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

        :root {
            --color-primary: #FF6B35;
            --color-primary-dark: #E8551E;
            --color-primary-light: #FF8A5C;
            --color-primary-bg: rgba(255, 107, 53, 0.08);
            --color-primary-bg-hover: rgba(255, 107, 53, 0.14);
            --color-secondary: #1E293B;
            --color-gray-50: #F8FAFC;
            --color-gray-100: #F1F5F9;
            --color-gray-200: #E2E8F0;
            --color-gray-300: #CBD5E1;
            --color-gray-400: #94A3B8;
            --color-gray-500: #64748B;
            --color-gray-600: #475569;
            --color-gray-700: #334155;
            --color-gray-800: #1E293B;
            --color-gray-900: #0F172A;

            --font-heading: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
            --font-body: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;

            --container-max-width: 1280px;
            --section-spacing: 88px;
            --shadow-sm: 0 1px 3px 0 rgba(0,0,0,0.06), 0 1px 2px -1px rgba(0,0,0,0.06);
            --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.05);
            --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.05);
            --radius-sm: 6px;
            --radius-md: 10px;
            --radius-lg: 16px;
            --radius-xl: 24px;
            --transition-fast: 150ms ease;
            --transition-base: 200ms ease;
        }

        html { scroll-behavior: smooth; }
        body {
            font-family: var(--font-body);
            font-weight: 400;
            font-size: 16px;
            color: var(--color-gray-800);
            background-color: #FFFFFF;
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        :focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; border-radius: var(--radius-xs); }
        h1, h2, h3 { font-family: var(--font-heading); font-weight: 600; line-height: 1.25; color: var(--color-gray-900); }
        h1 { font-size: clamp(30px, 4vw, 42px); font-weight: 700; letter-spacing: -0.02em; }
        h2 { font-size: clamp(24px, 3vw, 32px); font-weight: 700; }
        h3 { font-size: clamp(18px, 2vw, 22px); font-weight: 600; }
        a { text-decoration: none; color: inherit; transition: color var(--transition-fast); }
        ul { list-style: none; }
        .container { max-width: var(--container-max-width); margin: 0 auto; padding: 0 28px; }
        @media (max-width: 640px) { .container { padding: 0 18px; } }

        .btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 13px 28px; font-weight: 600; font-size: 15px; font-family: var(--font-body); border-radius: var(--radius-md); transition: all var(--transition-base); cursor: pointer; border: none; white-space: nowrap; }
        .btn:active { transform: scale(0.97); }
        .btn i { width: 18px; height: 18px; flex-shrink: 0; }
        .btn-primary { background: var(--color-primary); color: #FFFFFF; box-shadow: var(--shadow-sm), 0 0 0 0 rgba(255,107,53,0.4); }
        .btn-primary:hover { background: var(--color-primary-dark); box-shadow: 0 0 0 4px rgba(255,107,53,0.12); transform: translateY(-2px); }
        .btn-outline { background: transparent; color: var(--color-gray-800); border: 1.5px solid var(--color-gray-300); }
        .btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-bg); }

        .header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.95); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid var(--color-gray-200); }
        .header-container { display: flex; align-items: center; justify-content: space-between; height: 76px; padding: 0 28px; max-width: var(--container-max-width); margin: 0 auto; gap: 20px; }
        .logo { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
        .logo-icon { width: 46px; height: 46px; background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%); border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; color: #FFFFFF; font-weight: 700; font-size: 22px; box-shadow: 0 2px 8px rgba(255,107,53,0.3); }
        .logo-text { font-size: 22px; font-weight: 700; color: var(--color-gray-900); }
        .logo-text span { color: var(--color-primary); font-weight: 600; }
        .nav-menu { display: flex; align-items: center; gap: 32px; }
        .nav-link { font-weight: 500; font-size: 15px; color: var(--color-gray-700); position: relative; padding: 6px 2px; transition: color var(--transition-fast); white-space: nowrap; }
        .nav-link:hover { color: var(--color-primary); }
        .nav-link--active { color: var(--color-primary); font-weight: 600; }
        .nav-link--active::after { content: '';  bottom: -2px; left: 0; right: 0; height: 2.5px; background: var(--color-primary); border-radius: 2px; }
        .header-actions { display: flex; align-items: center; gap: 8px; }
        .icon-btn { background: none; border: none; cursor: pointer; color: var(--color-gray-600); padding: 10px; border-radius: var(--radius-sm); transition: all var(--transition-fast); display: flex; align-items: center; justify-content: center; }
        .icon-btn:hover { background: var(--color-gray-100); color: var(--color-primary); }
        .mobile-menu-btn { display: none; background: none; border: none; cursor: pointer; padding: 10px; color: var(--color-gray-700); }
        .mobile-menu-btn i { width: 24px; height: 24px; }
        @media (max-width: 1024px) { .nav-menu { display: none; } .mobile-menu-btn { display: flex; } }
        @media (max-width: 480px) { .header-container { height: 64px; padding: 0 16px; } .logo-icon { width: 38px; height: 38px; font-size: 18px; } .logo-text { font-size: 18px; } }

        .breadcrumb { padding: 20px 0; background: var(--color-gray-50); border-bottom: 1px solid var(--color-gray-200); }
        .breadcrumb-container { max-width: var(--container-max-width); margin: 0 auto; padding: 0 28px; }
        .breadcrumb ol { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--color-gray-500); }
        .breadcrumb li { display: flex; align-items: center; }
        .breadcrumb li:not(:last-child)::after { content: '/'; margin-left: 8px; color: var(--color-gray-400); }
        .breadcrumb a:hover { color: var(--color-primary); }

        .page-section { padding: 60px 0 80px; }
        .page-header { text-align: center; margin-bottom: 48px; }
        .page-header .badge { display: inline-block; padding: 5px 14px; font-size: 13px; font-weight: 500; border-radius: 100px; background: var(--color-primary-bg); color: var(--color-primary); margin-bottom: 16px; }
        .page-header p { color: var(--color-gray-500); max-width: 620px; margin: 0 auto; }

        .sample-layout { display: grid; grid-template-columns: 320px 1fr; gap: 40px; align-items: start; }
        .info-sidebar { background: var(--color-gray-50); border-radius: var(--radius-lg); border: 1px solid var(--color-gray-200); padding: 28px; position: sticky; top: 100px; }
        .info-sidebar h3 { display: flex; align-items: center; gap: 10px; margin-bottom: 20px; font-size: 18px; }
        .info-sidebar ul li { display: flex; align-items: flex-start; gap: 10px; margin-bottom: 16px; font-size: 14px; color: var(--color-gray-600); }
        .info-sidebar ul li i { color: var(--color-primary); width: 18px; height: 18px; flex-shrink: 0; margin-top: 2px; }

        .sample-form { background: #FFFFFF; border-radius: var(--radius-lg); border: 1px solid var(--color-gray-200); padding: 36px 32px; box-shadow: var(--shadow-sm); }
        .form-message { margin-bottom: 24px; padding: 12px 14px; border-radius: var(--radius-sm); font-size: 14px; line-height: 1.5; border: 1px solid transparent; }
        .form-message[hidden] { display: none; }
        .form-message--info { color: var(--color-gray-700); background: var(--color-gray-50); border-color: var(--color-gray-200); }
        .form-message--success { color: #166534; background: #F0FDF4; border-color: #BBF7D0; }
        .form-message--error { color: #B91C1C; background: #FEF2F2; border-color: #FECACA; }
        .form-section { margin-bottom: 32px; }
        .form-section h3 { margin-bottom: 20px; display: flex; align-items: center; gap: 10px; font-size: 18px; }
        .form-section h3 i { color: var(--color-primary); }
        .form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
        .form-group { display: flex; flex-direction: column; }
        .form-group.full { grid-column: 1 / -1; }
        .form-group label { font-weight: 500; font-size: 14px; margin-bottom: 6px; color: var(--color-gray-700); }
        .form-group label .required { color: var(--color-primary); margin-left: 2px; }
        .form-group input,
        .form-group select,
        .form-group textarea {
            padding: 12px 14px;
            border: 1px solid var(--color-gray-300);
            border-radius: var(--radius-sm);
            font-size: 15px;
            font-family: var(--font-body);
            background: var(--color-gray-50);
            transition: border-color var(--transition-fast);
        }
        .form-group input:focus,
        .form-group select:focus,
        .form-group textarea:focus {
            outline: none;
            border-color: var(--color-primary);
            background: #FFFFFF;
        }
        .form-group textarea { resize: vertical; min-height: 100px; }
        .checkbox-group { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--color-gray-600); margin-top: 8px; }
        .checkbox-group input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--color-primary); }
        .form-actions { display: flex; gap: 16px; justify-content: flex-end; margin-top: 8px; }

        .footer { background: var(--color-gray-900); color: #FFFFFF; padding: 56px 0 28px; margin-top: 40px; }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr 1.5fr; gap: 36px; margin-bottom: 44px; }
        .footer-brand p { color: var(--color-gray-400); margin: 18px 0; font-size: 14px; }
        .footer-links h4 { color: #FFFFFF; font-size: 15px; margin-bottom: 18px; font-weight: 600; }
        .footer-links ul li { margin-bottom: 10px; }
        .footer-links ul li a { color: var(--color-gray-400); font-size: 13px; transition: color var(--transition-fast); }
        .footer-links ul li a:hover { color: #FFFFFF; }
        .footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid rgba(255,255,255,0.08); color: var(--color-gray-500); font-size: 12px; }

        @media (max-width: 900px) {
            .sample-layout { grid-template-columns: 1fr; }
            .info-sidebar { position: static; }
            .form-grid { grid-template-columns: 1fr; }
        }
        @media (max-width: 640px) {
            .form-actions { flex-direction: column; }
            .form-actions .btn { width: 100%; }
        }