:root {
    --bg-color: #f3f6fc;
    --text-main: #2d3748;
    --text-muted: #718096;
    --primary-color: #5a67d8;
    --primary-hover: #4c51bf;
    --accent-color: #805ad5;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    --card-bg: #ffffff;
    --border-radius: 16px;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Background Blobs */
.background-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.6;
    animation: float 10s ease-in-out infinite;
}

.blob-1 {
    width: 400px;
    height: 400px;
    background: #a3bffa;
    top: -100px;
    left: -100px;
}

.blob-2 {
    width: 500px;
    height: 500px;
    background: #d6bcfa;
    bottom: -150px;
    right: -100px;
    animation-delay: -5s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -50px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
    100% { transform: translate(0, 0) scale(1); }
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
}

.search-type-toggle {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.toggle-btn {
    flex: 1;
    padding: 0.75rem;
    border: none;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 8px;
    font-family: inherit;
    font-weight: 500;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.3s ease;
}

.toggle-btn.active {
    background: var(--primary-color);
    color: white;
    box-shadow: 0 4px 12px rgba(90, 103, 216, 0.3);
}

textarea {
    width: 100%;
    min-height: 120px;
    padding: 1rem;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    font-family: inherit;
    font-size: 1rem;
    resize: vertical;
    outline: none;
    transition: border-color 0.3s ease;
    background: rgba(255, 255, 255, 0.8);
}

textarea:focus {
    border-color: var(--primary-color);
}

.search-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
}

.sort-options {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
}

select {
    padding: 0.5rem;
    border-radius: 6px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    font-family: inherit;
    outline: none;
    background: white;
}

.primary-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    font-family: inherit;
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 120px;
}

.primary-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(90, 103, 216, 0.3);
}

/* Spinner */
.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

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

.hidden {
    display: none !important;
}

/* Results */
#extracted-keywords {
    margin-bottom: 2rem;
}

#extracted-keywords h3 {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    background: rgba(128, 90, 213, 0.1);
    color: var(--accent-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.results-header h2 {
    font-size: 1.5rem;
    font-weight: 500;
}

#results-count {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.paper-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(0,0,0,0.03);
}

.paper-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.paper-title {
    font-size: 1.2rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: 0.5rem;
    display: block;
}

.paper-title:hover {
    text-decoration: underline;
}

.paper-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.paper-meta span {
    display: flex;
    align-items: center;
}

.paper-abstract {
    font-size: 0.95rem;
    color: var(--text-main);
    line-height: 1.5;
}