:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --accent-color: #38bdf8;
    --primary: #38bdf8;
    /* Required by app.js */
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: rgba(51, 65, 85, 0.5);
    --glass-blur: blur(12px);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    background-image:
        radial-gradient(circle at 20% 20%, rgba(56, 189, 248, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 80% 80%, rgba(56, 189, 248, 0.05) 0%, transparent 40%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 4rem;
    padding-top: 2rem;
}

h1 {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    background: linear-gradient(to right, #fff, #38bdf8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.2rem;
    font-weight: 400;
}

.tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.tab-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 0.5rem;
}

.tab-btn.active {
    color: var(--accent-color);
    background: rgba(56, 189, 248, 0.1);
}

.section {
    display: none;
    animation: fadeIn 0.4s ease-out;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Progress Bar Styles */
.progress-container {
    display: none;
    margin-top: 1.5rem;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.progress-bar {
    /* JS controls width and background color */
    height: 12px;
    border-radius: 999px;
    transition: width 0.5s ease, background-color 0.5s ease;
    box-shadow: 0 0 10px rgba(56, 189, 248, 0.3);
}

.progress-fill {
    height: 100%;
    background: var(--accent-color);
    width: 0%;
    transition: width 0.5s ease;
    box-shadow: 0 0 10px rgba(56, 189, 248, 0.5);
}

.progress-status {
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.partial-results-btn {
    display: none;
    margin-top: 1rem;
    background: white;
    color: #0f172a;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 0.25rem;
    font-weight: 600;
    cursor: pointer;
    font-size: 0.9rem;
    align-items: center;
    gap: 0.5rem;
}

.partial-results-btn:hover {
    background: #f1f5f9;
}

.card {
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
}

textarea,
input {
    width: 100%;
    background: rgba(15, 23, 42, 0.5);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

textarea:focus,
input:focus {
    outline: none;
    border-color: var(--accent-color);
}

button.primary {
    background: var(--accent-color);
    color: #0f172a;
    border: none;
    border-radius: 0.5rem;
    padding: 0.75rem 2rem;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
}

button.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.match-item {
    background: rgba(51, 65, 85, 0.4);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    padding: 1.5rem;
    transition: transform 0.3s ease;
}

.match-item:hover {
    transform: scale(1.01);
    border-color: var(--accent-color);
}

.match-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.prof-info h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.prof-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.email-link {
    color: var(--accent-color);
    text-decoration: none;
    border-bottom: 1px dashed transparent;
    transition: all 0.3s ease;
}

.email-link:hover {
    border-bottom-color: var(--accent-color);
    opacity: 0.8;
}

.paper-link {
    color: #fff;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: all 0.3s ease;
}

.paper-link:hover {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

.score-badge {
    background: rgba(56, 189, 248, 0.2);
    color: var(--accent-color);
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 700;
}

.papers-list {
    margin-top: 1rem;
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
}

.paper-item {
    margin-bottom: 0.75rem;
}

.paper-item h4 {
    font-size: 1rem;
    color: #fff;
    margin-bottom: 0.25rem;
}

.paper-meta {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.reasoning {
    margin-top: 1rem;
    background: rgba(30, 41, 59, 0.6);
    padding: 1rem;
    border-radius: 0.5rem;
    font-size: 0.9rem;
    font-style: italic;
    color: #e2e8f0;
    border-left: 3px solid var(--accent-color);
}

.loading {
    display: none;
    text-align: center;
    padding: 2rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(56, 189, 248, 0.1);
    border-left: 4px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

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