:root {
    --primary-color: #002147;
    --secondary-color: #ff69b4;
    --accent-color: #4a90e2;
    --background: #ffffff;
    --surface: #ffffff;
    --error: #b00020;
    --on-primary: #ffffff;
    --on-secondary: #000000;
    --on-background: #000000;
    --on-surface: #000000;
    --on-error: #ffffff;
}

.dark-mode {
    --primary-color: #001529;
    --secondary-color: #ff69b4;
    --accent-color: #4a90e2;
    --background: #0a192f;
    --surface: #0a192f;
    --error: #cf6679;
    --on-primary: #ffffff;
    --on-secondary: #000000;
    --on-background: #ffffff;
    --on-surface: #ffffff;
    --on-error: #000000;
}

body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background);
    color: var(--on-background);
    transition: background-color 0.3s, color 0.3s;
}

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

/* Top Bar */
.top-bar {
    background-color: var(--primary-color);
    padding: 10px 0;
}

.top-bar-content {
    display: flex;
    justify-content: flex-end;
    gap: 20px;
}

.top-bar a {
    color: var(--on-primary);
    text-decoration: none;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Hero Section */
.hero {
    background-color: var(--primary-color);
    padding: 60px 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: -20%;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, var(--secondary-color) 0%, transparent 75%);
    opacity: 0.1;
    transform: skewX(-30deg);
}

.site-header {
    text-align: center;
    margin-bottom: 40px;
}

.brand-name {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--on-primary);
    display: block;
}

.brand-subtitle {
    font-size: 1.5rem;
    color: var(--on-primary);
    opacity: 0.8;
}

.hero-content {
    text-align: center;
    color: var(--on-primary);
    max-width: 800px;
    margin: 40px auto 0;
}

.hero-content h2 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.hero-content p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

/* Search Form */
.search-form {
    max-width: 700px;
    margin: 0 auto;
}

.search-container {
    display: flex;
    background: var(--surface);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.dictionary-select {
    padding: 15px;
    border: none;
    background: var(--surface);
    color: var(--on-surface);
    font-size: 1rem;
    cursor: pointer;
    border-right: 1px solid rgba(0, 0, 0, 0.1);
}

.search-input {
    flex-grow: 1;
    padding: 15px;
    border: none;
    font-size: 1rem;
    background: var(--surface);
    color: var(--on-surface);
}

.search-button {
    padding: 15px 25px;
    border: none;
    background: var(--accent-color);
    color: var(--on-primary);
    cursor: pointer;
    transition: background-color 0.3s;
}

.search-button:hover {
    background-color: #357abd;
}

/* Features Section */
.features {
    padding: 60px 0;
    background-color: var(--surface);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background: var(--background);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.feature-card p {
    margin-bottom: 20px;
    line-height: 1.6;
}

.feature-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

/* Content Section */
.content-section {
    padding: 60px 0;
    background-color: #f5f5f5;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.content-card {
    background: var(--surface);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.content-card h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

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

.word-list li {
    margin-bottom: 10px;
}

.word-list a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s;
}

.word-list a:hover {
    color: var(--primary-color);
}

.word-of-day-content h4 {
    font-size: 1.8rem;
    margin-bottom: 5px;
    color: var(--primary-color);
}

.part-of-speech {
    display: inline-block;
    font-style: italic;
    color: var(--accent-color);
    margin-bottom: 10px;
}

/* CTA Button */
.cta-button {
    display: inline-block;
    padding: 12px 25px;
    background-color: var(--accent-color);
    color: var(--on-primary);
    text-decoration: none;
    border-radius: 5px;
    font-weight: 500;
    transition: background-color 0.3s;
}

.cta-button:hover {
    background-color: #357abd;
}

/* Footer */
.site-footer {
    background-color: var(--primary-color);
    color: var(--on-primary);
    padding: 20px 0;
    margin-top: auto;
}

.site-footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.dark-mode-toggle {
    background: none;
    border: none;
    color: var(--on-primary);
    cursor: pointer;
    padding: 5px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .features-grid,
    .content-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding: 40px 0;
    }

    .brand-name {
        font-size: 2rem;
    }

    .brand-subtitle {
        font-size: 1.2rem;
    }

    .hero-content h2 {
        font-size: 1.5rem;
    }

    .search-container {
        flex-direction: column;
    }

    .dictionary-select {
        border-right: none;
        border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    }
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero-content,
.feature-card,
.content-card {
    animation: fadeIn 0.5s ease-out forwards;
}

.feature-card:nth-child(2) {
    animation-delay: 0.2s;
}

.feature-card:nth-child(3) {
    animation-delay: 0.4s;
}

/* Form Styles */
.auth-form {
    max-width: 400px;
    margin: 0 auto;
    padding: 20px;
    background-color: var(--surface);
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--on-surface);
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
}

.button {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--accent-color);
    color: var(--on-primary);
    text-decoration: none;
    border-radius: 4px;
    font-size: 16px;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s;
}

.button:hover {
    background-color: #357abd;
}

/* Message Styles */
.message {
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 20px;
}

.message.error {
    background-color: var(--error);
    color: var(--on-error);
}

.message.success {
    background-color: #4caf50;
    color: #ffffff;
}

/* Word Details Styles */
.word-details {
    background-color: var(--surface);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    margin-bottom: 30px;
}

.word-details h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.word-details .pronunciation {
    font-style: italic;
    margin-bottom: 10px;
}

.word-details .part-of-speech {
    font-weight: bold;
    color: var(--accent-color);
    margin-bottom: 20px;
}

.word-details h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-top: 20px;
    margin-bottom: 10px;
}

.word-details .examples ul {
    list-style-type: disc;
    margin-left: 20px;
}

.suggestions-card {
    background-color: var(--surface);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.suggestions-card h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.suggestions-card ul {
    list-style-type: none;
    padding: 0;
}

.suggestions-card li {
    margin-bottom: 10px;
}

.suggestions-card a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s;
}

.suggestions-card a:hover {
    color: var(--primary-color);
}

/* Ripple effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    animation: ripple 0.6s linear;
    background-color: rgba(255, 255, 255, 0.7);
}

@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

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

/* Loading spinner */
.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--primary-color);
    border-top: 4px solid var(--background);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Scroll to top button */
.scroll-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--accent-color);
    color: var(--on-primary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    cursor: pointer;
    transition: background-color 0.3s;
    opacity: 0;
    visibility: hidden;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    background-color: #357abd;
}