/* ===================================
   CSS Reset and Base Styles
   =================================== */

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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #14b8a6;
    --dark-bg: #0f172a;
    --dark-secondary: #1e293b;
    --dark-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    min-height: 100vh;
}

/* ===================================
   Navigation Bar
   =================================== */

.navbar {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h2 {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1.5rem;
    font-weight: 700;
}

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

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--text-primary);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 3px;
    transition: var(--transition);
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===================================
   Main Content
   =================================== */

.main-content {
    padding: 3rem 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===================================
   Sections
   =================================== */

.intro-section,
.calculator-section,
.article-section,
.faq-section,
.features-section,
.similar-tools {
    margin-bottom: 4rem;
}

.intro-section h2,
.calculator-section h1,
.article-section h2,
.faq-section h2,
.features-section h2,
.similar-tools h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.intro-section p {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1.1rem;
}

/* ===================================
   Tools Grid
   =================================== */

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tool-card {
    background: rgba(30, 41, 59, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.3);
    border-color: var(--primary-color);
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.tool-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* ===================================
   Buttons
   =================================== */

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.4);
}

.btn-primary {
    width: 100%;
    margin-top: 1rem;
}

/* ===================================
   Features Section
   =================================== */

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-item {
    text-align: center;
    padding: 1.5rem;
}

.feature-icon {
    font-size: 2rem;
    color: var(--success-color);
    margin-bottom: 1rem;
}

.feature-item h4 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature-item p {
    color: var(--text-secondary);
}

/* ===================================
   Calculator Card
   =================================== */

.calculator-card {
    background: rgba(30, 41, 59, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    margin-top: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

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

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.input-field {
    width: 100%;
    padding: 0.75rem 1rem;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.radio-group {
    display: flex;
    gap: 2rem;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.radio-group input[type="radio"] {
    cursor: pointer;
}

/* ===================================
   Result Area
   =================================== */

.result-area {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: var(--border-radius);
    display: none;
}

.result-area.show {
    display: block;
    animation: fadeIn 0.5s ease;
}

.result-area h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.result-area p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.result-item {
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

/* ===================================
   Article Section
   =================================== */

.content-article {
    color: var(--text-secondary);
    line-height: 1.8;
}

.content-article h2 {
    color: var(--text-primary);
    font-size: 2rem;
    margin-bottom: 1.5rem;
    margin-top: 2rem;
}

.content-article h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    margin-top: 2rem;
}

.content-article p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

/* ===================================
   FAQ Section
   =================================== */

.faq-container {
    margin-top: 2rem;
}

.faq-item {
    background: rgba(30, 41, 59, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1rem;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 5px 15px rgba(99, 102, 241, 0.2);
}

.faq-question {
    color: var(--text-primary);
    font-size: 1.2rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ===================================
   Similar Tools Section
   =================================== */

.tools-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 1.5rem;
}

.tool-link {
    padding: 0.75rem 1.5rem;
    background: rgba(30, 41, 59, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    font-weight: 500;
}

.tool-link:hover {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--primary-color);
    color: var(--text-primary);
    transform: translateY(-2px);
}

/* ===================================
   Footer
   =================================== */

.footer {
    background: rgba(15, 23, 42, 0.95);
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 4rem;
}

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

/* ===================================
   Animations
   =================================== */

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

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(15, 23, 42, 0.98);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.5);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

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

    .calculator-card {
        padding: 1.5rem;
    }

    .radio-group {
        flex-direction: column;
        gap: 1rem;
    }

    .tools-links {
        flex-direction: column;
    }

    .tool-link {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 2rem 1rem;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .calculator-card {
        padding: 1rem;
    }
}