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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 900px;
    width: 100%;
}

.header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
}

.header h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.header h1 i {
    color: #ffd700;
    margin-right: 10px;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 70px rgba(0, 0, 0, 0.35);
}

.card-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.card-icon i {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.card h2 {
    font-size: 1.8rem;
    color: #333;
    margin-bottom: 10px;
}

.card p {
    color: #666;
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 40px 20px;
    margin-bottom: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f8f9ff;
}

.upload-area:hover {
    border-color: #764ba2;
    background: #f0f2ff;
}

.upload-area.dragover {
    border-color: #764ba2;
    background: #e8ebff;
    transform: scale(1.02);
}

.upload-placeholder {
    color: #667eea;
}

.upload-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 15px;
}

.upload-icon i {
    color: #667eea;
}

.file-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    color: white;
}

.file-name {
    font-weight: 600;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 200px;
}

.file-size {
    font-size: 0.9rem;
    opacity: 0.9;
}

.remove-file {
    background: rgba(255, 255, 255, 0.3);
    border: none;
    color: white;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s ease;
}

.remove-file:hover {
    background: rgba(255, 255, 255, 0.5);
}

.btn {
    border: none;
    padding: 15px 40px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

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

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(17, 153, 142, 0.4);
}

.btn-icon {
    font-size: 1.3rem;
}

.btn-icon i {
    color: white;
}

.progress-bar {
    margin-top: 20px;
    background: #e0e0e0;
    border-radius: 10px;
    height: 30px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 10px;
}

.progress-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #333;
    font-weight: 600;
    font-size: 0.9rem;
}

.upload-link {
    margin-top: 20px;
    padding: 20px;
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    border-radius: 10px;
    color: white;
}

.upload-link p {
    color: white;
    margin: 5px 0;
}

.upload-link p i {
    margin-right: 8px;
    font-size: 1.2rem;
}

.link-text {
    font-size: 1.2rem;
    margin-top: 10px;
}

.code-input input {
    width: 100%;
    padding: 15px 20px;
    border: 3px solid #e0e0e0;
    border-radius: 50px;
    font-size: 1.2rem;
    text-align: center;
    letter-spacing: 2px;
    text-transform: uppercase;
    transition: border-color 0.3s ease;
    margin-bottom: 20px;
}

.code-input input:focus {
    outline: none;
    border-color: #11998e;
}

.file-list {
    margin-top: 20px;
    max-height: 300px;
    overflow-y: auto;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    background: #f8f9ff;
    border-radius: 10px;
    margin-bottom: 10px;
    transition: background 0.3s ease;
}

.file-item:hover {
    background: #f0f2ff;
}

.file-item-name {
    font-weight: 600;
    color: #333;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    margin-right: 10px;
}

.file-item-size {
    color: #666;
    font-size: 0.9rem;
    margin-right: 15px;
}

.download-btn {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: transform 0.3s ease;
}

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

.footer {
    text-align: center;
    color: white;
    margin-top: 40px;
    opacity: 0.8;
}

.footer p {
    font-size: 0.9rem;
}

.app-download {
    margin-top: 40px;
    text-align: center;
    color: white;
}

.app-download h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    font-weight: 600;
}

.app-download > p {
    font-size: 1rem;
    opacity: 0.9;
    margin-bottom: 25px;
}

.download-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.download-btn-windows,
.download-btn-android {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px 30px;
    border-radius: 15px;
    text-decoration: none;
    color: white;
    transition: all 0.3s ease;
    min-width: 200px;
    justify-content: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.download-btn-windows {
    background: linear-gradient(135deg, #0078d4 0%, #00bcf2 100%);
}

.download-btn-windows:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 120, 212, 0.4);
}

.download-btn-android {
    background: linear-gradient(135deg, #3ddc84 0%, #2a9d8f 100%);
}

.download-btn-android:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(61, 220, 132, 0.4);
}

.os-icon {
    font-size: 2.5rem;
}

.os-icon i {
    color: white;
}

.os-info {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.os-name {
    font-size: 1.1rem;
    font-weight: 700;
}

.os-version {
    font-size: 0.85rem;
    opacity: 0.9;
}

.download-arrow {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.download-arrow i {
    color: white;
}

.download-btn-windows:hover .download-arrow,
.download-btn-android:hover .download-arrow {
    transform: translateY(3px);
}

/* Extra large screens (1200px and above) */
@media (min-width: 1200px) {
    .container {
        max-width: 1100px;
    }

    .card {
        padding: 50px;
    }

    .header h1 {
        font-size: 3.5rem;
    }

    .card-icon {
        font-size: 5rem;
    }
}

/* Large screens (992px - 1199px) */
@media (max-width: 1199px) and (min-width: 992px) {
    .container {
        max-width: 950px;
    }

    .card {
        padding: 45px;
    }
}

/* Medium screens (768px - 991px) - Tablet landscape */
@media (max-width: 991px) and (min-width: 768px) {
    .container {
        max-width: 700px;
    }

    .main-content {
        grid-template-columns: 1fr;
        gap: 25px;
    }

    .card {
        padding: 35px 25px;
    }

    .header h1 {
        font-size: 2.5rem;
    }

    .card-icon {
        font-size: 3.5rem;
    }

    .upload-area {
        padding: 35px 15px;
    }
}

/* Small screens (576px - 767px) - Tablet portrait */
@media (max-width: 767px) and (min-width: 576px) {
    .container {
        max-width: 540px;
    }

    .main-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .header h1 {
        font-size: 2.2rem;
    }

    .card {
        padding: 30px 20px;
    }

    .card-icon {
        font-size: 3rem;
    }

    .card h2 {
        font-size: 1.5rem;
    }

    .upload-area {
        padding: 30px 15px;
    }

    .upload-icon {
        font-size: 2.5rem;
    }

    .btn {
        padding: 12px 30px;
        font-size: 1rem;
    }

    .file-list {
        max-height: 250px;
    }
}

/* Extra small screens (below 576px) - Mobile phones */
@media (max-width: 575px) {
    body {
        padding: 15px;
    }

    .container {
        max-width: 100%;
    }

    .main-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .header {
        margin-bottom: 30px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .card {
        padding: 25px 15px;
        border-radius: 15px;
    }

    .card-icon {
        font-size: 2.5rem;
        margin-bottom: 15px;
    }

    .card h2 {
        font-size: 1.4rem;
    }

    .card p {
        font-size: 0.95rem;
        margin-bottom: 20px;
    }

    .upload-area {
        padding: 25px 15px;
        border-width: 2px;
    }

    .upload-icon {
        font-size: 2rem;
        margin-bottom: 10px;
    }

    .upload-placeholder p {
        font-size: 0.9rem;
    }

    .file-info {
        padding: 12px;
        flex-wrap: wrap;
    }

    .file-name {
        max-width: 150px;
        font-size: 0.9rem;
    }

    .file-size {
        font-size: 0.8rem;
    }

    .remove-file {
        width: 25px;
        height: 25px;
        font-size: 0.9rem;
    }

    .btn {
        padding: 12px 25px;
        font-size: 1rem;
        border-radius: 40px;
    }

    .btn-icon {
        font-size: 1.1rem;
    }

    .progress-bar {
        height: 25px;
    }

    .progress-text {
        font-size: 0.8rem;
    }

    .upload-link {
        padding: 15px;
    }

    .link-text {
        font-size: 1rem;
    }

    .file-list {
        max-height: 200px;
        margin-top: 15px;
    }

    .file-item {
        padding: 12px;
        flex-wrap: wrap;
        gap: 10px;
    }

    .file-item-name {
        font-size: 0.9rem;
        margin-right: 5px;
        order: 1;
    }

    .file-item-size {
        font-size: 0.8rem;
        margin-right: 0;
        order: 2;
    }

    .download-btn {
        padding: 8px 15px;
        font-size: 0.9rem;
        width: 100%;
        order: 3;
        margin-top: 5px;
    }

    .footer {
        margin-top: 30px;
    }

    .footer p {
        font-size: 0.85rem;
    }

    .app-download {
        margin-top: 30px;
    }

    .app-download h3 {
        font-size: 1.3rem;
    }

    .app-download > p {
        font-size: 0.95rem;
        margin-bottom: 20px;
    }

    .download-buttons {
        gap: 15px;
    }

    .download-btn-windows,
    .download-btn-android {
        padding: 15px 25px;
        min-width: 160px;
    }

    .os-icon {
        font-size: 2rem;
    }

    .os-name {
        font-size: 1rem;
    }

    .os-version {
        font-size: 0.8rem;
    }

    .download-arrow {
        font-size: 1.3rem;
    }
}

/* Landscape mobile devices */
@media (max-height: 500px) and (orientation: landscape) {
    body {
        padding: 10px;
        align-items: flex-start;
    }

    .header {
        margin-bottom: 20px;
    }

    .header h1 {
        font-size: 1.8rem;
        margin-bottom: 5px;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    .card {
        padding: 20px 15px;
    }

    .card-icon {
        font-size: 2rem;
        margin-bottom: 10px;
    }

    .card h2 {
        font-size: 1.2rem;
        margin-bottom: 5px;
    }

    .card p {
        font-size: 0.85rem;
        margin-bottom: 15px;
    }

    .upload-area {
        padding: 20px 15px;
    }

    .upload-icon {
        font-size: 1.8rem;
        margin-bottom: 8px;
    }

    .btn {
        padding: 10px 25px;
        font-size: 0.95rem;
    }

    .file-list {
        max-height: 150px;
    }

    .app-download {
        margin-top: 15px;
    }

    .app-download h3 {
        font-size: 1.1rem;
        margin-bottom: 8px;
    }

    .app-download > p {
        font-size: 0.85rem;
        margin-bottom: 15px;
    }

    .download-buttons {
        gap: 10px;
    }

    .download-btn-windows,
    .download-btn-android {
        padding: 12px 20px;
        min-width: 140px;
    }

    .os-icon {
        font-size: 1.8rem;
    }

    .os-name {
        font-size: 0.95rem;
    }

    .os-version {
        font-size: 0.75rem;
    }

    .download-arrow {
        font-size: 1.2rem;
    }
}