:root {
    --bg-color: #f5f5f7;
    --card-bg: #ffffff;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --accent-color: #0071e3;
    --accent-hover: #0077ed;
    --whatsapp-color: #25D366;
    --whatsapp-hover: #1EBE55;
    --border-color: rgba(0, 0, 0, 0.08);
    --border-radius: 20px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.05), 0 1px 3px rgba(0, 0, 0, 0.03);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    --nav-height: 60px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #000000;
        --card-bg: #1c1c1e;
        --text-primary: #f5f5f7;
        --text-secondary: #86868b;
        --accent-color: #0a84ff;
        --accent-hover: #007aff;
        --border-color: rgba(255, 255, 255, 0.1);
        --shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    }
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* NAVBAR */
.navbar {
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

@media (prefers-color-scheme: dark) {
    .navbar { background: rgba(28, 28, 30, 0.8); }
}

.nav-content {
    max-width: 1000px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 18px;
    color: var(--text-primary);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 16px;
}

.user-badge {
    background-color: rgba(0,0,0,0.05);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

@media (prefers-color-scheme: dark) {
    .user-badge { background-color: rgba(255,255,255,0.1); }
}

.btn-text {
    background: none;
    border: none;
    color: var(--accent-color);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    transition: var(--transition);
    text-decoration: none;
}

.btn-text:hover {
    color: var(--accent-hover);
    opacity: 0.8;
}

/* MAIN CONTENT */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
}

.app-container {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 40px;
    width: 100%;
    max-width: 480px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.app-header {
    text-align: center;
    margin-bottom: 30px;
}

.app-header h1 {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.app-header p {
    color: var(--text-secondary);
    font-size: 15px;
}

.upload-box {
    border: 2px dashed var(--border-color);
    border-radius: 16px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background-color: rgba(0,0,0,0.01);
}

@media (prefers-color-scheme: dark) {
    .upload-box { background-color: rgba(255,255,255,0.02); }
}

.upload-box:hover, .upload-box.dragover {
    border-color: var(--accent-color);
    background-color: rgba(0, 113, 227, 0.05);
}

@media (prefers-color-scheme: dark) {
    .upload-box:hover, .upload-box.dragover { background-color: rgba(10, 132, 255, 0.1); }
}

.upload-icon {
    color: var(--text-secondary);
    margin-bottom: 16px;
    transition: var(--transition);
}

.upload-box:hover .upload-icon, .upload-box.dragover .upload-icon {
    color: var(--accent-color);
}

.upload-text {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.highlight {
    color: var(--accent-color);
    font-weight: 500;
}

.progress-container {
    margin-top: 24px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 13px;
    color: var(--text-secondary);
}

.progress-bar-bg {
    height: 6px;
    background-color: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background-color: var(--accent-color);
    width: 0%;
    border-radius: 3px;
    transition: width 0.1s linear;
}

.result-container {
    margin-top: 24px;
    text-align: center;
    animation: fadeIn 0.4s ease-out;
}

.success-msg {
    color: var(--whatsapp-color);
    font-weight: 500;
    margin-bottom: 16px;
}

.link-box {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.link-box input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-size: 14px;
    font-family: 'Inter', sans-serif;
    outline: none;
    transition: var(--transition);
}

.link-box input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 113, 227, 0.2);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 20px;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-decoration: none;
    gap: 8px;
    font-family: inherit;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--bg-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.btn-whatsapp {
    background-color: var(--whatsapp-color);
    color: white;
    flex: 1;
}

.btn-whatsapp:hover {
    background-color: var(--whatsapp-hover);
    transform: translateY(-1px);
}

.share-box {
    display: flex;
    gap: 12px;
}

/* GALERIA */
.gallery-container {
    width: 100%;
    max-width: 800px;
    margin-top: 50px;
}

.gallery-container h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 4px;
}

.gallery-subtitle {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 24px;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 20px;
}

.gallery-item {
    background-color: var(--card-bg);
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    aspect-ratio: 1;
    display: block;
}

.gallery-item:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 12px 30px rgba(0,0,0,0.1);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.gallery-item .file-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0,0,0,0.6);
    color: white;
    font-size: 12px;
    padding: 10px;
    text-align: center;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* MODAL DE LOGIN */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-box {
    background-color: var(--card-bg);
    border-radius: 24px;
    padding: 40px;
    width: 90%;
    max-width: 400px;
    position: relative;
    transform: scale(0.95);
    transition: var(--transition);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.modal-overlay.active .modal-box {
    transform: scale(1);
}

.close-modal {
    position: absolute;
    top: 16px;
    right: 16px;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--text-secondary);
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.close-modal:hover {
    background-color: var(--border-color);
}

.modal-header {
    text-align: center;
    margin-bottom: 24px;
}

.modal-header h2 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 8px;
}

.modal-header p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.5;
}

.phone-input {
    width: 100%;
    padding: 16px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-size: 18px;
    font-family: 'Inter', sans-serif;
    outline: none;
    transition: var(--transition);
    margin-bottom: 16px;
    text-align: center;
}

.phone-input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(0, 113, 227, 0.2);
}

.login-btn {
    width: 100%;
    font-size: 16px;
    padding: 16px;
}

.error-msg {
    color: #ff3b30;
    margin-top: 12px;
    font-size: 14px;
    text-align: center;
}

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

@media (max-width: 480px) {
    .app-container {
        padding: 24px;
        border-radius: 24px;
    }
    .share-box {
        flex-direction: column;
    }
    .modal-box {
        padding: 30px 20px;
    }
}