/* iPhone风格科学计算器样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-color: #f2f2f7;
    --calculator-bg: #ffffff;
    --number-bg: #ffffff;
    --number-text: #000000;
    --operator-bg: #a8b5c7;
    --operator-text: #ffffff;
    --function-bg: #d1d1d6;
    --function-text: #000000;
    --clear-bg: #ff9500;
    --clear-text: #ffffff;
    --equals-bg: #007aff;
    --equals-text: #ffffff;
    --display-bg: #000000;
    --display-text: #ffffff;
    --expression-text: #cccccc;
    --border-radius: 12px;
    --button-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --transition: all 0.2s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', sans-serif;
    background: var(--bg-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    display: flex;
    gap: 20px;
    max-width: 1000px;
    width: 100%;
    align-items: flex-start;
    justify-content: center;
}

.calculator {
    background: var(--calculator-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--button-shadow);
    padding: 20px;
    width: 100%;
    max-width: 600px;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.header h1 {
    color: var(--number-text);
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.history-btn {
    background: var(--function-bg);
    border: none;
    border-radius: var(--border-radius);
    padding: 10px;
    color: var(--function-text);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--button-shadow);
}

.history-btn:hover {
    background: #c7c7cc;
}

.history-btn:active {
    transform: scale(0.95);
}

.display-container {
    background: var(--display-bg);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: var(--button-shadow);
}

.display {
    text-align: right;
    color: var(--display-text);
}

.expression {
    font-size: 1rem;
    color: var(--expression-text);
    margin-bottom: 10px;
    min-height: 20px;
    font-weight: 400;
}

.result {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    word-break: break-all;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    color: var(--display-text);
}

.scientific-buttons {
    display: grid;
    grid-template-columns: repeat(10, 1fr);
    gap: 8px;
    margin-bottom: 20px;
}

.btn {
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 400;
    cursor: pointer;
    transition: var(--transition);
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: inherit;
    box-shadow: var(--button-shadow);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.btn:active {
    transform: scale(0.95);
    opacity: 0.8;
}

.btn.number {
    background: var(--number-bg);
    color: var(--number-text);
}

.btn.number:hover {
    background: #f7f7f7;
}

.btn.operator {
    background: var(--operator-bg);
    color: var(--operator-text);
}

.btn.operator:hover {
    background: #9ca8b5;
}

.btn.function {
    background: var(--function-bg);
    color: var(--function-text);
    font-size: 0.9rem;
}

.btn.function:hover {
    background: #c7c7cc;
}

.btn.clear {
    background: var(--clear-bg);
    color: var(--clear-text);
}

.btn.clear:hover {
    background: #e6850e;
}

.btn.equals {
    background: var(--equals-bg);
    color: var(--equals-text);
}

.btn.equals:hover {
    background: #0056d6;
}

.btn.zero {
    grid-column: span 2;
}


.history-panel {
    background: var(--calculator-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--button-shadow);
    padding: 20px;
    width: 300px;
    max-height: 500px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    display: none;
    animation: slideIn 0.3s ease-out;
}

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

.history-panel.show {
    display: block;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.history-header h3 {
    color: var(--number-text);
    font-size: 1.2rem;
    font-weight: 600;
}

.clear-history {
    background: var(--clear-bg);
    border: none;
    border-radius: var(--border-radius);
    padding: 8px 16px;
    color: var(--clear-text);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--button-shadow);
}

.clear-history:hover {
    background: #e6850e;
}

.clear-history:active {
    transform: scale(0.95);
}

.history-list {
    max-height: 400px;
    overflow-y: auto;
}

.history-item {
    background: var(--function-bg);
    border-radius: var(--border-radius);
    padding: 15px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: var(--button-shadow);
}

.history-item:hover {
    background: #c7c7cc;
    transform: translateX(3px);
}

.history-expression {
    color: var(--function-text);
    font-size: 0.9rem;
    margin-bottom: 5px;
    opacity: 0.7;
}

.history-result {
    color: var(--function-text);
    font-size: 1.1rem;
    font-weight: 600;
}

.no-history {
    text-align: center;
    color: var(--function-text);
    font-style: italic;
    margin-top: 40px;
    opacity: 0.6;
}

/* 信息介绍区域 */
.info-section {
    width: 100%;
    display: flex;
    justify-content: center;
    margin: 40px 0;
    padding: 0 20px;
}

.info-container {
    background: var(--calculator-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--button-shadow);
    padding: 25px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 600px;
}

.info-container h2 {
    text-align: center;
    color: var(--number-text);
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 30px;
    letter-spacing: -0.02em;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 25px;
}

.info-grid-all {
    margin-top: 25px;
    margin-bottom: 0;
}

.info-card {
    background: var(--bg-color);
    border-radius: var(--border-radius);
    padding: 20px;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.info-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.info-icon {
    font-size: 2.2rem;
    margin-bottom: 12px;
    text-align: center;
}

.info-card h3 {
    color: var(--number-text);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
    text-align: center;
}

.info-card p {
    color: var(--function-text);
    font-size: 0.9rem;
    line-height: 1.5;
    text-align: left;
    opacity: 0.85;
}

/* 键盘快捷键说明 */
.keyboard-shortcuts {
    background: var(--bg-color);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 25px;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.keyboard-shortcuts h3 {
    color: var(--number-text);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 18px;
    text-align: left;
    padding-left: 5px;
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.shortcut-item {
    background: var(--calculator-bg);
    border-radius: 8px;
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.shortcut-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.1);
}

.shortcut-item .key {
    background: var(--function-bg);
    color: var(--function-text);
    padding: 6px 14px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    min-width: 55px;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.shortcut-item .desc {
    color: var(--function-text);
    font-size: 0.85rem;
    line-height: 1.4;
    flex: 1;
}

.footer {
    margin-top: 30px;
    margin-bottom: 30px;
    text-align: center;
}

.footer p {
    color: var(--function-text);
    font-size: 0.9rem;
    opacity: 0.7;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .info-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 18px;
    }
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
        align-items: center;
    }
    
    .calculator {
        max-width: 100%;
        margin-bottom: 20px;
    }
    
    .history-panel {
        width: 100%;
        max-width: 100%;
    }
    
    .scientific-buttons {
        grid-template-columns: repeat(5, 1fr);
    }
    
    .btn {
        height: 45px;
        font-size: 0.9rem;
    }
    
    .result {
        font-size: 2.5rem;
    }

    .info-container {
        padding: 20px;
    }

    .info-container h2 {
        font-size: 1.6rem;
    }

    .info-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .info-grid-all {
        margin-top: 20px;
    }

    .keyboard-shortcuts {
        padding: 18px;
        margin-bottom: 20px;
    }

    .keyboard-shortcuts h3 {
        font-size: 1.1rem;
        margin-bottom: 15px;
    }
}

@media (max-width: 480px) {
    .scientific-buttons {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .btn {
        height: 40px;
        font-size: 0.8rem;
    }
    
    .result {
        font-size: 2rem;
    }

    .info-container {
        padding: 15px;
    }

    .info-container h2 {
        font-size: 1.4rem;
        margin-bottom: 20px;
    }

    .info-card {
        padding: 18px;
    }

    .info-icon {
        font-size: 2rem;
    }

    .info-card h3 {
        font-size: 1.1rem;
    }

    .info-card p {
        font-size: 0.9rem;
    }

    .keyboard-shortcuts {
        padding: 15px;
        margin-bottom: 18px;
    }

    .keyboard-shortcuts h3 {
        font-size: 1.1rem;
        margin-bottom: 15px;
    }

    .shortcut-item {
        padding: 12px 15px;
    }

    .shortcut-item .key {
        font-size: 0.85rem;
        padding: 6px 12px;
        min-width: 50px;
    }

    .shortcut-item .desc {
        font-size: 0.85rem;
    }
}

/* 错误状态 */
.error {
    color: #ff3b30 !important;
}

/* 滚动条样式 */
.history-list::-webkit-scrollbar {
    width: 6px;
}

.history-list::-webkit-scrollbar-track {
    background: var(--function-bg);
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb {
    background: var(--operator-bg);
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb:hover {
    background: #9ca8b5;
}