:root {
    --color-bg: #f8f9fa;
    --color-card: #ffffff;
    --color-text: #212529;
    --color-text-muted: #6c757d;
    --color-primary: #0d6efd;
    --color-primary-dark: #0a58ca;
    --color-border: #dee2e6;
    --color-success: #198754;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

.noise-overlay {
    display: none;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
}

.header-line {
    display: none;
}

.title {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.title-main,
.title-sub {
    display: inline;
    font-style: normal;
    color: var(--color-text);
}

.subtitle {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    font-weight: 400;
    letter-spacing: normal;
    text-transform: none;
}

/* Upload Section */
.upload-section {
    margin-bottom: 3rem;
}

.upload-area {
    position: relative;
    border: 2px dashed var(--color-border);
    background: var(--color-card);
    border-radius: 8px;
    padding: 3rem 2rem;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-bottom: 1.5rem;
}

.upload-area::before {
    display: none;
}

.upload-area:hover {
    border-color: var(--color-primary);
    background: #f0f7ff;
}

.upload-area.drag-over {
    border-color: var(--color-primary);
    background: #e7f3ff;
}

#fileInput {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    opacity: 0;
    cursor: pointer;
}

.upload-content {
    text-align: center;
}

.upload-icon {
    color: var(--color-primary);
    margin-bottom: 1rem;
    animation: none;
}

.upload-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-style: normal;
    color: var(--color-text);
}

.upload-text {
    color: var(--color-text-muted);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.upload-format {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-transform: none;
    letter-spacing: normal;
}

/* File Preview */
.file-preview {
    text-align: center;
}

.file-preview svg {
    color: var(--color-primary);
    margin-bottom: 1rem;
}

.file-name {
    font-size: 1rem;
    margin-bottom: 0.25rem;
    color: var(--color-text);
    font-weight: 500;
    font-style: normal;
}

.file-size {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* Submit Button */
.btn-submit {
    width: 100%;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.875rem 1.5rem;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    letter-spacing: normal;
    text-transform: none;
}

.btn-submit::before {
    display: none;
}

.btn-submit:hover:not(:disabled) {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(13, 110, 253, 0.2);
}

.btn-submit:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-text,
.btn-arrow {
    position: static;
}

.btn-arrow {
    font-size: 1.25rem;
    transition: transform 0.2s ease;
}

.btn-submit:hover:not(:disabled) .btn-arrow {
    transform: translateX(3px);
}

/* Info Section */
.info-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.info-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.2s ease;
}

.info-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.info-number {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 0.75rem;
    font-style: normal;
    opacity: 1;
    position: static;
}

.info-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-style: normal;
    color: var(--color-text);
}

.info-card p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Alerts */
.alert {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 1rem 1.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    animation: slideIn 0.3s ease-out;
}

.alert-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.alert-error {
    border-color: #dc3545;
    background: #f8d7da;
    color: #721c24;
}

.alert-error .alert-icon {
    color: #dc3545;
}

.alert-success {
    border-color: var(--color-success);
    background: #d1e7dd;
    color: #0f5132;
}

.alert-success .alert-icon {
    color: var(--color-success);
}

/* Footer */
.footer {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

.footer-line {
    display: none;
}

.footer p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    text-transform: none;
    letter-spacing: normal;
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 2rem 1rem;
    }

    .header {
        margin-bottom: 2rem;
    }

    .title {
        font-size: 1.75rem;
    }

    .upload-area {
        padding: 2rem 1.5rem;
    }

    .info-section {
        gap: 1rem;
    }

    .info-card {
        padding: 1.25rem;
    }
}