/* --- Variabel & Global --- */
:root {
    /* Light Mode (Default) */
    --fn-primary-color: #3f51b5;
    --fn-primary-dark: #2c387e;
    --fn-primary-light: #7986cb;
    --fn-accent-color: #03a9f4;
    --fn-accent-dark: #0288d1;
    --fn-success-color: #4caf50;
    --fn-warning-color: #ff9800;
    --fn-danger-color: #f44336;
    
    /* Light Mode Text Colors */
    --fn-text-primary: #1a1a2e;
    --fn-text-secondary: #4a4a6a;
    --fn-text-muted: #7a7a9a;
    --fn-text-inverse: #ffffff;
    
    /* Light Mode Background Colors */
    --fn-bg-primary: #f8f9fa;
    --fn-bg-secondary: #ffffff;
    --fn-bg-tertiary: #f1f3f5;
    --fn-bg-card: #ffffff;
    
    /* Light Mode Border Colors */
    --fn-border-light: #e9ecef;
    --fn-border-medium: #dee2e6;
    --fn-border-dark: #ced4da;
    
    /* Light Mode Shadow */
    --fn-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --fn-shadow-md: 0 4px 6px rgba(0, 0, 0, 0.05);
    --fn-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.08);
    
    /* Transitions */
    --fn-transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --fn-border-radius: 12px;
    --fn-border-radius-sm: 8px;
    
    /* Header Heights */
    --fn-header-height-mobile: 60px;
    --fn-header-height-desktop: 70px;
}

/* Dark Mode Variables */
body.dark-mode {
    --fn-primary-color: #5c6bc0;
    --fn-primary-dark: #3f51b5;
    --fn-primary-light: #9fa8da;
    
    /* Dark Mode Text Colors */
    --fn-text-primary: #e8e8e8;
    --fn-text-secondary: #b0b0b8;
    --fn-text-muted: #88889a;
    --fn-text-inverse: #1a1a2e;
    
    /* Dark Mode Background Colors */
    --fn-bg-primary: #121212;
    --fn-bg-secondary: #1e1e2e;
    --fn-bg-tertiary: #2a2a3a;
    --fn-bg-card: #252535;
    
    /* Dark Mode Border Colors */
    --fn-border-light: #2a2a3a;
    --fn-border-medium: #353545;
    --fn-border-dark: #454555;
    
    /* Dark Mode Shadow */
    --fn-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --fn-shadow-md: 0 4px 6px rgba(0, 0, 0, 0.2);
    --fn-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.25);
}

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

body {
    font-family: 'Plus Jakarta Sans', sans-serif;
    background-color: var(--fn-bg-primary);
    color: var(--fn-text-primary);
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
    line-height: 1.5;
    font-size: 16px;
}

/* Typography - SEO Standards */
h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--fn-text-primary);
}

h2 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 0.875rem;
    color: var(--fn-text-primary);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 0.75rem;
    color: var(--fn-text-primary);
}

p {
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 1rem;
    color: var(--fn-text-secondary);
}

small, .fn-text-small {
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--fn-text-muted);
}

/* --- Hero & Grid Home --- */
.fn-hero-section {
    text-align: center;
    padding: 40px 20px;
    max-width: 800px;
    margin: 0 auto;
}

.fn-hero-section p {
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.fn-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    padding: 20px 0;
}

.fn-card {
    background: var(--fn-bg-card);
    border: 1px solid var(--fn-border-light);
    border-radius: var(--fn-border-radius);
    padding: 28px 20px;
    text-align: center;
    transition: var(--fn-transition-base);
    display: flex;
    flex-direction: column;
    box-shadow: var(--fn-shadow-sm);
}

.fn-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--fn-shadow-lg);
    border-color: var(--fn-border-medium);
}

.fn-card h2 {
    font-size: 1.5rem;
    margin: 16px 0 8px;
    color: var(--fn-text-primary);
}

.fn-card p {
    font-size: 0.9375rem;
    margin-bottom: 20px;
    flex-grow: 1;
    color: var(--fn-text-secondary);
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: 12px;
}

.tool-jpg .tool-icon { color: var(--fn-accent-color); }
.tool-png .tool-icon { color: #e91e63; }
.tool-webp .tool-icon { color: var(--fn-success-color); }
.tool-gif .tool-icon { color: var(--fn-warning-color); }

.fn-primary-button {
    display: inline-block;
    text-decoration: none;
    padding: 12px 24px;
    border-radius: var(--fn-border-radius-sm);
    font-weight: 600;
    font-size: 0.9375rem;
    margin-top: auto;
    background: var(--fn-primary-color);
    color: white !important;
    transition: var(--fn-transition-base);
    border: none;
    cursor: pointer;
    text-align: center;
}

.fn-primary-button:hover {
    background: var(--fn-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--fn-shadow-md);
}

/* Tool-specific button colors */
.tool-png .fn-primary-button { background: #e91e63; }
.tool-png .fn-primary-button:hover { background: #c2185b; }
.tool-webp .fn-primary-button { background: var(--fn-success-color); }
.tool-webp .fn-primary-button:hover { background: #388e3c; }
.tool-gif .fn-primary-button { background: var(--fn-warning-color); }
.tool-gif .fn-primary-button:hover { background: #f57c00; }

/* SEO Text Section */
.fn-seo-text-section {
    margin-top: 60px;
    padding: 48px 24px;
    background: var(--fn-bg-tertiary);
    border-radius: var(--fn-border-radius);
}

.fn-seo-container {
    max-width: 800px;
    margin: 0 auto;
}

.fn-seo-container h2 {
    text-align: center;
    margin-bottom: 24px;
}

.fn-seo-container p {
    margin-bottom: 16px;
}

.fn-seo-container strong {
    color: var(--fn-primary-color);
    font-weight: 600;
}

/* --- Layout & Struktur --- */
.fn-main-content-container {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    padding: 0 20px;
    box-sizing: border-box;
    flex-grow: 1;
}

.fn-main-content-area {
    padding-top: calc(var(--fn-header-height-mobile) + 20px);
    padding-bottom: 40px;
    flex-grow: 1;
    width: 100%;
    box-sizing: border-box;
}

/* --- Header & Navbar --- */
.fn-main-header {
    display: flex;
    justify-content: center;
    padding: 0 20px;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    height: var(--fn-header-height-mobile);
    box-sizing: border-box;
    transition: var(--fn-transition-base);
    background-color: var(--fn-bg-card);
    box-shadow: var(--fn-shadow-sm);
    backdrop-filter: blur(10px);
}

.fn-header-container-inner {
    width: 100%;
    max-width: 1280px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.fn-main-nav {
    display: none;
}

.fn-logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.fn-logo {
    height: 40px;
    width: auto;
}

.fn-app-name {
    font-size: 1.25rem;
    font-weight: 700;
    white-space: nowrap;
    color: var(--fn-text-primary);
}

.fn-header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.fn-button {
    background-color: transparent;
    border: none;
    cursor: pointer;
    transition: var(--fn-transition-base);
    border-radius: 50%;
    outline: none;
}

.fn-icon-button {
    font-size: 1.25rem;
    color: var(--fn-text-secondary);
    padding: 10px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.fn-icon-button:hover {
    background-color: var(--fn-bg-tertiary);
    color: var(--fn-text-primary);
}

.fn-main-nav-mobile {
    display: block;
}

/* --- Navigation Links --- */
.fn-nav-link {
    font-size: 1rem;
    font-weight: 500;
    color: var(--fn-text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.fn-nav-link:hover {
    color: var(--fn-primary-color);
}

.fn-nav-link.active {
    color: var(--fn-primary-color);
    font-weight: 600;
}

/* --- Sidebar Navigation --- */
.fn-sidebar-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1500;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease-in-out;
}

.fn-sidebar-backdrop.active {
    opacity: 1;
    pointer-events: auto;
}

.fn-sidebar-nav {
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 300px;
    background-color: var(--fn-bg-card);
    box-shadow: var(--fn-shadow-lg);
    z-index: 2000;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    padding: 24px;
    display: flex;
    flex-direction: column;
    box-sizing: border-box;
}

.fn-sidebar-nav.active {
    transform: translateX(0);
}

.fn-sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--fn-border-light);
    margin-bottom: 20px;
}

.fn-sidebar-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--fn-primary-color);
}

#fn-sidebar-close {
    font-size: 1.25rem;
    color: var(--fn-text-secondary);
    padding: 8px;
    background: none;
    border: none;
    cursor: pointer;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--fn-transition-base);
}

#fn-sidebar-close:hover {
    background-color: var(--fn-bg-tertiary);
    color: var(--fn-text-primary);
}

.fn-sidebar-links {
    list-style: none;
    padding: 0;
    margin: 0;
    flex-grow: 1;
}

.fn-sidebar-links li {
    margin-bottom: 4px;
}

.fn-sidebar-links .fn-nav-link {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    text-decoration: none;
    color: var(--fn-text-secondary);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--fn-border-radius-sm);
    transition: var(--fn-transition-base);
}

.fn-sidebar-links .fn-nav-link:hover {
    background-color: var(--fn-bg-tertiary);
    color: var(--fn-text-primary);
}

.fn-sidebar-links .fn-nav-link.active {
    background-color: var(--fn-primary-color);
    color: white;
}

.fn-sidebar-links .fn-nav-link i {
    margin-right: 12px;
    font-size: 1.125rem;
    width: 24px;
    text-align: center;
}

.fn-sidebar-footer {
    padding-top: 20px;
    border-top: 1px solid var(--fn-border-light);
    margin-top: auto;
}

.fn-sidebar-footer .fn-theme-toggle {
    display: flex;
    align-items: center;
    width: 100%;
    justify-content: flex-start;
    padding: 12px 16px;
    border-radius: var(--fn-border-radius-sm);
    color: var(--fn-text-secondary);
    background: none;
    border: none;
    cursor: pointer;
    transition: var(--fn-transition-base);
}

.fn-sidebar-footer .fn-theme-toggle:hover {
    background-color: var(--fn-bg-tertiary);
    color: var(--fn-text-primary);
}

.fn-sidebar-footer .fn-theme-toggle span {
    color: var(--fn-text-secondary);
    font-weight: 500;
    margin-left: 12px;
}

/* --- Footer Styles --- */
.fn-main-footer {
    padding: 60px 20px 30px;
    background-color: var(--fn-bg-card);
    border-top: 1px solid var(--fn-border-light);
    margin-top: 50px;
    transition: var(--fn-transition-base);
}

.fn-footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    max-width: 1280px;
    margin: 0 auto;
}

.fn-footer-logo {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--fn-primary-color);
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.fn-footer-brand p {
    font-size: 0.9375rem;
    line-height: 1.7;
    color: var(--fn-text-secondary);
    margin-bottom: 20px;
}

.fn-footer-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--fn-text-primary);
    position: relative;
}

.fn-footer-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 40px;
    height: 2px;
    background-color: var(--fn-primary-color);
}

.fn-footer-links {
    list-style: none;
    padding: 0;
}

.fn-footer-links li {
    margin-bottom: 12px;
}

.fn-footer-links a {
    text-decoration: none;
    color: var(--fn-text-secondary);
    transition: all 0.3s ease;
    font-size: 0.9375rem;
}

.fn-footer-links a:hover {
    color: var(--fn-primary-color);
    padding-left: 4px;
}

.fn-social-wrapper {
    display: flex;
    gap: 12px;
}

.fn-social-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background-color: var(--fn-bg-tertiary);
    color: var(--fn-text-secondary);
    transition: all 0.3s ease;
    text-decoration: none;
}

.fn-social-icon:hover {
    background-color: var(--fn-primary-color);
    color: white;
    transform: translateY(-3px);
}

.fn-footer-bottom {
    text-align: center;
    margin-top: 50px;
    padding-top: 25px;
    border-top: 1px solid var(--fn-border-light);
    font-size: 0.875rem;
    color: var(--fn-text-muted);
}

/* --- Media Queries --- */
@media (min-width: 768px) {
    .fn-main-content-area {
        padding-top: calc(var(--fn-header-height-desktop) + 20px);
    }
    
    .fn-main-header {
        height: var(--fn-header-height-desktop);
        padding: 0 32px;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
    }

    .fn-main-nav {
        display: flex;
        gap: 32px;
        align-items: center;
    }

    .fn-nav-link {
        position: relative;
    }

    .fn-nav-link::after {
        content: '';
        position: absolute;
        bottom: -4px;
        left: 0;
        width: 0;
        height: 2px;
        background-color: var(--fn-primary-color);
        transition: width 0.3s ease;
    }

    .fn-nav-link.active::after,
    .fn-nav-link:hover::after {
        width: 100%;
    }

    .fn-main-nav-mobile {
        display: none;
    }

    .fn-footer-content {
        grid-template-columns: 2fr 1fr 1fr;
    }
}

@media (min-width: 1024px) {
    .fn-main-content-container {
        padding: 0 32px;
    }
    
    .fn-tools-grid {
        gap: 32px;
    }
}

/* Responsive Adjustments for Mobile */
@media (max-width: 768px) {
    .fn-main-content-container {
        padding: 0 16px;
    }
    
    .fn-hero-section {
        padding: 30px 16px;
    }
    
    .fn-card {
        padding: 20px 16px;
    }
    
    .fn-seo-text-section {
        padding: 32px 16px;
        margin-top: 40px;
    }
    
    .fn-main-footer {
        padding: 40px 16px 24px;
    }
    
    .fn-footer-content {
        gap: 32px;
    }
}

/* Print Styles for SEO */
@media print {
    .fn-main-header,
    .fn-sidebar-nav,
    .fn-sidebar-backdrop,
    .fn-main-nav-mobile,
    .fn-header-actions {
        display: none !important;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .fn-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
}