@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');

:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --secondary: #7c3aed;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --ad-bg: #f1f5f9;
    --success: #10b981;
    --radius: 12px;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --header-height: 65px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========================
   HEADER & NAVBAR
======================== */
header {
    background: var(--card-bg);
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
    padding: 0 20px;
    max-width: 1100px;
    margin: 0 auto;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.logo svg { flex-shrink: 0; }

/* Desktop Nav */
.nav-links {
    display: flex;
    align-items: center;
    gap: 5px;
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-links li { list-style: none; }

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.9rem;
    padding: 7px 14px;
    border-radius: 8px;
    transition: all 0.2s;
    white-space: nowrap;
    display: block;
}

.nav-links a:hover, .nav-links a.active {
    background: #eef2ff;
    color: var(--primary);
}

/* Hamburger Button */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 38px;
    height: 38px;
    background: none;
    border: 1px solid var(--border-color);
    cursor: pointer;
    padding: 9px 8px;
    border-radius: 8px;
    transition: background 0.2s, border-color 0.2s;
    flex-shrink: 0;
}

.hamburger:hover { background: #eef2ff; border-color: var(--primary); }

.hamburger span {
    display: block;
    height: 2px;
    width: 100%;
    background: var(--text-main);
    border-radius: 4px;
    transition: all 0.35s cubic-bezier(0.4,0,0.2,1);
    transform-origin: center;
}

/* Hamburger → X animation */
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile Drawer */
.mobile-menu {
    display: none;
    flex-direction: column;
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 15px 20px;
    gap: 5px;
}

.mobile-menu.open { display: flex; }

.mobile-menu a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 10px;
}

.mobile-menu a:hover {
    background: #eef2ff;
    color: var(--primary);
}

.mobile-menu .back-home {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white !important;
    font-weight: 600;
    margin-top: 8px;
}

.mobile-menu .back-home:hover {
    opacity: 0.9;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
}

/* ========================
   AD SLOTS
======================== */
.ad-slot {
    width: 100%;
    background: var(--ad-bg);
    border: 2px dashed #cbd5e1;
    border-radius: var(--radius);
    display: block;
    color: var(--text-muted);
    font-weight: 500;
    margin: 30px 0;
    text-align: center;
    padding: 10px;
    overflow: hidden;
}
.ad-slot.top { min-height: 90px; }
.ad-slot.middle { min-height: 250px; }
.ad-slot.bottom { min-height: 90px; }

/* ========================
   PAGE LAYOUT
======================== */
.page-title {
    text-align: center;
    margin: 40px 0 20px;
    font-size: 2.5rem;
    color: var(--text-main);
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.page-subtitle {
    text-align: center;
    color: var(--text-muted);
    margin-bottom: 40px;
    font-size: 1.1rem;
}

/* ========================
   CALCULATOR CARD
======================== */
.calculator-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 30px;
    margin-bottom: 40px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.input-group { margin-bottom: 20px; }

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-main);
}

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

.input-prefix, .input-suffix {
    position: absolute;
    color: var(--text-muted);
    font-weight: 500;
}
.input-prefix { left: 15px; }
.input-suffix { right: 15px; }

.form-control {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: var(--bg-color);
}
.form-control.has-prefix { padding-left: 35px; }
.form-control.has-suffix { padding-right: 35px; }

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
    background: #fff;
}

input[type="range"] {
    width: 100%;
    margin-top: 10px;
    accent-color: var(--primary);
}

.btn-primary {
    background: var(--primary);
    color: white;
    border: none;
    padding: 14px 24px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.4);
}

/* ========================
   RESULTS AREA
======================== */
.results-area {
    background: linear-gradient(135deg, var(--bg-color), #fff);
    border-radius: var(--radius);
    padding: 30px;
    border: 1px solid var(--border-color);
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.result-item { margin-bottom: 20px; }
.result-item:last-child { margin-bottom: 0; }

.result-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 5px;
}

.result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}
.result-value.secondary {
    font-size: 1.5rem;
    color: var(--text-main);
}

/* ========================
   CONTENT SECTION
======================== */
.content-section {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow);
    margin-bottom: 40px;
}

.content-section h2 {
    color: var(--text-main);
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.content-section p {
    margin-bottom: 15px;
    color: #334155;
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    overflow-x: auto;
    display: block;
}

.comparison-table th, .comparison-table td {
    padding: 15px;
    border: 1px solid var(--border-color);
    text-align: left;
    white-space: nowrap;
}

.comparison-table th {
    background: var(--bg-color);
    font-weight: 600;
}

/* ========================
   FAQ SECTION
======================== */
.faq-section { margin-bottom: 40px; }

.faq-item {
    background: var(--card-bg);
    border-radius: 8px;
    margin-bottom: 15px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.faq-question {
    padding: 18px 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: var(--text-main);
    transition: background 0.3s;
    font-size: 0.95rem;
}

.faq-question:hover { background: var(--bg-color); }

.faq-icon {
    font-size: 1.2rem;
    transition: transform 0.3s;
    flex-shrink: 0;
    margin-left: 10px;
}

.faq-answer {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease;
    color: #475569;
}

.faq-item.active .faq-answer {
    padding: 20px;
    border-top: 1px solid var(--border-color);
    max-height: 500px;
}

.faq-item.active .faq-icon { transform: rotate(45deg); }

/* ========================
   INTERNAL LINKS
======================== */
.internal-links { margin-bottom: 40px; }
.internal-links h3 {
    margin-bottom: 20px;
    text-align: center;
    font-size: 1.5rem;
}
.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 15px;
}

.link-card {
    background: var(--card-bg);
    padding: 18px;
    border-radius: var(--radius);
    text-align: center;
    text-decoration: none;
    color: var(--text-main);
    font-weight: 500;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
    font-size: 0.95rem;
}

.link-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(79, 70, 229, 0.1);
    color: var(--primary);
}

/* ========================
   FOOTER
======================== */
footer {
    background: #0f172a;
    color: #94a3b8;
    text-align: center;
    padding: 30px 20px;
    margin-top: 60px;
}

footer a {
    color: #818cf8;
    text-decoration: none;
}
footer a:hover { text-decoration: underline; }

/* ========================
   RESPONSIVE BREAKPOINTS
======================== */

/* Tablet */
@media (max-width: 900px) {
    .calculator-card {
        grid-template-columns: 1fr;
    }
    .page-title { font-size: 2rem; }
}

/* Mobile */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: flex; }

    .page-title { font-size: 1.7rem; }
    .page-subtitle { font-size: 1rem; }

    .content-section {
        padding: 25px 18px;
    }

    .calculator-card {
        padding: 20px;
        gap: 20px;
    }

    .result-value { font-size: 1.6rem; }
    .result-value.secondary { font-size: 1.2rem; }

    .links-grid {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }

    .link-card { padding: 13px 10px; font-size: 0.85rem; }
}

/* Small Mobile */
@media (max-width: 480px) {
    .container { padding: 0 14px; }

    .page-title { font-size: 1.4rem; margin: 25px 0 10px; }
    .page-subtitle { font-size: 0.9rem; margin-bottom: 25px; }

    .calculator-card { padding: 16px; }
    .results-area { padding: 20px 15px; }

    .content-section { padding: 18px 14px; }
    .content-section h2 { font-size: 1.4rem; }

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

    .faq-question { font-size: 0.9rem; padding: 15px; }
}