:root {
    --bg-primary: #ffffff;
    --bg-secondary: #fafbfc;
    --bg-tertiary: #f3f4f6;
    --text-primary: #0f1419;
    --text-secondary: #536471;
    --text-tertiary: #8b98a5;
    --border-light: #eff3f4;
    --border-medium: #e1e8ed;
    --accent-blue: #1d9bf0;
    --accent-green: #00ba7c;
    --accent-red: #f4212e;
    --accent-purple: #7856ff;
    --accent-orange: #ff6a00;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.06);
}

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

body {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
}

.navbar {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-light);
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
}

.back-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.back-link:hover {
    color: var(--accent-blue);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px 60px;
}

.page-header {
    text-align: center;
    margin-bottom: 48px;
}

.page-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    font-weight: 500;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.section {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 32px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
}

.section.full-width {
    grid-column: 1 / -1;
}

.section.highlight {
    background: linear-gradient(135deg, rgba(29, 155, 240, 0.05), rgba(120, 86, 255, 0.05));
    text-align: center;
}

.highlight-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 24px;
}

.section-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    margin-bottom: 20px;
}

.section-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.section-text {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

.feature-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 15px;
    color: var(--text-secondary);
}

.feature-list li i {
    color: var(--accent-green);
    font-size: 18px;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 24px;
}

.tech-item {
    text-align: center;
    padding: 24px;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 1px solid var(--border-light);
}

.tech-item i {
    font-size: 32px;
    color: var(--accent-blue);
    margin-bottom: 12px;
}

.tech-item h3 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.tech-item p {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Form Styles */
.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border-medium);
    border-radius: 12px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 15px;
    font-family: 'Plus Jakarta Sans', sans-serif;
    transition: all 0.2s;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent-blue);
    background: var(--bg-primary);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

.form-button {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: white;
    border: none;
    border-radius: 12px;
    padding: 14px 32px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.form-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(29, 155, 240, 0.3);
}

.form-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.alert {
    padding: 16px 20px;
    border-radius: 12px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    font-weight: 600;
}

.alert-success {
    background: #e8f5e9;
    color: #2e7d32;
    border: 1px solid #81c784;
}

.alert-error {
    background: #ffebee;
    color: #c62828;
    border: 1px solid #ef9a9a;
}

.alert i {
    font-size: 18px;
}

/* List Styles */
.content-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.content-list li {
    padding-left: 28px;
    position: relative;
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.7;
}

.content-list li::before {
    content: "•";
    position: absolute;
    left: 12px;
    color: var(--accent-blue);
    font-size: 20px;
    font-weight: 700;
}

/* FAQ Styles */
.faq-item {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 16px;
    border: 1px solid var(--border-light);
}

.faq-question {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.faq-question i {
    color: var(--accent-blue);
    margin-top: 2px;
    flex-shrink: 0;
}

.faq-answer {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    padding-left: 28px;
}

/* Responsive */
@media (max-width: 1024px) {
    .tech-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .page-title {
        font-size: 36px;
    }

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

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

    .section {
        padding: 24px;
    }

    .back-link span {
        display: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 24px 16px;
    }

    .page-header {
        margin-bottom: 32px;
    }

    .page-title {
        font-size: 28px;
    }

    .page-subtitle {
        font-size: 16px;
    }

    .section {
        padding: 20px;
    }
}