@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

:root {
    --primary-color: #4e54c8;
    --secondary-color: #8f94fb;
    --accent-color: #ff6b6b;
    --text-color: #333;
    --light-bg: #f9f9f9;
    --dark-bg: #2c3e50;
    --success-color: #2ecc71;
    --border-radius: 12px;
    --box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --force-repaint: 0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
}

body {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 850px;
    margin: 30px auto;
    padding: 30px;
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    position: relative;
    overflow: hidden;
}

.container::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color), var(--accent-color));
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    color: var(--primary-color);
    font-size: 2.2rem;
    position: relative;
    padding-bottom: 15px;
}

h1::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

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

.tabs {
    display: flex;
    margin-bottom: 30px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    flex-direction: row; /* 确保标签在一行显示 */
    flex-wrap: nowrap; /* 防止标签换行 */
}

.tab-btn {
    flex: 1;
    padding: 15px;
    background: var(--light-bg);
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    color: var(--text-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.tab-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    z-index: -1;
    transform: translateY(100%);
    transition: var(--transition);
}

.tab-btn:hover {
    color: white;
}

.tab-btn:hover::before {
    transform: translateY(0);
}

.tab-btn.active {
    color: white;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

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

.tab-pane {
    display: none;
    padding: 25px;
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    animation: fadeIn 0.5s ease;
}

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

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

.form-group {
    margin-bottom: 20px;
    position: relative;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark-bg);
}

input, select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: var(--transition);
    background-color: #f8f9fa;
}

input:focus, select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(78, 84, 200, 0.2);
    outline: none;
}

.hint {
    display: block;
    font-size: 13px;
    color: #6c757d;
    margin-top: 6px;
    font-style: italic;
}

.calculate-btn {
    display: block;
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 25px;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.calculate-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    z-index: -1;
    opacity: 0;
    transition: var(--transition);
}

.calculate-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 7px 14px rgba(78, 84, 200, 0.3);
}

.calculate-btn:hover::before {
    opacity: 1;
}

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

.result {
    margin-top: 35px;
    padding: 25px;
    background-color: var(--light-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    position: relative;
    overflow: hidden;
    transition: var(--transition);
    border-left: none;
    opacity: 0.9;
}

.result.show {
    animation: slideUp 0.5s forwards;
}

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

.result::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
}

.result h3 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.3rem;
    position: relative;
    display: inline-block;
}

.result h3::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), transparent);
}

.calculation-process {
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px dashed #ccc;
}

.calculation-process h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.process-content {
    background-color: rgba(255, 255, 255, 0.7);
    padding: 15px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    line-height: 1.5;
    font-size: 14px;
    color: #333;
    border-left: 3px solid var(--primary-color);
    overflow-x: auto;
}

body.dark-theme .process-content {
    background-color: rgba(0, 0, 0, 0.2);
    color: #ddd;
    border-left-color: var(--secondary-color);
}

.formula {
    font-weight: bold;
    color: var(--primary-color);
}

body.dark-theme .formula {
    color: var(--secondary-color);
}

.step {
    margin-bottom: 10px;
    padding-left: 20px;
    position: relative;
}

.step::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

.result p {
    margin-bottom: 12px;
    font-size: 16px;
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px dashed #e0e0e0;
}

.result p:last-child {
    border-bottom: none;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 2px solid #e0e0e0;
    font-weight: bold;
}

.result span {
    font-weight: bold;
    color: var(--accent-color);
}

.result-label {
    color: var(--dark-bg);
}

@media (max-width: 768px) {
    .container {
        margin: 15px auto;
        padding: 20px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    h2 {
        font-size: 1.3rem;
    }
    
    .tab-btn {
        padding: 12px;
        font-size: 15px;
    }
}

/* 添加动画效果 */
.floating {
    animation: floating 3s ease-in-out infinite;
}

@keyframes floating {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0px); }
}

/* 添加主题切换按钮 */
.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 20px;
    color: var(--primary-color);
    transition: var(--transition);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    z-index: 100;
}

.theme-toggle:hover {
    transform: rotate(180deg);
    color: var(--accent-color);
    background: rgba(255, 255, 255, 0.3);
}

/* 暗色主题 */
body.dark-theme {
    background: linear-gradient(135deg, #2c3e50, #4c669f);
}

body.dark-theme .container {
    background-color: rgba(44, 62, 80, 0.95);
    color: #f5f5f5;
}

body.dark-theme h1,
body.dark-theme h2,
body.dark-theme label,
body.dark-theme .result h3 {
    color: #8f94fb;
}

body.dark-theme input,
body.dark-theme select {
    background-color: #34495e;
    border-color: #4c669f;
    color: #f5f5f5;
}

body.dark-theme .result {
    background-color: #34495e;
}

body.dark-theme .result p {
    border-bottom-color: #4c669f;
}

body.dark-theme .result-label {
    color: #ddd;
}

body.dark-theme .theme-toggle {
    color: #f5f5f5;
    background: rgba(0, 0, 0, 0.3);
}

body.dark-theme .tab-pane {
    background-color: #34495e;
    color: #f5f5f5;
}

body.dark-theme .tab-btn {
    background: #2c3e50;
    color: #f5f5f5;
}

body.dark-theme .tab-btn:not(.active):hover {
    background: #3a506b;
}

body.dark-theme .hint {
    color: #a0b0c0;
}

body.dark-theme .calculate-btn {
    background: linear-gradient(135deg, #3a506b, #4c669f);
}

body.dark-theme .calculate-btn:hover {
    background: linear-gradient(135deg, #4c669f, #3a506b);
}