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

:root {
    --bg-color: #f7f7f7;
    --container-bg: #ffffff;
    --text-color: #111;
    --border-color: #eaeaea;
    --input-border: #eaeaea;
    --focus-color: #0070f3;
    --focus-shadow: rgba(0, 112, 243, 0.1);
    --primary-color: #0070f3;
    --primary-hover: #0366d6;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --placeholder-color: #666;
    --font-family: 'Cairo', sans-serif;
}

.dark-mode {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --border-color: #333;
    --input-border: #333;
    --focus-color: #0070f3;
    --focus-shadow: rgba(0, 112, 243, 0.2);
    --primary-color: #0070f3;
    --primary-hover: #2186ff;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --placeholder-color: #999;
}

body {
    font-family: 'Cairo', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px 20px 70px 20px; /* Added bottom padding for footer */
    transition: background-color 0.4s ease, color 0.4s ease;
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10;
}

#themeToggleBtn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--container-bg);
    box-shadow: 0 2px 8px var(--shadow-color);
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

#themeToggleBtn:hover {
    transform: rotate(15deg) scale(1.1);
}

#themeToggleBtn:hover .toggle-icon {
    animation: pulse 1s infinite alternate;
}

@keyframes pulse {
    from {
        transform: scale(1);
    }
    to {
        transform: scale(1.2);
    }
}

.toggle-icon {
    transition: transform 0.5s ease;
    font-size: 20px;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.dark-mode .toggle-icon {
    color: #FFD700; /* Golden color for sun in dark mode */
}

.light-mode .toggle-icon {
    color: #5B6DCD; /* Deep blue color for moon in light mode */
}

.container {
    background: var(--container-bg);
    border-radius: 8px;
    padding: 32px;
    box-shadow: 0 4px 12px var(--shadow-color);
    max-width: 550px;
    width: 100%;
    transition: background-color 0.4s ease, box-shadow 0.4s ease;
    animation: containerFadeIn 0.7s ease forwards;
}

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

h1 {
    text-align: center;
    color: var(--text-color);
    margin-bottom: 24px;
    font-size: 1.8em;
    font-weight: 700;
    animation: fadeInDown 0.8s ease;
    letter-spacing: 0.5px;
}

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

.input-section {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 32px;
    animation: fadeIn 0.6s ease 0.2s forwards;
    opacity: 0;
}

@keyframes fadeIn {
    to { opacity: 1; }
}

#qrInput {
    padding: 12px;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    font-size: 16px;
    font-family: 'Cairo', sans-serif;
    background-color: var(--container-bg);
    color: var(--text-color);
    transition: border-color 0.2s, box-shadow 0.2s, background-color 0.4s, color 0.4s;
}

#qrInput:focus {
    outline: none;
    border-color: var(--focus-color);
    box-shadow: 0 0 0 3px var(--focus-shadow);
}

#qrInput::placeholder {
    color: var(--placeholder-color);
    opacity: 0.7;
    transition: opacity 0.3s ease;
    font-family: 'Cairo', sans-serif;
    font-weight: 400;
}

#qrInput:focus::placeholder {
    opacity: 0.5;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-6px); }
    40% { transform: translateX(6px); }
    60% { transform: translateX(-6px); }
    80% { transform: translateX(6px); }
}

.shake {
    animation: shake 0.6s ease;
    border-color: #e53935 !important;
}

.tooltip {
    position: fixed;
    background-color: #e53935;
    color: white;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 14px;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    opacity: 1;
    transition: opacity 0.3s;
    font-family: 'Cairo', sans-serif;
    font-weight: 500;
}

.tooltip::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 0 8px 8px 8px;
    border-style: solid;
    border-color: transparent transparent #e53935 transparent;
}

.tooltip-fade {
    opacity: 0;
}

.size-selector {
    display: flex;
    align-items: center;
    gap: 12px;
}

.size-selector label {
    font-weight: 600;
    color: var(--text-color);
    font-family: 'Cairo', sans-serif;
}

#qrSize {
    flex: 1;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
    font-family: 'Cairo', sans-serif;
    background-color: var(--container-bg);
    color: var(--text-color);
    cursor: pointer;
    transition: border-color 0.2s, box-shadow 0.2s, background-color 0.4s, color 0.4s;
}

#qrSize:focus {
    outline: none;
    border-color: var(--focus-color);
    box-shadow: 0 0 0 3px var(--focus-shadow);
}

#generateBtn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 16px;
    border-radius: 4px;
    font-size: 16px;
    font-family: 'Cairo', sans-serif;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
}

#generateBtn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1, 1) translate(-50%);
    transform-origin: 50% 50%;
}

#generateBtn:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 14px rgba(0, 118, 255, 0.39);
    transform: translateY(-2px);
}

#generateBtn:active::after {
    animation: ripple 0.6s ease-out;
}

@keyframes ripple {
    0% {
        transform: scale(0, 0);
        opacity: 0.5;
    }
    20% {
        transform: scale(25, 25);
        opacity: 0.5;
    }
    100% {
        opacity: 0;
        transform: scale(40, 40);
    }
}

#generateBtn:active {
    transform: translateY(0);
}

.qr-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    animation: fadeIn 0.6s ease 0.4s forwards;
    opacity: 0;
}

.qr-placeholder {
    padding: 40px 20px;
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    text-align: center;
    color: var(--placeholder-color);
    transition: border-color 0.4s, color 0.4s, transform 0.3s;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    cursor: default;
}

.qr-placeholder:hover {
    transform: translateY(-2px);
    border-color: var(--focus-color);
}

.placeholder-icon {
    color: var(--placeholder-color);
    margin-bottom: 8px;
    opacity: 0.7;
    transition: all 0.3s ease;
    animation: pulse 2s infinite ease-in-out;
}

.qr-placeholder:hover .placeholder-icon {
    color: var(--focus-color);
    opacity: 1;
    transform: scale(1.05);
}

.placeholder-hint {
    font-size: 14px;
    opacity: 0.7;
    margin-top: -5px;
    font-weight: 300;
}

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

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 20px 0;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#qrImage {
    max-width: 100%;
    border-radius: 4px;
    box-shadow: 0 4px 10px var(--shadow-color);
    animation: popIn 0.5s cubic-bezier(0.26, 1.32, 0.46, 1.43);
    transition: box-shadow 0.4s, transform 0.3s;
}

#qrImage:hover {
    transform: scale(1.02);
    box-shadow: 0 6px 20px var(--shadow-color);
}

@keyframes popIn {
    0% {
        opacity: 0;
        transform: scale(0.9);
    }
    70% {
        transform: scale(1.05);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

#downloadBtn {
    background-color: var(--container-bg);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 10px 20px;
    border-radius: 4px;
    font-size: 14px;
    font-family: 'Cairo', sans-serif;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s, transform 0.3s;
    animation: slideUp 0.5s ease;
}

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

#downloadBtn:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

#downloadBtn:active {
    transform: translateY(0);
}

/* Format Selection Styles */
.format-selector {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 4px;
}

.format-selector label {
    font-weight: 600;
    color: var(--text-color);
    font-family: 'Cairo', sans-serif;
}

.format-toggle {
    display: flex;
    flex: 1;
    background-color: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.format-btn {
    flex: 1;
    background: none;
    border: none;
    padding: 10px;
    font-family: 'Cairo', sans-serif;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-color);
    position: relative;
    overflow: hidden;
}

.format-btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1, 1) translate(-50%);
    transform-origin: 50% 50%;
}

.format-btn:active::after {
    animation: ripple 0.6s ease-out;
}

.format-btn.active {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 2px 8px rgba(0, 118, 255, 0.25);
}

@media (max-width: 600px) {
    .container {
        padding: 25px;
    }

    h1 {
        font-size: 1.5em;
    }
    
    .theme-toggle {
        top: 10px;
        right: 10px;
    }
    
    /* Footer responsiveness */
    .footer {
        padding: 8px 15px;
    }
    
    .social-links {
        gap: 15px;
    }
    
    .social-link {
        width: 32px;
        height: 32px;
        font-size: 18px;
    }
    
    .copyright {
        font-size: 12px;
    }
}

/* Footer Styles */
.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 10px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
    z-index: 10;
    transition: background-color 0.4s ease, box-shadow 0.4s ease;
    animation: footerSlideUp 0.8s ease forwards;
}

@keyframes footerSlideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.social-links {
    display: flex;
    gap: 20px;
    margin-bottom: 5px;
}

.social-link {
    color: var(--text-color);
    font-size: 20px;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: transparent;
    opacity: 0.8;
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0) 70%);
    transform: scale(0);
    opacity: 0;
    transition: transform 0.5s ease, opacity 0.3s ease;
    border-radius: 50%;
}

.social-link:hover {
    transform: translateY(-3px);
    opacity: 1;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.social-link:hover::before {
    transform: scale(2);
    opacity: 1;
}

.social-link:focus {
    outline: none;
    box-shadow: 0 0 0 2px var(--focus-color);
}

.social-link:active {
    transform: translateY(0);
}

.social-link .fa-github {
    transition: color 0.3s ease, transform 0.3s ease;
}

.social-link .fa-linkedin-in {
    transition: color 0.3s ease, transform 0.3s ease;
}

.social-link:hover .fa-github {
    color: #333;
    transform: rotate(360deg) scale(1.2);
}

.social-link:hover .fa-linkedin-in {
    color: #0077B5;
    transform: rotate(360deg) scale(1.2);
}

.copyright {
    font-family: 'Cairo', sans-serif;
    font-size: 14px;
    color: var(--text-color);
    opacity: 0.7;
    text-align: center;
    font-weight: 300;
}

.copyright a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}