/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Google Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #3c4043;
    background: linear-gradient(135deg, #0068ff 0%, #00d4ff 100%);
    min-height: 100vh;
}

/* Zalo Group Container */
.zalo-group-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: linear-gradient(135deg, #0068ff 0%, #00d4ff 100%);
}

/* Header with Zalo Logo */
.zalo-header {
    padding: 24px 0 0 24px;
}

.zalo-logo {
    display: flex;
    align-items: center;
}

.zalo-logo-img {
    height: 40px;
    width: auto;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
    transition: transform 0.2s ease;
}

.zalo-logo-img:hover {
    transform: scale(1.05);
}

/* Main Group Invitation Content */
.group-invitation-main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 24px;
}

.group-invitation-content {
    max-width: 1200px;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

/* Left Side - Form Section */
.group-invitation-section {
    max-width: 500px;
    background: rgba(255, 255, 255, 0.95);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.group-invitation-title {
    font-size: 32px;
    font-weight: 600;
    color: #0068ff;
    margin-bottom: 16px;
    line-height: 1.2;
}

.group-invitation-description {
    font-size: 16px;
    color: #5f6368;
    margin-bottom: 32px;
    line-height: 1.6;
}

.learn-more-link {
    color: #0068ff;
    text-decoration: none;
    font-weight: 500;
}

.learn-more-link:hover {
    text-decoration: underline;
}

/* Group Information Section */
.group-info-section {
    margin-bottom: 32px;
}

.group-info-item {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
    padding: 16px;
    background: rgba(0, 104, 255, 0.05);
    border-radius: 12px;
    border-left: 4px solid #0068ff;
}

.info-icon {
    font-size: 24px;
    margin-right: 16px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 104, 255, 0.1);
    border-radius: 50%;
}

.info-content h3 {
    font-size: 16px;
    font-weight: 600;
    color: #0068ff;
    margin-bottom: 4px;
}

.info-content p {
    font-size: 14px;
    color: #5f6368;
    line-height: 1.4;
}

/* Message Input */
.message-section {
    margin-bottom: 32px;
}

.message-input {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid #e1e5e9;
    border-radius: 12px;
    font-size: 16px;
    font-family: inherit;
    color: #3c4043;
    background-color: #ffffff;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.message-input:focus {
    outline: none;
    border-color: #0068ff;
    box-shadow: 0 0 0 3px rgba(0, 104, 255, 0.1);
}

.message-input::placeholder {
    color: #9aa0a6;
}

/* Join Group Button */
.join-group-btn {
    width: 100%;
    padding: 16px 24px;
    background: linear-gradient(135deg, #0068ff, #00d4ff);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 104, 255, 0.3);
}

.join-group-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 104, 255, 0.4);
}

.join-group-btn:active {
    transform: translateY(0);
}

/* Right Side - Illustration */
.group-illustration {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.illustration-container {
    position: relative;
    width: 400px;
    height: 400px;
}

/* Abstract Shapes */
.abstract-shape {
    position: absolute;
    border-radius: 50%;
}

.blue-circle {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.2);
    top: 20px;
    left: 20px;
    animation: float 3s ease-in-out infinite;
}

.green-diamond {
    width: 60px;
    height: 60px;
    background: rgba(0, 212, 255, 0.3);
    border-radius: 20%;
    transform: rotate(45deg);
    top: 40px;
    right: 60px;
    animation: float 3s ease-in-out infinite 1s;
}

.orange-heart {
    width: 50px;
    height: 50px;
    background: rgba(255, 165, 0, 0.3);
    border-radius: 50% 50% 50% 0;
    transform: rotate(-45deg);
    bottom: 60px;
    right: 40px;
    animation: float 3s ease-in-out infinite 2s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

/* Main Illustration */
.main-illustration {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 280px;
    height: 280px;
}

.group-chat {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 240px;
    height: 160px;
}

.chat-bubble {
    position: absolute;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 20px;
    padding: 12px 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.bubble-1 {
    top: 0;
    left: 0;
    animation: slideInLeft 0.8s ease-out;
}

.bubble-2 {
    top: 50px;
    right: 0;
    animation: slideInRight 0.8s ease-out 0.3s both;
}

.bubble-3 {
    top: 100px;
    left: 20px;
    animation: slideInLeft 0.8s ease-out 0.6s both;
}

.bubble-content {
    font-size: 14px;
    color: #0068ff;
    font-weight: 500;
}

.group-avatar {
    position: absolute;
    bottom: 20px;
    right: 20px;
    width: 100px;
    height: 100px;
}

.avatar-circle {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #0068ff, #00d4ff);
    border-radius: 50%;
    position: relative;
    box-shadow: 0 8px 20px rgba(0, 104, 255, 0.3);
    animation: pulse 2s ease-in-out infinite;
}

.avatar-inner {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 40px;
    height: 40px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.avatar-inner::before {
    content: '👥';
}

.avatar-indicators {
    position: absolute;
    top: -10px;
    right: -10px;
}

.indicator {
    width: 12px;
    height: 12px;
    background: #4caf50;
    border-radius: 50%;
    margin-bottom: 4px;
    animation: blink 1.5s ease-in-out infinite;
}

.indicator:nth-child(2) {
    animation-delay: 0.5s;
}

.indicator:nth-child(3) {
    animation-delay: 1s;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes blink {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.3;
    }
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 104, 255, 0.9);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.loading-overlay.show {
    display: flex;
}

.loading-spinner {
    text-align: center;
    color: white;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-spinner p {
    color: white;
    font-size: 14px;
    font-weight: 500;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .group-invitation-content {
        gap: 60px;
    }
    
    .illustration-container {
        width: 350px;
        height: 350px;
    }
}

@media (max-width: 768px) {
    .group-invitation-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .group-invitation-section {
        max-width: 100%;
        padding: 30px 20px;
    }
    
    .group-invitation-title {
        font-size: 28px;
    }
    
    .illustration-container {
        width: 300px;
        height: 300px;
    }
    
    .main-illustration {
        width: 220px;
        height: 220px;
    }
    
    .group-chat {
        width: 180px;
        height: 120px;
    }
    
    .avatar-circle {
        width: 60px;
        height: 60px;
    }
    
    .avatar-inner {
        width: 30px;
        height: 30px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .group-invitation-main {
        padding: 20px 16px;
    }
    
    .zalo-header {
        padding: 16px 0 0 16px;
    }
    
    .zalo-logo-img {
        height: 32px;
    }
    
    .group-invitation-section {
        padding: 24px 16px;
    }
    
    .group-invitation-title {
        font-size: 24px;
    }
    
    .group-invitation-description {
        font-size: 14px;
    }
    
    .message-input {
        font-size: 14px;
        padding: 12px 16px;
    }
    
    .join-group-btn {
        font-size: 14px;
        padding: 12px 20px;
    }
    
    .illustration-container {
        width: 250px;
        height: 250px;
    }
    
    .main-illustration {
        width: 180px;
        height: 180px;
    }
    
    .group-chat {
        width: 140px;
        height: 100px;
    }
    
    .bubble-content {
        font-size: 12px;
    }
    
    .avatar-circle {
        width: 50px;
        height: 50px;
    }
    
    .avatar-inner {
        width: 25px;
        height: 25px;
        font-size: 14px;
    }
}