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

:root {
    --primary-color: #0052cc;
    --primary-hover: #0747a6;
    --secondary-color: #42526e;
    --background: #ffffff;
    --surface: #f4f5f7;
    --surface-hover: #ebecf0;
    --text-primary: #172b4d;
    --text-secondary: #6b778c;
    --border: #dfe1e6;
    --success: #00875a;
    --error: #de350b;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.08);
    --radius: 8px;
    --radius-sm: 4px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--background);
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #0747a6 100%);
    color: white;
    padding: 40px 30px;
    text-align: center;
    position: relative;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.95;
    margin-bottom: 20px;
}

.lang-selector {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 20px;
}

.lang-btn {
    padding: 8px 16px;
    background: rgba(255,255,255,0.2);
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    font-weight: 500;
}

.lang-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-1px);
}

.lang-btn.active {
    background: white;
    color: var(--primary-color);
}

main {
    padding: 30px;
}

section {
    margin-bottom: 40px;
}

h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border);
}

.current-time-section {
    background: var(--surface);
    padding: 25px;
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.current-time-display {
    display: grid;
    gap: 15px;
    margin-top: 15px;
}

.time-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px;
    background: white;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}

.time-item .label {
    font-weight: 500;
    color: var(--text-secondary);
    min-width: 120px;
}

.time-item .value {
    flex: 1;
    font-size: 1.1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.mono {
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
}

.copy-btn {
    padding: 6px 10px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
}

.copy-btn:hover {
    background: var(--surface-hover);
    transform: scale(1.05);
}

.copy-btn.inline {
    margin-left: 10px;
}

.conversion-section {
    background: white;
    padding: 25px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    margin-bottom: 30px;
}

.input-group {
    display: flex;
    gap: 15px;
    align-items: center;
    flex-wrap: wrap;
}

.input-field {
    flex: 1;
    min-width: 200px;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0,82,204,0.1);
}

.input-field.short {
    flex: 0;
    min-width: 100px;
}

.select-field {
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.select-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0,82,204,0.1);
}

.radio-group {
    display: flex;
    gap: 20px;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.95rem;
}

.radio-group input[type="radio"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.btn-primary {
    padding: 12px 24px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.result-box {
    margin-top: 20px;
    padding: 20px;
    background: var(--surface);
    border-radius: var(--radius-sm);
    min-height: 60px;
}

.result-item {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
}

.result-item:last-child {
    border-bottom: none;
}

.result-item strong {
    min-width: 150px;
    color: var(--text-secondary);
}

.separator {
    padding: 0 10px;
    color: var(--text-secondary);
    font-weight: 500;
}

.toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    padding: 12px 20px;
    background: var(--success);
    color: white;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 1000;
    font-weight: 500;
}

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

footer {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    background: var(--surface);
    border-top: 1px solid var(--border);
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .input-field,
    .select-field {
        width: 100%;
    }
    
    .time-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .time-item .label {
        min-width: auto;
    }
    
    .result-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .result-item strong {
        min-width: auto;
        margin-bottom: 5px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.5rem;
    }
    
    .subtitle {
        font-size: 0.95rem;
    }
    
    main {
        padding: 20px;
    }
    
    .conversion-section {
        padding: 15px;
    }
}