:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --accent: #3b82f6;
    --accent-light: rgba(59, 130, 246, 0.1);
}

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

body {
    background-color: var(--bg);
    color: var(--text-dark);
    font-family: 'Inter', sans-serif;
    line-height: 1.5;
    overflow-x: hidden;
}

.bg-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 400px;
    background: linear-gradient(180deg, #eff6ff 0%, #f8fafc 100%);
    z-index: -1;
}

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

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    font-weight: 800;
}

.logo-text span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-link.active, .nav-link:hover {
    color: var(--text-dark);
}

.brand-tag {
    font-weight: 700;
    color: var(--primary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-premium {
    background: var(--text-dark);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s;
}

.btn-premium:hover {
    transform: scale(1.05);
}

/* Hero */
.hero {
    text-align: center;
    padding: 4rem 0 3rem;
}

.hero h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.accent {
    color: var(--primary);
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* Upload Section */
.upload-section {
    margin-bottom: 2rem;
}

.drop-zone {
    background: var(--card-bg);
    border: 2px dashed var(--border);
    border-radius: 24px;
    padding: 4rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--primary);
    background: var(--accent-light);
}

.icon-circle {
    width: 80px;
    height: 80px;
    background: var(--accent-light);
    color: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.drop-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.drop-content p {
    color: var(--text-muted);
}

.drop-content span {
    color: var(--primary);
    font-weight: 600;
}

.file-info {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    animation: slideUp 0.3s ease-out;
}

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

.file-details {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.file-icon {
    font-size: 1.5rem;
}

.file-meta {
    display: flex;
    flex-direction: column;
}

.file-meta #fileName {
    font-weight: 600;
}

.size-tag {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.btn-remove {
    background: #fee2e2;
    color: #ef4444;
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Options */
.options-section {
    animation: fadeIn 0.5s ease-out;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.option-card {
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 20px;
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.3s;
}

.option-card:hover {
    border-color: var(--primary);
}

.option-card.active {
    border-color: var(--primary);
    background: var(--accent-light);
}

.option-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.radio-check {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-radius: 50%;
    position: relative;
}

.option-card.active .radio-check {
    border-color: var(--primary);
}

.option-card.active .radio-check::after {
    content: '';
    position: absolute;
    width: 10px;
    height: 10px;
    background: var(--primary);
    border-radius: 50%;
    top: 3px;
    left: 3px;
}

.target-size {
    font-weight: 800;
    color: var(--primary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.option-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Actions */
.action-bar {
    text-align: center;
}

.btn-primary {
    background: var(--primary);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}

/* Success Card */
.success-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 32px;
    padding: 3rem;
    text-align: center;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

.success-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.stats-row {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin: 2.5rem 0;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 800;
}

.stat-arrow {
    font-size: 1.5rem;
    color: var(--text-muted);
}

.stat-percent {
    background: var(--success);
    color: white;
    padding: 4px 12px;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9rem;
}

.success-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    padding: 1rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
}

/* Features */
.features-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 5rem;
}

.feature {
    text-align: center;
}

.f-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.feature h4 {
    margin-bottom: 0.5rem;
}

.feature p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Footer */
.footer {
    text-align: center;
    padding: 4rem 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Loader */
.loader {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@media (max-width: 640px) {
    .options-grid { grid-template-columns: 1fr; }
    .features-row { grid-template-columns: 1fr; }
    .hero h1 { font-size: 2.2rem; }
    .stats-row { flex-direction: column; gap: 1rem; }
    .stat-arrow { transform: rotate(90deg); }
}