:root {
    --primary-color-start: #11998e; /* Green theme for security */
    --primary-color-end: #38ef7d;
    --background-color: #f4f7fc;
    --card-background: #ffffff;
    --text-color-primary: #1e293b;
    --text-color-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-color: rgba(17, 153, 142, 0.1);
}
body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
}
.main-container {
    width: 100%;
    max-width: 750px;
}
.tool-card, .extra-section {
    background: var(--card-background);
    padding: 30px;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    border: 1px solid var(--border-color);
    margin-bottom: 25px;
}
h1 {
    text-align: center;
    color: var(--text-color-primary);
    font-size: 28px;
    font-weight: 700;
    margin-top: 0;
    margin-bottom: 10px;
}
.tagline {
    text-align: center;
    color: var(--text-color-secondary);
    font-size: 16px;
    margin-top: 0;
    margin-bottom: 30px;
}
.password-display-wrapper {
    position: relative;
    margin-bottom: 25px;
}
#passwordOutput {
    width: 100%;
    padding: 15px 50px 15px 20px;
    background-color: #f8f9fa;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-family: 'Roboto Mono', monospace;
    font-size: 20px;
    color: var(--text-color-primary);
    box-sizing: border-box;
}
#copyBtn {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    color: var(--text-color-secondary);
    font-size: 20px;
    cursor: pointer;
    padding: 5px;
    transition: color 0.2s;
}
#copyBtn:hover {
    color: var(--primary-color-start);
}
.options-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
    margin-bottom: 25px;
}
.option-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.option-item label {
    font-weight: 500;
    color: var(--text-color-primary);
}
#length-display {
    font-weight: 600;
    background-color: var(--background-color);
    padding: 3px 8px;
    border-radius: 5px;
}
input[type="range"] {
    width: 100%;
    accent-color: var(--primary-color-start);
    cursor: pointer;
}
input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary-color-start);
    cursor: pointer;
}
.strength-indicator {
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: var(--background-color);
    padding: 10px 15px;
    border-radius: 10px;
    margin-bottom: 25px;
}
.strength-indicator span {
    font-weight: 500;
}
.strength-bar-container {
    flex-grow: 1;
    background-color: #e2e8f0;
    height: 10px;
    border-radius: 5px;
    overflow: hidden;
}
.strength-bar {
    height: 100%;
    width: 0;
    border-radius: 5px;
    transition: width 0.3s, background-color 0.3s;
}
.action-btn {
    width: 100%;
    padding: 15px;
    border-radius: 10px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    background-image: linear-gradient(45deg, var(--primary-color-start), var(--primary-color-end));
    color: white;
}
.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--shadow-color);
}
.section-title {
    font-size: 22px; font-weight: 600; color: var(--text-color-primary); margin-bottom: 20px;
    border-bottom: 3px solid var(--primary-color-start); padding-bottom: 10px;
}
.tools-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 15px; }
.tool-button {
    display: block; padding: 15px; background-color: var(--background-color);
    color: var(--primary-color-start); text-decoration: none; font-weight: 600;
    text-align: center; border-radius: 10px; border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}
.tool-button:hover {
    background-color: var(--primary-color-start); color: white;
    transform: translateY(-3px); box-shadow: 0 4px 10px var(--shadow-color);
}
.ad-container { margin: 30px auto; text-align: center; }
footer {
    text-align: center;
    padding: 20px;
    margin-top: 10px;
    color: var(--text-color-secondary);
    font-size: 14px;
}
@media (max-width: 600px) {
    body { padding: 15px; }
    .tool-card, .extra-section { padding: 20px; }
    h1 { font-size: 24px; }
    #passwordOutput { font-size: 16px; }
}