/* --- CSS Variables & Theming --- */
:root {
    --primary: #0066ff;
    --primary-hover: #0052cc;
    --secondary: #00bfff;
    --bg-color: #f1f5f9;
    --sidebar-bg: #ffffff;
    --surface-color: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

body.dark-mode {
    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    --secondary: #00d4ff;
    --bg-color: #0f172a;
    --sidebar-bg: #1e293b;
    --surface-color: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    transition: background-color 0.4s ease, color 0.4s ease;
    overflow: hidden; /* Hide scrollbar on body, handle in main */
}

h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

p {
    color: var(--text-muted);
}

.text-center { text-align: center; }
.mt-3 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }

/* --- Layout (App Container) --- */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
}

/* --- Sidebar --- */
.sidebar {
    width: 220px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    z-index: 10;
    transition: var(--transition);
}

.sidebar-header {
    height: 60px;
    display: flex;
    align-items: center;
    padding: 0 1rem;
    font-size: 1rem;
    font-weight: 800;
    color: var(--primary);
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header .logo-icon {
    margin-right: 0.75rem;
}

.sidebar-nav {
    flex: 1;
    padding: 1.5rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.55rem 0.75rem;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.nav-item:hover {
    background-color: rgba(0, 102, 255, 0.05);
    color: var(--primary);
}

body.dark-mode .nav-item:hover {
    background-color: rgba(59, 130, 246, 0.1);
}

.nav-item.active {
    background-color: var(--primary);
    color: white;
    box-shadow: 0 4px 12px rgba(0, 102, 255, 0.3);
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.theme-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    background: transparent;
    border: 1px solid var(--border-color);
    padding: 0.75rem;
    border-radius: 8px;
    color: var(--text-main);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.theme-btn:hover {
    background-color: var(--bg-color);
}

body.light-mode .sun-icon { display: none; }
body.dark-mode .moon-icon { display: none; }

/* --- Main Content Area --- */
.main-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 1.5rem 1.5rem;
    position: relative;
}

.content-section {
    display: none;
    animation: fadeIn 0.4s ease forwards;
    max-width: 1200px;
    margin: 0 auto;
}

.content-section.active {
    display: block;
}

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

.content-header {
    margin-bottom: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

.content-header h1 {
    font-size: 1.6rem;
}

.content-header h2 {
    font-size: 1.5rem;
}

.subtitle {
    font-size: 0.95rem;
    max-width: 800px;
}

.highlight {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* --- Content Layouts --- */
.split-layout {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.text-block {
    flex: 1;
}

.text-block p {
    font-size: 1rem;
    margin-bottom: 1.2rem;
}

.image-block {
    flex: 1;
    display: flex;
    justify-content: center;
}

.mockup-img {
    max-width: 100%;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
    border: 1px solid var(--border-color);
}

body.dark-mode .mockup-img {
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}

.error-img { border-color: #ef4444; }
.success-img { border-color: #22c55e; }

/* --- Specific Elements --- */
.highlight-box {
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.1), rgba(0, 191, 255, 0.1));
    border-left: 4px solid var(--primary);
    padding: 1.5rem;
    border-radius: 0 8px 8px 0;
    margin: 2rem 0;
    color: var(--text-main);
    font-weight: 500;
}

.success-box {
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.1), rgba(20, 184, 166, 0.1));
    border-left-color: #22c55e;
}

.bad-list, .check-list {
    list-style: none;
    margin: 2rem 0;
}

.bad-list li, .check-list li {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.bad-list i { color: #ef4444; }
.check-list i { color: #22c55e; }

.impact-box {
    background-color: var(--surface-color);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid #ef4444;
    margin: 2rem 0;
}

.impact-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.impact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: #ef4444;
    font-weight: 500;
}

/* --- Features Grid --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--primary);
    transform: translateY(-5px);
}

.icon-wrapper {
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.1), rgba(0, 191, 255, 0.1));
    color: var(--primary);
    width: 50px;
    height: 50px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

/* --- Benefits List --- */
.benefits-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.benefit-row {
    display: flex;
    gap: 1.5rem;
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    align-items: center;
}

.benefit-number {
    background-color: var(--primary);
    color: white;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.5rem;
    flex-shrink: 0;
}

/* --- Tags --- */
.target-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
}

.tag {
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.1), rgba(0, 191, 255, 0.1));
    color: var(--primary);
    border: 1px solid rgba(0, 102, 255, 0.2);
    padding: 0.75rem 2rem;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1.2rem;
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    outline: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
    box-shadow: 0 4px 14px rgba(0, 102, 255, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 102, 255, 0.4);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-main);
    border: 2px solid var(--border-color);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

.cta-box {
    background: var(--surface-color);
    padding: 3rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    display: inline-block;
}

/* --- Responsive --- */
@media (max-width: 992px) {
    .split-layout {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
    }
    
    .sidebar-header {
        height: 60px;
    }
    
    .sidebar-nav {
        flex-direction: row;
        overflow-x: auto;
        padding: 1rem;
        white-space: nowrap;
    }
    
    .sidebar-footer {
        display: none; /* Hide toggle on mobile header for simplicity */
    }
    
    .main-content {
        padding: 2rem 1.5rem;
    }
    
}

/* --- Mockup UI --- */
.mockup-ui {
    background-color: #f8fafc;
    border-radius: 16px;
    padding: 0.85rem;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border: 1px solid var(--border-color);
    width: 100%;
    max-width: 360px;
    color: #0f172a;
    font-family: 'Inter', sans-serif;
    transform: none;
    transition: box-shadow 0.5s ease;
    overflow: hidden;
}

.mockup-ui:hover {
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
}

body.dark-mode .mockup-ui {
    background-color: #0f172a;
    border-color: #334155;
    color: #f8fafc;
}

.mockup-header {
    margin-bottom: 1.5rem;
}

.mockup-header h3 {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
    color: #1e293b;
}

body.dark-mode .mockup-header h3 { color: #f8fafc; }

.mockup-header p {
    font-size: 0.9rem;
    color: #64748b;
    margin-bottom: 0;
}

.mockup-stats {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.mockup-stat-card {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 0.6rem;
    flex: 1;
    min-width: 80px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

body.dark-mode .mockup-stat-card {
    background: #1e293b;
    border-color: #334155;
}

.stat-icon {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: #64748b;
    font-weight: 600;
    margin-bottom: 0.5rem;
    white-space: nowrap;
}

.stat-icon i {
    width: 14px;
    height: 14px;
}

.stat-value {
    font-size: 1.1rem;
    font-weight: 800;
    color: #0f172a;
    display: flex;
    align-items: baseline;
    gap: 0.25rem;
    line-height: 1.2;
}

body.dark-mode .stat-value { color: #f8fafc; }

.stat-sub {
    font-size: 0.75rem;
    font-weight: 500;
    color: #94a3b8;
}

.text-green { color: #10b981 !important; }
.badge-green { background: #d1fae5; color: #059669; padding: 2px 6px; border-radius: 4px; font-size: 0.7rem; }
body.dark-mode .badge-green { background: rgba(16, 185, 129, 0.2); color: #34d399; }

.mockup-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.6rem;
}

.mockup-btn {
    background: #ffffff;
    border: none;
    border-radius: 1rem;
    padding: 0.6rem 0.3rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 0.65rem;
    font-weight: 600;
    color: #0f172a;
    box-shadow: 0 8px 25px rgba(0,0,0,0.06);
    transition: transform 0.2s, box-shadow 0.2s;
    text-align: center;
    aspect-ratio: 1/1;
}

body.dark-mode .mockup-btn {
    background: #1e293b;
    color: #f8fafc;
}

.mockup-btn:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.btn-icon-wrapper {
    background: transparent;
    padding: 0;
}

.btn-icon-wrapper svg {
    width: 32px;
    height: 32px;
}

body.dark-mode .btn-icon-wrapper {
    background: transparent;
}

@media (max-width: 600px) {
    .mockup-grid { grid-template-columns: repeat(3, 1fr); }
    .mockup-stats { flex-wrap: wrap; }
}

/* --- Forms (Contact & Registration) --- */
.form-container {
    background: var(--surface-color);
    padding: 2.5rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-main);
    font-size: 0.95rem;
}

.form-control {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

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