/* Percentage Calculator - Professional Styling */

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
    overflow: hidden;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="25" cy="25" r="2" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="2" fill="rgba(255,255,255,0.1)"/></svg>');
    animation: float 20s ease-in-out infinite;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-title .highlight {
    background: linear-gradient(45deg, #fff, #e0e0e0);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.hero-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}

.feature-item i {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.1rem;
}

.hero-cta .btn {
    font-size: 1.1rem;
    padding: 1rem 2rem;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.hero-cta .btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.calculator-preview {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 1.5rem;
    min-width: 400px;
}

.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.preview-controls {
    display: flex;
    gap: 0.5rem;
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
}

.preview-title {
    color: white;
    font-weight: 600;
}

.preview-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.preview-tab {
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.preview-tab.active {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.preview-calculation {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 1rem;
}

.calculation-input {
    color: white;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.calculation-input .result {
    color: #ffd700;
}

.calculation-formula {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

/* Tool Section */
.tool-section {
    padding: 4rem 0;
    background: #f8f9fa;
}

/* Tool Container */
.tool-container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

/* Mode Selector Tabs */
.tool-tabs {
    display: flex;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-bottom: 1px solid #dee2e6;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.mode-tab {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    font-weight: 500;
    color: #6c757d;
    min-width: 140px;
    justify-content: center;
}

.mode-tab:hover {
    background: rgba(102, 126, 234, 0.1);
    color: #667eea;
}

.mode-tab.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 2px 10px rgba(102, 126, 234, 0.3);
}

.mode-tab i {
    font-size: 1.1rem;
}

/* Tab Content */
.tab-content-container .tab-content {
    display: none;
    padding: 2rem;
    animation: fadeIn 0.3s ease-in-out;
}

.tab-content-container .tab-content.active {
    display: block;
}

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

/* Tab Headers */
.tab-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e9ecef;
}

.tab-header h3 {
    color: #333;
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0 0 0.5rem 0;
}

.tab-header p {
    color: #6c757d;
    margin: 0;
    font-size: 1rem;
}

/* Calculator Section */
.calculator-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.calculator-main {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Input Groups */
.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.input-group label {
    font-weight: 500;
    color: #333;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.input-group label i {
    color: #667eea;
    width: 16px;
}

.input-group input,
.input-group select {
    padding: 0.75rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-size: 1rem;
    background: white;
    transition: all 0.3s ease;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    transform: translateY(-1px);
}

.input-group input:hover,
.input-group select:hover {
    border-color: #adb5bd;
}

/* Result Display */
.result-section {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid #e9ecef;
    position: sticky;
    top: 2rem;
}

.result-display {
    text-align: center;
    padding: 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    color: white;
    margin-bottom: 1.5rem;
    position: relative;
    overflow: hidden;
}

.result-display::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="25" cy="25" r="2" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="2" fill="rgba(255,255,255,0.1)"/></svg>');
    animation: float 20s ease-in-out infinite;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    position: relative;
    z-index: 1;
}

.result-label {
    font-size: 1rem;
    opacity: 0.9;
    margin: 0.5rem 0 0 0;
    position: relative;
    z-index: 1;
}

.result-breakdown {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 1rem;
    margin-top: 1rem;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    color: #6c757d;
}

/* Control Buttons */
.control-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.control-buttons .btn {
    flex: 1;
    min-width: 120px;
}

/* Options Section */
.options-section {
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid #e9ecef;
    margin-top: 1.5rem;
    display: flex;
    gap: 2rem;
    align-items: center;
}

.option-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.option-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #667eea;
}

.option-item label {
    font-weight: 500;
    color: #333;
    cursor: pointer;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn:active {
    transform: scale(0.98);
}

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

.btn-primary:hover {
    background: linear-gradient(135deg, #5a6fd8 0%, #6a4190 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background: linear-gradient(135deg, #6c757d 0%, #495057 100%);
    color: white;
}

.btn-secondary:hover {
    background: linear-gradient(135deg, #5a6268 0%, #3d4246 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(108, 117, 125, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
}

.btn-success:hover {
    background: linear-gradient(135deg, #218838 0%, #1fa085 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(40, 167, 69, 0.3);
}

.btn-info {
    background: linear-gradient(135deg, #17a2b8 0%, #6610f2 100%);
    color: white;
}

.btn-info:hover {
    background: linear-gradient(135deg, #138496 0%, #520dc2 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(23, 162, 184, 0.3);
}

/* History Section */
.history-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.history-header {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 1.5rem 2rem;
    border-bottom: 1px solid #dee2e6;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-header h3 {
    margin: 0;
    color: #333;
    font-size: 1.3rem;
    font-weight: 600;
}

.history-content {
    padding: 1.5rem 2rem;
    max-height: 400px;
    overflow-y: auto;
}

.history-item {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 1px solid #e9ecef;
}

.history-item:hover {
    background: #e9ecef;
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.history-calculation {
    font-weight: 600;
    color: #333;
    margin-bottom: 0.25rem;
}

.history-result {
    color: #667eea;
    font-weight: 600;
    font-size: 1.1rem;
}

.history-timestamp {
    color: #6c757d;
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

.history-placeholder {
    text-align: center;
    padding: 2rem;
    color: #6c757d;
}

.history-placeholder i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(1deg); }
}

/* Help Section */
.help-section {
    margin-top: 3rem;
    padding: 2rem;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-radius: 16px;
    border: 1px solid #e9ecef;
}

.help-header {
    text-align: center;
    margin-bottom: 2rem;
}

.help-header h2 {
    color: #333;
    font-size: 1.8rem;
    font-weight: 600;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.help-header i {
    color: #667eea;
}

.help-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.help-item {
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
    border: 1px solid #e9ecef;
    transition: transform 0.2s ease;
}

.help-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.help-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.help-icon i {
    color: white;
    font-size: 1.5rem;
}

.help-item h3 {
    color: #333;
    font-size: 1.2rem;
    font-weight: 600;
    margin: 0 0 0.5rem 0;
}

.help-item p {
    color: #6c757d;
    line-height: 1.6;
    margin: 0;
}

/* Features Section */
.features-section {
    margin-top: 2rem;
    padding: 2rem;
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 16px;
    border: 1px solid #e9ecef;
}

.features-header {
    text-align: center;
    margin-bottom: 2rem;
}

.features-header h2 {
    color: #333;
    font-size: 1.8rem;
    font-weight: 600;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature-card {
    padding: 2rem;
    background: white;
    border-radius: 16px;
    text-align: center;
    border: 1px solid #e9ecef;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.feature-card i {
    font-size: 3rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

.feature-card h3 {
    color: #333;
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0 0 1rem 0;
}

.feature-card p {
    color: #6c757d;
    line-height: 1.6;
    margin: 0;
}

/* Features Section Styles */
.features-section {
    padding: 4rem 0;
    background: white;
}

.features-section .feature-card {
    background: #f8f9fa;
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    border: 1px solid #e9ecef;
    transition: all 0.3s ease;
    height: 100%;
}

.features-section .feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
    background: white;
}

.features-section .feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 1.5rem;
    color: white;
}

.features-section h4 {
    color: #333;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.features-section p {
    color: #6c757d;
    line-height: 1.6;
    margin: 0;
}

/* How to Use Section */
.how-to-use-section {
    padding: 4rem 0;
    background: #f8f9fa;
}

.step-list {
    list-style: none;
    padding: 0;
}

.step-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.step-number {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.step-content h4 {
    color: #333;
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0 0 0.5rem 0;
}

.step-content p {
    color: #6c757d;
    line-height: 1.6;
    margin: 0;
}

.percentage-examples {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.percentage-examples h3 {
    color: #333;
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0 0 1.5rem 0;
}

.example-item {
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 8px;
    margin-bottom: 1rem;
    border-left: 4px solid #667eea;
}

.example-answer {
    color: #667eea;
    font-weight: 600;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-features {
        grid-template-columns: 1fr;
    }
    
    .calculator-preview {
        min-width: 300px;
    }
    
    .tool-container {
        margin: 1rem;
        border-radius: 12px;
    }
    
    .tab-content-container .tab-content {
        padding: 1rem;
    }
    
    .tool-tabs {
        flex-wrap: wrap;
    }
    
    .mode-tab {
        min-width: 120px;
        padding: 0.75rem 1rem;
    }
    
    .input-group {
        margin-bottom: 1rem;
    }
    
    .control-buttons {
        flex-direction: column;
    }
    
    .options-section {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .help-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .result-value {
        font-size: 2rem;
    }
    
    .step-item {
        flex-direction: column;
        text-align: center;
    }
    
    .step-number {
        align-self: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .tab-content-container .tab-content,
    .result-section {
        padding: 1rem;
    }
    
    .result-value {
        font-size: 1.5rem;
    }
    
    .mode-tab {
        min-width: 100px;
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
    }
    
    .btn {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
    
    .calculator-preview {
        min-width: 280px;
    }
}