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

:root {
    --primary-color: #0088cc;
    --primary-hover: #006699;
    --danger-color: #dc3545;
    --danger-hover: #c82333;
    --success-color: #28a745;
    --bg-color: #f5f5f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-muted: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    transition: all 0.2s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background-color: var(--danger-hover);
}

.btn-large {
    padding: 16px 48px;
    font-size: 18px;
}

.btn-small {
    padding: 8px 16px;
    font-size: 14px;
}

/* Login Page */
.login-box {
    max-width: 400px;
    margin: 80px auto;
    background: var(--card-bg);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
}

.login-box h1 {
    margin-bottom: 30px;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 20px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.login-box .btn {
    width: 100%;
    margin-top: 10px;
}

.error {
    color: var(--danger-color);
    margin-top: 15px;
    font-size: 14px;
}

/* Admin Page */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

header h1 {
    color: var(--primary-color);
}

/* Upload Section */
.upload-section {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.upload-section h2 {
    margin-bottom: 20px;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(0, 136, 204, 0.05);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background-color: rgba(0, 136, 204, 0.1);
}

.upload-area p {
    margin: 5px 0;
}

.upload-area .hint {
    color: var(--text-muted);
    font-size: 14px;
}

/* Progress */
.progress-container {
    margin-top: 20px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 14px;
}

.progress-bar {
    height: 8px;
    background-color: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background-color: var(--primary-color);
    width: 0%;
    transition: width 0.3s;
}

.status {
    margin-top: 10px;
    font-size: 14px;
    color: var(--text-muted);
}

.status.success {
    color: var(--success-color);
}

.status.error {
    color: var(--danger-color);
}

/* Files List */
.files-section {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.files-section h2 {
    margin-bottom: 20px;
}

.files-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    background: var(--bg-color);
    border-radius: 12px;
    gap: 15px;
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-meta {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 4px;
}

.file-actions {
    display: flex;
    gap: 10px;
    flex-shrink: 0;
}

.loading {
    text-align: center;
    color: var(--text-muted);
    padding: 20px;
}

.empty {
    text-align: center;
    color: var(--text-muted);
    padding: 40px;
}

/* Download Page */
.download-box {
    max-width: 500px;
    margin: 80px auto;
    background: var(--card-bg);
    padding: 50px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
}

.file-icon {
    color: var(--primary-color);
    margin-bottom: 20px;
}

.filename {
    font-size: 20px;
    margin-bottom: 10px;
    word-break: break-all;
}

.filesize {
    color: var(--text-muted);
    margin-bottom: 30px;
}

.powered-by {
    margin-top: 30px;
    font-size: 13px;
    color: var(--text-muted);
}

/* Error Page */
.error-box {
    max-width: 500px;
    margin: 80px auto;
    background: var(--card-bg);
    padding: 50px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
}

.error-icon {
    color: var(--danger-color);
    margin-bottom: 20px;
}

.error-box h1 {
    margin-bottom: 15px;
}

.error-box p {
    color: var(--text-muted);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: #333;
    color: white;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    visibility: visible;
}

.toast.success {
    background: var(--success-color);
}

.toast.error {
    background: var(--danger-color);
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 15px;
    }

    .login-box,
    .download-box,
    .error-box {
        margin: 40px auto;
        padding: 30px 20px;
    }

    header {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .file-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .file-actions {
        width: 100%;
        justify-content: flex-end;
    }

    .upload-section,
    .files-section {
        padding: 20px;
    }
}