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

:root {
    --primary-color: #4F46E5;
    --primary-dark: #4338CA;
    --secondary-color: #10B981;
    --danger-color: #EF4444;
    --bg-color: #F9FAFB;
    --card-bg: #FFFFFF;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --border-color: #E5E7EB;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 8px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    padding: 12px 24px;
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    transition: all 0.2s;
    font-family: inherit;
    margin-bottom: -2px;
}

.tab-btn:hover {
    color: var(--primary-color);
    background: var(--bg-color);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    position: relative;
}

.tab-panel {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.tab-panel.active {
    display: block;
}

.filter-status {
    background: linear-gradient(135deg, #FEF3C7 0%, #FDE68A 100%);
    border-left: 4px solid #F59E0B;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    color: #92400E;
    font-size: 0.95rem;
    display: none;
    box-shadow: var(--shadow);
}

.filter-status strong {
    color: #78350F;
}

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

.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

textarea {
    resize: vertical;
}

.form-hint {
    display: block;
    margin-top: 4px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
}

.hidden {
    display: none !important;
}

#newProjectInput {
    margin-top: 8px;
}

.time-slot {
    margin-bottom: 12px;
    padding: 12px;
    background: var(--bg-color);
    border-radius: 8px;
    border: 2px solid var(--border-color);
}

.time-slot-row {
    display: flex;
    align-items: center;
    gap: 12px;
}

.time-slot-times {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.time-to {
    font-weight: 500;
    color: var(--text-secondary);
    padding: 0 8px;
}

.time-inputs {
    display: flex;
    align-items: center;
    gap: 8px;
}

.time-inputs input[type="number"] {
    width: 70px;
    text-align: center;
}

.time-inputs select {
    width: 80px;
}

.time-separator {
    font-weight: bold;
    font-size: 1.2rem;
    color: var(--text-secondary);
}

.btn-remove {
    padding: 8px 12px;
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.2rem;
    flex-shrink: 0;
    transition: background 0.2s;
}

.btn-remove:hover {
    background: #DC2626;
}

#addTimeSlot {
    margin-top: 8px;
    width: 100%;
}

@media (max-width: 768px) {
    .time-slot-row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .time-slot-times {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }
    
    .time-to {
        text-align: center;
        padding: 4px 0;
    }
    
    .btn-remove {
        width: 100%;
    }
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background-color: #059669;
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--text-secondary);
    background-color: var(--bg-color);
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-danger:hover {
    background-color: #DC2626;
}

.filter-controls {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.filter-shortcuts {
    display: flex;
    gap: 8px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.btn-shortcut {
    background-color: #F3F4F6;
    color: var(--text-primary);
    padding: 8px 16px;
    font-size: 0.9rem;
    border: 2px solid var(--border-color);
}

.btn-shortcut:hover {
    background-color: #E5E7EB;
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.filter-buttons {
    display: flex;
    gap: 12px;
}

.filter-buttons button {
    flex: 1;
}

.summary-section {
    background: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 100%);
}

#summaryByProject {
    margin-bottom: 20px;
}

.project-summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: white;
    border-radius: 8px;
    margin-bottom: 8px;
    border-left: 4px solid var(--primary-color);
}

.project-summary .project-name {
    font-weight: 600;
    color: var(--text-primary);
}

.project-summary .project-time {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.1rem;
}

.total-time {
    padding: 16px;
    background: white;
    border-radius: 8px;
    text-align: center;
    font-size: 1.2rem;
    border: 2px solid var(--primary-color);
}

.total-time span {
    color: var(--primary-color);
    font-size: 1.5rem;
}

.entry-item {
    padding: 16px;
    background: var(--bg-color);
    border-radius: 8px;
    margin-bottom: 12px;
    border-left: 4px solid var(--primary-color);
    transition: transform 0.2s, box-shadow 0.2s;
}

.entry-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
}

.entry-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.entry-project {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.1rem;
}

.entry-date-time {
    display: flex;
    gap: 16px;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.entry-date-time span {
    display: flex;
    align-items: center;
    gap: 4px;
}

.entry-duration {
    font-weight: 600;
    color: var(--secondary-color);
}

.entry-description {
    color: var(--text-primary);
    margin-bottom: 12px;
    line-height: 1.5;
}

.entry-actions {
    display: flex;
    justify-content: flex-end;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

.empty-state p {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

/* Responsive Design */
@media (max-width: 640px) {
    body {
        padding: 12px;
    }

    header h1 {
        font-size: 2rem;
    }

    .tabs {
        gap: 4px;
    }

    .tab-btn {
        padding: 10px 16px;
        font-size: 0.9rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .filter-buttons {
        flex-direction: column;
    }

    .entry-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .entry-date-time {
        flex-direction: column;
        gap: 4px;
    }
}

/* PWA Install Prompt */
.install-prompt {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--card-bg);
    padding: 16px 24px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    display: none;
    align-items: center;
    gap: 16px;
    z-index: 1000;
    max-width: 90%;
}

.install-prompt.show {
    display: flex;
}

.install-prompt button {
    white-space: nowrap;
}