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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #22d3ee;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #1e293b;
    --gray: #64748b;
    --light: #f1f5f9;
    --white: #ffffff;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: #f8fafc;
    min-height: 100vh;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 40px 20px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    50% { transform: translate(-50px, -50px) rotate(180deg); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 600px;
    margin: 0 auto;
}

.hero-content h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.hero-content p {
    font-size: 1.25rem;
    opacity: 0.9;
}

.container {
    max-width: 1200px;
    margin: -30px auto 0;
    padding: 0 20px 30px;
    position: relative;
    z-index: 2;
}

.settings-bar {
    background: var(--white);
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.setting-item {
    flex: 1;
    min-width: 200px;
    position: relative;
}

.setting-item label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray);
    margin-bottom: 8px;
}

.setting-item .info-text {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    z-index: 20;
    background: var(--white);
    box-shadow: var(--shadow-lg);
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.currency {
    position: absolute;
    left: 16px;
    color: var(--gray);
    font-weight: 500;
}

.input-wrapper input {
    width: 100%;
    padding: 12px 16px 12px 40px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.2s;
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.metrics-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 60px;
    position: relative;
    z-index: 1;
}

.metric-card {
    background: var(--white);
    border-radius: 16px;
    padding: 24px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.metric-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.metric-card.primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

.metric-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.metric-content h3 {
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 4px;
    opacity: 0.8;
    display: flex;
    align-items: center;
}

.metric-content {
    position: relative;
}

.metric-content .info-text {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 320px;
    max-width: 90vw;
    z-index: 1000;
    background: var(--white);
    box-shadow: var(--shadow-xl);
    border-radius: 8px;
}

@media (max-width: 768px) {
    .metric-content .info-text {
        width: calc(100vw - 40px);
    }
}

.metric-card.primary .metric-content h3 {
    opacity: 0.9;
}

.metric-content p {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.graph-section {
    background: var(--white);
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
}

.graph-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.graph-section h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark);
    margin: 0;
}

.chart-controls {
    display: flex;
    gap: 8px;
}

.chart-toggle {
    padding: 8px 16px;
    border: 2px solid var(--primary);
    background: transparent;
    color: var(--primary);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.chart-toggle.active,
.chart-toggle:hover {
    background: var(--primary);
    color: var(--white);
}

.graph-container {
    position: relative;
    height: 400px;
    width: 100%;
}

#revenue-chart {
    width: 100% !important;
    height: 100% !important;
}

.books-section {
    background: var(--white);
    border-radius: 16px;
    padding: 24px;
    box-shadow: var(--shadow);
    position: relative;
    z-index: 0;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.section-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark);
}

.btn-add {
    background: var(--primary);
    color: var(--white);
    border: none;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.btn-add:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.button-group {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.btn-secondary {
    background: var(--secondary);
    color: var(--white);
    border: none;
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.btn-secondary:hover {
    background: #06b6d4;
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-reset {
    background: var(--gray);
    color: var(--white);
    border: none;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.btn-reset:hover {
    background: var(--dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

#books-container {
    display: grid;
    gap: 24px;
}

.book-card {
    background: #f8fafc;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 20px;
    position: relative;
    transition: all 0.2s;
}

.book-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.book-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.book-number {
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: var(--white);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.125rem;
}

.book-header h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--dark);
}

.book-inputs {
    margin-bottom: 20px;
}

.input-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
}

.input-field label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray);
    margin-bottom: 6px;
}

.input-field input {
    width: 100%;
    padding: 10px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.2s;
    background: var(--white);
}

.input-field .input-wrapper input {
    padding: 10px 16px 10px 40px;
}

.input-field input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.book-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
    padding-top: 20px;
    border-top: 2px solid #e2e8f0;
}

.metric-item {
    text-align: center;
    padding: 12px;
    border-radius: 8px;
    background: var(--white);
    transition: all 0.2s;
}

.metric-item.highlight {
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
    color: var(--white);
}

.metric-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gray);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.metric-item.highlight .metric-label {
    color: rgba(255, 255, 255, 0.9);
}

.metric-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark);
}

.metric-item.highlight .metric-value {
    color: var(--white);
}

.readthrough-badge {
    position: absolute;
    top: 24px;
    left: 180px;
    background: var(--success);
    color: var(--white);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
}

.remove-book {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    color: var(--danger);
    font-size: 1.25rem;
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.remove-book:hover {
    background: rgba(239, 68, 68, 0.1);
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .container {
        margin-top: -20px;
        padding: 0 16px 40px;
    }
    
    .settings-bar {
        flex-direction: column;
        gap: 20px;
        padding: 20px;
    }
    
    .metrics-overview {
        grid-template-columns: 1fr;
        gap: 16px;
        margin-bottom: 32px;
    }
    
    .metric-card {
        padding: 20px;
        flex-direction: column;
        text-align: center;
        gap: 12px;
    }
    
    .metric-icon {
        font-size: 2rem;
    }
    
    .metric-content p {
        font-size: 1.5rem;
    }
    
    .books-section {
        padding: 20px;
    }
    
    .input-row {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .book-card {
        padding: 20px;
    }
    
    .button-group {
        flex-direction: column;
        gap: 8px;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }
}

@media (min-width: 1400px) {
    .container {
        max-width: 1400px;
    }
}

.info-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-light);
    color: var(--white);
    border: none;
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    margin-left: 6px;
    transition: all 0.2s;
}

.info-btn:hover {
    background: var(--primary);
    transform: scale(1.1);
}

.info-text {
    display: none;
    margin-top: 8px;
    padding: 12px;
    background: #f0f4f8;
    border-left: 3px solid var(--primary);
    border-radius: 4px;
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--gray);
    animation: slideDown 0.3s ease;
}

.info-text.show {
    display: block;
}

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

.input-field {
    position: relative;
}

.input-field .info-text {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    z-index: 10;
    background: var(--white);
    box-shadow: var(--shadow);
}

footer {
    text-align: center;
    padding: 40px 20px;
    background: var(--dark);
    color: var(--white);
    margin-top: 60px;
}

footer p {
    font-size: 0.875rem;
}

footer a {
    color: var(--primary-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

footer a:hover {
    color: var(--secondary);
    text-decoration: underline;
}