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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8fafc;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1e293b;
    text-decoration: none;
}

    .logo span {
        color: #3b82f6;
    }

.nav-list {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-link {
    color: #64748b;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

    .nav-link:hover,
    .nav-link.active {
        color: #3b82f6;
    }

.language-switcher {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.lang-link {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    background: #f1f5f9;
    color: #1e293b;
    text-decoration: none;
    font-weight: 500;
}

.lang-current {
    padding: 0.25rem 0.5rem;
    color: #3b82f6;
    font-weight: 700;
}

/* Hero */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    max-width: 600px;
    margin: 0 auto;
}

/* Sections */
.section-title {
    font-size: 2rem;
    color: #1e293b;
    margin-bottom: 2rem;
    text-align: center;
}

/* Cards grid */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    padding: 2rem 0;
}

.topic-card {
    background: white;
    border-radius: 8px;
    padding: 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

    .topic-card:hover {
        transform: translateY(-2px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.15);
    }

.topic-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.topic-title {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.topic-desc {
    color: #64748b;
    margin-bottom: 1.5rem;
}

.topic-link {
    color: #3b82f6;
    text-decoration: none;
    font-weight: 500;
}

/* Page header */
.page-header {
    padding: 3rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    max-width: 600px;
    margin: 0 auto;
}

/* Content */
.content-page {
    padding: 4rem 0;
    max-width: 800px;
    margin: 0 auto;
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

    .content-grid h2 {
        font-size: 2rem;
        margin-bottom: 1.5rem;
        color: #1e293b;
    }

    .content-grid ul {
        margin: 1.5rem 0;
        padding-left: 1.5rem;
    }

    .content-grid li {
        margin-bottom: 0.5rem;
        color: #475569;
    }

/* Dashboard preview */
.dashboard-preview {
    background: #f1f5f9;
    padding: 2rem;
    border-radius: 8px;
}

.mockup-dashboard {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.mockup-header {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.mockup-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.stat-item {
    background: #f1f5f9;
    padding: 1rem;
    border-radius: 6px;
    text-align: center;
}

    .stat-item span {
        display: block;
        color: #64748b;
        font-size: 0.9rem;
        margin-bottom: 0.5rem;
    }

    .stat-item strong {
        font-size: 1.5rem;
        color: #1e293b;
    }

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

    .form-group label {
        display: block;
        margin-bottom: 0.5rem;
        font-weight: 600;
        color: #1e293b;
    }

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 1rem;
}

    .form-control:focus {
        outline: none;
        border-color: #3b82f6;
        box-shadow: 0 0 0 3px rgba(59,130,246,0.1);
    }

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: background 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #3b82f6;
    color: white;
}

    .btn-primary:hover {
        background: #2563eb;
    }

/* Result card */
.result-card {
    background: #f1f5f9;
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 2rem;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid #e2e8f0;
}

    .result-item:last-child {
        border-bottom: none;
    }

    .result-item strong {
        color: #1e293b;
    }

/* Tasks */
.task-meta-header {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

    .task-meta-header span {
        background: rgba(255,255,255,0.2);
        padding: 0.5rem 1rem;
        border-radius: 20px;
    }

.task-page {
    padding: 2rem 0;
}

.task-description h2,
.task-form h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.task-description h3 {
    font-size: 1.3rem;
    margin: 1.5rem 0 1rem;
    color: #1e293b;
}

/* Footer */
footer {
    background: #1e293b;
    color: white;
    padding: 3rem 0;
    margin-top: 4rem;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-links a {
    color: #94a3b8;
    text-decoration: none;
    margin-left: 2rem;
    transition: color 0.2s;
}

    .footer-links a:hover {
        color: white;
    }

/* Responsive */
@media (max-width: 768px) {
    .nav-list {
        gap: 1rem;
    }

    .header-inner {
        flex-direction: column;
        gap: 1rem;
    }

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

    .footer-inner {
        flex-direction: column;
        text-align: center;
    }

    .footer-links a {
        margin: 0 1rem;
    }
}