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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #ffffff;
    --text-color: #111827;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #ffffff;
    min-height: 100vh;
    padding: 40px 20px;
    color: var(--text-color);
}

.container {
    max-width: 580px;
    margin: 0 auto;
    background: #ffffff;
}

.header {
    text-align: center;
    margin-bottom: 0px;
    position: relative;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    padding-left: 16px;
    padding-right: 16px;
    padding-bottom: 8px;
    color: var(--text-color);
}

.subtitle {
    font-size: 0.95rem;
    color: var(--text-muted);
    font-weight: 400;
}

.logout-link {
    position: absolute;
    top: 0;
    right: 0;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.875rem;
    padding: 6px 12px;
}

.logout-link:hover {
    color: var(--text-color);
}

.upload-box {
    background: white;
    padding: 32px;
    margin: 12px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-color);
}

.form-group small {
    display: block;
    margin-top: 6px;
    color: var(--text-muted);
    font-size: 0.8125rem;
}

.form-group input[type="password"],
.form-group input[type="number"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    font-size: 0.9375rem;
    font-family: inherit;
}

.form-group input[type="password"]:focus,
.form-group input[type="number"]:focus {
    outline: none;
    border-color: #2563eb;
}

.captcha-container {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.captcha-image {
    border: 1px solid var(--border-color);
    background: #ffffff;
    max-width: 200px;
    height: auto;
}

.refresh-captcha {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border: 1px solid var(--border-color);
    background: white;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

.refresh-captcha:hover {
    border-color: #2563eb;
}

.file-input-wrapper {
    position: relative;
}

.file-input-wrapper input[type="file"] {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.file-label {
    display: block;
    padding: 40px 20px;
    border: 1px solid var(--border-color);
    text-align: center;
    cursor: pointer;
    background: #ffffff;
    min-height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.file-label.has-file {
    border-color: var(--success-color);
}

#fileName {
    font-size: 0.9375rem;
    color: var(--text-muted);
}

.submit-btn {
    width: 100%;
    padding: 14px 28px;
    background: #2563eb;
    color: white;
    border: none;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.submit-btn:hover:not(:disabled) {
    background: #1d4ed8;
}

.submit-btn:disabled {
    background: #e5e7eb;
    color: #9ca3af;
    cursor: not-allowed;
}

.spinner {
    width: 16px;
    height: 16px;
    border: 2px 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); }
}

.progress-bar {
    width: 100%;
    height: 3px;
    background: var(--border-color);
    border-radius: 2px;
    margin-top: 12px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    width: 0%;
    animation: progress 1.5s ease-in-out infinite;
}

@keyframes progress {
    0% { width: 0%; }
    50% { width: 70%; }
    100% { width: 100%; }
}

.result {
    margin-top: 16px;
    padding: 16px;
    border: 1px solid;
}

.result.success {
    background: #f0fdf4;
    border-color: #10b981;
    color: #059669;
}

.result.error {
    background: #fef2f2;
    border-color: #ef4444;
    color: #dc2626;
}

.result-content h4 {
    margin-bottom: 8px;
    font-size: 0.9375rem;
    font-weight: 600;
}

.result-content p {
    margin: 4px 0;
    line-height: 1.5;
    font-size: 0.875rem;
}

.result-content a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.result-content a:hover {
    text-decoration: underline;
}

.footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8125rem;
    margin-top: 32px;
}

@media (max-width: 640px) {
    body {
        padding: 24px 16px;
    }

    .header {
        margin-bottom: 32px;
    }

    .header h1 {
        font-size: 1.5rem;
        margin: 32px;
    }

    .upload-box {
        padding: 24px;
    }

    .file-label {
        padding: 24px 16px;
    }
}