/* ==========================================================================
   CSS Variables & Theming
   ========================================================================== */
:root {
    /* Light Theme (Default) */
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    
    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.4);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    
    /* Layout */
    --max-width: 1200px;
    --border-radius: 16px;
    --transition: all 0.3s ease;
}

.dark-mode {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --accent-color: #60a5fa;
    --accent-hover: #3b82f6;
    
    /* Dark Glassmorphism */
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

button, a, input {
    touch-action: manipulation;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
    overflow-x: hidden;
}

/* Background Gradient blobs for premium feel */
body::before, body::after {
    content: '';
    position: fixed;
    border-radius: 50%;
    filter: blur(100px);
    z-index: -1;
    opacity: 0.5;
    pointer-events: none;
}

body::before {
    top: -10%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-color) 0%, transparent 70%);
}

body::after {
    bottom: -10%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, #8b5cf6 0%, transparent 70%);
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--accent-color);
    transition: var(--transition);
}

a:hover {
    color: var(--accent-hover);
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: clamp(1.8rem, 3vw, 2.5rem);
}

h2 {
    font-size: clamp(1.2rem, 1.8vw, 1.4rem);
}

h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

/* ==========================================================================
   Components
   ========================================================================== */
/* Glassmorphism Classes */
.glass-hero, .glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    box-shadow: var(--glass-shadow);
}

.glass-card {
    padding: 24px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.15);
}

.dark-mode .glass-card:hover {
    box-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.5);
}

/* Buttons */
.btn-primary {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-color), #8b5cf6);
    color: white !important;
    padding: 12px 28px;
    border-radius: 30px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    display: inline-block;
    background: transparent;
    color: var(--accent-color);
    padding: 10px 24px;
    border-radius: 30px;
    font-weight: 600;
    border: 2px solid var(--accent-color);
    cursor: pointer;
}

.btn-secondary:hover {
    background: var(--accent-color);
    color: white !important;
    transform: scale(1.02);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.2);
}

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.btn-icon:hover {
    background: var(--bg-secondary);
}

/* Forms & Inputs */
.input-group {
    margin-bottom: 15px;
    display: flex;
    flex-direction: column;
}

.input-group label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper .unit {
    position: absolute;
    right: 30px; /* Moved left to avoid overlap with number spinner */
    color: var(--text-secondary);
    font-weight: 600;
    pointer-events: none;
}

.input-wrapper input {
    padding-right: 45px;
}

input[type="number"], input[type="text"], input[type="email"], textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    background: #ffffff;
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    transition: var(--transition);
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
}

.dark-mode input[type="number"], .dark-mode input[type="text"], .dark-mode input[type="email"], .dark-mode textarea {
    border: 1px solid var(--glass-border);
    background: var(--bg-primary);
    box-shadow: none;
}

input[type="number"]:focus, input[type="text"]:focus, input[type="email"]:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.radio-group {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

/* Result Area */
.result-area {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}

.multi-result {
    flex-direction: column;
    align-items: flex-start;
}

.multi-result div {
    display: flex;
    justify-content: space-between;
    width: 100%;
}

.result-label {
    font-weight: 600;
    color: var(--text-secondary);
}

.result-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent-color);
}

.copy-btn {
    background: var(--bg-secondary);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
}

.copy-btn:hover {
    background: var(--accent-color);
    color: white;
}

.fraction-inputs {
    display: flex;
    align-items: center;
    gap: 10px;
}

.fraction-divider {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--text-secondary);
    margin-top: 15px;
}

/* ==========================================================================
   Layout Sections
   ========================================================================== */
/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
    letter-spacing: -0.5px;
    white-space: nowrap;
}

.logo-w1 {
    color: var(--text-primary);
}

.logo-w2 {
    color: var(--accent-color);
}

.logo-w3 {
    color: #8b5cf6;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--accent-color);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* Theme Toggle Icons */
.sun-icon, .moon-icon {
    width: 22px;
    height: 22px;
}

.moon-icon { display: none; }
.dark-mode .sun-icon { display: none; }
.dark-mode .moon-icon { display: block; }

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    width: 30px;
    height: 24px;
    position: relative;
}

.mobile-menu-btn span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    position: absolute;
    left: 0;
    transition: var(--transition);
}

.mobile-menu-btn span:nth-child(1) { top: 0; }
.mobile-menu-btn span:nth-child(2) { top: 11px; }
.mobile-menu-btn span:nth-child(3) { bottom: 0; }

/* Hero */
.hero {
    margin: 10px auto;
    padding: 15px 20px;
    text-align: center;
    max-width: 100%;
}

.hero h1 {
    font-size: clamp(1.2rem, 1.8vw, 1.4rem);
    margin-bottom: 5px;
}

.hero h1 span {
    background: linear-gradient(135deg, var(--accent-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    max-width: 750px;
    margin: 0 auto 10px;
}

.hero .btn-primary {
    padding: 10px 20px;
    font-size: 0.9rem;
}



/* Calculators Grid */
.calculators-section {
    padding: 10px 0 30px;
}

.section-header {
    text-align: center;
    margin-bottom: 25px;
}

.faq-section .section-header {
    margin-bottom: 10px;
}

.section-header h2 {
    margin-bottom: 5px;
}

.section-header p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 280px), 1fr));
    gap: 20px;
}

.calc-card {
    scroll-margin-top: 100px;
}

.calc-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

/* SEO Content & FAQ */
.seo-content, .faq-section {
    padding: 20px 0;
}

.content-box {
    padding: 40px;
}

.content-box h3 {
    margin-top: 30px;
}

.content-box ul {
    margin-left: 20px;
    margin-bottom: 20px;
}

.content-box li {
    margin-bottom: 10px;
}

.content-box blockquote {
    background: var(--bg-secondary);
    padding: 20px;
    border-left: 4px solid var(--accent-color);
    border-radius: 0 8px 8px 0;
    margin: 20px 0;
}

/* Accordion */
.accordion-item {
    border-bottom: 1px solid var(--glass-border);
}

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

.accordion-header {
    width: 100%;
    text-align: left;
    background: none;
    border: none;
    padding: 20px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    padding: 0 20px;
}

.accordion-content p {
    padding-bottom: 20px;
    color: var(--text-secondary);
}

.accordion-header.active .icon {
    transform: rotate(45deg);
}

.icon {
    font-size: 1.5rem;
    transition: var(--transition);
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    padding: 60px 0 20px;
    margin-top: 60px;
    border-top: 1px solid var(--glass-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col {
    position: relative;
}

@media (min-width: 993px) {
    .footer-col:not(:last-child)::after {
        content: '';
        position: absolute;
        right: -20px;
        top: 0;
        height: 100%;
        width: 1px;
        background: var(--glass-border);
    }
}

.footer-col h4 {
    margin-bottom: 20px;
    font-size: 1.1rem;
    color: var(--text-primary);
}

.footer-col ul {
    list-style: none;
}

.footer-col li {
    margin-bottom: 10px;
}

.footer-col a {
    color: var(--text-secondary);
}

.footer-col a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
}

/* Toast */
.toast {
    position: fixed;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-color);
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transition: bottom 0.3s ease;
    z-index: 2000;
    white-space: nowrap;
    font-size: 0.9rem;
    font-weight: 500;
}

.toast.show {
    bottom: calc(40px + env(safe-area-inset-bottom, 0px));
}

/* Sidebar Layout */
.main-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 40px;
    align-items: start;
    padding-top: 20px;
}

.sidebar-column {
    position: sticky;
    top: 90px;
}

.sidebar-ad {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 600px;
    background: var(--bg-secondary);
    border: 1px dashed var(--glass-border);
    color: var(--text-secondary);
    padding: 0;
    overflow: hidden;
    flex-direction: column;
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 992px) {
    .main-layout {
        grid-template-columns: 1fr;
    }

    .sidebar-column {
        position: relative;
        top: 0;
    }

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

    .sidebar-ad {
        min-height: 250px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--glass-bg);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        border-bottom: 1px solid var(--glass-border);
        box-shadow: var(--glass-shadow);
        clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
        transition: clip-path 0.3s ease-in-out;
    }

    .nav-links.active {
        clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    }

    .mobile-menu-btn {
        display: block;
    }



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

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
}