:root {
    --sc-primary: #00C853;
    --sc-primary-dark: #00A845;
    --sc-secondary: #666;
    --sc-secondary-light: #888;
    --sc-bg: #0a0a1a;
    --sc-bg-card: rgba(255, 255, 255, 0.05);
    --sc-bg-card-hover: rgba(255, 255, 255, 0.08);
    --sc-text: #e0e0e0;
    --sc-text-light: #aaa;
    --sc-text-heading: #ffffff;
    --sc-border: rgba(255, 255, 255, 0.1);
    --sc-danger: #ff4444;
    --sc-warning: #ffbb33;
    --sc-info: #33b5e5;
    --sc-radius: 12px;
    --sc-radius-sm: 8px;
    --sc-glow: 0 0 20px rgba(0, 200, 83, 0.15);
}

.studycore-dashboard {
    max-width: 960px;
    margin: 0 auto;
    padding: 30px 20px;
    color: var(--sc-text);
}

.studycore-glass-header {
    background: var(--sc-bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius);
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--sc-glow);
}

.studycore-glass-header h2 {
    font-size: 1.8em;
    color: var(--sc-text-heading);
    margin: 0 0 5px;
}

.studycore-glass-header p {
    color: var(--sc-text-light);
    margin: 0;
    font-size: 0.95em;
}

.studycore-timer-container {
    background: var(--sc-bg-card);
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius);
    padding: 30px;
    max-width: 400px;
    margin: 0 auto 30px;
    text-align: center;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.timer-display {
    font-size: 3em;
    font-family: 'Courier New', Courier, monospace;
    text-align: center;
    padding: 20px;
    color: var(--sc-text-heading);
    letter-spacing: 3px;
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--sc-radius-sm);
    margin-bottom: 20px;
    border: 1px solid var(--sc-border);
}

.timer-controls {
    display: flex;
    flex-direction: row;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.timer-btn {
    padding: 10px 24px;
    border: none;
    border-radius: var(--sc-radius-sm);
    font-size: 0.95em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.timer-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.timer-btn:active {
    transform: translateY(0);
}

.timer-btn-primary {
    background: var(--sc-primary);
    color: #fff;
}

.timer-btn-primary:hover {
    background: var(--sc-primary-dark);
}

.timer-btn-secondary {
    background: var(--sc-secondary);
    color: #fff;
}

.timer-btn-secondary:hover {
    background: var(--sc-secondary-light);
}

.timer-btn-danger {
    background: var(--sc-danger);
    color: #fff;
}

.timer-btn-danger:hover {
    background: #cc3333;
}

.subject-selector {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius-sm);
    background: rgba(0, 0, 0, 0.3);
    color: var(--sc-text);
    font-size: 0.95em;
    margin-bottom: 20px;
    cursor: pointer;
    transition: border-color 0.2s ease;
}

.subject-selector:focus {
    outline: none;
    border-color: var(--sc-primary);
}

.subject-selector option {
    background: var(--sc-bg);
    color: var(--sc-text);
}

.studycore-stat-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    margin-bottom: 30px;
}

@media (max-width: 768px) {
    .studycore-stat-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .studycore-stat-cards {
        grid-template-columns: 1fr;
    }
}

.stat-card {
    padding: 20px;
    text-align: center;
    border-radius: var(--sc-radius);
    background: linear-gradient(135deg, var(--sc-bg-card), rgba(0, 200, 83, 0.08));
    border: 1px solid var(--sc-border);
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-4px);
    background: var(--sc-bg-card-hover);
    box-shadow: var(--sc-glow);
}

.stat-value {
    font-size: 2em;
    font-weight: 700;
    color: var(--sc-text-heading);
    display: block;
    line-height: 1.2;
}

.stat-label {
    font-size: 0.85em;
    color: var(--sc-text-light);
    display: block;
    margin-top: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.progress-ring-container {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--sc-bg-card);
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius);
}

.progress-ring-container canvas {
    max-width: 100%;
}

.studycore-session-form label {
    display: block;
    color: var(--sc-text);
    font-size: 0.9em;
    font-weight: 600;
    margin-bottom: 6px;
}

.studycore-session-form input,
.studycore-session-form select,
.studycore-session-form textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius-sm);
    background: rgba(0, 0, 0, 0.3);
    color: var(--sc-text);
    font-size: 0.95em;
    margin-bottom: 16px;
    transition: border-color 0.2s ease;
    box-sizing: border-box;
}

.studycore-session-form input:focus,
.studycore-session-form select:focus,
.studycore-session-form textarea:focus {
    outline: none;
    border-color: var(--sc-primary);
}

.studycore-session-form textarea {
    min-height: 100px;
    resize: vertical;
}

.studycore-streak-display {
    font-size: 2.5em;
    text-align: center;
    padding: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.studycore-streak-display .streak-fire {
    font-size: 1.2em;
}

.studycore-streak-display .streak-count {
    font-weight: 700;
    color: var(--sc-text-heading);
}

.confetti-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 99999;
    overflow: hidden;
}

.studycore-message {
    padding: 12px 20px;
    border-radius: var(--sc-radius-sm);
    margin-bottom: 20px;
    font-size: 0.95em;
    font-weight: 500;
    animation: scFadeIn 0.3s ease;
}

.studycore-message-success {
    background: rgba(0, 200, 83, 0.15);
    border: 1px solid var(--sc-primary);
    color: var(--sc-primary);
}

.studycore-message-error {
    background: rgba(255, 68, 68, 0.15);
    border: 1px solid var(--sc-danger);
    color: var(--sc-danger);
}

.studycore-message-info {
    background: rgba(51, 181, 229, 0.15);
    border: 1px solid var(--sc-info);
    color: var(--sc-info);
}

@keyframes scFadeIn {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.studycore-leaderboard {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

.studycore-leaderboard th,
.studycore-leaderboard td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--sc-border);
}

.studycore-leaderboard th {
    color: var(--sc-text-light);
    font-size: 0.85em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.studycore-leaderboard td {
    color: var(--sc-text);
}

.studycore-leaderboard tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.03);
}

.studycore-leaderboard tr:hover {
    background: rgba(255, 255, 255, 0.06);
}

.studycore-leaderboard .rank-num {
    font-weight: 700;
    color: var(--sc-text-heading);
}

.studycore-leaderboard .rank-1 {
    color: #FFD700;
}

.studycore-leaderboard .rank-2 {
    color: #C0C0C0;
}

.studycore-leaderboard .rank-3 {
    color: #CD7F32;
}

.leaderboard-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--sc-border);
    padding-bottom: 0;
}

.leaderboard-tab button {
    padding: 10px 20px;
    border: none;
    background: transparent;
    color: var(--sc-text-light);
    font-size: 0.9em;
    font-weight: 600;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.leaderboard-tab button:hover {
    color: var(--sc-text-heading);
    background: rgba(255, 255, 255, 0.04);
}

.leaderboard-tab.active button {
    color: var(--sc-primary);
    border-bottom-color: var(--sc-primary);
}

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

.studycore-session-list li {
    padding: 12px 16px;
    border-bottom: 1px solid var(--sc-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s ease;
}

.studycore-session-list li:hover {
    background: rgba(255, 255, 255, 0.03);
}

.studycore-session-list li:last-child {
    border-bottom: none;
}

.studycore-section-title {
    font-size: 1.3em;
    color: var(--sc-text-heading);
    margin: 0 0 16px;
    font-weight: 700;
}

.studycore-card {
    background: var(--sc-bg-card);
    border: 1px solid var(--sc-border);
    border-radius: var(--sc-radius);
    padding: 24px;
    margin-bottom: 24px;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.studycore-avatar {
    border-radius: 50%;
    width: 40px;
    height: 40px;
    object-fit: cover;
}

.studycore-user-link {
    color: var(--sc-text-heading);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

.studycore-user-link:hover {
    color: var(--sc-primary);
}

.studycore-achievement {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.85em;
    font-weight: 600;
    margin: 4px;
}

.studycore-achievement-unlocked {
    background: rgba(0, 200, 83, 0.15);
    border: 1px solid var(--sc-primary);
    color: var(--sc-primary);
}

.studycore-achievement-locked {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--sc-border);
    color: var(--sc-text-light);
    opacity: 0.6;
}

.studycore-login-message {
    text-align: center;
    padding: 60px 20px;
    color: var(--sc-text-light);
}

.studycore-login-message a {
    color: var(--sc-primary);
    text-decoration: none;
    font-weight: 600;
}

.studycore-login-message a:hover {
    text-decoration: underline;
}