/* CSS Variables for Theming */
:root {
    --primary: #ffffff;
    --secondary: #f8f9fa;
    --text: #333333;
    --accent: #28828b;
    --accent-light: #4dbdc7;
    --accent-dark: #1c5a60;
    --border: #e0e0e0;
    --shadow: rgba(0, 0, 0, 0.1);
    --card-bg: #ffffff;
    --footer-bg: #f1f1f1;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --primary: #121212;
    --secondary: #181a1b;
    --text: #f5f5f5;
    --accent: #28828b;
    --accent-light: #4dbdc7;
    --accent-dark: #1c5a60;
    --border: #22292b;
    --shadow: rgba(0, 0, 0, 0.5);
    --card-bg: #181a1b;
    --footer-bg: #161718;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--primary);
    color: var(--text);
    line-height: 1.6;
    transition: var(--transition);
    -webkit-font-smoothing: antialiased;
    -webkit-text-size-adjust: 100%;
    -webkit-overflow-scrolling: touch;
}

button, a, input, select, label {
    min-height: 44px;
    min-width: 44px;
}

@supports (-webkit-touch-callout: none) {
    input, select {
        font-size: 16px;
    }
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

img {
    max-width: 100%;
}

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

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

.btn {
    display: inline-block;
    padding: 12px 24px;
    background-color: var(--accent);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    user-select: none;
    font-size: 1rem;
}

.btn:hover {
    background-color: var(--accent-dark);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--accent);
    color: var(--accent);
}

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

section {
    padding: 60px 0;
}

h1, h2, h3, h4 {
    margin-bottom: 20px;
    line-height: 1.2;
    color: var(--text);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
    position: relative;
    padding-bottom: 15px;
}

h2:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

p {
    margin-bottom: 15px;
}

header {
    background-color: var(--primary);
    box-shadow: 0 2px 10px var(--shadow);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent);
}

.logo i {
    margin-right: 10px;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    font-weight: 500;
    color: var(--text);
}

nav ul li a:hover, 
nav ul li a.active {
    color: var(--accent);
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text);
    margin-left: 20px;
    transition: var(--transition);
}

.theme-toggle:hover {
    color: var(--accent);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text);
    margin-left: 20px;
    transition: var(--transition);
    z-index: 10001;
}

.hero {
    background: linear-gradient(135deg, var(--accent-light) 0%, var(--accent) 100%);
    color: white;
    text-align: center;
    padding: 100px 0;
}

.hero h1 {
    color: white;
    font-size: 3rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 30px;
}

.calculator-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
}

@media (min-width: 992px) {
    .calculator-container {
        grid-template-columns: 1fr 1fr;
    }
}

.calculator-form {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 5px 15px var(--shadow);
}

.calculator-result {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 5px 15px var(--shadow);
}

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

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

input, select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background-color: var(--primary);
    color: var(--text);
    font-size: 1rem;
    transition: var(--transition);
    -webkit-appearance: none;
    appearance: none;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(40, 130, 139, 0.2);
}

select {
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23e63946' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 16px;
    padding-right: 30px;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.result-box {
    background: var(--secondary);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent);
    margin: 10px 0;
}

.result-label {
    font-size: 1rem;
    color: var(--text);
}

.teaspoons {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 15px;
}

.teaspoons i {
    color: var(--accent);
    margin: 0 5px;
    font-size: 1.5rem;
}

.section-title {
    text-align: center;
    margin-bottom: 40px;
}

.section-title h2:after {
    left: 50%;
    transform: translateX(-50%);
}

.tools-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

@media (min-width: 768px) {
    .tools-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.tool-card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 15px var(--shadow);
    transition: var(--transition);
}

.tool-card:hover {
    transform: translateY(-10px);
}

.tool-card i {
    font-size: 3rem;
    color: var(--accent);
    margin-bottom: 20px;
}

.tool-card h3 {
    margin-bottom: 15px;
}

.info-content {
    max-width: 800px;
    margin: 0 auto;
}

.info-box {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 5px 15px var(--shadow);
}

.info-box h3 {
    color: var(--accent);
    margin-bottom: 15px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background-color: var(--secondary);
    font-weight: 600;
}

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

.sources-list li {
    margin-bottom: 15px;
    padding-left: 20px;
    position: relative;
}

.sources-list li:before {
    content: "•";
    color: var(--accent);
    position: absolute;
    left: 0;
}

footer {
    background: var(--footer-bg);
    padding: 60px 0 20px;
}

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

@media (min-width: 768px) {
    .footer-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.footer-col h4 {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.footer-links {
    list-style: none;
}

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

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

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

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--accent);
    color: white;
    border-radius: 50%;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--accent-dark);
    transform: translateY(-5px);
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
    color: var(--text);
}

.go-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--accent);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: 0 5px 15px var(--shadow);
    z-index: 99;
}

.go-top.active {
    opacity: 1;
    visibility: visible;
}

.go-top i {
    color: white !important;
    font-size: 2rem !important;
}

.fas, .fa {
    color: inherit;
    font-size: inherit;
    vertical-align: middle;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.95);
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}
.overlay.active {
    display: flex;
    opacity: 1;
    visibility: visible;
}
.overlay .close-menu {
    position: absolute;
    top: 30px;
    right: 30px;
    font-size: 2rem;
    color: white;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 10001;
}
.overlay nav ul li a {
    color: white;
    font-size: 2rem;
    font-weight: 600;
    transition: color 0.2s;
}
.overlay nav ul li a:hover {
    color: var(--accent-light);
}

@media (max-width: 320px) {
    .hero h1 {
        font-size: 1.8rem;
    }
    .hero p {
        font-size: 0.9rem;
    }
    .btn {
        padding: 10px 20px;
    }
}

@media (max-width: 375px) {
    .hero {
        padding: 60px 0;
    }
    .calculator-form, 
    .calculator-result {
        padding: 15px;
    }
}

@media (max-width: 414px) {
    .tools-grid {
        grid-template-columns: 1fr;
    }
    .tool-card {
        padding: 20px;
    }
}

@media (max-width: 991px) {
    .hamburger {
        display: block;
    }
    nav ul {
        display: none;
        flex-direction: column;
        align-items: flex-start;
        background: var(--primary);
        position: absolute;
        top: 60px;
        right: 20px;
        width: 200px;
        box-shadow: 0 5px 15px var(--shadow);
        border-radius: 8px;
        padding: 20px 0;
        z-index: 1000;
        transition: var(--transition);
    }
    nav.open ul {
        display: flex;
    }
    nav ul li {
        margin: 0 0 20px 0;
        width: 100%;
        text-align: left;
        padding-left: 20px;
    }
    nav ul li:last-child {
        margin-bottom: 0;
    }
    
    h1 {
        font-size: 2.2rem;
    }
    
    h2 {
        font-size: 1.8rem;
    }
    
    .hero {
        padding: 80px 0;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
}

@media (min-width: 992px) {
    .hamburger {
        display: none;
    }
    nav ul {
        display: flex !important;
        position: static;
        flex-direction: row;
        align-items: center;
        background: none;
        box-shadow: none;
        border-radius: 0;
        padding: 0;
        width: auto;
    }
    nav ul li {
        margin: 0 0 0 30px;
        padding-left: 0;
        text-align: left;
    }
}

@media (max-width: 576px) {
    section {
        padding: 40px 0;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .calculator-form, 
    .calculator-result {
        padding: 20px;
    }
    
    .result-value {
        font-size: 2rem;
    }

    .calculator-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .form-group {
        margin-bottom: 15px;
    }

    input, select {
        padding: 10px;
    }

    .btn {
        padding: 10px 20px;
        width: 100%;
    }
}

@media (max-width: 768px) {
    .responsive-table-wrapper {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .responsive-table-wrapper table {
        min-width: 700px;
    }
}

/* 404 Error Page Styles */
.error-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 0;
}

.error-icon {
    font-size: 4rem;
    color: var(--accent);
    margin-bottom: 20px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

.error-content h1 {
    color: var(--text);
    margin-bottom: 20px;
    font-size: 2.5rem;
}

.error-content p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    color: var(--text);
    opacity: 0.8;
}

.error-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 30px;
}

.error-actions .btn {
    min-width: 150px;
}

@media (max-width: 576px) {
    .error-content h1 {
        font-size: 2rem;
    }
    
    .error-content p {
        font-size: 1rem;
    }
    
    .error-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .error-actions .btn {
        width: 100%;
        max-width: 250px;
    }
    
    .error-icon {
        font-size: 3rem;
    }
}