:root {
    --wa-green: #25D366;
    --wa-green-dark: #128c7e;
    --wa-dark: #111b21;
    --wa-light: #e9edef;
    --wa-text-primary: #111b21;
    --wa-text-secondary: #8696a0;
    --wa-text-muted: #54656f;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--wa-dark);
    min-height: 100vh;
    padding: 20px;
    color: var(--wa-text-primary);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background: var(--wa-light);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    padding: 40px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 3px solid var(--wa-green);
}

.header-actions {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

header h1 {
    font-size: 2.5em;
    color: var(--wa-green);
    font-weight: 700;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.1s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background-color: var(--wa-green);
    color: var(--wa-dark);
    box-shadow: 0 8px 0 var(--wa-green-dark), 0 12px 20px rgba(37, 211, 102, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 0 var(--wa-green-dark), 0 15px 25px rgba(37, 211, 102, 0.4);
}

.btn-primary:active {
    transform: translateY(6px);
    box-shadow: 0 2px 0 var(--wa-green-dark);
}

.btn-secondary {
    background-color: var(--wa-green);
    color: var(--wa-dark);
    box-shadow: 0 8px 0 var(--wa-green-dark), 0 12px 20px rgba(37, 211, 102, 0.3);
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 0 var(--wa-green-dark), 0 15px 25px rgba(37, 211, 102, 0.4);
}

.btn-secondary:active {
    transform: translateY(6px);
    box-shadow: 0 2px 0 var(--wa-green-dark);
}

.upload-section {
    margin-bottom: 30px;
}

.upload-container {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.upload-area {
    border: 3px dashed var(--wa-green);
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: var(--wa-light);
}

.upload-area:hover {
    border-color: var(--wa-green-dark);
    background: rgba(37, 211, 102, 0.05);
}

.upload-area.dragover {
    border-color: #764ba2;
    background: #e9ecef;
    transform: scale(1.02);
}

.upload-content {
    pointer-events: none;
}

.upload-icon {
    font-size: 4em;
    margin-bottom: 20px;
}

.upload-text {
    font-size: 1.2em;
    color: var(--wa-green);
    font-weight: 600;
    margin-bottom: 10px;
}

.upload-subtext {
    color: #666;
    margin: 10px 0;
}

.upload-info {
    color: #999;
    font-size: 0.9em;
    margin-top: 15px;
}

.upload-status {
    margin-top: 20px;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
}

.upload-status.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.upload-status.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.upload-status.loading {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.filter-section {
    margin-bottom: 30px;
}

.filters-container {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.filter-group {
    margin-bottom: 20px;
}

.filter-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--wa-green);
}

.filter-select {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
    background: white;
    min-height: 100px;
}

.filter-select:focus {
    outline: none;
    border-color: var(--wa-green);
}

.filter-input {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
}

.filter-input:focus {
    outline: none;
    border-color: var(--wa-green);
}

.filter-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.stat-card {
    background: linear-gradient(135deg, var(--wa-green) 0%, var(--wa-green-dark) 100%);
    color: var(--wa-dark);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(37, 211, 102, 0.3);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-value {
    font-size: 2.5em;
    font-weight: 700;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 1em;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section {
    margin-bottom: 50px;
}

.section h2 {
    font-size: 1.8em;
    color: var(--wa-green);
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid rgba(37, 211, 102, 0.3);
}

.wordcloud-container {
    text-align: center;
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.wordcloud-image {
    max-width: 60%;
    height: auto;
    border-radius: 10px;
}

.chart-container {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.chart-container h3 {
    font-size: 1.2em;
    color: var(--wa-green);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(37, 211, 102, 0.3);
}

.time-charts-grid,
.sentiment-charts-grid,
.additional-charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.word-counts {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 15px;
}

.word-count-item {
    background: linear-gradient(135deg, var(--wa-green) 0%, var(--wa-green-dark) 100%);
    color: var(--wa-dark);
    padding: 20px;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 5px 15px rgba(37, 211, 102, 0.3);
}

.word-count-item .word {
    font-weight: 600;
    font-size: 1.1em;
}

.word-count-item .count {
    font-size: 1.5em;
    font-weight: 700;
}

.words-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 15px;
    max-height: 600px;
    overflow-y: auto;
    padding: 10px;
}

.word-item {
    background: var(--wa-light);
    padding: 15px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 15px;
    border-left: 4px solid var(--wa-green);
    transition: all 0.3s ease;
}

.word-item:hover {
    background: #e9ecef;
    transform: translateX(5px);
}

.word-rank {
    background: var(--wa-green);
    color: var(--wa-dark);
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9em;
}

.word-text {
    flex: 1;
    font-weight: 600;
    font-size: 1.1em;
    color: #333;
}

.word-frequency {
    background: var(--wa-green-dark);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9em;
}

.error-message {
    text-align: center;
    padding: 60px 20px;
}

.error-message p {
    font-size: 1.2em;
    color: #d32f2f;
    margin-bottom: 30px;
    padding: 20px;
    background: #ffebee;
    border-radius: 10px;
    border-left: 4px solid #d32f2f;
}

/* Scrollbar styling */
.words-list::-webkit-scrollbar {
    width: 8px;
}

.words-list::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

.words-list::-webkit-scrollbar-thumb {
    background: var(--wa-green);
    border-radius: 10px;
}

.words-list::-webkit-scrollbar-thumb:hover {
    background: var(--wa-green-dark);
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.loading-spinner {
    background: white;
    padding: 40px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--wa-green);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

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

.loading-spinner p {
    color: var(--wa-green);
    font-weight: 600;
    font-size: 1.1em;
}

.error-message {
    background: #ffebee;
    color: #c62828;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #c62828;
    margin: 20px 0;
}

.success-message {
    background: #e8f5e9;
    color: #2e7d32;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #2e7d32;
    margin: 20px 0;
}

/* Welcome page styles */
.welcome-page {
    margin: 0;
    padding: 0;
    min-height: 100vh;
    background: var(--wa-dark);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

.welcome-container {
    width: 100%;
    max-width: 800px;
    padding: 40px;
}

.welcome-content {
    text-align: center;
    color: white;
}

.welcome-title {
    font-size: 4em;
    font-weight: 900;
    margin-bottom: 20px;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    animation: fadeInDown 0.8s ease;
}

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

.welcome-subtitle {
    font-size: 2em;
    font-weight: 300;
    margin-bottom: 30px;
    opacity: 0.95;
    animation: fadeInDown 0.8s ease 0.2s both;
}

.welcome-description {
    font-size: 1.2em;
    line-height: 1.8;
    margin-bottom: 50px;
    opacity: 0.9;
    animation: fadeInDown 0.8s ease 0.4s both;
}

.upload-section-welcome {
    animation: fadeInUp 0.8s ease 0.6s both;
}

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

.upload-area-welcome {
    border: 3px dashed rgba(255, 255, 255, 0.5);
    border-radius: 20px;
    padding: 60px 40px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.upload-area-welcome:hover {
    border-color: rgba(255, 255, 255, 0.8);
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.upload-area-welcome.dragover {
    border-color: rgba(255, 255, 255, 1);
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.02);
}

.upload-content-welcome {
    pointer-events: none;
}

.upload-icon-welcome {
    font-size: 5em;
    margin-bottom: 30px;
}

.upload-text-welcome {
    font-size: 1.5em;
    color: white;
    font-weight: 600;
    margin-bottom: 15px;
}

.upload-subtext-welcome {
    color: rgba(255, 255, 255, 0.8);
    margin: 15px 0;
    font-size: 1.1em;
}

.btn-welcome {
    background-color: var(--wa-green);
    color: var(--wa-dark);
    padding: 16px 40px;
    font-size: 1.2em;
    font-weight: 700;
    border-radius: 50px;
    border: none;
    cursor: pointer;
    transition: all 0.1s ease;
    pointer-events: auto;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 8px 0 var(--wa-green-dark), 0 12px 20px rgba(37, 211, 102, 0.3);
}

.btn-welcome:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 0 var(--wa-green-dark), 0 15px 25px rgba(37, 211, 102, 0.4);
}

.btn-welcome:active {
    transform: translateY(6px);
    box-shadow: 0 2px 0 var(--wa-green-dark);
}

.upload-info-welcome {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9em;
    margin-top: 20px;
}

.upload-status-welcome {
    margin-top: 30px;
    padding: 20px;
    border-radius: 15px;
    text-align: center;
    font-weight: 600;
    font-size: 1.1em;
}

.upload-status-welcome.success {
    background: rgba(212, 237, 218, 0.9);
    color: #155724;
    border: 2px solid rgba(195, 230, 203, 0.8);
}

.upload-status-welcome.error {
    background: rgba(248, 215, 218, 0.9);
    color: #721c24;
    border: 2px solid rgba(245, 198, 203, 0.8);
}

.upload-status-welcome.loading {
    background: rgba(209, 236, 241, 0.9);
    color: #0c5460;
    border: 2px solid rgba(190, 229, 235, 0.8);
}

/* Loading page styles */
.loading-page {
    margin: 0;
    padding: 0;
    min-height: 100vh;
    background: var(--wa-dark);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

.loading-container {
    width: 100%;
    max-width: 600px;
    padding: 40px;
}

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

.loading-icon {
    font-size: 5em;
    margin-bottom: 30px;
    animation: spin 3s linear infinite;
}

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

.loading-title {
    font-size: 2.5em;
    font-weight: 700;
    margin-bottom: 40px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.loading-sentence {
    font-size: 1.5em;
    margin-bottom: 50px;
    min-height: 50px;
    transition: opacity 0.3s ease;
    opacity: 1;
}

.progress-container {
    margin-top: 40px;
}

.progress-bar-wrapper {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-bar {
    height: 100%;
    background: white;
    border-radius: 10px;
    transition: width 0.1s linear;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.progress-text {
    font-size: 1.2em;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }

    header {
        flex-direction: column;
        gap: 20px;
    }

    header h1 {
        font-size: 2em;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .word-counts,
    .words-list {
        grid-template-columns: 1fr;
    }
    
    .welcome-title {
        font-size: 2.5em;
    }
    
    .welcome-subtitle {
        font-size: 1.5em;
    }
    
    .welcome-description {
        font-size: 1em;
    }
    
    .upload-area-welcome {
        padding: 40px 20px;
    }
    
    .loading-title {
        font-size: 2em;
    }
    
    .loading-sentence {
        font-size: 1.2em;
    }
}