/* ===== Equation Solver App Styles ===== */
.equation-solver-app {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Solver Container */
.solver-container {
    background: rgba(139, 92, 246, 0.08);
    border-radius: 16px;
    padding: 1.25rem;
    border: 2px solid rgba(139, 92, 246, 0.2);
    transition: var(--transition);
}

/* Light Theme */
.solver-container.light-theme {
    background: #f8f9fa;
    border-color: #e0e0e0;
}

.solver-container.light-theme .equation-input {
    background: #ffffff;
    color: #1a1a2e;
    border-color: #e0e0e0;
}

.solver-container.light-theme .math-key {
    background: #ffffff;
    color: #1a1a2e;
    border-color: #e0e0e0;
}

.solver-container.light-theme .math-key:hover {
    background: #f0f0f0;
}

.solver-container.light-theme .solution-panel {
    background: #ffffff;
    border-color: #e0e0e0;
}

.solver-container.light-theme .input-label {
    color: #1a1a2e;
}

/* Main Panel */
.solver-main-panel {
    margin-bottom: 1rem;
}

.solver-input-section {
    margin-bottom: 1rem;
}

.input-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

/* Equation Preview - Formatted Math Display */
.equation-preview {
    min-height: 2.5rem;
    padding: 0.75rem 1rem;
    background: rgba(139, 92, 246, 0.03);
    border: 2px solid rgba(139, 92, 246, 0.15);
    border-radius: 12px 12px 0 0;
    border-bottom: none;
    font-size: 1.4rem;
    font-family: 'Times New Roman', 'Georgia', serif;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    min-height: 3rem;
    letter-spacing: 0.5px;
}

.equation-preview:empty {
    display: none;
}

.equation-preview .preview-placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
    font-style: italic;
}

.equation-preview:empty + .equation-input-wrapper .equation-input {
    border-radius: 12px;
}

.equation-preview + .equation-input-wrapper .equation-input {
    border-radius: 0 0 12px 12px;
    border-top: none;
}

.equation-preview sup {
    font-size: 0.7em;
    vertical-align: super;
    line-height: 0;
    position: relative;
    top: -0.5em;
}

.equation-preview .math-op {
    position: relative;
    top: 0.1em;
}

/* Integral notation display */
.equation-preview .integral-notation {
    display: inline-flex;
    align-items: center;
    gap: 0.1em;
}

.equation-preview .integral-sign {
    font-size: 1.6em;
    line-height: 1;
    position: relative;
}

.equation-preview .integral-bounds-display {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.7em;
    margin-left: -0.2em;
    margin-right: 0.1em;
}

.equation-preview .int-upper {
    margin-bottom: -0.3em;
}

.equation-preview .int-lower {
    margin-top: -0.3em;
}

.equation-preview .integral-func {
    margin: 0 0.15em;
}

.equation-preview .integral-dx {
    font-style: italic;
    margin-left: 0.1em;
}

/* Sigma notation display */
.equation-preview .sigma-notation {
    display: inline-flex;
    align-items: center;
    gap: 0.1em;
}

.equation-preview .sigma-sign {
    font-size: 1.4em;
    line-height: 1;
    position: relative;
}

.equation-preview .sigma-bounds-display {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.7em;
    margin-right: 0.2em;
}

.equation-preview .sigma-upper {
    margin-bottom: -0.2em;
    order: -1;
}

.equation-preview .sigma-lower {
    margin-top: -0.2em;
    order: 1;
}

.equation-preview .sigma-func {
    margin: 0 0.15em;
}

/* Derivative notation display */
.equation-preview .derivative-notation {
    display: inline-flex;
    align-items: center;
    gap: 0.1em;
}

.equation-preview .deriv-symbol {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.95em;
    line-height: 1;
    margin-right: 0.1em;
}

.equation-preview .deriv-symbol sup {
    font-size: 0.9em;
    position: relative;
    top: 0;
}

.equation-preview .deriv-symbol sub {
    font-size: 0.85em;
    position: relative;
    top: 0;
}

.equation-preview .deriv-func {
    margin: 0 0.1em;
}

.equation-preview .placeholder {
    color: var(--text-secondary);
    opacity: 0.5;
    font-style: italic;
    font-size: 0.85em;
}

.equation-preview sub {
    font-size: 0.7em;
    vertical-align: sub;
    line-height: 0;
    position: relative;
    top: 0.5em;
}

.equation-preview .sqrt-symbol {
    display: inline-flex;
    align-items: flex-start;
}

.equation-preview .sqrt-symbol::before {
    content: '√';
    font-size: 1.2em;
}

.equation-preview .sqrt-content {
    border-top: 1.5px solid currentColor;
    padding: 0 3px;
    margin-left: 1px;
}

.equation-preview .fraction {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    vertical-align: middle;
    margin: 0 3px;
}

.equation-preview .frac-num {
    border-bottom: 1.5px solid currentColor;
    padding: 0 4px 2px;
    font-size: 0.85em;
}

.equation-preview .frac-den {
    padding: 2px 4px 0;
    font-size: 0.85em;
}

.equation-preview .math-var {
    font-style: italic;
}

.equation-preview .math-op {
    margin: 0 4px;
}

.equation-preview .math-func {
    font-style: normal;
    margin-right: 2px;
}

.equation-preview .math-const {
    font-style: normal;
    color: var(--primary-violet);
}

.solver-container.light-theme .equation-preview {
    background: #fafafa;
    border-color: #e0e0e0;
    color: #1a1a2e;
}

.equation-input-wrapper {
    display: flex;
    gap: 0.5rem;
}

.equation-input {
    flex: 1;
    padding: 0.9rem 1rem;
    font-size: 1.1rem;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    background: rgba(139, 92, 246, 0.05);
    border: 2px solid rgba(139, 92, 246, 0.3);
    border-radius: 12px;
    color: var(--text-primary);
    transition: var(--transition);
}

.equation-input:focus {
    outline: none;
    border-color: var(--primary-violet);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.15);
}

.equation-input::placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
    font-size: 0.95rem;
}

.solve-main-btn {
    padding: 0.9rem 1.5rem;
    background: var(--gradient-main);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-violet);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.solve-main-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(139, 92, 246, 0.4);
}

/* Math Keyboard */
.math-keyboard {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    margin-top: 1rem;
}

.math-keyboard.number-keyboard {
    margin-top: 0.4rem;
}

.keyboard-row {
    display: grid;
    gap: 0.4rem;
}

.keyboard-row.math-functions {
    grid-template-columns: repeat(11, 1fr);
}

.keyboard-row.number-keys {
    grid-template-columns: repeat(7, 1fr);
}

.math-key {
    padding: 0.59rem 0.4rem;
    font-size: 0.9rem;
    font-weight: 500;
    border: 2px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(139, 92, 246, 0.08);
    color: var(--text-primary);
    border-color: rgba(139, 92, 246, 0.15);
}

.math-key:hover {
    background: rgba(139, 92, 246, 0.2);
    transform: translateY(-2px);
}

.math-key sup {
    font-size: 0.65em;
    vertical-align: super;
    line-height: 0;
    position: relative;
    top: -0.4em;
}

.math-key.num {
    background: rgba(139, 92, 246, 0.1);
    font-size: 1rem;
}

.math-key.op {
    background: rgba(139, 92, 246, 0.15);
    color: var(--primary-violet);
    font-size: 1rem;
}

.math-key.var {
    background: rgba(99, 102, 241, 0.15);
    color: #6366f1;
    font-style: italic;
    font-size: 1rem;
}

.math-key.eq {
    background: rgba(34, 197, 94, 0.15);
    color: #22c55e;
    font-size: 1.1rem;
}

.math-key.clear {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.math-key.ac {
    background: rgba(239, 68, 68, 0.15);
    color: #ef4444;
    font-weight: 700;
}

.math-key.enter {
    background: var(--gradient-main);
    color: white;
    border: none;
    font-size: 1rem;
    font-weight: bold;
}

.math-key.infinity {
    font-family: 'Arial', 'Helvetica', sans-serif;
    font-size: 1.3rem;
    font-weight: normal;
}

.math-key.expand {
    background: rgba(59, 130, 246, 0.15);
    color: #3b82f6;
    font-weight: 600;
    font-size: 0.75rem;
}

.math-key.expand:hover {
    background: rgba(59, 130, 246, 0.25);
}

/* Solution Panel */
.solution-panel {
    background: rgba(139, 92, 246, 0.05);
    border: 2px solid rgba(139, 92, 246, 0.2);
    border-radius: 12px;
    padding: 1rem;
    min-height: 120px;
}

.solution-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(139, 92, 246, 0.2);
}

.solution-header h3 {
    font-size: 1rem;
    color: var(--primary-violet);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
}

.copy-solution-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.4rem;
    border-radius: 6px;
    transition: var(--transition);
}

.copy-solution-btn:hover {
    background: rgba(139, 92, 246, 0.1);
    color: var(--primary-violet);
}

.solution-content {
    font-size: 1.3rem;
    font-family: 'Times New Roman', 'Georgia', serif;
    letter-spacing: 0.5px;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.solution-placeholder {
    color: var(--text-secondary);
    font-size: 0.95rem;
    opacity: 0.7;
}

.solutions-list {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.solution-item {
    color: var(--text-primary);
    font-size: 1.4rem;
    font-family: 'Times New Roman', 'Georgia', serif;
    letter-spacing: 0.5px;
}

/* Math display styles for solution content */
.solution-content sup {
    font-size: 0.7em;
    vertical-align: super;
    line-height: 0;
    position: relative;
    top: 0.1em;
}

.solution-content .math-op {
    padding: 0 0.15em;
    opacity: 0.85;
}

.solution-content .math-func {
    font-style: normal;
}

.solution-content .sqrt-symbol {
    position: relative;
    padding-left: 0.6em;
}

.solution-content .sqrt-symbol::before {
    content: '√';
    position: absolute;
    left: 0;
}

.solution-content .sqrt-content {
    border-top: 1px solid currentColor;
    padding: 0 0.1em;
}

.solution-content i {
    font-style: italic;
}

.solution-content .integral-notation,
.solution-content .sigma-notation,
.solution-content .derivative-notation {
    display: inline-flex;
    align-items: center;
    gap: 0.1em;
}

.solution-content .integral-sign {
    font-size: 1.6em;
    line-height: 1;
}

.solution-content .sigma-sign {
    font-size: 1.4em;
    line-height: 1;
}

.solution-content .integral-bounds-display,
.solution-content .sigma-bounds-display {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.7em;
}

.solution-content .deriv-symbol {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.95em;
    line-height: 1;
    margin-right: 0.1em;
}

.solution-content .deriv-symbol sup {
    font-size: 0.9em;
    position: relative;
    top: 0;
}

.solution-content .deriv-symbol sub {
    font-size: 0.85em;
    position: relative;
    top: 0;
}

.solution-steps {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.8;
    border-top: 1px solid rgba(139, 92, 246, 0.15);
    padding-top: 0.75rem;
    margin-top: 0.5rem;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    margin-bottom: 0.4rem;
    padding: 0.3rem 0;
}

.step-num {
    background: var(--gradient-main);
    color: white;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-math {
    font-family: 'Consolas', 'Monaco', monospace;
    background: rgba(139, 92, 246, 0.08);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    display: inline-block;
    margin: 0.2rem 0;
}

/* About Section */
.solver-about-container {
    margin-top: 8rem;
    padding-top: 1rem;
    border-top: 2px solid rgba(139, 92, 246, 0.2);
}

.solver-info-section {
    background: rgba(139, 92, 246, 0.05);
    border-radius: 16px;
    padding: 1.5rem;
    border: 2px solid rgba(139, 92, 246, 0.15);
}

.solver-info-section h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.solver-info-section h4 {
    color: var(--text-primary);
    margin: 1.5rem 0 1rem;
    font-size: 1rem;
}

.solver-info-section h4.solver-section-header {
    margin-top: 2rem;
}

.solver-info-section p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0.75rem;
}

.solver-info-section ol {
    color: var(--text-secondary);
    line-height: 1.8;
    padding-left: 1.5rem;
}

.solver-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.solver-info-card {
    background: rgba(139, 92, 246, 0.08);
    border-radius: 12px;
    padding: 1rem;
    border: 1px solid rgba(139, 92, 246, 0.2);
}

.solver-info-card h4 {
    color: var(--primary-violet);
    margin: 0 0 0.5rem;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.solver-info-card p {
    font-size: 0.8rem;
    margin: 0;
    font-family: 'Consolas', 'Monaco', monospace;
}

/* Responsive Styles */
@media (max-width: 768px) {
    .keyboard-row.math-functions {
        grid-template-columns: repeat(6, 1fr);
    }
    
    .keyboard-row.number-keys {
        grid-template-columns: repeat(7, 1fr);
    }
    
    .math-key {
        padding: 0.49rem 0.3rem;
        font-size: 0.8rem;
    }
    
    .equation-input-wrapper {
        flex-direction: column;
    }
    
    .solve-main-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .keyboard-row.math-functions {
        grid-template-columns: repeat(6, 1fr);
    }
    
    .keyboard-row.number-keys {
        grid-template-columns: repeat(7, 1fr);
    }
    
    .math-key {
        padding: 0.46rem 0.25rem;
        font-size: 0.75rem;
    }
    
    .solution-item {
        font-size: 1.1rem;
    }
}

/* ===== LANDSCAPE RESPONSIVE DESIGN ===== */

/* Large Tablets and Small Laptops in Landscape (1024px - 1200px) */
@media screen and (orientation: landscape) and (max-width: 1200px) {
    .equation-solver-app {
        gap: 0.875rem;
    }
    
    .solver-container {
        padding: 1rem;
    }
    
    .solver-about-container {
        margin-top: 6rem;
    }
    
    .solver-info-section h3 {
        font-size: 1.1rem;
    }
}

/* Tablets in Landscape (768px - 1024px) */
@media screen and (orientation: landscape) and (max-width: 1024px) and (min-width: 768px) {
    .equation-solver-app {
        gap: 0.75rem;
    }
    
    .solver-container {
        padding: 0.875rem;
        border-radius: 12px;
    }
    
    .solver-main-panel {
        margin-bottom: 0.75rem;
    }
    
    .solver-input-section {
        margin-bottom: 0.75rem;
    }
    
    .input-label {
        font-size: 0.8rem;
        margin-bottom: 0.4rem;
    }
    
    .equation-preview {
        min-height: 2.25rem;
        padding: 0.6rem 0.85rem;
        font-size: 1.2rem;
        border-radius: 10px 10px 0 0;
    }
    
    .equation-input {
        padding: 0.75rem 0.85rem;
        font-size: 0.95rem;
        border-radius: 10px;
    }
    
    .equation-input::placeholder {
        font-size: 0.85rem;
    }
    
    .solve-main-btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
        border-radius: 10px;
        gap: 0.4rem;
    }
    
    .math-keyboard {
        gap: 0.3rem;
        margin-top: 0.75rem;
    }
    
    .keyboard-row {
        gap: 0.3rem;
    }
    
    .math-key {
        padding: 0.5rem 0.35rem;
        font-size: 0.8rem;
        border-radius: 6px;
    }
    
    .math-key.num,
    .math-key.op,
    .math-key.var,
    .math-key.eq {
        font-size: 0.9rem;
    }
    
    .math-key.infinity {
        font-size: 1.1rem;
    }
    
    .math-key.expand {
        font-size: 0.65rem;
    }
    
    .solution-panel {
        padding: 0.85rem;
        border-radius: 10px;
        min-height: 100px;
    }
    
    .solution-header {
        margin-bottom: 0.6rem;
        padding-bottom: 0.4rem;
    }
    
    .solution-header h3 {
        font-size: 0.9rem;
        gap: 0.4rem;
    }
    
    .solution-content {
        font-size: 1.15rem;
        margin-bottom: 0.6rem;
    }
    
    .solution-placeholder {
        font-size: 0.85rem;
    }
    
    .solution-item {
        font-size: 1.2rem;
    }
    
    .solution-steps {
        font-size: 0.8rem;
        padding-top: 0.6rem;
        margin-top: 0.4rem;
    }
    
    .step {
        gap: 0.4rem;
        margin-bottom: 0.35rem;
        padding: 0.25rem 0;
    }
    
    .step-num {
        width: 18px;
        height: 18px;
        font-size: 0.65rem;
    }
    
    .step-math {
        padding: 0.15rem 0.4rem;
        font-size: 0.75rem;
    }
    
    /* About Section */
    .solver-about-container {
        margin-top: 4rem;
        padding-top: 0.875rem;
    }
    
    .solver-info-section {
        padding: 1.25rem;
        border-radius: 12px;
    }
    
    .solver-info-section h3 {
        font-size: 1rem;
        margin-bottom: 0.75rem;
    }
    
    .solver-info-section h4 {
        font-size: 0.9rem;
        margin: 1rem 0 0.75rem;
    }
    
    .solver-info-section p {
        font-size: 0.8rem;
        margin-bottom: 0.5rem;
    }
    
    .solver-info-section ol {
        font-size: 0.8rem;
        padding-left: 1.25rem;
    }
    
    .solver-info-grid {
        gap: 0.75rem;
        margin-top: 0.75rem;
    }
    
    .solver-info-card {
        padding: 0.85rem;
        border-radius: 10px;
    }
    
    .solver-info-card h4 {
        font-size: 0.8rem;
        margin-bottom: 0.4rem;
    }
    
    .solver-info-card p {
        font-size: 0.7rem;
    }
}

/* Small Tablets / Large Phones in Landscape (600px - 768px) */
@media screen and (orientation: landscape) and (max-width: 768px) and (min-width: 480px) {
    .equation-solver-app {
        gap: 0.5rem;
    }
    
    .solver-container {
        padding: 0.65rem;
        border-radius: 10px;
    }
    
    .solver-main-panel {
        margin-bottom: 0.5rem;
    }
    
    .solver-input-section {
        margin-bottom: 0.5rem;
    }
    
    .input-label {
        font-size: 0.7rem;
        margin-bottom: 0.3rem;
    }
    
    .equation-preview {
        min-height: 1.75rem;
        padding: 0.45rem 0.6rem;
        font-size: 1rem;
        border-radius: 8px 8px 0 0;
    }
    
    .equation-input {
        padding: 0.55rem 0.65rem;
        font-size: 0.8rem;
        border-radius: 8px;
    }
    
    .equation-input::placeholder {
        font-size: 0.7rem;
    }
    
    .equation-input-wrapper {
        gap: 0.35rem;
    }
    
    .solve-main-btn {
        padding: 0.55rem 0.9rem;
        font-size: 0.75rem;
        border-radius: 8px;
        gap: 0.3rem;
    }
    
    .solve-main-btn i {
        font-size: 0.7rem;
    }
    
    .math-keyboard {
        gap: 0.25rem;
        margin-top: 0.5rem;
    }
    
    .math-keyboard.number-keyboard {
        margin-top: 0.25rem;
    }
    
    .keyboard-row {
        gap: 0.25rem;
    }
    
    .math-key {
        padding: 0.4rem 0.25rem;
        font-size: 0.65rem;
        border-radius: 5px;
    }
    
    .math-key sup {
        font-size: 0.55em;
    }
    
    .math-key.num,
    .math-key.op,
    .math-key.var {
        font-size: 0.75rem;
    }
    
    .math-key.eq {
        font-size: 0.8rem;
    }
    
    .math-key.infinity {
        font-size: 0.95rem;
    }
    
    .math-key.expand {
        font-size: 0.55rem;
    }
    
    .solution-panel {
        padding: 0.6rem;
        border-radius: 8px;
        min-height: 75px;
    }
    
    .solution-header {
        margin-bottom: 0.45rem;
        padding-bottom: 0.3rem;
    }
    
    .solution-header h3 {
        font-size: 0.75rem;
        gap: 0.3rem;
    }
    
    .solution-header h3 i {
        font-size: 0.7rem;
    }
    
    .copy-solution-btn {
        padding: 0.3rem;
        border-radius: 5px;
    }
    
    .solution-content {
        font-size: 0.95rem;
        margin-bottom: 0.45rem;
    }
    
    .solution-placeholder {
        font-size: 0.7rem;
    }
    
    .solutions-list {
        gap: 0.3rem;
    }
    
    .solution-item {
        font-size: 0.95rem;
    }
    
    .solution-steps {
        font-size: 0.65rem;
        padding-top: 0.45rem;
        margin-top: 0.3rem;
        line-height: 1.6;
    }
    
    .step {
        gap: 0.3rem;
        margin-bottom: 0.25rem;
        padding: 0.2rem 0;
    }
    
    .step-num {
        width: 15px;
        height: 15px;
        font-size: 0.55rem;
    }
    
    .step-math {
        padding: 0.1rem 0.3rem;
        font-size: 0.6rem;
        border-radius: 3px;
    }
    
    /* About Section */
    .solver-about-container {
        margin-top: 2rem;
        padding-top: 0.65rem;
    }
    
    .solver-info-section {
        padding: 0.85rem;
        border-radius: 10px;
    }
    
    .solver-info-section h3 {
        font-size: 0.85rem;
        margin-bottom: 0.5rem;
    }
    
    .solver-info-section h4 {
        font-size: 0.75rem;
        margin: 0.75rem 0 0.5rem;
    }
    
    .solver-info-section h4.solver-section-header {
        margin-top: 1rem;
    }
    
    .solver-info-section p {
        font-size: 0.65rem;
        margin-bottom: 0.4rem;
        line-height: 1.5;
    }
    
    .solver-info-section ol {
        font-size: 0.65rem;
        padding-left: 1rem;
        line-height: 1.6;
    }
    
    .solver-info-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 0.5rem;
        margin-top: 0.5rem;
    }
    
    .solver-info-card {
        padding: 0.6rem;
        border-radius: 8px;
    }
    
    .solver-info-card h4 {
        font-size: 0.65rem;
        margin-bottom: 0.3rem;
        gap: 0.3rem;
    }
    
    .solver-info-card h4 i {
        font-size: 0.6rem;
    }
    
    .solver-info-card p {
        font-size: 0.55rem;
    }
}

/* Mobile Phones in Landscape (height < 500px) */
@media screen and (orientation: landscape) and (max-height: 500px) {
    .equation-solver-app {
        gap: 0.35rem;
    }
    
    .solver-container {
        padding: 0.5rem;
        border-radius: 8px;
        border-width: 1.5px;
    }
    
    .solver-main-panel {
        margin-bottom: 0.35rem;
    }
    
    .solver-input-section {
        margin-bottom: 0.35rem;
    }
    
    .input-label {
        font-size: 0.55rem;
        margin-bottom: 0.2rem;
    }
    
    .equation-preview {
        min-height: 1.5rem;
        padding: 0.3rem 0.5rem;
        font-size: 0.85rem;
        border-radius: 6px 6px 0 0;
        border-width: 1.5px;
    }
    
    .equation-input {
        padding: 0.4rem 0.5rem;
        font-size: 0.7rem;
        border-radius: 6px;
        border-width: 1.5px;
    }
    
    .equation-input::placeholder {
        font-size: 0.6rem;
    }
    
    .equation-input-wrapper {
        gap: 0.25rem;
    }
    
    .solve-main-btn {
        padding: 0.4rem 0.65rem;
        font-size: 0.6rem;
        border-radius: 6px;
        gap: 0.25rem;
    }
    
    .solve-main-btn i {
        font-size: 0.55rem;
    }
    
    .math-keyboard {
        gap: 0.2rem;
        margin-top: 0.35rem;
    }
    
    .math-keyboard.number-keyboard {
        margin-top: 0.2rem;
    }
    
    .keyboard-row {
        gap: 0.2rem;
    }
    
    .math-key {
        padding: 0.3rem 0.2rem;
        font-size: 0.55rem;
        border-radius: 4px;
        border-width: 1.5px;
    }
    
    .math-key sup {
        font-size: 0.5em;
        top: -0.3em;
    }
    
    .math-key.num,
    .math-key.op,
    .math-key.var {
        font-size: 0.65rem;
    }
    
    .math-key.eq {
        font-size: 0.7rem;
    }
    
    .math-key.infinity {
        font-size: 0.85rem;
    }
    
    .math-key.expand {
        font-size: 0.45rem;
    }
    
    .solution-panel {
        padding: 0.45rem;
        border-radius: 6px;
        min-height: 55px;
        border-width: 1.5px;
    }
    
    .solution-header {
        margin-bottom: 0.35rem;
        padding-bottom: 0.25rem;
    }
    
    .solution-header h3 {
        font-size: 0.6rem;
        gap: 0.25rem;
    }
    
    .solution-header h3 i {
        font-size: 0.55rem;
    }
    
    .copy-solution-btn {
        padding: 0.2rem;
        border-radius: 4px;
    }
    
    .copy-solution-btn i {
        font-size: 0.55rem;
    }
    
    .solution-content {
        font-size: 0.8rem;
        margin-bottom: 0.35rem;
    }
    
    .solution-placeholder {
        font-size: 0.6rem;
    }
    
    .solutions-list {
        gap: 0.2rem;
    }
    
    .solution-item {
        font-size: 0.8rem;
    }
    
    .solution-steps {
        font-size: 0.55rem;
        padding-top: 0.35rem;
        margin-top: 0.2rem;
        line-height: 1.5;
    }
    
    .step {
        gap: 0.25rem;
        margin-bottom: 0.2rem;
        padding: 0.15rem 0;
    }
    
    .step-num {
        width: 13px;
        height: 13px;
        font-size: 0.5rem;
    }
    
    .step-math {
        padding: 0.1rem 0.2rem;
        font-size: 0.5rem;
        border-radius: 2px;
    }
    
    /* About Section */
    .solver-about-container {
        margin-top: 1.5rem;
        padding-top: 0.5rem;
    }
    
    .solver-info-section {
        padding: 0.65rem;
        border-radius: 8px;
    }
    
    .solver-info-section h3 {
        font-size: 0.7rem;
        margin-bottom: 0.4rem;
    }
    
    .solver-info-section h4 {
        font-size: 0.6rem;
        margin: 0.5rem 0 0.35rem;
    }
    
    .solver-info-section h4.solver-section-header {
        margin-top: 0.75rem;
    }
    
    .solver-info-section p {
        font-size: 0.55rem;
        margin-bottom: 0.3rem;
        line-height: 1.4;
    }
    
    .solver-info-section ol {
        font-size: 0.55rem;
        padding-left: 0.85rem;
        line-height: 1.5;
    }
    
    .solver-info-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 0.35rem;
        margin-top: 0.4rem;
    }
    
    .solver-info-card {
        padding: 0.45rem;
        border-radius: 6px;
    }
    
    .solver-info-card h4 {
        font-size: 0.55rem;
        margin-bottom: 0.2rem;
        gap: 0.2rem;
    }
    
    .solver-info-card h4 i {
        font-size: 0.5rem;
    }
    
    .solver-info-card p {
        font-size: 0.45rem;
        line-height: 1.3;
    }
}

/* Very small mobile landscape (height < 400px) */
@media screen and (orientation: landscape) and (max-height: 400px) {
    .equation-solver-app {
        gap: 0.25rem;
    }
    
    .solver-container {
        padding: 0.35rem;
    }
    
    .input-label {
        font-size: 0.5rem;
    }
    
    .equation-preview {
        min-height: 1.25rem;
        padding: 0.2rem 0.4rem;
        font-size: 0.75rem;
    }
    
    .equation-input {
        padding: 0.3rem 0.4rem;
        font-size: 0.6rem;
    }
    
    .solve-main-btn {
        padding: 0.3rem 0.5rem;
        font-size: 0.5rem;
    }
    
    .math-key {
        padding: 0.2rem 0.15rem;
        font-size: 0.5rem;
    }
    
    .math-key.num,
    .math-key.op,
    .math-key.var {
        font-size: 0.55rem;
    }
    
    .solution-panel {
        padding: 0.35rem;
        min-height: 45px;
    }
    
    .solution-header h3 {
        font-size: 0.5rem;
    }
    
    .solution-content {
        font-size: 0.7rem;
    }
    
    .solution-item {
        font-size: 0.7rem;
    }
    
    .solver-about-container {
        margin-top: 1rem;
    }
    
    .solver-info-section {
        padding: 0.5rem;
    }
    
    .solver-info-section h3 {
        font-size: 0.6rem;
    }
    
    .solver-info-section p {
        font-size: 0.45rem;
    }
    
    .solver-info-card {
        padding: 0.35rem;
    }
    
    .solver-info-card h4 {
        font-size: 0.45rem;
    }
    
    .solver-info-card p {
        font-size: 0.4rem;
    }
}