/* 禁止使用 body, *, html 选择器 — 所有样式基于类与 :root */
        :root {
            --primary-gold: #ffb347;
            --primary-orange: #ff7b2c;
            --dark-bg: rgba(10, 18, 28, 0.88);
            --card-bg: rgba(20, 30, 40, 0.85);
            --border-light: rgba(255, 255, 255, 0.25);
            --text-light: #eef2f5;
            --shadow: 0 12px 28px rgba(0, 0, 0, 0.3);
            --radius: 16px;
        }

        .form-wrapper {
            max-width: 680px;
            margin: 40px auto;
            padding: 28px 24px;
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            font-family: 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            color: var(--text-light);
        }

        .form-header {
            text-align: center;
            margin-bottom: 28px;
        }

        .form-header h1 {
            font-size: 1.9rem;
            margin: 0 0 6px;
            font-weight: 700;
            letter-spacing: 1px;
        }

        .form-title {
            background: linear-gradient(135deg, #ffd966, #ffb347);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }

        .form-header p {
            font-size: 0.9rem;
            opacity: 0.85;
            margin: 0;
        }

        .form-container {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }

        .form-group {
            display: flex;
            flex-direction: column;
            gap: 6px;
        }

        .form-label {
            font-size: 0.9rem;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .required-star {
            color: #ff7b72;
            font-size: 1rem;
        }

        .form-input, .captcha-input, .form-select {
            background: rgba(0, 0, 0, 0.6);      /* 深色背景，提高对比度 */
            border: 1px solid var(--border-light);
            border-radius: 12px;
            padding: 12px 14px;
            font-size: 0.9rem;
            color: #fff;
            transition: all 0.2s;
            outline: none;
            width: 100%;
            box-sizing: border-box;
        }

        /* 修复下拉菜单选项的背景色 */
        .form-select option {
            background: #2c3e50;
            color: #fff;
        }

        .form-select {
            cursor: pointer;
            appearance: none;
            background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='white'><path d='M7 10l5 5 5-5z'/></svg>");
            background-repeat: no-repeat;
            background-position: right 14px center;
            background-color: rgba(0, 0, 0, 0.6);
        }

        .form-input:focus, .captcha-input:focus, .form-select:focus {
            border-color: var(--primary-gold);
            background: rgba(0, 0, 0, 0.75);
            box-shadow: 0 0 0 3px rgba(255, 180, 71, 0.3);
        }

        .form-input::placeholder, .captcha-input::placeholder {
            color: rgba(255, 255, 255, 0.6);
        }

        textarea.form-input {
            resize: vertical;
            min-height: 100px;
        }

        .row-2col {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }
        .row-2col .form-group {
            flex: 1;
            min-width: 160px;
        }

        .captcha-group {
            display: flex;
            gap: 12px;
            align-items: center;
        }

        .captcha-input {
            flex: 2;
        }

        .captcha-img {
            flex: 1;
            height: 48px;
            border-radius: 12px;
            cursor: pointer;
            object-fit: cover;
            background: rgba(0, 0, 0, 0.4);
            border: 1px solid var(--border-light);
        }

        .button-group {
            display: flex;
            gap: 16px;
            margin-top: 8px;
        }

        .btn {
            flex: 1;
            padding: 12px;
            border: none;
            border-radius: 40px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: 0.2s;
            background: rgba(255, 255, 255, 0.2);
            color: white;
        }

        .btn-submit {
            background: linear-gradient(135deg, var(--primary-gold), var(--primary-orange));
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
        }

        .btn-submit:hover {
            transform: translateY(0px);
            filter: brightness(1.05);
        }

        .btn-reset:hover {
            background: rgba(255, 255, 255, 0.35);
        }

        .notice {
            font-size: 0.7rem;
            text-align: center;
            margin-top: 20px;
            color: rgba(255, 255, 255, 0.7);
        }

        .notice strong {
            color: var(--primary-gold);
        }

        @media (max-width: 640px) {
            .form-wrapper {
                margin: 20px;
                padding: 20px;
            }
            .form-header h1 {
                font-size: 1.5rem;
            }
            .captcha-group {
                flex-direction: column;
            }
            .captcha-img {
                width: 100%;
                height: 44px;
            }
            .button-group {
                flex-direction: column;
            }
            .row-2col {
                flex-direction: column;
                gap: 12px;
            }
        }