/* ========================================
   全局样式和变量
   ======================================== */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    
    --bg-color: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    --transition: all 0.2s ease;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(to bottom, #ffffff 0%, #f8fafc 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========================================
   容器和布局
   ======================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    width: 100%;
}

/* ========================================
   头部区域
   ======================================== */
.header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 0.6s ease;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.title .icon {
    width: 3rem;
    height: 3rem;
    flex-shrink: 0;
    filter: drop-shadow(0 2px 4px rgba(37, 99, 235, 0.2));
    animation: iconFloat 3s ease-in-out infinite;
}

@keyframes iconFloat {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-5px);
    }
}

.subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* ========================================
   主内容区域
   ======================================== */
.main-content {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 1.5rem;
    align-items: center;
    animation: fadeInUp 0.6s ease;
}

.input-panel {
    grid-column: 1;
    align-self: stretch;
}

.converter-section {
    grid-column: 2;
    align-self: center;
}

.output-panel {
    grid-column: 3;
    align-self: stretch;
}

.panel {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
}

.panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #2563eb, #7c3aed, #2563eb);
    background-size: 200% 100%;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.panel:hover {
    box-shadow: var(--shadow-lg);
    border-color: #cbd5e1;
}

.panel:hover::before {
    opacity: 1;
    animation: shimmer 2s linear infinite;
}

@keyframes shimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(to bottom, var(--bg-secondary), var(--bg-color));
    border-bottom: 2px solid var(--border-color);
    position: relative;
    z-index: 1;
}

.panel-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.panel-header h2::before {
    content: '';
    width: 4px;
    height: 1.25rem;
    background: var(--primary-color);
    border-radius: 2px;
}

.textarea {
    width: 100%;
    min-height: 400px;
    padding: 1.5rem;
    border: none;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9375rem;
    line-height: 1.6;
    resize: vertical;
    outline: none;
    background: var(--bg-color);
    color: var(--text-primary);
    transition: var(--transition-smooth);
    flex: 1;
}

.textarea:focus {
    background: linear-gradient(to bottom, #ffffff, #fafbfc);
}

.textarea::-webkit-input-placeholder {
    opacity: 0.6;
}

.textarea:focus::-webkit-input-placeholder {
    opacity: 0.8;
}

.textarea::placeholder {
    color: #94a3b8;
}

.panel-footer {
    padding: 0.875rem 1.5rem;
    background: linear-gradient(to top, var(--bg-secondary), var(--bg-color));
    border-top: 1px solid var(--border-color);
}

.info-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-family: 'Consolas', 'Monaco', monospace;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.info-text::before {
    content: '📊';
    font-size: 1rem;
}

/* ========================================
   转换按钮区域
   ======================================== */
.converter-section {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 1.5rem;
    min-width: 180px;
    gap: 0.5rem;
}

.options {
    margin-top: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    width: 100%;
}

.checkbox-label {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 0.5rem;
    cursor: pointer;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    transition: var(--transition);
    white-space: nowrap;
    padding: 0.375rem 0.625rem;
    border-radius: var(--radius-sm);
    background: transparent;
}

.checkbox-label:hover {
    color: var(--text-primary);
    background: var(--bg-secondary);
}

.checkbox-label span {
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
    cursor: pointer;
    accent-color: var(--primary-color);
    flex-shrink: 0;
}

/* ========================================
   按钮样式
   ======================================== */
.button-group {
    display: flex;
    gap: 0.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1.125rem;
    font-size: 0.9375rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    white-space: nowrap;
}

.btn-icon {
    width: 1.125rem;
    height: 1.125rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-convert {
    padding: 1.5rem 2rem;
    font-size: 1.125rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    font-weight: 600;
    flex-direction: row;
    gap: 0.75rem;
    min-height: auto;
    width: 100%;
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    align-items: center;
    justify-content: center;
}

.btn-convert:hover:not(:disabled) {
    box-shadow: var(--shadow-xl);
    background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
    transform: translateX(3px);
}

.btn-convert .convert-icon {
    width: 1.5rem;
    height: 1.5rem;
    transform: rotate(0deg);
    transition: var(--transition);
    order: 2;
}

.btn-convert:hover:not(:disabled) .convert-icon {
    transform: translateX(5px);
    animation: slideRight 0.6s ease-in-out;
}

.convert-text {
    font-size: 1.125rem;
    writing-mode: horizontal-tb;
    letter-spacing: 0.05em;
    order: 1;
}

.btn-secondary {
    background: white;
    color: var(--secondary-color);
    border: 1.5px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.btn-secondary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: var(--bg-secondary);
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease;
}

.btn-secondary:hover:not(:disabled)::before {
    width: 300px;
    height: 300px;
}

.btn-secondary:hover:not(:disabled) {
    border-color: #cbd5e1;
    color: var(--text-primary);
}

.btn-secondary span,
.btn-secondary svg {
    position: relative;
    z-index: 1;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ========================================
   Toast 提示
   ======================================== */
.toast {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    font-size: 0.9375rem;
    font-weight: 500;
    opacity: 0;
    transform: translateX(400px);
    transition: all 0.3s ease;
    z-index: 1000;
    max-width: 400px;
}

.toast.show {
    opacity: 1;
    transform: translateX(0);
}

.toast.success {
    background: var(--success-color);
    color: white;
}

.toast.error {
    background: var(--error-color);
    color: white;
}

.toast.info {
    background: var(--primary-color);
    color: white;
}

/* ========================================
   页脚
   ======================================== */
.footer {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem 0;
    color: var(--text-secondary);
    font-size: 0.9375rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--primary-color), transparent);
    border-radius: 2px;
}

/* ========================================
   动画
   ======================================== */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: rotate(90deg) translateY(0);
    }
    50% {
        transform: rotate(90deg) translateY(6px);
    }
}

@keyframes slideRight {
    0%, 100% {
        transform: translateX(0);
    }
    50% {
        transform: translateX(8px);
    }
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto;
    }
    
    .input-panel {
        grid-column: 1;
        grid-row: 1;
    }
    
    .converter-section {
        grid-column: 1;
        grid-row: 2;
        padding: 1.5rem 0;
        min-width: auto;
    }
    
    .output-panel {
        grid-column: 1;
        grid-row: 3;
    }
    
    .btn-convert {
        flex-direction: row;
        min-height: auto;
        padding: 1rem 2rem;
        gap: 0.75rem;
    }
    
    .btn-convert .convert-icon {
        width: 1.25rem;
        height: 1.25rem;
        transform: rotate(0deg);
    }
    
    .btn-convert:hover:not(:disabled) .convert-icon {
        transform: translateX(3px);
    }
    
    .options {
        flex-direction: row;
        justify-content: center;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1.5rem 1rem;
    }
    
    .title {
        font-size: 1.875rem;
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .panel-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    
    .button-group {
        justify-content: center;
    }
    
    .options {
        flex-direction: column;
        gap: 0.75rem;
        align-items: center;
    }
    
    .textarea {
        min-height: 250px;
        font-size: 0.875rem;
    }
    
    .toast {
        right: 1rem;
        left: 1rem;
        max-width: calc(100% - 2rem);
    }
}

/* ========================================
   滚动条美化
   ======================================== */
.textarea::-webkit-scrollbar {
    width: 12px;
}

.textarea::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.textarea::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 6px;
}

.textarea::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}