/*
Theme Name: FastAllCalc
Theme URI: https://fastallcalc.com
Author: Aditya Gupta
Author URI: https://fastallcalc.com
Description: Free online calculator hub with 400+ calculators for finance, health, math, and engineering.
Version: 1.0.2
Requires at least: 5.8
Tested up to: 6.8
Requires PHP: 7.4
License: GNU General Public License v2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: fastallcalc
*/
:root {
            --bg-main: #ffffff;
            --bg-dark: #111111;
            --bg-dark-soft: #1d1d1d;
            --bg-panel: #f5f5f5;
            --border-light: #e0e0e0;
            --border-dark: #333333;
            --text-main: #000000;
            --text-invert: #ffffff;
            --accent: #000000;
            --muted: #777777;
            --btn-dark: #000000;
            --btn-light: #ffffff;
            --btn-grey: #2b2b2b;
            --btn-border: #444444;
            --shadow-soft: 0 6px 20px rgba(0, 0, 0, 0.25);
            --radius-lg: 10px;
            --radius-md: 6px;
            --radius-pill: 999px;
            --transition-fast: 0.15s ease-out;
            --max-width: 1160px;
            --header-height: 72px;
            --font-main: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
        }

        * {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            font-family: var(--font-main);
            background: var(--bg-main);
            color: var(--text-main);
            -webkit-font-smoothing: antialiased;
        }

        a {
            color: inherit;
            text-decoration: none;
        }

        a:hover {
            text-decoration: underline;
        }

        .page {
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        /* HEADER */
        .site-header {
            height: var(--header-height);
            border-bottom: 1px solid var(--border-light);
            display: flex;
            align-items: center;
            position: sticky;
            top: 0;
            background: var(--bg-main);
            z-index: 40;
        }

        .header-inner {
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 16px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 16px;
        }

        .brand {
            display: flex;
            align-items: center;
            gap: 10px;
            min-width: 0;
            pointer-events: none;
        }

        .brand-logo {
            width: 34px;
            height: 34px;
            border-radius: 8px;
            background: var(--bg-dark);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-invert);
            font-weight: 700;
            font-size: 18px;
            pointer-events: none;
        }

        .brand-text {
            display: flex;
            flex-direction: column;
            align-items: flex-start;
            line-height: 1.2;
        }

        .brand-text-main {
            font-weight: 700;
            font-size: 20px;
            letter-spacing: 0.03em;
            text-transform: lowercase;
            white-space: nowrap;
            pointer-events: none;
        }

        .brand-text-sub {
            font-size: 10px;
            color: var(--muted);
            white-space: nowrap;
            pointer-events: none;
            margin-top: 2px;
        }

        /* DESKTOP NAVIGATION (visible only on desktop) */
        .desktop-nav {
            display: flex;
            gap: 8px;
            align-items: center;
        }

        .nav-link {
            background: transparent;
            border: none;
            font-size: 14px;
            font-weight: 500;
            padding: 8px 14px;
            border-radius: 40px;
            cursor: pointer;
            transition: all 0.2s ease;
            color: #1a1a1a;
            font-family: var(--font-main);
            white-space: nowrap;
        }

        .nav-link:hover {
            background: #f0f0f0;
            color: #000;
        }

        /* Hide desktop nav on mobile, show menu button */
        @media (max-width: 768px) {
            .desktop-nav {
                display: none;
            }
        }

        /* MAIN INNER LAYOUT */
        .main {
            flex: 1;
        }

        .main-inner {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 20px 16px 40px;
        }

        .top-row {
            display: grid;
            grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
            gap: 24px;
        }

        @media (max-width: 960px) {
            .top-row {
                grid-template-columns: minmax(0, 1fr);
                display: flex;
                flex-direction: column;
            }

            .right-panel {
                order: -1;
            }

            .header-inner {
                flex-wrap: wrap;
                align-items: flex-start;
            }
        }

        @media (max-width: 600px) {
            .main-inner {
                padding: 14px 12px 32px;
            }

            .hero-heading {
                font-size: 18px;
                line-height: 1.35;
            }

            .right-panel p {
                font-size: 14px;
                line-height: 1.6;
            }

            .section-card {
                padding: 16px 14px;
            }

            .site-header {
                height: auto;
                padding: 8px 0;
            }

            .brand-text-main {
                font-size: 18px;
            }

            .brand-text-sub {
                font-size: 9px;
            }

            .brand-logo {
                width: 30px;
                height: 30px;
                font-size: 16px;
            }
        }

        /* SCIENTIFIC CALCULATOR */
        .calc-panel {
            padding: 0;
            background: transparent;
            box-shadow: none;
            color: var(--text-invert);
        }

        .sci-calc-section {
            user-select: none;
            width: 100%;
        }

        .sci-calc-section .expression-input {
            user-select: text;
        }

        .sci-calc-section .calculator-container {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
            justify-content: center;
            width: 100%;
        }

        .sci-calc-section .calculator {
            background: #000000;
            border-radius: 28px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.25), inset 0 1px 0 rgba(255, 255, 255, 0.08);
            padding: 20px;
            border: 1px solid #333;
            flex: 2;
            min-width: 0;
            width: 100%;
        }

        .sci-calc-section .history-panel {
            background: #0a0a0a;
            border-radius: 28px;
            border: 1px solid #333;
            padding: 20px;
            flex: 1;
            min-width: 200px;
            max-width: 260px;
            display: flex;
            flex-direction: column;
        }

        .sci-calc-section .history-title {
            color: #ccc;
            font-size: 1rem;
            font-weight: bold;
            padding-bottom: 12px;
            border-bottom: 2px solid #333;
            margin-bottom: 15px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .sci-calc-section .history-title button {
            background: #1a1a1a;
            border: 1px solid #444;
            color: #ff8888;
            padding: 4px 12px;
            border-radius: 20px;
            cursor: pointer;
            font-size: 0.7rem;
        }

        .sci-calc-section .history-list {
            flex: 1;
            overflow-y: auto;
            max-height: 500px;
        }

        .sci-calc-section .history-item {
            background: #111;
            border-radius: 12px;
            padding: 10px;
            margin-bottom: 8px;
            border-left: 3px solid #666;
            cursor: pointer;
            transition: all 0.2s;
        }

        .sci-calc-section .history-item:hover {
            background: #1a1a1a;
            border-left-color: #4caf50;
        }

        .sci-calc-section .history-expr {
            font-size: 0.9rem;
            color: #4caf50;
            word-break: break-word;
            font-family: 'Segoe UI', monospace;
        }

        .sci-calc-section .history-result {
            font-size: 0.9rem;
            color: #fff;
            font-weight: bold;
            margin-top: 5px;
            word-break: break-word;
        }

        .sci-calc-section .history-empty {
            color: #555;
            text-align: center;
            padding: 20px;
            font-size: 0.8rem;
        }

        .sci-calc-section .casio-header {
            text-align: center;
            margin-bottom: 15px;
        }

        .sci-calc-section .casio-brand {
            font-size: 1.3rem;
            font-weight: 700;
            font-family: 'Segoe UI', sans-serif;
            color: #ffffff;
            letter-spacing: 1px;
        }

        .sci-calc-section .status-bar {
            display: flex;
            justify-content: space-between;
            background: #111;
            padding: 5px 12px;
            border-radius: 12px;
            margin-bottom: 12px;
        }

        .sci-calc-section .status-item {
            color: #ddd;
            font-size: 0.65rem;
            font-weight: bold;
            font-family: monospace;
        }

        .sci-calc-section .display-panel {
            background: #0d0d0d;
            border-radius: 16px;
            padding: 16px;
            margin-bottom: 20px;
            border: 1px solid #2a2a2a;
        }

        .sci-calc-section .expression-wrapper {
            background: #080808;
            border-radius: 12px;
            margin-bottom: 8px;
            border: 1px solid #2a2a2a;
            transition: all 0.2s;
        }

        .sci-calc-section .expression-wrapper:focus-within {
            border-color: #4caf50;
        }

        .sci-calc-section .expression-input {
            width: 100%;
            min-height: 65px;
            font-size: 1.3rem;
            font-family: 'Segoe UI', 'Orbitron', monospace;
            color: #4caf50;
            text-align: right;
            background: transparent;
            border: none;
            padding: 12px 16px;
            outline: none;
            font-weight: 500;
            letter-spacing: 1px;
        }

        .sci-calc-section .calc-result-display {
            font-size: 2.2rem;
            font-weight: 700;
            font-family: 'Orbitron', monospace;
            text-align: right;
            color: #ffffff;
            background: #080808;
            padding: 8px 14px;
            border-radius: 12px;
            min-height: 75px;
            word-break: break-word;
        }

        .sci-calc-section .buttons-grid {
            display: grid;
            grid-template-columns: repeat(5, 1fr);
            gap: 8px;
        }

        .sci-calc-section .btn {
            border: none;
            border-radius: 12px;
            padding: 12px 0;
            font-size: 0.85rem;
            font-weight: 600;
            font-family: 'Segoe UI', monospace;
            cursor: pointer;
            transition: all 0.05s linear;
            text-align: center;
        }

        .sci-calc-section .btn:active {
            transform: scale(0.96);
        }

        .sci-calc-section .btn-func { background: #2a2a2a; color: white; border: 1px solid #444; }
        .sci-calc-section .btn-func:active { background: #444; }
        .sci-calc-section .btn-inv { background: #1a1a1a; color: #ddd; border: 1px solid #3a3a3a; }
        .sci-calc-section .btn-inv:active { background: #333; }
        .sci-calc-section .btn-mem { background: #222; color: #ccc; border: 1px solid #3a3a3a; }
        .sci-calc-section .btn-mem:active { background: #3a3a3a; }
        .sci-calc-section .btn-clear { background: #1a1a1a; color: #ff8888; border: 1px solid #553333; }
        .sci-calc-section .btn-clear:active { background: #331111; }
        .sci-calc-section .btn-equal { background: #ffffff; color: #000000; border: 1px solid #aaa; font-size: 1.1rem; font-weight: bold; }
        .sci-calc-section .btn-equal:active { background: #ddd; }
        .sci-calc-section .btn-op { background: #222; color: #ffaa66; border: 1px solid #443322; font-size: 1rem; font-weight: bold; }
        .sci-calc-section .btn-op:active { background: #3a2a1a; }
        .sci-calc-section .btn-num { background: #1a1a1a; color: white; border: 1px solid #3a3a3a; font-size: 1rem; font-weight: bold; }
        .sci-calc-section .btn-num:active { background: #333; }
        .sci-calc-section .btn-special { background: #252525; color: #aaa; border: 1px solid #3a3a3a; }
        .sci-calc-section .btn-special:active { background: #3a3a3a; }

        @media (max-width: 750px) {
            .sci-calc-section .calculator-container { flex-direction: column; align-items: stretch; }
            .sci-calc-section .history-panel { max-width: 100%; width: 100%; }
            .sci-calc-section .btn { font-size: 0.7rem; padding: 10px 0; }
            .sci-calc-section .calc-result-display { font-size: 1.5rem; }
            .sci-calc-section .expression-input { font-size: 1rem; }
        }

        .right-panel {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .hero-heading {
            font-size: 22px;
            font-weight: 700;
            margin: 0;
        }

        /* CALCULATOR SEARCH */
        .calc-search-wrap {
            margin-top: 16px;
            position: relative;
        }

        .calc-search-box {
            position: relative;
        }

        .calc-search-icon {
            position: absolute;
            left: 14px;
            top: 50%;
            transform: translateY(-50%);
            width: 18px;
            height: 18px;
            color: #888;
            pointer-events: none;
        }

        .calc-search-input {
            width: 100%;
            padding: 12px 14px 12px 42px;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-md);
            font-size: 15px;
            font-family: var(--font-main);
            background: #ffffff;
            transition: border-color var(--transition-fast);
            outline: none;
            -webkit-appearance: none;
        }

        .calc-search-input:focus {
            border-color: #000000;
        }

        .calc-search-input::placeholder {
            color: #999;
        }

        .calc-search-results {
            position: absolute;
            top: calc(100% + 6px);
            left: 0;
            right: 0;
            background: #ffffff;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-md);
            max-height: 280px;
            overflow-y: auto;
            box-shadow: var(--shadow-soft);
            z-index: 60;
            display: none;
        }

        .calc-search-results.visible {
            display: block;
        }

        .calc-search-result {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 10px;
            padding: 11px 14px;
            text-decoration: none;
            color: inherit;
            border-bottom: 1px solid #f0f0f0;
        }

        .calc-search-result:last-child {
            border-bottom: none;
        }

        .calc-search-result:hover,
        .calc-search-result.active {
            background: #f5f5f5;
        }

        .calc-search-result-name {
            font-size: 14px;
        }

        .calc-search-result-cat {
            font-size: 11px;
            color: var(--muted);
            white-space: nowrap;
            flex-shrink: 0;
        }

        .calc-search-empty {
            padding: 14px;
            text-align: center;
            font-size: 13px;
            color: var(--muted);
        }

        @media (max-width: 600px) {
            .calc-search-input {
                font-size: 16px;
                padding: 13px 14px 13px 42px;
            }

            .calc-search-results {
                max-height: 50vh;
            }

            .calc-search-result {
                padding: 13px 14px;
            }
        }

        .sections-grid {
            margin-top: 26px;
            display: flex;
            flex-direction: column;
            gap: 28px;
        }

        .section-card {
            background: var(--bg-panel);
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-light);
            padding: 20px 20px 18px;
            display: flex;
            flex-direction: column;
            gap: 14px;
            scroll-margin-top: 88px;
        }

        .section-head {
            display: flex;
            align-items: center;
            gap: 12px;
            padding-bottom: 12px;
            border-bottom: 2px solid var(--border-light);
        }

        .section-icon {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background: #000000;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #ffffff;
            font-size: 22px;
            font-weight: 600;
        }

        .section-title {
            font-size: 16px;
            font-weight: 600;
        }

        .section-subtitle {
            font-size: 12px;
            color: var(--muted);
        }

        .section-list {
            margin: 0;
            padding: 0;
            list-style: none;
        }

        .section-list li {
            font-size: 13px;
            margin-bottom: 0;
        }

        .section-list a {
            display: block;
            padding: 5px 0;
            text-decoration: none;
            border-bottom: 1px dotted transparent;
            transition: border-color var(--transition-fast), color var(--transition-fast);
        }

        .section-list a:hover {
            border-bottom-color: #000000;
            color: #000000;
        }

        .calc-link-grid {
            display: grid;
            grid-template-columns: repeat(3, minmax(0, 1fr));
            gap: 2px 24px;
        }

        @media (max-width: 900px) {
            .calc-link-grid {
                grid-template-columns: repeat(2, minmax(0, 1fr));
            }
        }

        @media (max-width: 520px) {
            .calc-link-grid {
                grid-template-columns: minmax(0, 1fr);
            }
        }

        .section-list-container {
            width: 100%;
        }

        .section-subgroup-title {
            font-size: 13px;
            font-weight: 600;
            margin: 0 0 8px;
            color: var(--text-main);
            padding: 6px 10px;
            background: #ebebeb;
            border-radius: 4px;
        }

        .section-count {
            font-size: 11px;
            color: var(--muted);
            font-weight: 500;
            margin-left: 4px;
        }

        .eng-disciplines-wrap {
            display: flex;
            flex-direction: column;
            gap: 32px;
        }

        .eng-discipline-block {
            background: #ffffff;
            border: 1px solid var(--border-light);
            border-radius: var(--radius-lg);
            overflow: hidden;
            scroll-margin-top: 96px;
        }

        .eng-discipline-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            padding: 14px 18px;
            background: #000000;
            color: #ffffff;
        }

        .eng-discipline-title {
            font-size: 16px;
            font-weight: 700;
            margin: 0;
            padding: 0;
            border: none;
        }

        .eng-discipline-count {
            font-size: 11px;
            opacity: 0.75;
            white-space: nowrap;
        }

        .eng-discipline-body {
            padding: 16px 18px 8px;
        }

        .eng-subgroup-grid {
            display: grid;
            grid-template-columns: repeat(2, minmax(0, 1fr));
            gap: 14px;
        }

        @media (max-width: 900px) {
            .eng-subgroup-grid {
                grid-template-columns: minmax(0, 1fr);
            }
        }

        .eng-subgroup-card {
            border: 1px solid var(--border-light);
            border-radius: var(--radius-md);
            background: #fafafa;
            padding: 12px 14px 10px;
            display: flex;
            flex-direction: column;
            gap: 8px;
        }

        .eng-subgroup-title {
            font-size: 12px;
            font-weight: 700;
            margin: 0;
            color: #111;
            padding: 0 0 8px;
            border-bottom: 1px solid var(--border-light);
            border-left: none;
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }

        .eng-subgroup-card .section-list {
            display: flex;
            flex-direction: column;
            gap: 0;
        }

        .eng-subgroup-card .section-list a {
            padding: 4px 0;
            font-size: 12px;
        }

        .eng-subgroup-count {
            font-size: 10px;
            color: var(--muted);
            font-weight: 500;
        }

        .all-calcs-wrapper {
            display: flex;
            justify-content: center;
            margin-top: 26px;
        }

        .all-calcs-button {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 10px 18px;
            border-radius: var(--radius-pill);
            border: 1px solid #000000;
            background: #000000;
            color: #ffffff;
            font-size: 13px;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            cursor: pointer;
            transition: background var(--transition-fast), color var(--transition-fast);
        }

        .all-calcs-button:hover {
            background: #ffffff;
            color: #000000;
        }

        .all-calcs-icon {
            width: 16px;
            height: 16px;
            border-radius: 3px;
            border: 1px solid currentColor;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            grid-template-rows: repeat(2, 1fr);
        }

        .all-calcs-icon span {
            border-left: 1px solid currentColor;
            border-bottom: 1px solid currentColor;
        }

        .all-calcs-icon span:nth-child(2),
        .all-calcs-icon span:nth-child(4) {
            border-left: none;
        }

        .all-calcs-icon span:nth-child(3),
        .all-calcs-icon span:nth-child(4) {
            border-bottom: none;
        }

        /* ALL CALCULATORS OVERLAY */
        .all-calcs-overlay {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.72);
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 9999;
            padding: 16px;
        }

        .all-calcs-overlay.visible {
            display: flex;
        }

        .all-calcs-dialog {
            max-width: 1100px;
            width: 100%;
            max-height: 90vh;
            background: #ffffff;
            color: #000000;
            border-radius: 12px;
            box-shadow: 0 18px 60px rgba(0, 0, 0, 0.4);
            display: flex;
            flex-direction: column;
            overflow: hidden;
        }

        .all-calcs-header {
            padding: 14px 18px;
            border-bottom: 1px solid var(--border-light);
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 10px;
        }

        .all-calcs-title {
            font-size: 16px;
            font-weight: 600;
        }

        .all-calcs-close {
            border: none;
            background: transparent;
            cursor: pointer;
            font-size: 24px;
            padding: 0 6px;
            line-height: 1;
            color: #666;
        }

        .all-calcs-close:hover {
            color: #000;
        }

        .all-calcs-body {
            padding: 12px 18px 16px;
            overflow-y: auto;
        }

        .all-calcs-block {
            margin-bottom: 24px;
        }

        .all-calcs-block:last-child {
            margin-bottom: 0;
        }

        .all-calcs-grid {
            display: grid;
            grid-template-columns: repeat(2, minmax(0, 1fr));
            gap: 18px;
        }

        @media (max-width: 700px) {
            .all-calcs-grid {
                grid-template-columns: minmax(0, 1fr);
            }
        }

        .all-calcs-section-title {
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 4px;
        }

        .all-calcs-list {
            margin: 0;
            padding-left: 18px;
            font-size: 13px;
        }

        .all-calcs-list li {
            margin-bottom: 4px;
        }

        .all-calcs-list a {
            text-decoration: none;
            border-bottom: 1px dotted transparent;
        }

        .all-calcs-list a:hover {
            border-bottom-color: #000000;
        }

        /* FOOTER */
        .site-footer {
            border-top: 1px solid var(--border-light);
            padding: 12px 16px 18px;
            font-size: 12px;
            color: var(--muted);
        }

        .footer-inner {
            max-width: var(--max-width);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 8px;
        }

        .footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
        }

        .footer-links a {
            color: inherit;
        }

        .footer-copy {
            white-space: nowrap;
        }

        @media (max-width: 600px) {
            .footer-inner {
                flex-direction: column;
                align-items: flex-start;
            }
        }

        /* ============== MENU BUTTON & POPUP STYLES (mobile only) ============== */
        .fixed-menu-btn {
            position: fixed !important;
            top: 14px !important;
            right: 20px !important;
            width: 36px !important;
            height: 36px !important;
            border-radius: 50%;
            background: #111111;
            border: 1px solid #333;
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            z-index: 9999;
            box-shadow: 0 4px 12px rgba(0,0,0,0.25);
            transition: background 0.15s ease-out;
            margin: 0;
            padding: 0;
        }

        .fixed-menu-btn:hover {
            background: #333;
        }

        .fixed-menu-btn svg {
            width: 20px;
            height: 20px;
            fill: currentColor;
        }

        @media (min-width: 769px) {
            .fixed-menu-btn {
                display: none !important;
            }
        }

        .popup-overlay {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.5);
            z-index: 9998;
            display: none;
            align-items: flex-start;
            justify-content: flex-end;
            padding: 70px 20px 20px 20px;
        }

        .popup-overlay.active {
            display: flex;
        }

        .popup-container {
            width: 100%;
            max-width: 380px;
            max-height: calc(100vh - 90px);
            background: white;
            border-radius: 12px;
            box-shadow: 0 12px 40px rgba(0,0,0,0.3);
            overflow: hidden;
            display: flex;
            flex-direction: column;
            animation: slideIn 0.2s ease-out;
        }

        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .popup-header {
            padding: 16px 18px;
            border-bottom: 1px solid #e0e0e0;
            display: flex;
            align-items: center;
            justify-content: space-between;
            background: #f8f8f8;
        }

        .popup-title {
            font-size: 16px;
            font-weight: 600;
        }

        .popup-close {
            background: none;
            border: none;
            font-size: 24px;
            cursor: pointer;
            padding: 0 6px;
            line-height: 1;
            color: #666;
        }

        .popup-close:hover {
            color: #000;
        }

        .popup-body {
            overflow-y: auto;
            padding: 10px 0;
        }

        .category-list {
            list-style: none;
        }

        .category-item {
            padding: 14px 20px;
            cursor: pointer;
            font-weight: 500;
            border-bottom: 1px solid #f0f0f0;
            transition: background 0.1s;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .category-item:hover {
            background: #f5f5f5;
        }

        .category-item::after {
            content: "›";
            font-size: 20px;
            color: #999;
        }

        .calculators-list {
            list-style: none;
        }

        .calculator-item {
            display: block;
            padding: 12px 20px;
            border-bottom: 1px solid #f0f0f0;
            font-size: 14px;
            text-decoration: none;
            color: inherit;
            transition: background 0.1s;
        }

        .calculator-item:hover {
            background: #f5f5f5;
            color: #000;
        }

        .category-group-title {
            background: #f0f0f0;
            padding: 8px 20px;
            font-size: 13px;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: #555;
            border-bottom: 1px solid #ddd;
        }

        .popup-back {
            background: none;
            border: none;
            font-size: 15px;
            cursor: pointer;
            padding: 8px 16px;
            margin: 8px 12px;
            border-radius: 4px;
            color: #000;
            font-weight: 500;
            display: inline-block;
        }

        .popup-back:hover {
            background: #eee;
        }

        /* Smooth scroll behavior */
        html {
            scroll-behavior: smooth;
        }