/* ============================================
   KUBANZA EBOOK GENERATOR - Design System
   Professional & Modern UI
   ============================================ */

:root {
    /* Kubanza Brand Colors */
    --primary: #FF6B00;
    --primary-light: #FF8533;
    --primary-dark: #E55A00;
    --primary-bg: #FFF8F3;

    /* Neutral Colors */
    --bg: #FAFAFA;
    --card-bg: #FFFFFF;
    --text: #1A1A1A;
    --text-secondary: #5F6368;
    --text-muted: #9AA0A6;
    --border: #E8EAED;
    --border-light: #F1F3F4;

    /* Status Colors */
    --success: #1E8E3E;
    --success-bg: #E6F4EA;
    --warning: #F9AB00;
    --warning-bg: #FEF7E0;
    --error: #D93025;
    --error-bg: #FCE8E6;
    --info: #1A73E8;
    --info-bg: #E8F0FE;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(60,64,67,0.1);
    --shadow-md: 0 2px 6px rgba(60,64,67,0.15);
    --shadow-lg: 0 8px 24px rgba(60,64,67,0.18);
    --shadow-hover: 0 4px 12px rgba(255,107,0,0.25);

    /* Typography */
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-display: 'Google Sans', 'Inter', sans-serif;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 50px;
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.3;
    color: var(--text);
    margin-bottom: 1rem;
}

h1 { font-size: 2rem; letter-spacing: -0.02em; }
h2 { font-size: 1.5rem; letter-spacing: -0.01em; }
h3 { font-size: 1.25rem; }

p { margin-bottom: var(--space-md); }

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover { color: var(--primary-dark); }

/* Header */
header {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: 0 var(--space-xl);
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.02em;
    text-transform: uppercase;
}

.logo span {
    color: var(--text);
    font-weight: 500;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

/* Container */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: var(--space-xl);
}

.container-sm { max-width: 700px; }
.container-lg { max-width: 1400px; }

/* Page Header */
.page-header {
    margin-bottom: var(--space-xl);
}

.page-header h1 {
    margin-bottom: var(--space-xs);
}

.page-header p {
    color: var(--text-secondary);
    margin: 0;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    font-family: inherit;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

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

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

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary-bg);
}

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

.btn-success:hover {
    background: #157a32;
    color: white;
}

.btn-lg {
    padding: 0.875rem 1.75rem;
    font-size: 1rem;
}

.btn-sm {
    padding: 0.4rem 0.75rem;
    font-size: 0.8rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border-light);
}

.card-title {
    margin: 0;
    font-size: 1.125rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.stat-card {
    background: var(--card-bg);
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--space-xs);
}

/* Ebook List */
.ebook-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.ebook-item {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: all 0.2s ease;
}

.ebook-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.ebook-cover {
    width: 60px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-bg), var(--primary-light));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    overflow: hidden;
}

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

.ebook-info {
    flex: 1;
    min-width: 0;
}

.ebook-title {
    font-weight: 600;
    color: var(--text);
    margin-bottom: var(--space-xs);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.ebook-meta {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.ebook-actions {
    display: flex;
    gap: var(--space-sm);
    flex-shrink: 0;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: capitalize;
}

.badge-pending { background: var(--bg); color: var(--text-secondary); }
.badge-planning { background: var(--info-bg); color: var(--info); }
.badge-generating { background: var(--warning-bg); color: var(--warning); }
.badge-refining { background: var(--primary-bg); color: var(--primary); }
.badge-completed { background: var(--success-bg); color: var(--success); }
.badge-failed { background: var(--error-bg); color: var(--error); }

/* Chapter List */
.chapter-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.chapter-item {
    background: var(--bg);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    border-left: 3px solid var(--border);
}

.chapter-item.completed { border-left-color: var(--success); }
.chapter-item.generating { border-left-color: var(--warning); }
.chapter-item.failed { border-left-color: var(--error); }

.chapter-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--space-md);
}

.chapter-title-group {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.chapter-number {
    background: var(--primary);
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 600;
    flex-shrink: 0;
}

.chapter-title {
    font-weight: 600;
    color: var(--text);
}

.chapter-goal {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--space-sm);
    padding-left: calc(28px + var(--space-md));
}

.chapter-preview {
    margin-top: var(--space-md);
    padding: var(--space-md);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    color: var(--text-secondary);
    max-height: 150px;
    overflow: hidden;
}

.chapter-actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

/* Forms */
.form-group {
    margin-bottom: var(--space-lg);
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--space-sm);
    color: var(--text);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: var(--space-md);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    background: var(--card-bg);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(255, 107, 0, 0.1);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-hint {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
}

/* Action Box */
.action-box {
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    text-align: center;
}

.action-box h3 {
    margin-bottom: var(--space-sm);
}

.action-box p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.action-box-primary {
    background: linear-gradient(135deg, var(--primary-bg) 0%, #FFEEE0 100%);
    border: 1px solid rgba(255, 107, 0, 0.2);
}

.action-box-success {
    background: linear-gradient(135deg, var(--success-bg) 0%, #D4EDDA 100%);
    border: 1px solid rgba(30, 142, 62, 0.2);
}

.action-box-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Export Section */
.export-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.export-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--space-lg);
}

.export-btn {
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all 0.2s;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text);
}

.export-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.export-btn-pdf { border-color: #D93025; color: #D93025; }
.export-btn-pdf:hover { background: #D93025; color: white; }

.export-btn-docx { border-color: #1A73E8; color: #1A73E8; }
.export-btn-docx:hover { background: #1A73E8; color: white; }

.export-btn-md { border-color: #1E8E3E; color: #1E8E3E; }
.export-btn-md:hover { background: #1E8E3E; color: white; }

.export-btn-view { border-color: var(--primary); color: var(--primary); }
.export-btn-view:hover { background: var(--primary); color: white; }

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--space-2xl);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: var(--space-lg);
    opacity: 0.8;
}

.empty-state h3 {
    color: var(--text);
    margin-bottom: var(--space-sm);
}

.empty-state p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

/* Utility Classes */
.text-primary { color: var(--primary); }
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }
.text-success { color: var(--success); }
.text-error { color: var(--error); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

/* Main content area */
main {
    min-height: calc(100vh - 64px);
    padding-bottom: var(--space-2xl);
}

main.container {
    padding-top: var(--space-xl);
}

/* Responsive */
@media (max-width: 768px) {
    header {
        padding: 0 var(--space-md);
    }

    .container {
        padding: var(--space-md);
    }

    .ebook-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .ebook-actions {
        width: 100%;
    }

    .ebook-actions .btn {
        flex: 1;
    }

    .chapter-header {
        flex-direction: column;
    }

    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .action-box-buttons {
        flex-direction: column;
    }

    .action-box-buttons .btn {
        width: 100%;
    }

    .export-buttons {
        flex-direction: column;
    }

    .export-btn {
        width: 100%;
    }
}

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

.fade-in {
    animation: fadeIn 0.3s ease forwards;
}

/* Loading/Skeleton States */
.skeleton {
    background: linear-gradient(90deg, var(--bg) 25%, var(--border-light) 50%, var(--bg) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}