:root {
    --primary-color: #4a6fa5;
    --secondary-color: #6e9de4;
    --background-light: #f9f9f9;
    --text-light: #333;
    --card-light: #fff;
    --shadow-light: 0 4px 6px rgba(0, 0, 0, 0.1);
    --background-dark: #1a1a1a;
    --text-dark: #e0e0e0;
    --card-dark: #2a2a2a;
    --shadow-dark: 0 4px 6px rgba(0, 0, 0, 0.3);
    --sun-color: #f1c40f;
    --moon-color: #f1c40f;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-light);
    color: var(--text-light);
    transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
    background-color: var(--background-dark);
    color: var(--text-dark);
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

h1 {
    margin: 0;
    color: var(--primary-color);
}

/* Theme Toggle Button Styles */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    width: 40px;
    height: 40px;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--primary-color);
    border-radius: 50%;
    padding: 0;
    overflow: hidden;
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.dark-mode .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.theme-toggle-icon {
    width: 24px;
    height: 24px;
    position: relative;
}

/* Sun Icon Animation */
.sun-icon {
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transform: scale(0.5) rotate(-45deg);
    transition: transform 0.5s ease, opacity 0.3s ease;
    color: var(--sun-color);
}

.sun-ray {
    stroke-dasharray: 3;
    stroke-dashoffset: 3;
    transition: stroke-dashoffset 0.5s ease;
}

body:not(.dark-mode) .sun-icon {
    opacity: 1;
    transform: scale(1) rotate(0);
}

body:not(.dark-mode) .sun-ray {
    stroke-dashoffset: 0;
    animation: rays 2s ease-in-out infinite alternate;
}

@keyframes rays {
    from {
        stroke-width: 2;
    }
    to {
        stroke-width: 3;
    }
}

/* Moon Icon Animation */
.moon-icon {
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transform: translateX(50%) scale(0.5);
    transition: transform 0.5s ease, opacity 0.3s ease;
    color: var(--moon-color);
}

.dark-mode .moon-icon {
    opacity: 1;
    transform: translateX(0) scale(1);
    animation: glowing 2s ease-in-out infinite alternate;
}

@keyframes glowing {
    from {
        filter: drop-shadow(0 0 1px rgba(241, 196, 15, 0.3));
    }
    to {
        filter: drop-shadow(0 0 3px rgba(241, 196, 15, 0.7));
    }
}

.card {
    background-color: var(--card-light);
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    padding: 24px;
    margin-bottom: 24px;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.dark-mode .card {
    background-color: var(--card-dark);
    box-shadow: var(--shadow-dark);
}

.tabs {
    display: flex;
    margin-bottom: 20px;
}

.tab {
    flex: 1;
    padding: 12px;
    text-align: center;
    background-color: #e0e0e0;
    cursor: pointer;
    border: none;
    font-weight: 600;
    transition: background-color 0.3s;
}

.tab:first-child {
    border-top-left-radius: 8px;
    border-bottom-left-radius: 8px;
}

.tab:last-child {
    border-top-right-radius: 8px;
    border-bottom-right-radius: 8px;
}

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

.dark-mode .tab {
    background-color: #444;
}

.dark-mode .tab.active {
    background-color: var(--secondary-color);
}

.tab-content {
    display: none;
}

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

.input-group {
    margin-bottom: 16px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
}

input {
    width: 100%;
    padding: 12px;
    border-radius: 6px;
    border: 1px solid #ddd;
    font-size: 16px;
    box-sizing: border-box;
    transition: border-color 0.3s;
}

.dark-mode input {
    background-color: #333;
    border-color: #555;
    color: var(--text-dark);
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 111, 165, 0.2);
}

.result {
    margin-top: 20px;
    padding: 16px;
    background-color: #f0f8ff;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    color: var(--primary-color);
    transition: background-color 0.3s;
}

.dark-mode .result {
    background-color: #2c3e50;
}

.error {
    color: #e74c3c;
    font-size: 14px;
    margin-top: 4px;
    display: none;
}

.history-container {
    margin-top: 30px;
}

.history-item {
    padding: 12px;
    margin-bottom: 10px;
    background-color: #f0f0f0;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s;
}

.dark-mode .history-item {
    background-color: #3a3a3a;
}

.history-text {
    flex: 1;
}

.delete-btn {
    background-color: #e74c3c;
    color: white;
    border: none;
    border-radius: 4px;
    padding: 6px 12px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.delete-btn:hover {
    background-color: #c0392b;
}

@media (max-width: 600px) {
    .container {
        padding: 10px;
    }
    
    .card {
        padding: 16px;
    }
    
    input {
        padding: 10px;
    }
}