:root {
    --primary-color: #000000;
    --secondary-color: #86868b;
    --background: #ffffff;
    --surface: #fbfbfd;
    --border: rgba(0, 0, 0, 0.08);
    --hover: rgba(0, 0, 0, 0.04);
    --accent: #0071e3;
    --success: #34c759;
    --error: #ff3b30;
    --radius: 18px;
    --radius-small: 12px;
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    --font-main: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-main);
    background: var(--surface);
    color: var(--primary-color);
    line-height: 1.5;
    font-size: 17px;
    min-height: 100vh;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 18px;
}

.logo-icon {
    font-size: 24px;
}

.nav {
    display: flex;
    gap: 32px;
}

.nav-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 15px;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary-color);
}

.main-content {
    flex: 1;
    padding: 100px 24px 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 300px);
}

.container {
    background: var(--background);
    border-radius: var(--radius);
    padding: 48px;
    max-width: 580px;
    width: 100%;
    box-shadow: var(--shadow);
    margin: 0 auto;
    animation: fadeIn 0.5s ease;
}

h1 {
    font-size: 32px;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
    text-align: center;
}

.subtitle {
    color: var(--secondary-color);
    text-align: center;
    margin-bottom: 40px;
    font-size: 19px;
    font-weight: 400;
}

.info {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-small);
    padding: 20px;
    margin-bottom: 32px;
}

.info-item {
    display: flex;
    align-items: center;
    padding: 8px 0;
    color: var(--secondary-color);
    font-size: 15px;
}

.info-item:not(:last-child) {
    border-bottom: 1px solid var(--border);
}

.info-icon {
    margin-right: 12px;
    font-size: 20px;
}

.upload-area {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 64px 32px;
    text-align: center;
    transition: all 0.2s ease;
    cursor: pointer;
    background: var(--background);
    margin-bottom: 24px;
}

.upload-area:hover {
    border-color: var(--accent);
    background: var(--hover);
}

.upload-area.dragging {
    border-color: var(--accent);
    background: rgba(0, 113, 227, 0.04);
    transform: scale(1.01);
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #007AFF, #5AC8FA);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: white;
}

.upload-text {
    font-size: 20px;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.upload-subtext {
    color: var(--secondary-color);
    font-size: 15px;
}

.btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 980px;
    font-size: 17px;
    font-weight: 400;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 120px;
    height: 44px;
    letter-spacing: -0.01em;
}

.btn:hover {
    background: #0077ed;
    transform: scale(1.02);
}

.btn:active {
    transform: scale(0.98);
}

.btn:disabled {
    background: var(--border);
    color: var(--secondary-color);
    cursor: not-allowed;
}

.progress {
    display: none;
    margin: 32px 0;
}

.progress-track {
    height: 4px;
    background: var(--border);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

.progress-text {
    margin-top: 12px;
    text-align: center;
    color: var(--secondary-color);
    font-size: 14px;
}

.message {
    padding: 16px;
    border-radius: var(--radius-small);
    margin-top: 24px;
    font-size: 15px;
    line-height: 1.4;
}

.message.success {
    background: rgba(52, 199, 89, 0.1);
    color: var(--success);
}

.message.error {
    background: rgba(255, 59, 48, 0.1);
    color: var(--error);
}

.url-display {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 16px;
    margin: 12px 0;
    font-family: 'SF Mono', Monaco, monospace;
    font-size: 14px;
    word-break: break-all;
    color: var(--primary-color);
}

.selected-file {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-small);
    padding: 16px;
    margin-top: 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.file-details {
    display: flex;
    align-items: center;
}

.file-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #5AC8FA, #007AFF);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    margin-right: 12px;
}

.file-name {
    font-weight: 500;
    color: var(--primary-color);
    font-size: 15px;
}

.file-size {
    color: var(--secondary-color);
    font-size: 13px;
    margin-top: 2px;
}

.remove-file {
    color: var(--secondary-color);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s;
}

.remove-file:hover {
    background: var(--hover);
    color: var(--error);
}

.footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 48px 24px 24px;
    margin-top: auto;
    width: 100%;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 80px;
    margin-bottom: 32px;
}

.footer-section {
    flex: 1;
    padding-right: 4%;
    padding-left: 4%;
}

.footer-section:first-child {
    flex: 1.5;
    max-width: 400px;
}

.footer-section:last-child {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.footer-section:last-child > div {
    text-align: left;
}

.footer-section h4 {
    text-align: left;
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.footer-section p {
    color: var(--secondary-color);
    font-size: 14px;
    line-height: 1.5;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section li {
    margin: 8px 0;
}

.footer-section a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
    display: inline-block;
}

.footer-section a:hover {
    color: var(--accent);
}

.footer-section:last-child {
    text-align: left;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.footer-section:last-child > * {
    text-align: left;
    width: fit-content;
}

.footer-section:last-child ul {
    text-align: left;
    display: inline-block;
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    color: var(--secondary-color);
    font-size: 13px;
}

.error-message-container {
    text-align: center;
    padding: 40px 20px;
}

.error-message-container ul {
    list-style: none;
    padding: 0;
    margin: 20px auto;
    max-width: 400px;
    text-align: left;
}

.error-message-container li {
    margin: 12px 0;
    color: var(--primary-color);
    font-size: 15px;
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 16px;
    }
    
    .nav {
        gap: 20px;
    }
    
    .main-content {
        padding: 80px 20px 60px;
        min-height: calc(100vh - 400px);
    }
    
    .footer-content {
        flex-direction: column;
        gap: 32px;
        text-align: center;
    }
    .footer-section:last-child {
        text-align: left;
    }
    
    .footer-section:last-child ul {
        text-align: left;
    }
}

@media (max-width: 600px) {
    .container {
        padding: 32px 24px;
    }
    
    h1 {
        font-size: 28px;
    }
    
    .subtitle {
        font-size: 17px;
    }
    
    .upload-area {
        padding: 48px 24px;
    }
}

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

::-webkit-scrollbar {
    width: 12px;
    height: 12px;
}

::-webkit-scrollbar-track {
    background: var(--surface);
}

::-webkit-scrollbar-thumb {
    background: var(--accent);
    border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
    background: #0077ed;
}