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

        :root {
            --bg: #fafaf9;
            --surface: #ffffff;
            --text: #1c1917;
            --text-secondary: #57534e;
            --text-muted: #a8a29e;
            --primary: #4f46e5;
            --primary-hover: #4338ca;
            --accent: #d97706;
            --danger: #dc2626;
            --border: #e7e5e4;
            --radius: 10px;
            --shadow-sm: 0 1px 3px rgba(0,0,0,.06);
            --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
            --font-mono: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
        }

        html { font-size: 16px; }

        body {
            font-family: var(--font-sans);
            background: var(--bg);
            color: var(--text);
            line-height: 1.6;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        /* ── Inline Back ── */
        .top-bar {
            max-width: 960px;
            width: 100%;
            margin: 0 auto;
            padding: 20px 20px 0;
            display: flex;
            align-items: center;
            gap: 12px;
        }
        .back-link {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 6px 14px;
            font-size: .82rem;
            font-weight: 500;
            color: var(--text-secondary);
            text-decoration: none;
            border-radius: 20px;
            border: 1px solid var(--border);
            transition: all .15s ease;
            font-family: var(--font-mono);
            white-space: nowrap;
        }
        .back-link:hover {
            color: var(--primary);
            border-color: var(--primary);
            background: rgba(79,70,229,.04);
        }
        .top-title {
            font-size: .88rem;
            font-weight: 600;
            color: var(--text);
        }

        /* ── Form ── */
        .form-container {
            max-width: 960px;
            width: 100%;
            margin: 28px auto 48px;
            padding: 0 20px;
            flex: 1;
        }
        .form-card {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-sm);
        }
        .form-heading {
            font-size: 1.15rem;
            font-weight: 700;
            margin-bottom: 24px;
            padding-bottom: 14px;
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .form-heading::before {
            content: '';
            display: inline-block;
            width: 4px;
            height: 18px;
            background: var(--primary);
            border-radius: 2px;
        }

        .form-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 22px 28px;
        }
        .field-full { grid-column: 1 / -1; }
        .field { margin-bottom: 0; }
        .field-label { display: block; font-size: .82rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 8px; font-family: var(--font-mono); letter-spacing: .05em; text-transform: uppercase; }
        .field-input { width: 100%; padding: 11px 14px; border: 1px solid var(--border); border-radius: 6px; font-size: .95rem; outline: none; transition: border-color .15s, box-shadow .15s; background: var(--surface); color: var(--text); font-family: var(--font-sans); }
        .field-input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79,70,229,.1); }
        .field-input::placeholder { color: var(--text-muted); }
        .field-hint { font-size: .78rem; color: var(--text-muted); margin-top: 6px; font-family: var(--font-mono); }

        .drop-zone { display: block; border: 2px dashed var(--border); border-radius: var(--radius); padding: 40px 24px; text-align: center; cursor: pointer; transition: all .2s ease; background: var(--surface); }
        .drop-zone:hover, .drop-zone.dragover { border-color: var(--primary); background: rgba(79,70,229,.03); }
        .drop-zone input[type="file"] { display: none; }
        .drop-icon { width: 52px; height: 52px; margin: 0 auto 14px; border: 1px solid var(--border); border-radius: 10px; display: flex; align-items: center; justify-content: center; color: var(--text-muted); font-family: var(--font-mono); font-size: .8rem; font-weight: 600; }
        .drop-label { font-size: .95rem; color: var(--text-secondary); }
        .drop-format { font-size: .8rem; color: var(--text-muted); margin-top: 6px; font-family: var(--font-mono); }
        .drop-filename { margin-top: 12px; color: var(--primary); font-weight: 600; font-size: .9rem; font-family: var(--font-mono); }

        .submit-btn { width: 100%; padding: 14px; background: var(--primary); color: #fff; border: none; border-radius: 6px; font-size: .95rem; font-weight: 600; cursor: pointer; transition: background .15s; font-family: var(--font-sans); margin-top: 4px; }
        .submit-btn:hover { background: var(--primary-hover); }
        .submit-btn:disabled { background: var(--text-muted); cursor: not-allowed; }

        .msg { padding: 12px 16px; margin-bottom: 20px; font-size: .85rem; border-radius: 6px; display: none; font-family: var(--font-mono); line-height: 1.5; }
        .msg.success { background: rgba(79,70,229,.06); color: var(--primary-hover); border: 1px solid rgba(79,70,229,.15); border-left: 3px solid var(--primary); }
        .msg.error { background: rgba(220,38,38,.06); color: var(--danger); border: 1px solid rgba(220,38,38,.15); border-left: 3px solid var(--danger); }
        .msg.locked { background: rgba(217,119,6,.06); color: #92400e; border: 1px solid rgba(217,119,6,.15); border-left: 3px solid var(--accent); display: block; text-align: center; padding: 20px; font-size: .9rem; }

        /* ── Footer ── */
        .site-footer { text-align: center; padding: 22px 20px; font-size: .78rem; color: var(--text-muted); border-top: 1px solid var(--border); font-family: var(--font-mono); margin-top: auto; }
        .footer-meta { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 6px 16px; line-height: 1.8; }
        .site-footer a { color: var(--text-secondary); text-decoration: none; transition: color .15s; }
        .site-footer a:hover { color: var(--primary); }

        /* ── Responsive ── */
        @media (max-width: 640px) {
            html { font-size: 15px; }
            .top-bar { padding: 16px 16px 0; }
            .back-link { padding: 6px 12px; font-size: .85rem; }
            .top-title { font-size: .9rem; }
            .form-container { margin: 20px auto 36px; padding: 0 16px; }
            .form-card { padding: 24px 18px; }
            .form-grid { grid-template-columns: 1fr; gap: 18px; }
            .field-full { grid-column: auto; }
            .form-heading { font-size: 1.15rem; }
            .field-label { font-size: .82rem; }
            .field-input { padding: 12px 14px; font-size: 1rem; }
            .drop-zone { padding: 28px 16px; }
            .drop-label { font-size: .95rem; }
            .drop-format { font-size: .82rem; }
            .drop-filename { font-size: .88rem; }
            .submit-btn { padding: 14px; font-size: .95rem; }
        }

        @media (min-width: 641px) and (max-width: 1024px) {
            .form-card { padding: 32px; }
            .form-grid { gap: 20px 22px; }
        }

        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
        }