:root {
            --primary: #2D6A4F;
            --primary-dark: #1B4332;
            --primary-light: #D8F3DC;
            --primary-bg: rgba(45,106,79,0.06);
            --accent: #D4A574;
            --accent-light: #FDF2E9;
            --success: #2D6A4F;
            --success-light: #D8F3DC;
            --warning: #B08968;
            --warning-light: #FDF2E9;
            --danger: #BC4749;
            --danger-light: #FEF2F2;
            --text: #2D3436;
            --text-secondary: #636E72;
            --text-light: #B2BEC3;
            --bg: #FAFAF5;
            --card: #FFFFFF;
            --border: #E8E4DE;
            --shadow-sm: 0 1px 3px rgba(45,52,54,0.06);
            --shadow-md: 0 4px 12px rgba(45,52,54,0.08);
            --shadow-lg: 0 8px 24px rgba(45,52,54,0.1);
            --shadow-xl: 0 16px 40px rgba(45,52,54,0.12);
            --radius-sm: 6px;
            --radius-md: 10px;
            --radius-lg: 14px;
            --radius-xl: 20px;
            --radius-2xl: 28px;
            --sidebar-bg: #2D3436;
            --sidebar-hover: rgba(255,255,255,0.08);
            --sidebar-active: rgba(45,106,79,0.35);
        }

        body.dark-mode {
            --primary: #52B788;
            --primary-dark: #40916C;
            --primary-light: rgba(82,183,136,0.12);
            --primary-bg: rgba(82,183,136,0.08);
            --accent: #D4A574;
            --accent-light: rgba(212,165,116,0.1);
            --success: #52B788;
            --success-light: rgba(82,183,136,0.12);
            --warning: #D4A574;
            --warning-light: rgba(212,165,116,0.1);
            --danger: #E07A7C;
            --danger-light: rgba(224,122,124,0.1);
            --text: #ECEBE4;
            --text-secondary: #A8A29E;
            --text-light: #78716C;
            --bg: #1C1917;
            --card: #292524;
            --border: #44403C;
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
            --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
            --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
            --shadow-xl: 0 16px 40px rgba(0,0,0,0.5);
            --sidebar-bg: #1C1917;
            --sidebar-hover: rgba(255,255,255,0.06);
            --sidebar-active: rgba(82,183,136,0.2);
        }

        body.dark-mode .sidebar { background: var(--sidebar-bg); }
        body.dark-mode .nav-item:not(.active) { color: var(--text-secondary); }
        body.dark-mode .nav-item:not(.active):hover { background: var(--sidebar-hover); color: var(--text); }
        body.dark-mode .admin-item { background: var(--card); border: 1px solid var(--border); }
        body.dark-mode input, body.dark-mode textarea, body.dark-mode select { color: var(--text); background: var(--card); }
        body.dark-mode .login-card { background: var(--card); color: var(--text); }
        body.dark-mode .input-field, body.dark-mode .form-input { background: var(--sidebar-bg); color: var(--text); border-color: var(--border); }
        body.dark-mode .input-field:focus, body.dark-mode .form-input:focus { border-color: var(--primary); background: var(--sidebar-bg); box-shadow: 0 0 0 3px rgba(82,183,136,0.15); }
        body.dark-mode .captcha-image { border-color: var(--border); }
        body.dark-mode .error-message { background: var(--danger-light); border-color: rgba(224,122,124,0.3); color: #FCA5A5; }
        body.dark-mode .success-banner { background: var(--success-light); border-color: rgba(82,183,136,0.3); color: #6EE7B7; }
        body.dark-mode .btn-secondary:hover { background: var(--primary-bg); }

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

        body {
            font-family: 'Outfit', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
            background: var(--bg);
            color: var(--text);
            min-height: 100vh;
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        /* ========== LOGIN PAGE ========== */
        .login-container {
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            background: #F5F0EB;
            padding: 24px;
            position: relative;
            overflow: hidden;
        }

        body.dark-mode .login-container { background: #1C1917; }

        .login-split {
            display: flex;
            width: 100%;
            max-width: 960px;
            background: var(--card);
            border-radius: var(--radius-2xl);
            overflow: hidden;
            box-shadow: 0 20px 60px rgba(45,52,54,0.12);
            position: relative;
            z-index: 1;
            min-height: 560px;
            border: 1px solid var(--border);
        }

        body.dark-mode .login-split { box-shadow: 0 20px 60px rgba(0,0,0,0.4); }

        .login-promo {
            flex: 1;
            background: var(--primary);
            position: relative;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            padding: 40px 36px;
            color: white;
        }

        .promo-header { z-index: 3; position: relative; }

        .promo-brand {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 8px;
        }

        .promo-brand-icon {
            width: 48px;
            height: 48px;
            background: rgba(255,255,255,0.2);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 22px;
        }

        .promo-brand-text { font-size: 26px; font-weight: 800; }

        .promo-tagline { font-size: 14px; opacity: 0.85; margin-top: 4px; }

        .promo-slider {
            flex: 1;
            position: relative;
            margin-top: 24px;
            border-radius: var(--radius-lg);
            overflow: hidden;
            background: rgba(0,0,0,0.12);
        }

        .promo-slide {
            position: absolute;
            inset: 0;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 28px;
            color: white;
            opacity: 0;
            transform: translateY(12px);
            transition: opacity 0.6s ease, transform 0.6s ease;
            text-align: center;
        }

        .promo-slide.active { opacity: 1; transform: translateY(0); }

        .promo-emoji { font-size: 64px; margin-bottom: 16px; }

        .promo-title { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
        .promo-desc { font-size: 14px; opacity: 0.9; line-height: 1.6; max-width: 320px; }

        .promo-features { display: flex; gap: 8px; margin-top: 16px; flex-wrap: wrap; justify-content: center; }

        .promo-feature {
            background: rgba(255,255,255,0.18);
            padding: 5px 12px;
            border-radius: 6px;
            font-size: 12px;
            font-weight: 600;
        }

        .promo-dots { position: absolute; bottom: 14px; left: 50%; transform: translateX(-50%); display: flex; gap: 6px; z-index: 4; }

        .promo-dot {
            width: 7px;
            height: 7px;
            border-radius: 50%;
            background: rgba(255,255,255,0.35);
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .promo-dot.active { width: 22px; border-radius: 4px; background: white; }

        .promo-deco { position: absolute; border-radius: 50%; pointer-events: none; }

        .promo-deco.deco-1 { width: 200px; height: 200px; top: -60px; right: -40px; background: rgba(255,255,255,0.08); }
        .promo-deco.deco-2 { width: 160px; height: 160px; bottom: -40px; left: -30px; background: rgba(255,255,255,0.06); }
        .promo-deco.deco-3 { width: 100px; height: 100px; top: 40%; left: -20px; background: rgba(255,255,255,0.05); }

        .login-form-wrapper {
            flex: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 36px 40px;
        }

        .login-form-wrapper .login-card {
            max-width: 400px;
            width: 100%;
            background: transparent;
            box-shadow: none;
            padding: 0;
            border-radius: 0;
        }

        @media (max-width: 900px) {
            .login-split { flex-direction: column; max-width: 480px; min-height: auto; }
            .login-promo { padding: 28px 24px; min-height: 240px; }
            .promo-emoji { font-size: 48px; }
            .promo-title { font-size: 17px; }
            .login-form-wrapper { padding: 28px 24px; }
        }

        .login-card {
            background: var(--card);
            border-radius: var(--radius-xl);
            padding: 32px 36px;
            width: 100%;
            max-width: 400px;
            box-shadow: var(--shadow-md);
            position: relative;
            z-index: 1;
        }

        .theme-switch-btn {
            position: absolute;
            top: 14px;
            right: 14px;
            width: 36px;
            height: 36px;
            border-radius: 50%;
            border: 1px solid var(--border);
            background: var(--bg);
            color: var(--text-secondary);
            cursor: pointer;
            font-size: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.2s ease;
            font-family: inherit;
        }

        .theme-switch-btn:hover { border-color: var(--primary); color: var(--primary); }

        .auth-tabs { display: flex; justify-content: center; gap: 24px; margin-bottom: 22px; }

        .auth-tabs button {
            background: none;
            border: none;
            padding: 8px 4px;
            font-size: 15px;
            font-weight: 600;
            color: var(--text-light);
            border-bottom: 2px solid transparent;
            cursor: pointer;
            transition: color 0.2s ease, background 0.2s ease, border-radius 0.2s ease;
            font-family: inherit;
            border-radius: 8px 8px 0 0;
        }

        .auth-tabs button:hover { color: var(--text); background: var(--bg); }

        .auth-tabs button.active { color: var(--primary); background: var(--primary-bg); border-bottom-color: var(--primary); }

        body.dark-mode .auth-tabs button.active { background: transparent; }

        .login-logo {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            margin-bottom: 22px;
        }

        .login-logo-icon {
            width: 48px;
            height: 48px;
            background: var(--primary);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 22px;
        }

        .login-logo-text { font-size: 22px; font-weight: 800; color: var(--text); }

        .login-title { font-size: 26px; font-weight: 800; color: var(--text); text-align: center; margin-bottom: 4px; }
        .login-subtitle { font-size: 14px; color: var(--text-secondary); text-align: center; margin-bottom: 22px; }

        .form-group { margin-bottom: 16px; }

        .form-label { display: block; font-size: 13px; font-weight: 600; color: var(--text); margin-bottom: 7px; }

        .form-input {
            width: 100%;
            height: 44px;
            padding: 0 14px;
            border: 1.5px solid var(--border);
            border-radius: var(--radius-md);
            font-size: 14px;
            font-family: inherit;
            outline: none;
            transition: border-color 0.2s ease, box-shadow 0.2s ease;
            background: var(--bg);
            box-sizing: border-box;
            color: var(--text);
        }

        .form-input:focus { border-color: var(--primary); background: var(--card); box-shadow: 0 0 0 3px var(--primary-bg); }
        .form-input::placeholder { color: var(--text-light); }

        .captcha-group { display: flex; gap: 10px; }
        .captcha-group .form-input { flex: 1; }

        .captcha-image { height: 46px; border-radius: var(--radius-md); cursor: pointer; border: 2px solid var(--border); transition: all 0.2s; }
        .captcha-image:hover { border-color: var(--primary); }

        .form-options { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }

        .login-card.wide { max-width: 520px; padding: 28px 32px 24px; }
        .compact-layout .login-logo { margin-bottom: 14px; }
        .compact-layout .login-logo-icon { width: 42px; height: 42px; font-size: 20px; }
        .compact-layout .login-logo-text { font-size: 20px; }
        .compact-layout .login-title { font-size: 24px; margin-bottom: 4px; }
        .compact-layout .login-subtitle { font-size: 13px; margin-bottom: 18px; }
        .compact-layout .form-group { margin-bottom: 12px; }
        .compact-layout .form-label { font-size: 12px; margin-bottom: 5px; }
        .compact-layout .form-input { height: 40px; font-size: 13px; padding: 0 14px; }
        .compact-layout .captcha-image { height: 40px; }

        .form-section {
            background: var(--bg);
            border: 1px solid var(--border);
            border-radius: var(--radius-lg);
            padding: 16px 18px;
            margin-bottom: 14px;
        }

        body.dark-mode .form-section { background: rgba(255,255,255,0.03); }

        .form-section-title {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 12.5px;
            font-weight: 700;
            color: var(--text);
            margin-bottom: 12px;
        }

        .form-section-title::before {
            content: '';
            width: 3px;
            height: 14px;
            background: var(--primary);
            border-radius: 2px;
        }

        .form-two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 10px 14px; }
        .form-two-col .form-group { margin-bottom: 0; }
        .form-two-col .form-group.full-width { grid-column: 1 / -1; }

        .success-banner {
            background: var(--success-light);
            border: 1px solid rgba(16,185,129,0.3);
            color: #059669;
            padding: 12px 16px;
            border-radius: var(--radius-md);
            margin-bottom: 14px;
            font-size: 13px;
            text-align: center;
            font-weight: 500;
        }

        .error-message {
            background: var(--danger-light);
            color: #DC2626;
            padding: 10px 14px;
            border-radius: var(--radius-md);
            font-size: 13px;
            margin: 10px 0;
            text-align: center;
            border: 1px solid rgba(239,68,68,0.2);
        }

        .btn-primary {
            width: 100%;
            height: 44px;
            border: none;
            border-radius: var(--radius-md);
            font-size: 15px;
            font-weight: 600;
            font-family: inherit;
            cursor: pointer;
            transition: background-color 0.2s ease, transform 0.15s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            background: var(--primary);
            color: white;
            margin-top: 6px;
        }

        .btn-primary:hover { background: var(--primary-dark); }
        .btn-primary:active { transform: scale(0.98); }
        .btn-primary:active { transform: translateY(0); }
        .btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }
        .btn-primary span, .btn-primary .spinner { position: relative; z-index: 1; }

        .btn-secondary {
            width: 100%;
            height: 40px;
            margin-top: 10px;
            background: transparent;
            border: 1.5px solid var(--border);
            border-radius: var(--radius-md);
            color: var(--text-secondary);
            cursor: pointer;
            font-size: 13px;
            font-family: inherit;
            font-weight: 500;
            transition: all 0.2s ease;
        }

        .btn-secondary:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-bg); }

        .checkbox-label { display: flex; align-items: center; gap: 7px; cursor: pointer; font-size: 13px; color: var(--text-secondary); }
        .checkbox-label input[type="checkbox"] { width: 16px; height: 16px; accent-color: var(--primary); cursor: pointer; }

        .forgot-link { font-size: 13px; color: var(--primary); text-decoration: none; font-weight: 600; transition: all 0.2s; }
        .forgot-link:hover { color: var(--primary-dark); transform: translateY(-1px); }

        .spinner { width: 16px; height: 16px; border: 2.5px solid rgba(255,255,255,0.3); border-top-color: white; border-radius: 50%; animation: spin 0.6s linear infinite; }
        @keyframes spin { to { transform: rotate(360deg); } }

        .login-footer {
            text-align: center;
            margin-top: 18px;
            padding-top: 14px;
            border-top: 1px solid var(--border);
            font-size: 13px;
            color: var(--text-secondary);
        }

        .login-footer a { color: var(--primary); text-decoration: none; font-weight: 600; transition: all 0.2s; }
        .login-footer a:hover { color: var(--primary-dark); }

        @media (max-width: 540px) { .login-card.wide { max-width: 100%; padding: 24px 22px 20px; } .form-two-col { grid-template-columns: 1fr; gap: 0; } .form-two-col .form-group { margin-bottom: 12px; } }

        /* ========== DASHBOARD ========== */
        .dashboard { display: flex; min-height: 100vh; }

        /* ========== SIDEBAR ========== */
        .sidebar {
            width: 240px;
            min-width: 240px;
            background: var(--card);
            border-right: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            height: 100vh;
            position: sticky;
            top: 0;
            z-index: 50;
        }

        .sidebar-header { padding: 24px 20px; border-bottom: 1px solid var(--border); }

        .sidebar-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }

        .sidebar-logo-icon {
            width: 40px;
            height: 40px;
            background: var(--primary);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 20px;
        }

        .sidebar-logo-text { font-size: 18px; font-weight: 700; color: var(--text); }

        .sidebar-nav { flex: 1; padding: 16px 12px; display: flex; flex-direction: column; gap: 2px; overflow-y: auto; }

        .nav-section-title {
            font-size: 11px;
            font-weight: 600;
            color: var(--text-light);
            text-transform: uppercase;
            letter-spacing: 0.5px;
            padding: 14px 12px 6px;
        }

        .nav-item {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 10px 12px;
            border-radius: var(--radius-md);
            color: var(--text-secondary);
            text-decoration: none;
            font-size: 14px;
            font-weight: 500;
            transition: background 0.15s ease, color 0.15s ease;
            cursor: pointer;
            border: none;
            background: none;
            width: 100%;
            text-align: left;
        }

        .nav-item:hover { background: var(--bg); color: var(--text); }

        .nav-item.active {
            background: var(--primary-light);
            color: var(--primary);
            font-weight: 600;
        }

        .nav-icon { width: 20px; height: 20px; display: flex; align-items: center; justify-content: center; font-size: 18px; }
        .nav-icon i { font-size: 18px; }

        .nav-badge {
            margin-left: auto;
            background: var(--danger);
            color: white;
            font-size: 11px;
            font-weight: 600;
            padding: 2px 8px;
            border-radius: 10px;
        }

        .sidebar-footer { padding: 14px 12px; border-top: 1px solid var(--border); }

        .theme-toggle-btn {
            width: 100%;
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px 12px;
            background: var(--bg);
            border: 1px solid var(--border);
            border-radius: var(--radius-md);
            cursor: pointer;
            font-size: 13px;
            color: var(--text-secondary);
            font-family: inherit;
            transition: background 0.15s ease;
            margin-bottom: 10px;
        }

        .theme-toggle-btn:hover { background: var(--primary-light); color: var(--primary); border-color: var(--primary); }
        .theme-toggle-btn .theme-icon { font-size: 15px; }

        .user-profile {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 12px;
            border-radius: var(--radius-md);
            cursor: pointer;
            transition: background 0.15s ease;
        }

        .user-profile:hover { background: var(--bg); }

        .user-avatar {
            width: 40px;
            height: 40px;
            border-radius: 10px;
            background: var(--primary);
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 15px;
            font-weight: 700;
            flex-shrink: 0;
        }

        .user-info { flex: 1; min-width: 0; }
        .user-name { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 1px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .user-role { font-size: 12px; color: var(--text-secondary); }

        .logout-btn {
            display: flex;
            align-items: center;
            gap: 10px;
            width: 100%;
            padding: 10px 12px;
            border: none;
            background: none;
            border-radius: var(--radius-md);
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            cursor: pointer;
            transition: background 0.15s ease, color 0.15s ease;
            margin-top: 8px;
        }

        .logout-btn:hover { background: var(--danger-light); color: var(--danger); }

        /* ========== MAIN CONTENT ========== */
        .main-content { flex: 1; padding: 36px 52px; max-width: 1400px; margin: 0 auto; width: 100%; }
        .page-header { margin-bottom: 36px; }
        .page-title { font-size: 34px; font-weight: 900; color: var(--text); margin-bottom: 8px; letter-spacing: -1px; }
        .page-subtitle { font-size: 16px; color: var(--text-secondary); }

        /* ========== STATS ========== */
        .stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 20px; margin-bottom: 36px; }

        .stat-card {
            background: var(--card);
            border-radius: var(--radius-lg);
            padding: 26px;
            box-shadow: var(--shadow-sm);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            border: 1px solid var(--border);
            position: relative;
            overflow: hidden;
        }

        .stat-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }

        .stat-icon {
            width: 52px;
            height: 52px;
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 26px;
            margin-bottom: 18px;
        }

        .stat-icon.blue { background: #EFF6FF; color: #3B82F6; }
        .stat-icon.green { background: #ECFDF5; color: #059669; }
        .stat-icon.purple { background: #F5F3FF; color: #7C3AED; }
        .stat-icon.orange { background: #FFF7ED; color: #EA580C; }

        .stat-value { font-size: 32px; font-weight: 800; color: var(--text); line-height: 1; margin-bottom: 6px; letter-spacing: -1px; }
        .stat-label { font-size: 14px; color: var(--text-secondary); font-weight: 500; }

        /* ========== WELCOME BANNER ========== */
        .welcome-banner {
            background: var(--primary);
            border-radius: var(--radius-lg);
            padding: 36px;
            color: white;
            margin-bottom: 32px;
            position: relative;
            overflow: hidden;
        }

        .welcome-content { position: relative; z-index: 1; }

        .welcome-title { font-size: 26px; font-weight: 700; margin-bottom: 8px; }
        .welcome-subtitle { font-size: 15px; opacity: 0.9; margin-bottom: 24px; }

        .welcome-btn {
            background: white;
            color: var(--primary);
            padding: 12px 28px;
            border-radius: var(--radius-md);
            font-weight: 600;
            font-size: 14px;
            border: none;
            cursor: pointer;
            transition: opacity 0.2s ease;
        }

        .welcome-btn:hover { opacity: 0.9; }

        /* ========== CATEGORY GRID ========== */
        .section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 22px; }
        .section-title { font-size: 22px; font-weight: 800; color: var(--text); letter-spacing: -0.3px; }

        .category-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 20px; margin-bottom: 36px; }

        .category-card {
            background: var(--card);
            border-radius: var(--radius-lg);
            padding: 26px;
            box-shadow: var(--shadow-sm);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            cursor: pointer;
            border: 2px solid transparent;
            position: relative;
        }

        .category-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: var(--primary); }

        .category-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 18px; }

        .category-icon {
            width: 48px;
            height: 48px;
            border-radius: var(--radius-md);
            background: var(--primary-light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 26px;
        }

        .category-badge { background: var(--warning-light); color: #B45309; font-size: 12px; font-weight: 700; padding: 5px 12px; border-radius: 999px; }

        .category-name { font-size: 18px; font-weight: 800; color: var(--text); margin-bottom: 8px; letter-spacing: -0.2px; }
        .category-meta { font-size: 14px; color: var(--text-secondary); margin-bottom: 18px; }

        .category-progress { height: 8px; background: var(--bg); border-radius: 999px; overflow: hidden; margin-bottom: 12px; }

        .category-progress-bar {
            height: 100%;
            background: var(--primary);
            border-radius: 999px;
            transition: width 0.5s ease;
        }

        .category-progress-text { display: flex; justify-content: space-between; font-size: 13px; color: var(--text-secondary); font-weight: 500; }

        /* ========== EMPTY STATE ========== */
        .empty-state { text-align: center; padding: 80px 40px; background: var(--card); border-radius: var(--radius-lg); border: 2px dashed var(--border); }
        .empty-icon { font-size: 72px; margin-bottom: 24px; opacity: 0.6; }
        .empty-title { font-size: 20px; font-weight: 700; color: var(--text); margin-bottom: 8px; }
        .empty-subtitle { font-size: 15px; color: var(--text-secondary); margin-bottom: 28px; }

        /* ========== BUTTONS ========== */
        .btn { padding: 12px 24px; border-radius: var(--radius-md); font-size: 14px; font-weight: 600; cursor: pointer; transition: all 0.2s ease; border: none; display: inline-flex; align-items: center; gap: 8px; }

        .btn-primary-2 {
            background: var(--primary);
            color: white;
        }

        .btn-primary-2:hover { background: var(--primary-dark); }

        .btn-secondary { background: var(--bg); color: var(--text); border: 1px solid var(--border); }
        .btn-secondary:hover { background: var(--border); }

        /* ========== MODAL ========== */
        .modal-overlay {
            position: fixed;
            inset: 0;
            background: rgba(45,52,54,0.5);
            backdrop-filter: blur(4px);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            padding: 20px;
        }

        .modal-content-2 {
            background: var(--card);
            border-radius: var(--radius-xl);
            padding: 36px;
            width: 100%;
            max-width: 480px;
            box-shadow: var(--shadow-xl);
            animation: modalIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        @keyframes modalIn { from { opacity: 0; transform: scale(0.95) translateY(10px); } to { opacity: 1; transform: scale(1) translateY(0); } }

        .modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 28px; }
        .modal-title { font-size: 22px; font-weight: 800; color: var(--text); letter-spacing: -0.3px; }

        .modal-close {
            width: 40px;
            height: 40px;
            border-radius: var(--radius-md);
            border: none;
            background: var(--bg);
            color: var(--text-secondary);
            cursor: pointer;
            font-size: 20px;
            transition: all 0.2s ease;
        }

        .modal-close:hover { background: var(--danger-light); color: var(--danger); }

        /* ========== TABS ========== */
        .tabs-container {
            display: flex;
            gap: 8px;
            margin-bottom: 28px;
            background: var(--card);
            padding: 6px;
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-sm);
            width: fit-content;
            border: 1px solid var(--border);
        }

        .tab-btn {
            padding: 10px 22px;
            border: none;
            background: none;
            border-radius: var(--radius-sm);
            font-size: 14px;
            font-weight: 600;
            color: var(--text-secondary);
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .tab-btn:hover { color: var(--text); background: var(--bg); }

        .tab-btn.active {
            background: var(--primary);
            color: white;
        }

        /* ========== FLASHCARD ========== */
        .flashcard-container { max-width: 640px; margin: 0 auto; }

        .flashcard {
            background: var(--card);
            border-radius: var(--radius-xl);
            padding: 64px 44px;
            box-shadow: var(--shadow-lg);
            margin-bottom: 28px;
            min-height: 320px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            cursor: pointer;
            perspective: 1000px;
            border: 1px solid var(--border);
            position: relative;
        }

        .flashcard:hover { box-shadow: var(--shadow-lg); }

        .flashcard-text { font-size: 28px; font-weight: 800; color: var(--text); line-height: 1.5; margin-bottom: 16px; letter-spacing: -0.3px; }
        .flashcard-sub { font-size: 16px; color: var(--text-secondary); }
        .flashcard-content { width: 100%; text-align: center; padding: 0 80px; }

        .study-complete-overlay {
            position: fixed;
            inset: 0;
            background: rgba(15,23,42,0.7);
            backdrop-filter: blur(8px);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            animation: fadeIn 0.3s ease;
        }

        .study-complete-modal {
            background: var(--card);
            border-radius: var(--radius-2xl);
            padding: 52px 60px;
            text-align: center;
            box-shadow: 0 40px 80px rgba(0,0,0,0.3);
            max-width: 500px;
            width: calc(100% - 48px);
            animation: popIn 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }

        .study-complete-icon { font-size: 88px; margin-bottom: 20px; animation: bounceIn 0.6s ease; }

        .study-complete-title {
            font-size: 28px;
            font-weight: 800;
            color: var(--primary);
            margin-bottom: 12px;
        }

        .study-complete-summary { font-size: 18px; font-weight: 600; color: var(--text); margin-bottom: 18px; }

        .study-complete-message {
            font-size: 15px;
            color: var(--text-secondary);
            line-height: 1.7;
            background: var(--bg);
            padding: 18px 22px;
            border-radius: var(--radius-lg);
            margin-top: 18px;
        }

        @keyframes popIn { 0% { transform: scale(0.7); opacity: 0; } 100% { transform: scale(1); opacity: 1; } }
        @keyframes bounceIn { 0% { transform: scale(0); } 50% { transform: scale(1.15); } 100% { transform: scale(1); } }

        .feedback-buttons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 28px; }

        .feedback-btn {
            padding: 24px 18px;
            border-radius: var(--radius-lg);
            border: 2px solid transparent;
            cursor: pointer;
            transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 10px;
            font-weight: 600;
            font-size: 14px;
        }

        .feedback-btn:hover { transform: translateY(-4px); }

        .feedback-btn.forgot { background: var(--danger-light); border-color: rgba(188,71,73,0.2); color: #BC4749; }
        .feedback-btn.forgot:hover { border-color: rgba(188,71,73,0.4); }

        .feedback-btn.hard { background: var(--warning-light); border-color: rgba(176,137,104,0.2); color: #B08968; }
        .feedback-btn.hard:hover { border-color: rgba(176,137,104,0.4); }

        .feedback-btn.easy { background: var(--success-light); border-color: rgba(45,106,79,0.2); color: #2D6A4F; }
        .feedback-btn.easy:hover { border-color: rgba(45,106,79,0.4); }

        .feedback-emoji { font-size: 32px; }

        .feedback-corners { position: absolute; bottom: 14px; left: 18px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; z-index: 3; }

        .feedback-current { font-size: 12px; color: var(--text-secondary); background: var(--bg); padding: 5px 12px; border-radius: 999px; font-weight: 500; }

        .feedback-divider { width: 1px; height: 16px; background: var(--border); }

        .feedback-corner-btn {
            font-size: 12px;
            font-weight: 600;
            padding: 5px 14px;
            border-radius: 999px;
            border: 1.5px solid;
            cursor: pointer;
            transition: all 0.2s ease;
            background: var(--card);
        }

        .feedback-corner-btn.forgot { color: #DC2626; border-color: rgba(239,68,68,0.3); background: var(--danger-light); }
        .feedback-corner-btn.forgot:hover { border-color: #DC2626; transform: translateY(-1px); }

        .feedback-corner-btn.hard { color: #B45309; border-color: rgba(245,158,11,0.3); background: var(--warning-light); }
        .feedback-corner-btn.hard:hover { border-color: #B45309; transform: translateY(-1px); }

        .feedback-corner-btn.easy { color: #059669; border-color: rgba(16,185,129,0.3); background: var(--success-light); }
        .feedback-corner-btn.easy:hover { border-color: #059669; transform: translateY(-1px); }

        /* ========== LEARNING VIEW ========== */
        .learning-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 28px;
            padding: 22px 26px;
            background: var(--card);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border);
        }

        .learning-info { display: flex; align-items: center; gap: 18px; flex-shrink: 0; }
        .learning-info .btn-secondary { width: auto; margin-top: 0; flex-shrink: 0; }

        .learning-title { font-size: 18px; font-weight: 700; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

        .learning-progress-bar { flex: 1; max-width: 300px; height: 8px; background: var(--bg); border-radius: 999px; overflow: hidden; margin: 0 22px; }

        .learning-progress-fill {
            height: 100%;
            background: var(--primary);
            border-radius: 999px;
            transition: width 0.5s ease;
        }

        .learning-stats { display: flex; gap: 24px; font-size: 14px; color: var(--text-secondary); font-weight: 500; }

        /* ========== ADMIN ========== */
        .admin-section { background: var(--card); border-radius: var(--radius-lg); padding: 36px; margin-bottom: 28px; box-shadow: var(--shadow-sm); border: 1px solid var(--border); }
        .admin-list { display: flex; flex-direction: column; gap: 12px; }

        .admin-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 22px;
            background: var(--bg);
            border-radius: var(--radius-md);
            transition: all 0.2s ease;
        }

        .admin-item:hover { background: var(--border); }

        .admin-item-info { display: flex; align-items: center; gap: 16px; }

        .admin-item-avatar {
            width: 40px;
            height: 40px;
            border-radius: 10px;
            background: var(--primary-light);
            color: var(--primary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 14px;
        }

        .admin-item-name { font-weight: 600; color: var(--text); }
        .admin-item-sub { font-size: 13px; color: var(--text-secondary); }
        .admin-item-actions { display: flex; gap: 8px; }

        .action-btn { padding: 8px 18px; border-radius: var(--radius-sm); border: none; font-size: 13px; font-weight: 600; cursor: pointer; transition: all 0.2s ease; }
        .action-btn.approve { background: var(--success-light); color: #059669; }
        .action-btn.approve:hover { background: #D1FAE5; }
        .action-btn.reject { background: var(--danger-light); color: #DC2626; }
        .action-btn.reject:hover { background: #FEE2E2; }

        .input-group { margin-bottom: 22px; }
        .input-label { display: block; font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }

        .input-field {
            width: 100%;
            padding: 12px 16px;
            border: 2px solid var(--border);
            border-radius: var(--radius-md);
            font-size: 15px;
            font-family: inherit;
            outline: none;
            transition: all 0.2s ease;
            background: var(--bg);
        }

        .input-field:focus { border-color: var(--primary); background: var(--card); box-shadow: 0 0 0 4px rgba(99,102,241,0.1); }
        textarea.input-field { min-height: 100px; resize: vertical; line-height: 1.6; }

        .badge { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; border-radius: 999px; font-size: 12px; font-weight: 600; }
        .badge-primary { background: var(--primary-light); color: #4F46E5; }
        .badge-success { background: var(--success-light); color: #059669; }
        .badge-warning { background: var(--warning-light); color: #B45309; }
        .badge-danger { background: var(--danger-light); color: #DC2626; }

        /* ========== RESPONSIVE ========== */
        @media (max-width: 1024px) { .sidebar { width: 240px; min-width: 240px; } .main-content { padding: 28px 32px; } }
        @media (max-width: 768px) { .sidebar { display: none; } .main-content { padding: 20px; } .page-title { font-size: 26px; } .stats-grid { grid-template-columns: repeat(2, 1fr); } .category-grid { grid-template-columns: 1fr; } }

        .fade-in { animation: fadeIn 0.5s ease; }
        @keyframes fadeIn { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
        /* 章节折叠动画 */
        .chapter-kps-wrapper {
            overflow: hidden;
            transition: max-height 0.3s ease, opacity 0.3s ease, margin-top 0.3s ease, padding-top 0.3s ease;
            max-height: 0;
            opacity: 0;
            margin-top: 0;
            padding-top: 0;
        }
        .chapter-kps-wrapper.expanded {
            max-height: 2000px;
            opacity: 1;
            margin-top: 14px;
            padding-top: 12px;
        }

        /* 箭头旋转动画 */
        .chapter-arrow {
            transition: transform 0.3s ease;
        }
        .chapter-arrow.rotated {
            transform: rotate(180deg);
        }

        /* ========== BOOK / TEXTBOOK ========== */
        .book-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 22px; margin-bottom: 36px; }

        .book-card {
            background: var(--card);
            border-radius: var(--radius-lg);
            padding: 28px;
            box-shadow: var(--shadow-sm);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            border: 2px solid transparent;
            cursor: pointer;
            position: relative;
            overflow: hidden;
        }

        .book-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: var(--primary); }
        .book-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--primary); }

        .book-card-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 16px; }

        .book-card-icon {
            width: 52px;
            height: 52px;
            border-radius: var(--radius-md);
            background: var(--primary-light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 28px;
        }

        .book-card-name { font-size: 20px; font-weight: 800; color: var(--text); margin-bottom: 8px; letter-spacing: -0.3px; }
        .book-card-desc { font-size: 14px; color: var(--text-secondary); margin-bottom: 18px; line-height: 1.6; min-height: 44px; }
        .book-card-meta { display: flex; gap: 20px; font-size: 13px; color: var(--text-secondary); margin-bottom: 16px; }

        .book-progress-bar { height: 10px; background: var(--bg); border-radius: 999px; overflow: hidden; margin-bottom: 10px; }
        .book-progress-fill { height: 100%; background: var(--primary); border-radius: 999px; transition: width 0.5s ease; }
        .book-progress-text { display: flex; justify-content: space-between; font-size: 13px; color: var(--text-secondary); font-weight: 600; }

        .book-actions { display: flex; gap: 8px; margin-top: 16px; }

        .chapter-list { display: flex; flex-direction: column; gap: 14px; }

        .chapter-item {
            background: var(--card);
            border-radius: var(--radius-lg);
            padding: 22px 26px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border);
            transition: all 0.2s ease;
        }

        .chapter-item:hover { box-shadow: var(--shadow-md); }
        .chapter-item.completed { border-left: 4px solid #10B981; }
        .chapter-item.current { border-left: 4px solid var(--primary); background: var(--primary-bg); }

        .chapter-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
        .chapter-name { font-size: 17px; font-weight: 700; color: var(--text); }
        .chapter-order { font-size: 12px; color: var(--text-light); background: var(--bg); padding: 3px 10px; border-radius: 999px; font-weight: 600; }

        .chapter-progress { display: flex; align-items: center; gap: 12px; }
        .chapter-progress-bar { flex: 1; height: 8px; background: var(--bg); border-radius: 999px; overflow: hidden; }
        .chapter-progress-fill { height: 100%; background: var(--primary); border-radius: 999px; }
        .chapter-progress-text { font-size: 13px; color: var(--text-secondary); font-weight: 600; white-space: nowrap; }

        .book-study-header {
            background: var(--card);
            border-radius: var(--radius-lg);
            padding: 24px 28px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border);
            margin-bottom: 24px;
        }

        .book-study-chapters {
            display: flex;
            gap: 10px;
            margin-top: 16px;
            overflow-x: auto;
            padding-bottom: 4px;
        }

        .book-study-chapter-pill {
            padding: 6px 14px;
            border-radius: 999px;
            font-size: 12px;
            font-weight: 600;
            white-space: nowrap;
            border: 1.5px solid var(--border);
            color: var(--text-secondary);
            background: var(--bg);
        }

        .book-study-chapter-pill.active { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
        .book-study-chapter-pill.done { border-color: #10B981; color: #059669; background: #ECFDF5; }

        .book-empty { text-align: center; padding: 80px 40px; }
        .book-empty-icon { font-size: 80px; margin-bottom: 20px; opacity: 0.5; }

        .admin-book-section { margin-bottom: 24px; }
        .admin-book-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
        .admin-book-title { font-size: 18px; font-weight: 700; color: var(--text); }

        .chapter-manage-item {
            display: flex; align-items: center; justify-content: space-between;
            padding: 14px 18px; background: var(--bg); border-radius: var(--radius-md); margin-bottom: 8px;
        }
        .chapter-manage-info { display: flex; align-items: center; gap: 12px; }
        .chapter-manage-order { font-size: 12px; font-weight: 700; color: var(--primary); background: var(--primary-bg); padding: 3px 10px; border-radius: 999px; }
        .chapter-manage-name { font-weight: 600; color: var(--text); }

        .kp-assign-item {
            display: flex; align-items: center; justify-content: space-between;
            padding: 12px 16px; background: var(--bg); border-radius: var(--radius-md); margin-bottom: 8px;
            border: 1px solid var(--border);
        }
        .kp-assign-info { flex: 1; }
        .kp-assign-name { font-weight: 600; color: var(--text); font-size: 14px; }
        .kp-assign-cat { font-size: 12px; color: var(--text-secondary); }
        /* ========== CSS FX EFFECTS ========== */
        
        /* 输入框高亮效果 */
        .form-input {
            position: relative;
            transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .form-input:focus {
            transform: translateY(-1px);
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }

        /* 卡片悬浮发光效果 */
        .stat-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            transform: scaleX(0);
            transition: transform 0.3s ease;
            transform-origin: left;
        }
        .stat-card:hover::before {
            transform: scaleX(1);
        }

        /* 导航项悬浮效果 - 左侧竖条渐入 */
        .nav-item {
            position: relative;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        .nav-item::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            width: 3px;
            height: 0;
            background: var(--primary);
            transition: height 0.3s ease;
            border-radius: 0 2px 2px 0;
            pointer-events: none;
        }
        .nav-item:hover::before,
        .nav-item.active::before {
            height: 100%;
        }

        /* 标签页切换动画 - 背景高亮 */
        .tab-btn {
            position: relative;
            transition: all 0.3s ease;
            overflow: hidden;
        }
        .tab-btn::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 0;
            height: 0;
            background: var(--primary);
            opacity: 0;
            border-radius: 50%;
            transition: all 0.4s ease;
            transform: translate(-50%, -50%);
            pointer-events: none;
        }
        .tab-btn:hover::after {
            width: 200%;
            height: 200%;
            opacity: 0.05;
        }
        .tab-btn.active::after {
            width: 200%;
            height: 200%;
            opacity: 0.1;
        }

        /* 空状态图标浮动动画 */
        .empty-icon {
            animation: float 3s ease-in-out infinite;
        }
        @keyframes float {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-10px); }
        }

        /* 页面进入动画 */
        .fade-in {
            animation: fadeInUp 0.5s ease forwards;
        }
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* 进度条渐变效果 */
        .category-progress-bar,
        .book-progress-fill {
            background: linear-gradient(90deg, var(--primary), var(--accent));
            position: relative;
            overflow: hidden;
        }
        .category-progress-bar::after,
        .book-progress-fill::after {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
            animation: shimmer 2s infinite;
        }
        @keyframes shimmer {
            100% { left: 100%; }
        }

        /* 收藏按钮心跳效果 */
        .feedback-btn:hover {
            animation: heartbeat 0.3s ease;
        }
        @keyframes heartbeat {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.05); }
        }

        /* 课本卡片悬浮效果 */
        .book-card {
            transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .book-card:hover {
            transform: translateY(-6px) scale(1.01);
            box-shadow: 0 20px 40px rgba(0,0,0,0.15);
        }

        /* 分类卡片弹性效果 */
        .category-card {
            transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .category-card:active {
            transform: scale(0.98);
        }

        /* 搜索框聚焦效果 */
        .search-box input:focus + .search-btn {
            background: var(--primary-dark);
        }

        /* 徽章脉冲效果 */
        .nav-badge {
            animation: pulse 2s infinite;
        }
        @keyframes pulse {
            0% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.4); }
            70% { box-shadow: 0 0 0 10px rgba(239, 68, 68, 0); }
            100% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0); }
        }

        /* 侧边栏图标旋转效果 */
        .nav-icon {
            transition: transform 0.3s ease;
        }
        .nav-item:hover .nav-icon {
            transform: scale(1.2);
        }

        /* 表单提交按钮加载效果 */
        .btn-primary.loading {
            pointer-events: none;
            opacity: 0.8;
        }
        .btn-primary.loading .spinner {
            animation: spin 0.6s linear infinite;
        }

        /* 课本进度条动画 */
        .book-progress-bar {
            overflow: hidden;
            background: var(--bg);
        }

        /* 闪卡翻转效果 */
        .flashcard {
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .flashcard:hover {
            box-shadow: 0 25px 50px rgba(0,0,0,0.15);
        }

        /* 统计数字跳动效果 */
        .stat-value {
            transition: all 0.3s ease;
        }
        .stat-card:hover .stat-value {
            color: var(--primary);
        }

        /* 弹窗进入动画 */
        .modal-content-2 {
            animation: modalIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }

        /* 消息列表项悬浮效果 */
        .admin-item {
            transition: all 0.2s ease;
        }
        .admin-item:hover {
            transform: translateX(4px);
        }

        /* 课本章节进度条动画 */
        .chapter-progress-fill {
            transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
        }