:root {
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --card-bg: #ffffff;
    --border-color: #ced4da;
    --primary-color: #4361ee;
    --primary-hover: #3a56e4;
    --primary-active: #314cca;
    --success-bg: #d1e7dd;
    --success-color: #0f5132;
    --input-focus: rgba(67, 97, 238, 0.25);
    --shadow: rgba(0, 0, 0, 0.1);
    --code-bg: #f1f3f5;
    --button-small-bg: #e9ecef;
    --button-small-hover: #dee2e6;
}

.dark-mode {
    --bg-color: #121212;
    --text-color: #e9ecef;
    --card-bg: #1e1e1e;
    --border-color: #495057;
    --primary-color: #4361ee;
    --primary-hover: #5a75f0;
    --primary-active: #6885f2;
    --success-bg: #0f5132;
    --success-color: #d1e7dd;
    --input-focus: rgba(67, 97, 238, 0.5);
    --shadow: rgba(0, 0, 0, 0.5);
    --code-bg: #2d2d2d;
    --button-small-bg: #343a40;
    --button-small-hover: #495057;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s, box-shadow 0.3s;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 1rem;
}

.container {
    width: 100%;
    max-width: 800px;
    text-align: center;
    padding-bottom: 3rem;
}

.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 6px var(--shadow);
}

h1 {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

h4 {
    font-size: 1.1rem;
    margin: 1.5rem 0 1rem;
    color: var(--text-color);
}

.input-container {
    margin-bottom: 1.5rem;
}

.format-container {
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
}

.format-container label {
    font-weight: 500;
}

input {
    width: 100%;
    padding: 12px 15px;
    font-size: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    outline: none;
    transition: all 0.3s;
    background-color: var(--card-bg);
    color: var(--text-color);
}

input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.25rem var(--input-focus);
}

@keyframes highlight-pulse {
    0% { border-color: var(--primary-color); box-shadow: 0 0 0 0.25rem var(--input-focus); }
    50% { border-color: var(--primary-color); box-shadow: 0 0 0 0.35rem var(--input-focus); }
    100% { border-color: var(--primary-color); box-shadow: 0 0 0 0.25rem var(--input-focus); }
}

input.highlight {
    animation: highlight-pulse 0.5s ease;
    border-color: var(--primary-color);
}

.copy-button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-block;
    min-width: 120px;
}

.copy-button:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow);
}

.copy-button:active {
    background-color: var(--primary-active);
    transform: translateY(0);
}

.notification {
    margin-top: 1.5rem;
    padding: 12px;
    border-radius: 8px;
    background-color: var(--success-bg);
    color: var(--success-color);
    opacity: 0;
    transition: opacity 0.3s, transform 0.3s;
    transform: translateY(10px);
}

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

.format-examples {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    text-align: left;
    box-shadow: 0 4px 6px var(--shadow);
}

.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.example {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

.example code {
    background-color: var(--code-bg);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-family: monospace;
    display: inline-block;
}

.example span {
    font-size: 0.85rem;
    opacity: 0.85;
}

.common-examples {
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
}

.examples-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
}

.common-example {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
}

.common-example code {
    background-color: var(--code-bg);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-family: monospace;
    flex-grow: 1;
}

.use-format {
    background-color: var(--button-small-bg);
    color: var(--text-color);
    border: none;
    padding: 0.3rem 0.6rem;
    font-size: 0.85rem;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}

.use-format:hover {
    background-color: var(--button-small-hover);
}

.theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.logo {
    position: absolute;
    top: 1rem;
    left: 1rem;
}

.logo-svg {
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-svg svg {
    transition: transform 0.3s ease;
}

.logo-svg svg:hover {
    transform: scale(1.1);
}

.placeholder-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.2rem;
    color: var(--primary-color);
    font-weight: 700;
}

.placeholder-logo i {
    font-size: 1.5rem;
}

.theme-toggle button {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-color);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.theme-toggle button:hover {
    background-color: var(--card-bg);
    transform: rotate(15deg);
}

/* Improved Mobile responsiveness */
@media (max-width: 768px) {
    body {
        padding: 0.5rem;
    }
    
    .container {
        width: 100%;
        padding-top: 3rem;
    }
    
    h1 {
        font-size: 1.5rem;
        margin-bottom: 1.2rem;
    }
    
    .card {
        padding: 1.2rem;
        margin-bottom: 1rem;
    }
    
    .input-container {
        margin-bottom: 1rem;
    }
    
    input {
        padding: 10px;
        font-size: 0.95rem;
    }
    
    .format-container {
        margin-bottom: 1rem;
    }
    
    .copy-button {
        width: 100%;
        padding: 10px;
    }
    
    .notification {
        margin-top: 1rem;
        padding: 10px;
        font-size: 0.9rem;
    }
    
    .format-examples {
        padding: 1.2rem;
    }
    
    .examples-grid {
        grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
        gap: 0.8rem;
    }
    
    .examples-list {
        grid-template-columns: 1fr;
        gap: 0.8rem;
    }
    
    .example code,
    .common-example code {
        font-size: 0.85rem;
    }
    
    .example span {
        font-size: 0.8rem;
    }
    
    .use-format {
        padding: 0.25rem 0.5rem;
        font-size: 0.8rem;
    }
    
    h3 {
        font-size: 1.1rem;
    }
    
    h4 {
        font-size: 1rem;
        margin: 1.2rem 0 0.8rem;
    }
    
    .logo-svg svg {
        width: 40px;
        height: 40px;
    }
    
    .theme-toggle {
        top: 0.8rem;
        right: 0.8rem;
    }
    
    .theme-toggle button {
        font-size: 1.3rem;
        padding: 0.4rem;
    }
}

/* Small mobile screens */
@media (max-width: 480px) {
    .container {
        padding-top: 3.5rem;
    }
    
    h1 {
        font-size: 1.3rem;
    }
    
    .card {
        padding: 1rem;
    }
    
    .examples-grid {
        grid-template-columns: repeat(auto-fill, minmax(100%, 1fr));
    }
    
    .example {
        display: grid;
        grid-template-columns: 60px 1fr;
        align-items: center;
        gap: 0.5rem;
    }
    
    .logo-svg svg {
        width: 35px;
        height: 35px;
    }
}