/* 
 * File: style.css
 * OnlineCalculatorPlus.com - Modern Design System
 * Version: 3.0 - Full Redevelopment + Bug Fixes
 */

/* ===== GOOGLE FONT: INTER ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;900&display=swap');

/* ===== CSS VARIABLES ===== */
:root {
    --primary-50: #eff6ff; --primary-100: #dbeafe; --primary-200: #bfdbfe; --primary-300: #93c5fd; --primary-400: #60a5fa; --primary-500: #3b82f6; --primary-600: #2563eb; --primary-700: #1d4ed8; --primary-800: #1e40af; --primary-900: #1e3a8a;
    --secondary-50: #faf5ff; --secondary-100: #f3e8ff; --secondary-200: #e9d5ff; --secondary-300: #d8b4fe; --secondary-400: #c084fc; --secondary-500: #a855f7; --secondary-600: #9333ea; --secondary-700: #7e22ce; --secondary-800: #6b21a8; --secondary-900: #581c87;
    --accent-50: #f0fdfa; --accent-100: #ccfbf1; --accent-200: #99f6e4; --accent-300: #5eead4; --accent-400: #2dd4bf; --accent-500: #14b8a6; --accent-600: #0d9488; --accent-700: #0f766e; --accent-800: #115e59; --accent-900: #134e4a;
    --gray-50: #f9fafb; --gray-100: #f3f4f6; --gray-200: #e5e7eb; --gray-300: #d1d5db; --gray-400: #9ca3af; --gray-500: #6b7280; --gray-600: #4b5563; --gray-700: #374151; --gray-800: #1f2937; --gray-900: #111827;
    --success-50: #ecfdf5; --success-500: #10b981; --success-600: #059669;
    --warning-50: #fffbeb; --warning-500: #f59e0b; --warning-600: #d97706;
    --error-50: #fef2f2; --error-500: #ef4444; --error-600: #dc2626;
    --primary: var(--primary-600); --primary-dark: var(--primary-800); --primary-light: var(--primary-400);
    --secondary: var(--secondary-600); --accent: var(--accent-500);
    --bg-primary: #ffffff; --bg-secondary: #f8fafc; --bg-tertiary: #f1f5f9;
    --text-primary: var(--gray-900); --text-secondary: var(--gray-700); --text-tertiary: var(--gray-500);
    --border-light: var(--gray-200); --border-medium: var(--gray-300);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1); --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1); --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1); --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1);
    --gradient-primary: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-800) 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-ocean: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --radius-sm: 0.25rem; --radius-md: 0.375rem; --radius-lg: 0.5rem; --radius-xl: 0.75rem; --radius-2xl: 1rem; --radius-3xl: 1.5rem; --radius-full: 9999px;
    --transition-fast: 150ms; --transition-base: 200ms; --transition-slow: 300ms;
    /* Z-index scale */
    --z-base: 1; --z-dropdown: 100; --z-sticky: 200; --z-modal: 300; --z-toast: 400;
    /* Cookie banner */
    --z-cookie: 500;
}

/* ===== RESET & BASE ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:'Inter',system-ui,-apple-system,sans-serif;background:var(--bg-secondary);color:var(--text-primary);line-height:1.6;min-height:100vh;display:flex;flex-direction:column}
img{max-width:100%;height:auto}
a{text-decoration:none;color:var(--primary);transition:color var(--transition-fast)}
a:hover{color:var(--primary-dark)}
ul,ol{list-style:none}
button{cursor:pointer;border:none;outline:none;font:inherit}
input,textarea,select{font:inherit;border:1px solid var(--border-light);border-radius:var(--radius-md);padding:0.75rem;transition:all var(--transition-fast)}
input:focus,textarea:focus,select:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-100)}

/* ===== TYPOGRAPHY ===== */
h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.2;margin-bottom:1rem}
h1{font-size:clamp(2rem,5vw,3.5rem)} h2{font-size:clamp(1.75rem,4vw,2.75rem)} h3{font-size:clamp(1.5rem,3vw,2rem)} h4{font-size:clamp(1.25rem,2.5vw,1.5rem)}
p{margin-bottom:1rem;color:var(--text-secondary)}
.text-gradient{background:var(--gradient-primary);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.text-center{text-align:center}

/* ===== LAYOUT ===== */
.container{width:100%;max-width:1280px;margin:0 auto;padding:0 1.5rem}
.section{padding:4rem 0}
.grid{display:grid;gap:1.5rem}
.grid-2{grid-template-columns:repeat(2,1fr)} .grid-3{grid-template-columns:repeat(3,1fr)} .grid-4{grid-template-columns:repeat(4,1fr)}
@media(max-width:1024px){.grid-4{grid-template-columns:repeat(2,1fr)}}
@media(max-width:768px){.grid-3,.grid-2{grid-template-columns:1fr}}
@media(max-width:640px){.grid-4{grid-template-columns:1fr}}
.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-between{justify-content:space-between}.justify-center{justify-content:center}.gap-1{gap:0.5rem} .gap-2{gap:1rem} .gap-3{gap:1.5rem}

/* ===== HEADER ===== */
header{background:rgba(255,255,255,0.95);backdrop-filter:blur(10px);box-shadow:var(--shadow-md);position:sticky;top:0;z-index:var(--z-sticky);border-bottom:3px solid var(--primary)}
.header-flex{display:flex;justify-content:space-between;align-items:center;height:75px}
.logo{display:flex;align-items:center;gap:0.75rem;text-decoration:none}
.logo img{height:50px;width:auto;border-radius:var(--radius-lg);transition:transform var(--transition-slow)}
.logo:hover img{transform:rotate(5deg) scale(1.05)}
.logo-text{font-size:1.5rem;font-weight:700;color:var(--text-primary)}
.logo-text span{color:var(--primary)}
nav ul{display:flex;gap:2rem}
nav a{text-decoration:none;color:var(--text-secondary);font-weight:600;padding:0.5rem 0;position:relative;transition:color var(--transition-fast)}
nav a:hover{color:var(--primary)}
nav a::after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--gradient-primary);transition:width var(--transition-base)}
nav a:hover::after{width:100%}
.menu-toggle{display:none;font-size:1.75rem;cursor:pointer;color:var(--text-primary)}
@media(max-width:768px){
    .menu-toggle{display:block}
    nav ul{display:none;position:absolute;top:65px;left:0;width:100%;background:#fff;flex-direction:column;padding:1.5rem;gap:1rem;box-shadow:var(--shadow-lg);border-top:1px solid var(--border-light);z-index:var(--z-dropdown)}
    nav ul.active{display:flex}
    .header-flex{height:65px}
    .logo img{height:40px}
}

/* ===== HERO SECTION ===== */
.hero{background:var(--gradient-hero);color:#fff;padding:5rem 0;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,138.7C960,139,1056,117,1152,96C1248,75,1344,53,1392,42.7L1440,32L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;background-size:cover;opacity:0.5}
.hero-title{font-size:clamp(2.5rem,6vw,4rem);margin-bottom:1rem;color:#fff;text-shadow:0 2px 10px rgba(0,0,0,0.2)}
.hero-subtitle{font-size:clamp(1.125rem,2vw,1.5rem);max-width:700px;margin:0 auto 2rem;opacity:0.95}
.hero-badges{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap;margin-top:2rem}
.badge{background:rgba(255,255,255,0.2);backdrop-filter:blur(10px);padding:0.5rem 1.25rem;border-radius:var(--radius-full);font-size:0.875rem;font-weight:600;display:flex;align-items:center;gap:0.5rem}

/* ===== CARDS ===== */
.card{background:var(--surface-1);border-radius:var(--radius-2xl);padding:2rem;box-shadow:var(--shadow-md);border:1px solid var(--border-light);transition:all var(--transition-slow)}
.card:hover{transform:translateY(-5px);box-shadow:var(--shadow-xl);border-color:var(--primary-light)}
.section-title{font-size:1.75rem;color:var(--text-primary);margin-bottom:1rem;padding-left:1rem;border-left:4px solid var(--primary);display:flex;align-items:center;gap:0.75rem}
.section-title::before{content:'📊';font-size:1.5rem}

/* ===== CATEGORY GRID ===== */
.category-card{background:linear-gradient(135deg,#fff 0%,var(--primary-50) 100%);padding:2rem;border-radius:var(--radius-2xl);border:2px solid var(--border-light);cursor:pointer;transition:all var(--transition-slow);text-align:center}
.category-card:hover{border-color:var(--primary);transform:translateY(-8px);box-shadow:var(--shadow-xl)}
.category-icon{font-size:3rem;margin-bottom:1rem}
.category-title{font-size:1.25rem;font-weight:700;color:var(--text-primary);margin-bottom:0.5rem}
.category-desc{font-size:0.875rem;color:var(--text-tertiary)}
.category-count{display:inline-block;margin-top:1rem;background:var(--gradient-primary);color:#fff;padding:0.25rem 1rem;border-radius:var(--radius-full);font-size:0.75rem;font-weight:600}

/* ===== CALCULATOR INPUTS ===== */
.calc-input-group{margin-bottom:1.5rem}
.calc-label{display:block;margin-bottom:0.5rem;font-weight:600;color:var(--text-secondary)}
.calc-input,.calc-select{width:100%;padding:0.875rem;border:2px solid var(--border-light);border-radius:var(--radius-lg);font-size:1rem;transition:all var(--transition-fast);background:#fff}
.calc-input:focus,.calc-select:focus{border-color:var(--primary);box-shadow:0 0 0 4px var(--primary-100)}
.btn-calculate{background:var(--gradient-primary);color:#fff;padding:1rem 2rem;border:none;border-radius:var(--radius-xl);font-size:1.125rem;font-weight:700;cursor:pointer;width:100%;transition:all var(--transition-slow);box-shadow:var(--shadow-md)}
.btn-calculate:hover{transform:translateY(-2px);box-shadow:var(--shadow-xl);filter:brightness(1.1)}
.result-box{margin-top:1.5rem;padding:1.5rem;background:linear-gradient(135deg,var(--success-50) 0%,#fff 100%);border:2px solid var(--success-500);border-radius:var(--radius-xl);display:none}
.result-text{font-size:1.5rem;font-weight:700;color:var(--success-600);margin-bottom:0.5rem}

/* ===== TOOL CARDS ===== */
.tool-card{text-decoration:none;background:#fff;padding:1.5rem;border-radius:var(--radius-xl);border:2px solid var(--border-light);transition:all var(--transition-slow);display:block}
.tool-card:hover{border-color:var(--primary);transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.tool-icon{font-size:2.5rem;margin-bottom:0.75rem}
.tool-title{font-size:1.125rem;font-weight:700;color:var(--text-primary);margin-bottom:0.5rem}
.tool-desc{font-size:0.875rem;color:var(--text-tertiary);line-height:1.5}
.tool-rating{color:var(--warning-500);font-size:0.875rem;margin-top:0.5rem}

/* ===== EEAT SECTION ===== */
.eeat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:2rem;margin-top:2rem}
.eeat-item{text-align:center;padding:1.5rem;background:var(--bg-tertiary);border-radius:var(--radius-xl);transition:all var(--transition-slow)}
.eeat-item:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg)}
.eeat-icon{font-size:3rem;margin-bottom:1rem}
.eeat-title{font-size:1.125rem;font-weight:700;color:var(--text-primary);margin-bottom:0.5rem}
.eeat-desc{font-size:0.875rem;color:var(--text-tertiary)}

/* ===== FAQ SECTION ===== */
.faq-item{margin-bottom:1.5rem;padding:1.5rem;background:#fff;border-radius:var(--radius-xl);border:1px solid var(--border-light);transition:all var(--transition-fast)}
.faq-question{font-size:1.125rem;font-weight:700;color:var(--text-primary);cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:1rem;list-style:none;}
.faq-question::-webkit-details-marker{display:none;}
.faq-answer{margin-top:1rem;color:var(--text-secondary);line-height:1.8;}
details.faq-item[open]{border-color:var(--primary);box-shadow:var(--shadow-md);}

/* ===== FOOTER ===== */
footer{background:var(--gray-900);color:var(--gray-400);padding:3rem 0 1.5rem;margin-top:auto}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:2rem;margin-bottom:2rem}
.footer-col h4{color:#fff;margin-bottom:1rem;font-size:1rem}
.footer-col ul{list-style:none}
.footer-col li{margin-bottom:0.5rem}
.footer-col a{color:var(--gray-400);transition:color var(--transition-fast)}
.footer-col a:hover{color:#fff}
.copyright{text-align:center;border-top:1px solid var(--gray-800);padding-top:1.5rem;font-size:0.875rem}

/* ===== UTILITY CLASSES ===== */
.mt-1{margin-top:0.5rem} .mt-2{margin-top:1rem} .mt-3{margin-top:1.5rem} .mt-4{margin-top:2rem}
.mb-1{margin-bottom:0.5rem} .mb-2{margin-bottom:1rem} .mb-3{margin-bottom:1.5rem} .mb-4{margin-bottom:2rem}
.hidden{display:none} .block{display:block} .inline-block{display:inline-block}
.text-sm{font-size:0.875rem} .text-xs{font-size:0.75rem}
.font-bold{font-weight:700} .font-semibold{font-weight:600}

/* ===== RESPONSIVE ===== */
@media(max-width:640px){
    .section{padding:2rem 0}
    .card{padding:1.5rem}
    .hero{padding:3rem 0}
    .container{padding:0 1rem}
}

/* ===== DARK MODE (Prefers) ===== */
@media(prefers-color-scheme:dark){
    :root{
        --bg-primary:#0f172a; --bg-secondary:#1e293b; --bg-tertiary:#334155;
        --text-primary:#f1f5f9; --text-secondary:#cbd5e1; --text-tertiary:#94a3b8;
        --border-light:#334155; --border-medium:#475569;
    }
    header{background:rgba(15,23,42,0.97)}
    .tool-card,.calc-wrapper,.card{background:#1e293b;border-color:#334155}
    .category-card{background:linear-gradient(135deg,#1e293b 0%,#0f172a 100%)}
    footer{background:#020617}
}

/* ===== PRINT STYLES ===== */
@media print{
    header,footer,.hero-badges,.btn-calculate,nav,.menu-toggle,.adsbygoogle,.related-section,.breadcrumb-container{display:none!important}
    body{background:#fff;color:#000;font-size:12pt}
    .container{max-width:100%;padding:0}
    a{color:#000;text-decoration:underline}
    .result-box{border:2px solid #000;display:block!important}
}

/* ===== COOKIE CONSENT BANNER ===== */
.cookie-banner{
    position:fixed;bottom:0;left:0;right:0;
    background:var(--gray-900);color:var(--gray-300);
    padding:1.25rem 2rem;z-index:var(--z-cookie);
    display:flex;align-items:center;justify-content:space-between;
    flex-wrap:wrap;gap:1rem;
    box-shadow:0 -4px 20px rgba(0,0,0,0.3);
    border-top:3px solid var(--primary);
}
.cookie-banner p{margin:0;font-size:0.9rem;line-height:1.5;flex:1;min-width:200px;}
.cookie-banner a{color:var(--primary-300);text-decoration:underline;}
.cookie-actions{display:flex;gap:0.75rem;flex-shrink:0;}
.cookie-btn-accept{
    background:var(--gradient-primary);color:#fff;
    padding:0.6rem 1.5rem;border:none;border-radius:var(--radius-xl);
    font-size:0.9rem;font-weight:700;cursor:pointer;
    transition:all var(--transition-fast);
}
.cookie-btn-accept:hover{filter:brightness(1.15);transform:translateY(-1px);}
.cookie-btn-decline{
    background:transparent;color:var(--gray-400);
    padding:0.6rem 1rem;border:1px solid var(--gray-600);
    border-radius:var(--radius-xl);font-size:0.9rem;cursor:pointer;
    transition:all var(--transition-fast);
}
.cookie-btn-decline:hover{border-color:var(--gray-400);color:var(--gray-300);}
.cookie-banner.hidden{display:none;}

/* ===== FAQ DETAILS/SUMMARY NATIVE STYLING ===== */
details.faq-item{cursor:pointer;}
details.faq-item summary{list-style:none;}
details.faq-item summary::-webkit-details-marker{display:none;}
details.faq-item[open]{border-color:var(--primary);}
details.faq-item summary::after{content:' +';float:right;font-size:1.4rem;line-height:1;color:var(--primary);}
details.faq-item[open] summary::after{content:' −';}

/* --- BREADCRUMBS --- */
.breadcrumb-container {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-light);
    padding: 0.75rem 0;
}

.breadcrumb-nav {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.breadcrumb-nav a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.breadcrumb-nav a:hover {
    color: var(--primary-700);
}

.breadcrumb-separator {
    color: var(--gray-400);
}

.breadcrumb-current {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===== DISCLAIMER BOX ===== */
.disclaimer-box{
    background:#fffbeb;border-left:4px solid var(--warning-500);
    padding:1.25rem 1.5rem;border-radius:var(--radius-lg);
    margin:2rem 0;font-size:0.9rem;color:#78350f;line-height:1.6;
}
.disclaimer-box strong{color:#92400e;}

/* ===== COPY RESULT BUTTON ===== */
.btn-copy{
    display:inline-flex;align-items:center;gap:0.5rem;
    background:#fff;color:var(--primary);border:2px solid var(--primary);
    padding:0.5rem 1.25rem;border-radius:var(--radius-xl);
    font-size:0.875rem;font-weight:700;cursor:pointer;
    transition:all var(--transition-fast);
    margin-top:0.75rem;
}
.btn-copy:hover{background:var(--primary-50);}
.btn-copy.copied{background:var(--success-50);color:var(--success-600);border-color:var(--success-500);}

/* ===== LOADING STATES ===== */
.calculating {
    position: relative;
    pointer-events: none;
    opacity: 0.8;
}
.calculating::after {
    content: "";
    display: inline-block;
    width: 1rem;
    height: 1rem;
    margin-left: 0.5rem;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.6s linear infinite;
    vertical-align: middle;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}
.pulse {
    animation: pulse-animation 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}
@keyframes pulse-animation {
    0%, 100% { opacity: 1; }
    50% { opacity: .5; }
}

/* --- RELATED CALCULATORS --- */
.related-section {
    margin-top: 4rem;
    padding: 3rem;
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, #fff 100%);
    border-radius: var(--radius-3xl);
    border: 1px solid var(--border-light);
}

.related-section h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-primary);
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.related-card {
    background: #fff;
    padding: 1.25rem;
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-light);
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
    color: var(--text-primary);
    transition: all var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1);
}

.related-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-200);
    background: var(--primary-50);
}

.related-icon {
    font-size: 1.5rem;
    width: 44px;
    height: 44px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.related-info h4 {
    margin: 0 0 0.25rem 0;
    font-size: 0.95rem;
    font-weight: 600;
}

.related-info p {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    line-height: 1.4;
    margin: 0;
}

@media (prefers-color-scheme: dark) {
    .related-section {
        background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    }
    .related-card {
        background: #1e293b;
    }
    .related-card:hover {
        background: #334155;
    }
}