:root {
    --bg-light: #f5f6f8;
    --text-light: #18191c;
    --card-light: rgba(255, 255, 255, 0.4);
    --border-light: rgba(0, 0, 0, 0.08);
    --shadow-light: rgba(0, 0, 0, 0.05);
    --blue-accent: #007aff;
    --highlight-color: rgba(255, 255, 255, 0.6);
    --no-results-bg-light: #f0f4f7;
    --no-results-border-light: #d0d8e0;
    --no-results-text-light: #5a646e;
    --error-color: #ff3b30;
    --success-color: #34c759;

    --bg-dark: #1b1b1e;
    --text-dark: #e0e0e3;
    --card-dark: rgba(255, 255, 255, 0.05);
    --border-dark: rgba(255, 255, 255, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.3);
    --highlight-dark: rgba(255, 255, 255, 0.1);
    --no-results-bg-dark: #2a2a30;
    --no-results-border-dark: #40404a;
    --no-results-text-dark: #d0d8e0;
}

/* Skip link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--blue-accent);
    color: white;
    padding: 8px;
    z-index: 100;
    text-decoration: none;
}

.skip-link:focus {
    top: 0;
}

/* Loading overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-light);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.3s ease-out;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(0, 122, 255, 0.2);
    border-radius: 50%;
    border-top-color: var(--blue-accent);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

body {
    font-family: 'SF Pro Text', 'SF Pro Display', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-light);
    margin: 0;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
    position: relative;
}

.container {
    max-width: 800px;
    width: 100%;
    text-align: center;
}

.main-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.05em;
}

.tagline {
    font-size: 1.2rem;
    color: #888;
    margin-top: 0;
    margin-bottom: 3rem;
    letter-spacing: -0.02em;
}

.search-section {
    position: relative;
    width: 100%;
}

#search {
    width: 100%;
    box-sizing: border-box;
    padding: 1.2rem 1.5rem;
    font-size: 1.25rem;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow-light);
    transition: all 0.2s ease-in-out;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-color: var(--card-light);
    backdrop-filter: blur(50px) saturate(180%);
    color: var(--text-light);
}

#search:focus {
    outline: none;
    border-color: var(--blue-accent);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.2), 0 4px 20px var(--shadow-light);
}

.suggestions {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    list-style: none;
    padding: 0;
    margin-top: 0.5rem;
    background-color: var(--card-light);
    backdrop-filter: blur(50px) saturate(180%);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
    border: 1px solid var(--border-light);
    z-index: 10;
    max-height: 350px;
    overflow-y: auto;
    animation: fadeIn 0.2s ease-out;
    position: relative;
}

.suggestions::-webkit-scrollbar {
    display: none;
}
.suggestions {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.suggestions::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1rem;
    pointer-events: none;
    box-shadow: none;
}

.suggestions li {
    padding: 1.2rem 1.5rem;
    cursor: pointer;
    text-align: left;
    border-bottom: 1px solid var(--border-light);
    transition: all 0.2s ease-in-out;
    transform: scale(1);
    animation: slideIn 0.3s ease-out;
    display: flex;
    align-items: center;
}

.suggestions li:last-child {
    border-bottom: none;
}

.suggestions li:hover,
.suggestions li.selected {
    background-color: var(--highlight-color);
    transform: scale(1.01);
}

.suggestions li img {
    width: 24px;
    height: 24px;
    border-radius: 6px;
    margin-right: 1rem;
    object-fit: contain;
}

.placeholder-icon {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background-color: #fff;
    border: 1px solid var(--border-light);
    margin-right: 1rem;
    display: inline-block;
    flex-shrink: 0;
    box-shadow: inset 0 0 0 1px rgba(0,0,0,0.05);
}

.suggestions li .link-details {
    display: flex;
    flex-direction: column;
}

.suggestions li strong {
    font-weight: 600;
}

.suggestions li span {
    color: #8e8e93;
    font-size: 0.9em;
}

.no-results-message {
    margin-top: 1.5rem;
    padding: 1.5rem;
    background-color: var(--no-results-bg-light);
    backdrop-filter: blur(50px) saturate(180%);
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--no-results-border-light);
    animation: fadeIn 0.3s ease-out;
    text-align: center;
    color: var(--no-results-text-light);
}

.no-results-message p {
    margin: 0.5rem 0;
}

.no-results-message .highlight {
    font-weight: bold;
    color: var(--blue-accent);
}

.search-engines {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1rem;
}

.search-engine-btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.25rem;
    border-radius: 999px;
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    text-decoration: none;
    color: var(--text-light);
    font-weight: 600;
    transition: all 0.2s ease-in-out;
}
.search-engine-btn.selected {
    border-color: var(--blue-accent);
    box-shadow: 0 0 0 2px rgba(0, 122, 255, 0.2);
}

.search-engine-btn:hover {
    background-color: var(--highlight-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

.search-engine-btn img {
    width: 20px;
    height: 20px;
    margin-right: 0.5rem;
}

.category-buttons {
    margin-top: 3rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
}

.category-btn {
    font-family: inherit;
    padding: 0.75rem 1.5rem;
    border-radius: 999px;
    border: 1px solid var(--border-light);
    background-color: var(--card-light);
    color: var(--text-light);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: -0.02em;
    transition: all 0.2s ease-in-out;
}

.category-btn:hover {
    background-color: var(--highlight-color);
}

.category-btn.active {
    background-color: var(--blue-accent);
    color: #fff;
    border-color: var(--blue-accent);
}

.info-sections {
    max-width: 800px;
    width: 100%;
    margin-top: 5rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.info-card {
    background-color: var(--card-light);
    backdrop-filter: blur(50px) saturate(180%);
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow-light);
    padding: 2.5rem;
    border: 1px solid var(--border-light);
    transition: transform 0.2s ease-in-out;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 25px var(--shadow-light);
}

.collapsible-header {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-light);
    cursor: pointer;
    letter-spacing: -0.02em;
    position: relative;
    transition: border-color 0.3s;
}

.collapsible-header::after {
    content: '+';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    transition: transform 0.3s;
}

.collapsible-header.active::after {
    content: '−';
    transform: translateY(-50%) rotate(0deg);
}

.collapsible-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.collapsible-content.visible {
    max-height: 500px;
    margin-top: 1.5rem;
}

.feedback-form, .suggestion-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-top: 1.5rem;
    padding: 0 2rem;
}

.feedback-form label, .suggestion-form label {
    font-weight: 600;
    text-align: left;
}

.feedback-form input, .suggestion-form input, .feedback-form textarea, .suggestion-form select {
    width: 100%;
    box-sizing: border-box;
    padding: 1rem;
    border-radius: 12px;
    border: 1px solid var(--border-light);
    font-family: inherit;
    font-size: 1rem;
    background-color: var(--card-light);
    backdrop-filter: blur(50px) saturate(180%);
    color: var(--text-light);
    transition: box-shadow 0.2s ease-in-out, border-color 0.2s ease-in-out;
}

.feedback-form input:focus, .suggestion-form input:focus, .feedback-form textarea:focus, .suggestion-form select:focus {
    outline: none;
    border-color: var(--blue-accent);
    box-shadow: 0 0 0 2px rgba(0, 122, 255, 0.2);
}

.feedback-form textarea {
    resize: vertical;
}

.submit-btn {
    padding: 1rem;
    border-radius: 999px;
    border: none;
    background-color: var(--blue-accent);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s ease-in-out;
}

.submit-btn:hover {
    background-color: #006aff;
}

.footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-light);
    text-align: center;
    font-size: 0.9rem;
    color: #888;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    position: relative;
}

.settings-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: inherit;
    margin-top: 1rem;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.2s;
}

.settings-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

/* Error message */
.error-message {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--error-color);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    z-index: 10000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    animation: slideDown 0.3s ease-out;
}

.success-message {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--success-color);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    z-index: 10000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from { opacity: 0; transform: translate(-50%, -20px); }
    to { opacity: 1; transform: translate(-50%, 0); }
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    body {
        background-color: var(--bg-dark);
        color: var(--text-dark);
    }
    .tagline, .footer p {
        color: #a8a8ad;
    }
    #search, .suggestions, .info-card, .search-engine-btn, .feedback-form input, .suggestion-form input, .feedback-form textarea, .suggestion-form select, .category-btn {
        background-color: var(--card-dark);
        color: var(--text-dark);
        border: 1px solid var(--border-dark);
        box-shadow: 0 4px 20px var(--shadow-dark);
    }
    .suggestions::after {
        box-shadow: none;
    }
    #search:focus {
        border-color: var(--blue-accent);
        box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.2), 0 4px 20px var(--shadow-dark);
    }
    .suggestions li {
        border-bottom: 1px solid var(--border-dark);
    }
    .suggestions li:hover, .suggestions li.selected {
        background-color: var(--highlight-dark);
    }
    .suggestions li span {
        color: #8e8e93;
    }
    .collapsible-header {
        border-bottom: 1px solid var(--border-dark);
    }
    .category-btn:hover, .search-engine-btn:hover {
        background-color: var(--highlight-dark);
    }
    .feedback-form input:focus, .suggestion-form input:focus, .feedback-form textarea:focus, .suggestion-form select:focus {
        border-color: var(--blue-accent);
        box-shadow: 0 0 0 2px rgba(0, 122, 255, 0.2);
    }
    .feedback-form textarea, .suggestion-form select {
        background-color: var(--card-dark);
        color: var(--text-dark);
    }
    .no-results-message {
        background-color: var(--no-results-bg-dark);
        border: 1px solid var(--no-results-border-dark);
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
        color: var(--no-results-text-dark);
    }
    .placeholder-icon {
        background-color: #2c2c2e;
        border: 1px solid var(--border-dark);
        box-shadow: inset 0 0 0 1px rgba(255,255,255,0.05);
    }
    .settings-btn:hover {
        background-color: rgba(255, 255, 255, 0.05);
    }
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    body {
        padding: 1rem;
    }

    .main-title {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1rem;
        margin-bottom: 2rem;
    }

    #search {
        padding: 0.8rem 1rem;
        font-size: 1rem;
    }

    .search-engines {
        gap: 0.5rem;
    }

    .search-engine-btn {
        padding: 0.5rem 0.8rem;
        font-size: 0.8rem;
    }

    .search-engine-btn img {
        width: 16px;
        height: 16px;
    }

    .category-btn:focus {
        outline: 2px solid var(--blue-accent);
    }

    .search-engine-btn:focus {
        outline: 2px solid var(--blue-accent);
    }

    .category-buttons {
        margin-top: 2rem;
        gap: 0.5rem;
    }

    .category-btn {
        padding: 0.6rem 1rem;
        font-size: 0.8rem;
    }

    .info-sections {
        margin-top: 3rem;
        gap: 1rem;
    }

    .info-card {
        padding: 1.5rem;
    }

    .collapsible-header {
        font-size: 1.2rem;
    }

    .feedback-form, .suggestion-form {
        padding: 0 1rem;
    }

    .feedback-form input, .suggestion-form input, .feedback-form textarea, .suggestion-form select {
        font-size: 0.9rem;
    }
    
    .error-message, .success-message {
        width: 90%;
        text-align: center;
    }
}