);
            outline: none;
            transition: border-color var(--transition);
        }
        .sidebar-search input::placeholder { color: var(--text-tertiary); }
        .sidebar-search input:focus { border-color: var(--accent); }

        /* 사이드바 네비게이션 */
        .sidebar-nav {
            flex: 1;
            overflow-y: auto;
            padding: 6px 0;
        }
        .sidebar-nav::-webkit-scrollbar { width: 4px; }
        .sidebar-nav::-webkit-scrollbar-track { background: transparent; }
        .sidebar-nav::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 4px; }

        .nav-group {
            padding: 0 8px;
            margin-bottom: 4px;
        }
        .nav-group-label {
            font-size: 0.68rem;
            font-weight: 600;
            color: var(--text-tertiary);
            text-transform: uppercase;
            letter-spacing: 0.8px;
            padding: 14px 10px 5px;
        }

        .nav-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 6px 10px;
            border-radius: var(--radius-sm);
            color: var(--text-secondary);
            font-size: 0.88rem;
            cursor: pointer;
            transition: all var(--transition);
            text-decoration: none;
            user-select: none;
        }
        .nav-item:hover {
            background: var(--bg-hover);
            color: var(--text-primary);
        }
        .nav-item.open {
            color: var(--text-primary);
        }
        .nav-arrow {
            font-size: 0.65rem;
            transition: transform var(--transition);
            color: var(--text-tertiary);
        }
        .nav-item.open .nav-arrow { transform: rotate(180deg); }

        .sub-menu {
            padding-left: 12px;
            overflow: hidden;
        }
        .sub-item {
            display: block;
            padding: 5px 10px 5px 14px;
            border-left: 1px solid var(--border);
            color: var(--text-secondary);
            font-size: 0.82rem;
            cursor: pointer;
            transition: all var(--transition);
            text-decoration: none;
            border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
        }
        .sub-item:hover {
            background: var(--bg-hover);
            color: var(--text-primary);
            border-left-color: var(--text-tertiary);
        }
        .sub-item.active {
            background: var(--accent-subtle);
            color: var(--accent);
            border-left-color: var(--accent);
            font-weight: 500;
        }

        /* 사이드바 도구 영역 */
        .sidebar-tools {
            border-top: 1px solid var(--border);
            padding: 10px 8px;
            flex-shrink: 0;
        }
        .tool-item {
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 6px 10px;
            border-radius: var(--radius-sm);
            color: var(--text-secondary);
            font-size: 0.82rem;
            cursor: pointer;
            transition: all var(--transition);
            text-decoration: none;
        }
        .tool-item:hover {
            background: var(--bg-hover);
            color: var(--text-primary);
        }
        .tool-icon { font-size: 0.9rem; width: 18px; text-align: center; }

        /* ── 메인 영역 ── */
        .main {
            margin-left: var(--sidebar-w);
            flex: 1;
            display: flex;
            flex-direction: column;
            min-height: 100vh;
        }

        /* 탑바 */
        .topbar {
            height: var(--topbar-h);
            background: var(--bg-sidebar);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            padding: 0 24px;
            gap: 16px;
            position: sticky;
            top: 0;
            z-index: 50;
        }
        .topbar-search {
            flex: 1;
            max-width: 520px;
        }
        .topbar-search input {
            width: 100%;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            color: var(--text-primary);
            padding: 7px 14px 7px 36px;
            border-radius: var(--radius);
            font-size: 0.88rem;
            font-family: var(--font-sans);
            outline: none;
            transition: border-color var(--transition);
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b6b6b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Ccircle cx='11' cy='11' r='8'/%3E%3Cline x1='21' y1='21' x2='16.65' y2='16.65'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: 12px center;
        }
        .topbar-search input::placeholder { color: var(--text-tertiary); }
        .topbar-search input:focus { border-color: var(--accent); }
        .topbar-right {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .lang-dropdown {
            position: relative;
            display: inline-block;
        }
        .lang-dropdown-btn {
            display: flex;
            align-items: center;
            gap: 6px;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            color: var(--text-secondary);
            padding: 5px 10px;
            height: 32px;
            border-radius: var(--radius-sm);
            font-size: 0.78rem;
            cursor: pointer;
            font-family: var(--font-sans);
            transition: all var(--transition);
            outline: none;
        }
        .lang-dropdown-btn:hover {
            border-color: var(--accent);
            color: var(--text-primary);
        }
        .lang-flag { font-size: 1rem; line-height: 1; }
        .lang-label { white-space: nowrap; }
        .lang-arrow { transition: transform 0.2s; flex-shrink: 0; }
        .lang-dropdown.open .lang-arrow { transform: rotate(180deg); }
        .lang-dropdown-menu {
            display: none;
            position: absolute;
            top: calc(100% + 6px);
            right: 0;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            box-shadow: 0 8px 24px rgba(0,0,0,0.12);
            min-width: 160px;
            z-index: 9999;
            padding: 4px 0;
            animation: langFadeIn 0.15s ease;
        }
        @keyframes langFadeIn { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: translateY(0); } }
        .lang-dropdown.open .lang-dropdown-menu { display: block; }
        .lang-option {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 9px 14px;
            font-size: 0.82rem;
            color: var(--text-secondary);
            cursor: pointer;
            transition: background 0.15s, color 0.15s;
            text-decoration: none;
        }
        .lang-option:hover {
            background: var(--bg-hover);
            color: var(--text-primary);
        }
        .lang-option.active {
            color: var(--accent);
            font-weight: 600;
            background: var(--bg-hover);
        }
        .lang-opt-flag { font-size: 1.1rem; }

        /* 테마 토글 */
        .theme-btn {
            background: var(--bg-surface);
            border: 1px solid var(--border);
            color: var(--text-secondary);
            width: 32px;
            height: 32px;
            border-radius: var(--radius-sm);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1rem;
            transition: all var(--transition);
            line-height: 1;
            padding: 0;
        }
        .theme-btn:hover {
            border-color: var(--accent);
            color: var(--text-primary);
        }
        .unit-btn {
            background: var(--bg-surface);
            border: 1px solid var(--border);
            color: var(--text-secondary);
            padding: 4px 10px;
            height: 32px;
            border-radius: var(--radius-sm);
            font-size: .78rem;
            font-family: var(--font-mono);
            cursor: pointer;
            transition: all var(--transition);
        }
        .unit-btn:hover {
            border-color: var(--accent);
            color: var(--accent);
        }
        .calc-chip {
            background: color-mix(in srgb, var(--accent) 12%, transparent) !important;
            border-color: var(--accent) !important;
        }

        /* 북마크 FAB */
        .bookmark-fab {
            position: fixed;
            bottom: 24px;
            right: 24px;
            z-index: 200;
            background: var(--accent);
            color: #fff;
            border: none;
            width: 48px;
            height: 48px;
            border-radius: 50%;
            cursor: pointer;
            font-size: 1.2rem;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 12px rgba(0,0,0,0.2);
            transition: all 0.2s ease;
        }
        .bookmark-fab:hover {
            transform: scale(1.1);
            box-shadow: 0 6px 20px rgba(0,0,0,0.3);
        }
        .bookmark-tooltip {
            position: fixed;
            bottom: 80px;
            right: 16px;
            z-index: 200;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 12px 16px;
            font-size: 0.82rem;
            color: var(--text-primary);
            box-shadow: 0 4px 16px rgba(0,0,0,0.15);
            max-width: 260px;
            display: none;
            line-height: 1.5;
        }
        .bookmark-tooltip.show { display: block; }
        .bookmark-tooltip .shortcut {
            display: inline-block;
            padding: 2px 6px;
            background: var(--bg-elevated);
            border: 1px solid var(--border);
            border-radius: 3px;
            font-family: var(--font-mono);
            font-size: 0.75rem;
            color: var(--text-secondary);
        }

        /* ── 콘텐츠 영역 ── */
        .content {
            padding: 28px 32px;
            flex: 1;
        }

        /* 브레드크럼 */
        .breadcrumb {
            display: flex;
            align-items: center;
            gap: 6px;
            font-size: 0.8rem;
            color: var(--text-tertiary);
            margin-bottom: 16px;
        }
        .breadcrumb a {
            color: var(--text-secondary);
            text-decoration: none;
            transition: color var(--transition);
        }
        .breadcrumb a:hover { color: var(--accent); }
        .breadcrumb .sep { color: var(--text-tertiary); }

        /* 페이지 타이틀 */
        .page-title {
            margin-bottom: 24px;
        }
        .page-title h1 {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: 6px;
            letter-spacing: -0.3px;
        }
        .page-title .sub {
            font-size: 0.88rem;
            color: var(--text-secondary);
        }
        .page-title .sub strong {
            color: var(--accent);
            font-weight: 500;
        }

        /* 광고 슬롯 */
        /* 표준 탭 */
        .std-tabs {
            display: flex;
            gap: 2px;
            background: var(--bg-surface);
            padding: 3px;
            border-radius: var(--radius);
            margin-bottom: 20px;
            overflow-x: auto;
        }
        .std-tab {
            padding: 7px 18px;
            border-radius: 6px;
            color: var(--text-secondary);
            font-size: 0.82rem;
            font-weight: 500;
            cursor: pointer;
            transition: all var(--transition);
            text-decoration: none;
            white-space: nowrap;
            text-align: center;
            border: none;
            background: none;
            font-family: var(--font-sans);
        }
        .std-tab:hover {
            color: var(--text-primary);
            background: var(--bg-hover);
        }
        .std-tab.active {
            background: var(--accent);
            color: var(--text-inverse);
        }
        .std-tab .tab-count {
            font-size: 0.7rem;
            opacity: 0.7;
            margin-left: 4px;
        }

        /* 테이블 */
        .table-section {
            margin-bottom: 32px;
        }
        .table-section-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 12px;
        }
        .table-section-header h3 {
            font-size: 0.95rem;
            font-weight: 600;
            color: var(--text-primary);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .std-badge {
            display: inline-flex;
            align-items: center;
            padding: 2px 8px;
            border-radius: 3px;
            font-size: 0.7rem;
            font-weight: 600;
            font-family: var(--font-mono);
            letter-spacing: 0.3px;
        }
        .std-badge.ks { background: rgba(107,186,117,0.15); color: var(--success); }
        .std-badge.iso { background: rgba(122,173,204,0.15); color: var(--info); }
        .std-badge.jis { background: rgba(212,165,116,0.15); color: var(--accent); }
        .std-badge.din { background: rgba(180,140,200,0.15); color: #b48cc8; }
        .std-badge.ansi { background: rgba(200,140,140,0.15); color: #c88c8c; }
        .item-count {
            font-size: 0.78rem;
            color: var(--text-tertiary);
        }

        .table-wrap {
            border: 1px solid var(--border);
            border-radius: var(--radius);
            overflow: hidden;
            overflow-x: auto;
            -webkit-overflow-scrolling: touch;
        }
        table {
            width: 100%;
            border-collapse: collapse;
        }
        thead {
            background: var(--bg-elevated);
        }
        th {
            padding: 9px 14px;
            font-size: 0.78rem;
            font-weight: 600;
            color: var(--text-secondary);
            text-align: center;
            white-space: nowrap;
            border-bottom: 1px solid var(--border);
            letter-spacing: 0.2px;
        }
        td {
            padding: 8px 14px;
            font-size: 0.82rem;
            text-align: center;
            color: var(--text-primary);
            border-bottom: 1px solid var(--border-light);
            font-family: var(--font-mono);
            font-weight: 400;
        }
        tr:last-child td { border-bottom: none; }
        tr:hover td {
            background: var(--accent-subtle);
        }
        td:first-child {
            font-weight: 600;
            color: var(--accent);
        }

        /* 관련 규격 */
        .related {
            margin-top: 36px;
            padding: 20px;
            background: var(--bg-surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
        }
        .related h3 {
            font-size: 0.88rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 12px;
        }
        .related-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 6px;
        }
        .related-chip {
            padding: 5px 14px;
            background: var(--bg-elevated);
            border: 1px solid var(--border);
            border-radius: 20px;
            color: var(--text-secondary);
            font-size: 0.78rem;
            text-decoration: none;
            transition: all var(--transition);
        }
        .related-chip:hover {
            background: var(--accent-subtle);
            border-color: var(--accent-muted);
            color: var(--accent);
        }

        /* 푸터 */
        .footer {
            padding: 28px 32px;
            border-top: 1px solid var(--border);
            text-align: center;
            color: var(--text-tertiary);
            font-size: 0.75rem;
        }
        .footer a {
            color: var(--text-secondary);
            text-decoration: none;
        }
        .footer a:hover { color: var(--accent); }

        /* 모바일 햄버거 (데스크톱에서 숨김) */
        .hamburger {
            display: none;
            background: none;
            border: none;
            color: var(--text-secondary);
            cursor: pointer;
            padding: 4px;
        }

        /* ── 반응형 ── */
        @media (max-width: 1024px) {
            .sidebar {
                transform: translateX(-100%);
                transition: transform 0.25s ease;
            }
            .sidebar.open { transform: translateX(0); }
            .main { margin-left: 0; }
            .hamburger { display: block; }
            .content { padding: 20px 16px; }
        }
        @media (max-width: 640px) {
            .topbar { padding: 0 10px; gap: 8px; }
            .topbar-search { display: none; }
            .content { padding: 16px 12px; }
            th, td { padding: 6px 8px; font-size: 0.75rem; }
            .page-title h1 { font-size: 1.2rem; }
            .type-grid { grid-template-columns: 1fr; }
        }
.spec-images{display:flex;gap:16px;margin:0 0 24px;flex-wrap:wrap}
.spec-image{flex:1;min-width:240px;max-width:400px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.spec-image img{width:100%;height:auto;display:block}
.img-caption{display:block;padding:8px 12px;font-size:.78rem;color:var(--text-secondary);text-align:center;border-top:1px solid var(--border)}
.table-image{margin:24px 0}.table-image img{max-width:100%;height:auto;display:block;border-radius:var(--radius);border:1px solid var(--border)}
.type-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:12px;margin-top:20px}
.type-card{padding:16px 20px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius);text-decoration:none;transition:all .2s}
.type-card:hover{background:var(--accent-subtle);border-color:var(--accent);transform:translateY(-2px)}
.type-card h3{font-size:1rem;color:var(--text-primary);margin:0 0 4px}
.type-card p{font-size:.82rem;color:var(--text-secondary);margin:0}
.search-dropdown a:hover{background:var(--bg-elevated)!important}
.search-dropdown a:last-child{border-bottom:none!important}
.spec-desc{background:var(--bg-surface);border:1px solid var(--border);border-left:3px solid var(--accent);border-radius:var(--radius);padding:14px 18px;margin-bottom:20px;line-height:1.7}
.spec-desc p{font-size:.88rem;color:var(--text-secondary)}
.std-num-row{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.std-num-tag{display:inline-block;padding:2px 8px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:4px;font-size:.75rem;color:var(--text-tertiary);font-family:'IBM Plex Mono',monospace;letter-spacing:.02em}
.spec-desc h3{font-size:.9rem;font-weight:600;color:var(--text-primary);margin:16px 0 8px}
.spec-desc ul{margin:8px 0;padding-left:20px}
.spec-desc li{margin:4px 0;color:var(--text-secondary);font-size:.86rem}
.faq-section{margin-top:32px;padding:20px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius)}
.faq-section h2,.faq-section h3{font-size:1rem;font-weight:600;color:var(--text-primary);margin-bottom:16px}
.tips-list li{margin:8px 0;color:var(--text-secondary);font-size:.86rem;line-height:1.7;padding-left:4px}
.faq-section details{margin-bottom:12px;padding:12px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer}
.faq-section summary{font-size:.88rem;font-weight:500;color:var(--text-primary);cursor:pointer;user-select:none}
.faq-section details[open] summary{margin-bottom:8px;color:var(--accent)}
.faq-section details p{margin:4px 0 0;font-size:.84rem;color:var(--text-secondary);line-height:1.6}