:root {
    --primary-color-start: #11998e;
    --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);
    --hover-bg: #f8f9fa;
}
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: 900px; }
.tool-card {
    background: var(--card-background);
    padding: 30px 40px;
    border-radius: 20px;
    box-shadow: 0 10px 40px 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: 0 0 10px 0; }
.tagline { text-align: center; color: var(--text-color-secondary); font-size: 16px; margin: 0 0 30px 0; }
.main-layout { display: grid; grid-template-columns: 1fr 320px; gap: 40px; }
.options-panel { display: flex; flex-direction: column; }
.input-group label {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-color-primary);
    margin-bottom: 10px;
}
#qrInput {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-size: 16px;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
    resize: vertical;
    transition: all 0.3s ease;
}
#qrInput:focus {
    border-color: var(--primary-color-start);
    box-shadow: 0 0 0 3px rgba(17, 153, 142, 0.2);
    outline: none;
}
.accordion { margin-top: 25px; }
.accordion-item { border-bottom: 1px solid var(--border-color); }
.accordion-header {
    width: 100%;
    background: none;
    border: none;
    padding: 15px 5px;
    text-align: left;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-color-primary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.accordion-header span i { margin-right: 10px; color: var(--primary-color-start); }
.accordion-header .fa-chevron-down { transition: transform 0.3s ease; }
.accordion-item.active .accordion-header .fa-chevron-down { transform: rotate(180deg); }
.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
    padding: 0 15px;
}
.accordion-content .option-group { margin-bottom: 15px; display: grid; grid-template-columns: 100px 1fr; align-items: center; }
.accordion-content .option-group label { margin: 0; }
input[type="color"], select { padding: 5px; border-radius: 8px; border: 1px solid var(--border-color); }
input[type="color"] { height: 38px; }
input[type="file"] { border: none; padding: 0; }
#removeLogoBtn {
    background-color: #f1f3f5; color: var(--text-color-secondary); border: 1px solid var(--border-color);
    padding: 8px; margin-top: 10px; border-radius: 8px; cursor: pointer; font-weight: 500;
}
.qr-code-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: var(--hover-bg);
    padding: 20px;
    border-radius: 15px;
}
#qrCodeContainer {
    width: 100%;
    height: auto;
    aspect-ratio: 1 / 1;
    display: flex;
    justify-content: center;
    align-items: center;
}
.download-section {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    width: 100%;
}
.download-section select {
    flex-basis: 35%;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}
.action-btn {
    flex-grow: 1; padding: 12px; border-radius: 10px; font-size: 16px;
    font-weight: 600; cursor: pointer; border: none; display: inline-flex;
    justify-content: center; align-items: center; gap: 8px;
    background-image: linear-gradient(45deg, var(--primary-color-start), var(--primary-color-end));
    color: white; transition: all 0.3s ease;
}
.action-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px var(--shadow-color); }
.extra-section, footer, .ad-container, .tools-grid, .section-title, .how-to-use-list { /* ... existing styles ... */ }
.extra-section { background: var(--card-background); padding: 30px; border-radius: 20px; box-shadow: 0 10px 40px var(--shadow-color); border: 1px solid var(--border-color); margin-bottom: 25px; }
.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(--hover-bg); 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; }
.how-to-use-list { list-style-type: none; padding-left: 0; counter-reset: steps-counter; }
.how-to-use-list li { position: relative; padding-left: 45px; margin-bottom: 15px; font-size: 16px; color: var(--text-color-secondary); }
.how-to-use-list li::before { counter-increment: steps-counter; content: counter(steps-counter); position: absolute; left: 0; top: 0; width: 30px; height: 30px; background-color: var(--primary-color-start); color: white; border-radius: 50%; display: flex; justify-content: center; align-items: center; font-weight: 600; }
footer { text-align: center; padding: 20px; margin-top: 10px; color: var(--text-color-secondary); font-size: 14px; }
@media (max-width: 850px) {
    .main-layout { grid-template-columns: 1fr; }
    .qr-code-panel { margin-top: 30px; }
}
@media (max-width: 600px) {
    body { padding: 15px; }
    .tool-card { padding: 20px; }
    h1 { font-size: 24px; }
}