/* Global theme and reset */
:root {
    --primary: #0d6efd;
    --primary-dark: #0b57cc;
    --accent: #1fa971;
    --text: #15314b;
    --muted: #587187;
    --bg: #f2f8ff;
    --card-bg: #ffffff;
    --border: #d8e6f4;
    --surface: #ffffff;
    --surface-alt: #eaf2ff;
    --input-bg: #ffffff;
    --input-border: #c9d8e8;
    --result-bg: #f5fbff;
    --info-card-bg: #f8fbff;
    --tag-bg: #eaf2ff;
    --success-bg: #effdf5;
    --success-border: #bde8d2;
    --success-text: #1a7a4e;
    --error-bg: #fff1f1;
    --error-border: #f3bbbb;
    --error-text: #c62828;
    --hero-gradient: linear-gradient(135deg, #d8eaff 0%, #ffffff 40%, #d5f3e7 100%);
    --shadow: 0 8px 24px rgba(13, 45, 84, 0.1);
    --focus-ring: rgba(13, 110, 253, 0.18);
}

body.dark-mode {
    --primary: #4dabf7;
    --primary-dark: #74c0fc;
    --accent: #3dd598;
    --text: #f5f5f5;
    --muted: #bfd0e0;
    --bg: #121212;
    --card-bg: #1e1e1e;
    --border: #314252;
    --surface: #1a1a1a;
    --surface-alt: #213042;
    --input-bg: #1f2630;
    --input-border: #3a4f63;
    --result-bg: #1a2733;
    --info-card-bg: #1a2733;
    --tag-bg: #243649;
    --success-bg: #163325;
    --success-border: #2e6d52;
    --success-text: #8ce6b9;
    --error-bg: #3a2020;
    --error-border: #7a3a3a;
    --error-text: #ff9b9b;
    --hero-gradient: linear-gradient(135deg, #1a2533 0%, #121212 40%, #173529 100%);
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
    --focus-ring: rgba(116, 192, 252, 0.28);
}

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

body {
    font-family: "Poppins", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    width: min(1100px, 92%);
    margin: 0 auto;
}

/* Navbar */
.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: var(--surface);
    box-shadow: 0 2px 12px rgba(18, 52, 88, 0.08);
}

.navbar {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.logo {
    text-decoration: none;
    color: var(--text);
    font-size: 1.3rem;
    font-weight: 700;
}

.nav-links {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    text-decoration: none;
    color: var(--muted);
    font-weight: 500;
    padding: 10px 14px;
    border-radius: 8px;
    transition: all 0.25s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-dark);
    background: var(--surface-alt);
}

.menu-toggle {
    display: none;
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 8px;
    padding: 6px 10px;
    font-size: 1.1rem;
}

/* Hero section */
.hero {
    min-height: calc(100vh - 72px);
    display: flex;
    align-items: center;
    background: var(--hero-gradient);
}

.hero-content {
    text-align: center;
    padding: 60px 0;
}

.tagline {
    color: var(--accent);
    font-weight: 600;
}

h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    line-height: 1.2;
    margin: 10px 0 16px;
}

.mission {
    font-size: 1.1rem;
    max-width: 820px;
    margin: 0 auto 12px;
}

.description,
.section-intro {
    color: var(--muted);
    max-width: 760px;
    margin: 0 auto 28px;
}

.cta-group {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.cta-group-home {
    align-items: flex-start;
    gap: 14px;
}


/* Shared cards and forms */
.page-main {
    padding: 48px 0;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    box-shadow: var(--shadow);
    padding: 28px;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.calculator-wrapper,
.contact-card {
    max-width: 640px;
}

.field-group {
    margin-bottom: 18px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

input,
textarea {
    width: 100%;
    border: 1px solid var(--input-border);
    background: var(--input-bg);
    color: var(--text);
    border-radius: 10px;
    padding: 12px 14px;
    font: inherit;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--focus-ring);
}

button {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.input-wrapper {
    position: relative;
}

.input-prefix {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    left: 12px;
    color: var(--muted);
}

.input-wrapper input {
    padding-left: 28px;
}

.btn {
    display: inline-block;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font: inherit;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    padding: 12px 18px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.14);
}

.btn-primary {
    background: var(--primary);
    color: #ffffff;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--accent);
    color: #ffffff;
}

.btn-outline {
    border: 1px solid var(--primary);
    color: var(--primary);
    background: var(--surface);
}

.full-width {
    width: 100%;
    margin-bottom: 12px;
}

.result-card,
.form-message {
    margin-top: 10px;
    background: var(--result-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 14px;
}

.error-state {
    color: var(--error-text);
    border-color: var(--error-border);
    background: var(--error-bg);
}

.success-state {
    color: var(--success-text);
    border-color: var(--success-border);
    background: var(--success-bg);
}

/* Blogs */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.blog-card h2 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.blog-card p {
    color: var(--muted);
    margin-bottom: 16px;
}

.support-mail {
    margin-bottom: 16px;
}

.support-mail a {
    color: var(--primary-dark);
}

/* Responsive styles */
@media (max-width: 900px) {
    .blog-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: inline-block;
    }

    .nav-links {
        position: absolute;
        right: 4%;
        top: 80px;
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: 12px;
        box-shadow: var(--shadow);
        padding: 10px;
        width: min(280px, 90vw);
        flex-direction: column;
        align-items: stretch;
        display: none;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links a {
        display: block;
    }

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

    .key-terms-grid {
        grid-template-columns: 1fr;
    }
}

/* Calculators hub */
.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 18px;
}

.calc-card {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.calc-card h2 {
    font-size: 1.1rem;
}

.calc-card p {
    color: var(--muted);
    flex-grow: 1;
}

.calc-icon {
    width: 46px;
    height: 46px;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(13, 110, 253, 0.12), rgba(31, 169, 113, 0.18));
    display: grid;
    place-items: center;
    font-size: 1.35rem;
}

.calc-category {
    color: var(--accent);
    font-weight: 600;
    font-size: 0.85rem;
}


/* Calculator info content */
.calculator-info-section {
    margin-top: 18px;
}

.info-divider {
    border-top: 1px solid var(--border);
    margin-bottom: 18px;
}

.calculator-info-section h2 {
    font-size: 1.35rem;
    margin: 18px 0 10px;
}

.calculator-info-section h3 {
    font-size: 1rem;
    margin-bottom: 6px;
}

.calculator-info-section p,
.calculator-info-section li {
    color: var(--muted);
}

.calculator-info-section ul {
    padding-left: 18px;
    margin-bottom: 12px;
}

.key-terms-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 8px;
}

.key-terms-grid article,
.faq-item {
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--info-card-bg);
    padding: 12px;
    margin-bottom: 10px;
}

.blog-meta {
    display: flex;
    justify-content: space-between;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--muted);
    margin-bottom: 10px;
}

.blog-tag {
    background: var(--tag-bg);
    color: var(--primary-dark);
    padding: 4px 8px;
    border-radius: 999px;
    font-weight: 600;
}

.breadcrumb {
    font-size: 0.9rem;
    margin-bottom: 12px;
    color: var(--muted);
}

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

.article-content h2 {
    margin-top: 20px;
    margin-bottom: 8px;
}

.article-content h3 {
    margin-top: 14px;
    margin-bottom: 6px;
}

.article-content p {
    margin-bottom: 12px;
    color: var(--muted);
}

.theme-toggle {
    position: fixed;
    bottom: max(20px, env(safe-area-inset-bottom));
    right: max(20px, env(safe-area-inset-right));
    width: 50px;
    height: 50px;
    border: 0;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    z-index: 999;
    background-color: var(--primary-color);
    color: #fff;
    transition: transform 0.2s ease, background-color 0.3s ease, box-shadow 0.3s ease;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

body.dark-mode .theme-toggle {
    background-color: var(--primary-dark);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
}

@media (max-width: 768px) {
    .theme-toggle {
        bottom: max(16px, env(safe-area-inset-bottom));
        right: max(16px, env(safe-area-inset-right));
    }
}

/* Enhanced calculator UX */
.calculator-wrapper.calculator-shell,
.calculator-shell {
    max-width: 1120px;
}

.calculator-layout {
    display: grid;
    grid-template-columns: minmax(290px, 380px) minmax(0, 1fr);
    gap: 20px;
    align-items: start;
}

.inputs-card {
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 18px;
    background: linear-gradient(180deg, var(--input-bg), var(--card-bg));
}

.inputs-card h2,
.result-panel h2 {
    font-size: 1.1rem;
    margin-bottom: 14px;
}

.field-inline {
    display: grid;
    gap: 10px;
}

.field-help {
    color: var(--muted);
    font-size: 0.82rem;
    margin-top: 6px;
    display: block;
}

.range-control {
    width: 100%;
    accent-color: var(--primary);
    cursor: pointer;
    padding: 0;
}

.result-panel {
    margin: 0;
    padding: 18px;
}

.result-metrics {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    margin-bottom: 16px;
}

.result-metrics article {
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 12px;
    background: var(--result-bg);
}

.result-metrics span {
    font-size: 0.85rem;
    color: var(--muted);
    display: block;
}

.result-metrics strong {
    display: block;
    margin-top: 4px;
    font-size: 1.02rem;
}

.chart-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin-bottom: 14px;
}

.chart-card {
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--surface);
    height: 260px;
    padding: 10px;
}

.breakdown-table table {
    width: 100%;
    border-collapse: collapse;
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
    background: var(--surface);
}

.breakdown-table th,
.breakdown-table td {
    text-align: left;
    padding: 10px 12px;
    border-bottom: 1px solid var(--border);
    font-size: 0.93rem;
}

.breakdown-table th {
    color: var(--muted);
    font-weight: 500;
}

@media (max-width: 900px) {
    .calculator-layout {
        grid-template-columns: 1fr;
    }

    .result-metrics,
    .chart-grid {
        grid-template-columns: 1fr;
    }

    .chart-card {
        height: 220px;
    }
}


@media (max-width: 760px) {
    .cta-group-home {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
    }

    .cta-group-home .btn,
}