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

:root {
    --accent-color: #0066ff;
    --accent-gradient-start: #00c6ff;
    --accent-gradient-end: #005bea;
    --success-gradient-start: #2ebf91;
    --success-gradient-end: #1e9d76;
    --warning-gradient-start: #f6d365;
    --warning-gradient-end: #f093fb;
    --info-gradient-start: #43cea2;
    --info-gradient-end: #185a9d;
    --secondary-gradient-start: #9d50bb;
    --secondary-gradient-end: #6e48aa;
    --page-bg: #f5f5f5;
    --surface-bg: #ffffff;
    --surface-muted: #f9f9f9;
    --surface-accent: #f0f7ff;
    --border-color: #e0e0e0;
    --text-color: #1f2933;
    --text-muted: #4b5563;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

body[data-theme="dark"] {
    --page-bg: #0f172a;
    --surface-bg: #1e293b;
    --surface-muted: #24324a;
    --surface-accent: #12213a;
    --border-color: rgba(255, 255, 255, 0.1);
    --text-color: #f8fafc;
    --text-muted: #cbd5f5;
    --shadow-color: rgba(15, 23, 42, 0.6);
    --accent-color: #7dd3fc;
    --accent-gradient-start: #0ea5e9;
    --accent-gradient-end: #4338ca;
    --success-gradient-start: #10b981;
    --success-gradient-end: #047857;
    --warning-gradient-start: #f59e0b;
    --warning-gradient-end: #ef4444;
    --info-gradient-start: #1d976c;
    --info-gradient-end: #1e3c72;
    --secondary-gradient-start: #9333ea;
    --secondary-gradient-end: #6d28d9;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--page-bg);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.4);
    border-radius: 50px;
    padding: 0.45rem 1.25rem;
    font-weight: 600;
    cursor: pointer;
    backdrop-filter: blur(4px);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.theme-toggle:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

.back-arrow {
    background: linear-gradient(135deg, var(--accent-gradient-start), var(--accent-gradient-end));
    color: #fff;
    border: none;
    border-radius: 50px;
    padding: 0.5rem 1.25rem;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 1.5rem;
    box-shadow: 0 8px 20px rgba(0, 91, 234, 0.15);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.back-arrow:hover {
    transform: translateY(-1px);
    box-shadow: 0 12px 24px rgba(0, 91, 234, 0.2);
}

.container {
    max-width: auto;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: linear-gradient(135deg, var(--accent-gradient-start) 0%, var(--accent-gradient-end) 100%);
    color: white;
    text-align: center;
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2rem;
    font-weight: 300;
}

.subject-tag {
    font-size: 1rem;
    font-weight: 600;
    margin-left: 0.5rem;
    opacity: 0.9;
}

/* Setup Section */
.setup-grid {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.subject-panel,
.domain-panel {
    background: var(--surface-bg);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px var(--shadow-color);
}

.subject-panel {
    width: 100%;
}

.domain-panel {
    width: 100%;
}

.subject-panel h2,
.domain-panel h2 {
    margin-bottom: 0.5rem;
}

.muted {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.subject-list {
    list-style: none;
    margin-top: 1rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
}

.subject-item {
    width: 100%;
    text-align: left;
    padding: 0.85rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--surface-muted);
    color: var(--text-color);
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.subject-item:hover {
    background: var(--surface-accent);
    transform: translateY(-1px);
    border-color: var(--accent-color);
}

.subject-item.active {
    border-color: var(--accent-color);
    box-shadow: 0 4px 14px rgba(0, 102, 255, 0.12);
}

.subject-item.subject-custom {
    background: linear-gradient(135deg, var(--secondary-gradient-start), var(--secondary-gradient-end));
    color: #fff;
    border: none;
}

.domain-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.domain-header-actions {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 0.5rem;
}

/* Domain Configuration Section */
.domain-config-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.domain-config-item {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    padding: 0.85rem;
    background: var(--surface-muted);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.domain-config-item label {
    font-weight: 700;
    color: var(--accent-color);
}

.domain-config-item input[type="text"],
.domain-config-item input[type="number"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 0.95rem;
}

.domain-config-item input[type="number"] {
    text-align: center;
}

.config-total {
    font-weight: 700;
    font-size: 1.05rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.hidden {
    display: none;
}

.warning {
    color: red;
    font-weight: 600;
}

.actions {
    margin-top: 1rem;
    display: flex;
    justify-content: flex-end;
}

/* Main Section Layout */
.main-layout {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.sidebar {
    background: var(--surface-muted);
    border-radius: 8px;
    padding: 1rem;
    box-shadow: none;
    margin-bottom: 1rem;
}

.sidebar-section {
    margin-bottom: 0;
}

.sidebar-section:last-child {
    margin-bottom: 0;
}

.sidebar-section h4 {
    color: var(--accent-color);
    font-size: 1rem;
    margin-bottom: 1rem;
    text-align: center;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.sidebar-buttons {
    display: flex;
    flex-direction: row;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn-block {
    flex: 1;
    min-width: 150px;
    text-align: center;
}

.main-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.entries-section {
    background: var(--surface-bg);
    border-radius: 10px;
    box-shadow: 0 2px 10px var(--shadow-color);
    padding: 1.25rem;
}

.entries-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.entries-header h3 {
    margin: 0;
}

.entries-header .btn {
    white-space: nowrap;
    padding-inline: 1rem;
}

.all-grades-list {
    /* Auto-expand without scrollbar */
}

.modal-content select,
.modal-content input[type="number"],
.modal-content input[type="text"] {
    width: 100%;
    padding: 0.65rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--surface-muted);
    color: var(--text-color);
    caret-color: var(--accent-color);
}

.modal-content select {
    appearance: none;
    background-image: linear-gradient(45deg, transparent 50%, var(--text-muted) 50%),
                      linear-gradient(135deg, var(--text-muted) 50%, transparent 50%);
    background-position: calc(100% - 18px) calc(50% - 3px), calc(100% - 12px) calc(50% + 3px);
    background-size: 6px 6px, 6px 6px;
    background-repeat: no-repeat;
    cursor: pointer;
}

.modal-content select:focus,
.modal-content input:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 1px;
    background: var(--surface-bg);
    color: var(--text-color);
}

@media (max-width: 900px) {
    .main-layout {
        gap: 1.25rem;
    }

    .entries-header {
        flex-direction: column;
        align-items: stretch;
    }

    .entries-header .btn {
        width: 100%;
    }

    .all-grades-list {
        /* Auto-expand without scrollbar */
    }

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

    .sidebar-buttons .btn {
        width: 100%;
    }
}

/* Main Section */
.domains-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

.domain-card {
    background: var(--surface-bg);
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px var(--shadow-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.domain-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.domain-card.disabled {
    background-color: #f0f0f0;
    opacity: 0.6;
    pointer-events: none;
}

.domain-card h3 {
    color: var(--accent-color);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.domain-card input {
    width: 100%;
    padding: 10px;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.domain-card input:focus {
    outline: none;
    border-color: var(--accent-color);
}

.domain-card input:disabled {
    background-color: var(--surface-muted);
    cursor: not-allowed;
}

.domain-history {
    margin-top: 1rem;
    max-height: 150px;
    overflow-y: auto;
    background: var(--surface-muted);
    border-radius: 5px;
    padding: 0.5rem;
}

.domain-history.disabled {
    background-color: rgba(0,0,0,0.05);
}

body[data-theme="dark"] .domain-history.disabled {
    background-color: rgba(255,255,255,0.06);
}

.history-item {
    padding: 0.5rem;
    margin: 0.25rem 0;
    background: var(--surface-bg);
    border-radius: 3px;
    font-size: 0.9rem;
    border-left: 3px solid var(--accent-color);
}

/* Input Section */
.input-section {
    background: var(--surface-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px var(--shadow-color);
    margin-bottom: 2rem;
}

.date-input {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.date-input label {
    font-weight: 600;
    color: #555;
    font-size: 0.9rem;
}

.date-input input {
    padding: 8px 10px;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 0.9rem;
    transition: border-color 0.3s;
}

.date-input input:focus {
    outline: none;
    border-color: var(--accent-color);
}

.date-input span {
    color: #888;
    font-style: italic;
    font-size: 0.8rem;
}

.edit-controls-section {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.edit-instructions {
    text-align: center;
    padding: 0.5rem;
    background: var(--surface-accent);
    border-radius: 5px;
    border: 1px solid var(--border-color);
}

.edit-instructions small {
    color: var(--accent-color);
    font-style: italic;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-gradient-start) 0%, var(--accent-gradient-end) 100%);
    color: white;
}

.btn-success {
    background: linear-gradient(135deg, var(--success-gradient-start) 0%, var(--success-gradient-end) 100%);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning-gradient-start) 0%, var(--warning-gradient-end) 100%);
    color: #5c2c0c;
}

.btn-info {
    background: linear-gradient(135deg, var(--info-gradient-start) 0%, var(--info-gradient-end) 100%);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, var(--secondary-gradient-start) 0%, var(--secondary-gradient-end) 100%);
    color: white;
}

.mobile-action-bar {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 0.75rem 1rem;
    background: var(--surface-bg);
    border-top: 1px solid var(--border-color);
    box-shadow: 0 -4px 12px var(--shadow-color);
    display: none;
    justify-content: center;
    gap: 0.5rem;
    z-index: 999;
}

.mobile-action-bar .btn {
    flex: 1;
}

/* All Grades Section */
.all-grades-section {
    background: var(--surface-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px var(--shadow-color);
}

.all-grades-section h4 {
    color: var(--accent-color);
    margin-bottom: 1rem;
    text-align: center;
}

.all-grades-list {
    background: var(--surface-muted);
    border-radius: 5px;
    padding: 1rem;
    border: 1px solid var(--border-color);
}

.grade-entry {
    padding: 0.75rem;
    margin: 0.5rem 0;
    background: var(--surface-bg);
    border-radius: 5px;
    border-left: 4px solid var(--accent-color);
    font-family: 'Courier New', monospace;
    position: relative;
    transition: all 0.3s;
}

.grade-entry:hover {
    transform: translateX(2px);
    box-shadow: 0 2px 8px var(--shadow-color);
}

.grade-entry.editable {
    cursor: pointer;
    border-left-color: #ff9800;
}

.grade-entry.editable:hover {
    background-color: #fff8e1;
    border-left-color: #f57c00;
}

.grade-entry .edit-controls {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    display: none;
    gap: 0.5rem;
}

.grade-entry.editable .edit-controls {
    display: flex;
}

.edit-btn, .delete-btn {
    background: none;
    border: none;
    padding: 0.25rem;
    cursor: pointer;
    border-radius: 3px;
    font-size: 0.8rem;
    transition: background-color 0.3s;
}

.edit-btn {
    color: #2196F3;
}

.edit-btn:hover {
    background-color: #e3f2fd;
}

.delete-btn {
    color: #f44336;
}

.delete-btn:hover {
    background-color: #ffebee;
}

.grade-separator {
    border-top: 2px dashed var(--border-color);
    margin: 1rem 0;
}

/* Results Section */
.results-section {
    background: var(--surface-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px var(--shadow-color);
    margin-top: 1.5rem;
}

.results-section h3 {
    color: var(--accent-color);
    text-align: center;
    margin-bottom: 1.5rem;
}

.final-grade-display {
    text-align: center;
    font-size: 1.3rem;
    font-weight: 600;
    padding: 1rem;
    border-radius: 8px;
    background: var(--surface-accent);
    border: 1px solid var(--border-color);
    margin-bottom: 1.5rem;
}

.final-grade-display.has-value {
    background: #e6ffed;
    border-color: #b2f5bf;
    color: #1b5e20;
}

body[data-theme="dark"] .final-grade-display.has-value {
    background: rgba(34, 197, 94, 0.15);
    border-color: rgba(34, 197, 94, 0.5);
    color: #bbf7d0;
}

.final-grade-display .final-grade-main {
    font-size: 1.2rem;
}

.final-grade-breakdown {
    margin-top: 0.75rem;
    border-top: 1px solid rgba(27, 94, 32, 0.2);
    padding-top: 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    text-align: left;
}

.weighted-item {
    display: flex;
    justify-content: space-between;
    gap: 0.5rem;
    font-size: 0.95rem;
    flex-wrap: wrap;
}

.weighted-value {
    font-family: 'Courier New', monospace;
}

.domain-results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}

.domain-result-card {
    background: var(--surface-muted);
    border-radius: 8px;
    padding: 1rem;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.domain-result-card h4 {
    margin-bottom: 0.25rem;
    color: var(--accent-color);
}

.domain-result-card p {
    margin: 0.2rem 0;
    font-size: 0.95rem;
}

.domain-result-card .domain-average {
    font-weight: 600;
    color: var(--text-color);
}

.domain-result-card.inactive {
    opacity: 0.5;
    background: color-mix(in srgb, var(--surface-muted) 60%, var(--page-bg));
}

.domain-result-card:not(.inactive):hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 15px var(--shadow-color);
}

/* Edit Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
}

.modal-content {
    background-color: var(--surface-bg);
    margin: 15% auto;
    padding: 2rem;
    border-radius: 10px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 4px 20px var(--shadow-color);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h3 {
    margin: 0;
    color: var(--accent-color);
}

.close {
    color: #aaa;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    border: none;
    background: none;
}

.close:hover {
    color: #000;
}

body[data-theme="dark"] .close {
    color: #94a3b8;
}

body[data-theme="dark"] .close:hover {
    color: #fff;
}

.modal-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

.form-group input {
    padding: 10px;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    background: var(--surface-bg);
    color: var(--text-color);
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
}

.modal-buttons {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 1rem;
}

.btn-cancel {
    background: #6c757d;
    color: white;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding-bottom: 80px;
    }

    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 1.5rem;
    }
    
    header {
        padding: 1.25rem;
    }
    
    .setup-section,
    .sidebar,
    .right-sidebar,
    .results-section {
        padding: 1.25rem;
        box-shadow: none;
        border: 1px solid var(--border-color);
        margin-bottom: 1rem;
    }
    
    .main-layout {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr;
        height: auto;
        gap: 1rem;
    }
    
    .sidebar {
        order: 2;
    }
    
    .right-sidebar {
        order: 3;
        display: block;
    }
    
    .main-content {
        order: 1;
        padding-right: 0;
    }
    
    .domains-grid {
        grid-template-columns: 1fr;
    }
    
    .domain-config-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .domain-config-section {
        padding: 1rem;
    }
    
    .domain-config-item {
        padding: 0.5rem;
    }
    
    .domain-card,
    .domain-result-card {
        padding: 1.25rem;
    }
    
    .final-grade-display {
        font-size: 1.1rem;
    }
    
    .domain-results-grid {
        grid-template-columns: 1fr;
    }
    
    .sidebar-buttons .btn,
    .results-section .btn,
    .setup-section .btn {
        width: 100%;
    }
    
    .domain-history {
        max-height: 200px;
    }
    
    .all-grades-list {
        /* Auto-expand without scrollbar */
    }

    #mobileActionBar {
        display: flex;
    }
}

@media (max-width: 1024px) and (min-width: 769px) {
    .main-layout {
        grid-template-columns: 250px 1fr;
    }
    
    .right-sidebar {
        display: none;
    }
}

/* Alert Styles */
.alert {
    padding: 1rem 1.5rem;
    margin: 1rem 0;
    border-radius: 5px;
    font-weight: 600;
    border: 1px solid var(--border-color);
}

.alert-danger {
    background-color: rgba(248, 215, 218, 0.8);
    color: #721c24;
}

.alert-success {
    background-color: rgba(212, 237, 218, 0.8);
    color: #155724;
}

.alert-info {
    background-color: rgba(204, 231, 255, 0.8);
    color: var(--accent-color);
}

body[data-theme="dark"] .alert-danger {
    background-color: rgba(127, 29, 29, 0.35);
    color: #fecdd3;
}

body[data-theme="dark"] .alert-success {
    background-color: rgba(21, 128, 61, 0.35);
    color: #bbf7d0;
}

body[data-theme="dark"] .alert-info {
    background-color: rgba(56, 189, 248, 0.25);
}

/* Animation for transitions */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

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