/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
    --primary: #0fa171;
    --primary-dark: #0d8a62;
    --primary-light: #e8f7f1;
    --primary-glow: rgba(15, 161, 113, 0.15);
    --accent: #ff6b1b;
    --accent-light: #fff3eb;
    --bg: #f8faf9;
    --card-bg: #ffffff;
    --text: #1a2332;
    --text-secondary: #5f6d7e;
    --text-muted: #8f9bb3;
    --border: #e5e9ed;
    --border-light: #f0f2f5;
    --shadow-sm: 0 1px 3px rgba(0,0,0,.04), 0 1px 2px rgba(0,0,0,.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,.06), 0 2px 8px rgba(0,0,0,.04);
    --shadow-lg: 0 8px 32px rgba(0,0,0,.08), 0 4px 16px rgba(0,0,0,.04);
    --shadow-xl: 0 16px 48px rgba(0,0,0,.1), 0 8px 24px rgba(0,0,0,.06);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --transition: 0.25s cubic-bezier(.4,0,.2,1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* Dark mode */
[data-theme="dark"] {
    --bg: #0f1117;
    --card-bg: #1a1d2e;
    --text: #e8eaf0;
    --text-secondary: #9aa5b4;
    --text-muted: #6b7a8d;
    --border: #2d3348;
    --border-light: #232638;
    --primary-light: rgba(15, 161, 113, 0.12);
    --shadow-sm: 0 1px 3px rgba(0,0,0,.2);
    --shadow-md: 0 4px 16px rgba(0,0,0,.25);
    --shadow-lg: 0 8px 32px rgba(0,0,0,.3);
    --shadow-xl: 0 16px 48px rgba(0,0,0,.4);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ===========================
   Container
   =========================== */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===========================
   HEADER
   =========================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    transition: box-shadow var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
}

.header-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    position: relative;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--text);
}

.logo-img {
    height: 36px;
    width: auto;
    object-fit: contain;
}

.logo-accent {
    color: var(--primary);
}

.header-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: .3px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Theme Toggle Button */
.btn-theme {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    border: 1.5px solid var(--border);
    background: var(--card-bg);
    cursor: pointer;
    transition: all var(--transition);
    color: var(--text-secondary);
    font-size: 1.1rem;
    flex-shrink: 0;
}

.btn-theme:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
    transform: rotate(12deg) scale(1.08);
}

/* Dark mode: header & body bg */
[data-theme="dark"] .header {
    background: rgba(15, 17, 23, 0.88);
    border-bottom-color: var(--border);
}

[data-theme="dark"] .hero {
    background: linear-gradient(175deg, #0d1520 0%, #111827 40%, #0f1117 100%);
}

[data-theme="dark"] .hero-bg-pattern {
    opacity: 0.6;
}

[data-theme="dark"] .tool-card {
    background: var(--card-bg);
    border-color: var(--border);
}

[data-theme="dark"] .tool-right {
    background: #141624;
    border-left-color: var(--border);
}

[data-theme="dark"] .qr-preview {
    background: #141624;
    border-color: var(--border);
}

[data-theme="dark"] .input-textarea,
[data-theme="dark"] .input-field,
[data-theme="dark"] .input-select,
[data-theme="dark"] .size-number-input {
    background: #141624;
    border-color: var(--border);
    color: var(--text);
}

[data-theme="dark"] .accordion-item {
    background: #141624;
    border-color: var(--border);
}

[data-theme="dark"] .style-btn {
    background: #141624;
    border-color: var(--border);
}

[data-theme="dark"] .tab {
    background: #141624;
    border-color: var(--border);
    color: var(--text-secondary);
}

[data-theme="dark"] .tab.active {
    background: var(--primary);
    color: #fff;
}

[data-theme="dark"] .btn-download {
    background: #141624;
    border-color: var(--border);
    color: var(--text);
}

[data-theme="dark"] .logo-upload-btn {
    border-color: var(--border);
    color: var(--text-secondary);
}

[data-theme="dark"] .footer-simple {
    background: #0d0f19;
    border-top-color: var(--border);
}



.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: .9rem;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background: var(--primary-light);
}

.btn-install {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: .85rem;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
}

.btn-install:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px var(--primary-glow);
}

/* ===========================
   HERO
   =========================== */
.hero {
    padding: 100px 0 60px;
    position: relative;
    background: linear-gradient(175deg, #e2f5ed 0%, #d4f1e4 30%, #f0faf5 60%, var(--bg) 100%);
    overflow: hidden;
}

.hero-bg-pattern {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(15,161,113,.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(15,161,113,.06) 0%, transparent 40%),
        radial-gradient(circle at 60% 80%, rgba(255,107,27,.04) 0%, transparent 40%);
    pointer-events: none;
}

/* ===========================
   TOOL CARD
   =========================== */
.tool-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    position: relative;
    z-index: 1;
    border: 1px solid rgba(255,255,255,.6);
}

.tool-left {
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.tool-right {
    padding: 32px;
    background: var(--bg);
    border-left: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* ===========================
   TABS
   =========================== */
.tabs {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
}

.tab {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    font-size: .82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
    color: var(--text-secondary);
    font-family: var(--font);
}

.tab:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.tab.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.tab.active svg {
    stroke: #fff;
}

/* ===========================
   INPUT FORMS
   =========================== */
.input-forms {
    min-height: 140px;
}

.input-form {
    display: none;
    animation: fadeIn 0.3s ease;
}

.input-form.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}

.input-textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-md);
    font-size: .92rem;
    font-family: var(--font);
    color: var(--text);
    resize: vertical;
    transition: all var(--transition);
    background: var(--card-bg);
    line-height: 1.6;
}

.input-textarea:focus,
.input-field:focus,
.input-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.input-field {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-md);
    font-size: .92rem;
    font-family: var(--font);
    color: var(--text);
    transition: all var(--transition);
    background: var(--card-bg);
}

.input-select {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-md);
    font-size: .92rem;
    font-family: var(--font);
    color: var(--text);
    cursor: pointer;
    background: var(--card-bg);
    transition: all var(--transition);
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%235f6d7e' stroke-width='2' xmlns='http://www.w3.org/2000/svg'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 14px center;
}

.input-hint {
    font-size: .8rem;
    color: var(--text-muted);
    margin-top: 6px;
}

.form-group {
    margin-bottom: 14px;
}

.form-label {
    display: block;
    font-size: .82rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

/* ===========================
   CHECKBOX
   =========================== */
.options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: .88rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px 0;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    display: none;
}

.checkbox-custom {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-radius: 5px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    position: relative;
}

.checkbox-label input[type="checkbox"]:checked + .checkbox-custom {
    background: var(--primary);
    border-color: var(--primary);
}

.checkbox-label input[type="checkbox"]:checked + .checkbox-custom::after {
    content: '✓';
    color: #fff;
    font-size: 12px;
    font-weight: 700;
}

.badge-new {
    background: linear-gradient(135deg, #ff6b1b, #ff4500);
    color: #fff;
    font-size: .65rem;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 20px;
    letter-spacing: .5px;
    animation: pulse-badge 2s ease-in-out infinite;
}

@keyframes pulse-badge {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.08); }
}

/* ===========================
   GENERATE BUTTON
   =========================== */
.btn-generate {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, #0f9fa1, #359d15);
    color: #fff;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
    position: relative;
    overflow: hidden;
}

.btn-generate::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,.15), transparent);
    transition: left 0.5s;
}

.btn-generate:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(15, 159, 161, 0.35);
}

.btn-generate:hover::before {
    left: 100%;
}

.btn-generate:active {
    transform: translateY(0);
}

/* ===========================
   QR PREVIEW
   =========================== */
.qr-preview {
    background: var(--card-bg);
    border-radius: var(--radius-md);
    border: 2px dashed var(--border);
    min-height: 260px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    overflow: hidden;
}

.qr-preview.has-qr {
    border-style: solid;
    border-color: var(--primary-light);
}

.qr-placeholder {
    text-align: center;
    color: var(--text-muted);
}

.qr-placeholder svg {
    opacity: .3;
    margin-bottom: 12px;
}

.qr-placeholder p {
    font-size: .88rem;
}

.qr-output {
    padding: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    width: 100%;
}

.qr-output canvas,
.qr-output svg,
.qr-output img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
}

.qr-text-label {
    font-size: .78rem;
    color: var(--text-muted);
    text-align: center;
    word-break: break-all;
    max-width: 240px;
}

/* ===========================
   DOWNLOAD BUTTONS
   =========================== */
.download-actions {
    display: flex;
    gap: 10px;
}

.btn-download {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    background: var(--card-bg);
    border-radius: var(--radius-md);
    font-size: .85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    color: var(--text);
    font-family: var(--font);
}

.btn-download:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
    transform: translateY(-1px);
}

.btn-download-png:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-light);
}

.btn-download-all {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.btn-download-all:hover {
    background: var(--primary-dark);
    color: #fff;
    border-color: var(--primary-dark);
}

/* ===========================
   ADVANCED OPTIONS
   =========================== */
.advanced-toggle {
    padding-top: 4px;
}

.switch-label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: .88rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
}

.switch-icon {
    font-size: 1rem;
}

.switch {
    margin-left: auto;
    position: relative;
    width: 44px;
    height: 24px;
    flex-shrink: 0;
}

.switch input {
    display: none;
}

.switch-slider {
    position: absolute;
    inset: 0;
    background: var(--border);
    border-radius: 24px;
    cursor: pointer;
    transition: all var(--transition);
}

.switch-slider::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 18px;
    height: 18px;
    background: #fff;
    border-radius: 50%;
    transition: all var(--transition);
    box-shadow: 0 1px 3px rgba(0,0,0,.1);
}

.switch input:checked + .switch-slider {
    background: var(--primary);
}

.switch input:checked + .switch-slider::after {
    transform: translateX(20px);
}

.advanced-panel {
    display: none;
    flex-direction: column;
    gap: 4px;
    animation: slideDown 0.3s ease;
}

.advanced-panel.show {
    display: flex;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Accordion */
.accordion-item {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--card-bg);
}

.accordion-header {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 16px;
    border: none;
    background: transparent;
    font-size: .88rem;
    font-weight: 600;
    color: var(--text);
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
}

.accordion-header:hover {
    background: var(--primary-light);
}

.accordion-arrow {
    transition: transform var(--transition);
}

.accordion-header.open .accordion-arrow {
    transform: rotate(180deg);
}

.accordion-body {
    display: none;
    padding: 0 16px 16px;
    animation: fadeIn 0.3s ease;
}

.accordion-body.show {
    display: block;
}

/* Color Picker */
.color-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 0;
}

.color-label {
    font-size: .84rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.color-picker-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
}

.color-input {
    width: 36px;
    height: 36px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    padding: 2px;
    background: transparent;
}

.color-value {
    font-size: .78rem;
    color: var(--text-muted);
    font-family: monospace;
    background: var(--bg);
    padding: 4px 8px;
    border-radius: 4px;
}

/* Color row group (side by side) */
.color-row-group {
    display: flex;
    gap: 12px;
}

.color-row-half {
    flex: 1;
}

/* Toggle Row (label + small switch) */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 0;
}

.toggle-label {
    font-size: .82rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.switch-sm {
    position: relative;
    display: inline-block;
    width: 36px;
    height: 20px;
    flex-shrink: 0;
}

.switch-sm input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider-sm {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--border);
    border-radius: 20px;
    transition: all var(--transition);
}

.slider-sm::before {
    content: '';
    position: absolute;
    height: 14px;
    width: 14px;
    left: 3px;
    bottom: 3px;
    background: white;
    border-radius: 50%;
    transition: all var(--transition);
}

.switch-sm input:checked + .slider-sm {
    background: var(--primary);
}

.switch-sm input:checked + .slider-sm::before {
    transform: translateX(16px);
}

/* Style Grid 4 columns (for frames) */
.style-grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Frame Options */
.frame-options {
    padding: 8px 0 0;
    border-top: 1px solid var(--border-light);
    margin-top: 8px;
}

.frame-option-half {
    flex: 1;
}

/* Gradient direction selector */
.gradient-section {
    padding: 6px 0 4px;
}

.gradient-dir-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 6px;
    margin-top: 6px;
}

.grad-dir-btn {
    cursor: pointer;
    position: relative;
}

.grad-dir-btn input[type="radio"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.grad-dir-btn span {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 36px;
    border-radius: 6px;
    border: 1.5px solid var(--border);
    background: var(--bg);
    font-size: 1rem;
    color: var(--text-secondary);
    transition: all var(--transition);
    cursor: pointer;
}

.grad-dir-btn input:checked + span {
    border-color: var(--primary);
    background: var(--primary-light, rgba(15,161,113,0.12));
    color: var(--primary);
    font-weight: 700;
}

.grad-dir-btn span:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Fix spacing: toggle-row & color-row */
.toggle-row {
    gap: 12px;
    min-height: 34px;
}

.color-row {
    padding: 5px 0;
}

/* Ensure color-row-group children have consistent gap */
.color-row-group .color-row,
.color-row-group .toggle-row {
    padding: 4px 0;
}

/* Size */
.size-row {
    padding: 8px 0;
}

.range-input {
    width: 100%;
    margin: 8px 0;
    accent-color: var(--primary);
    cursor: pointer;
}

.range-value {
    font-size: .82rem;
    font-weight: 600;
    color: var(--primary);
}

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

.size-controls .range-input {
    flex: 1;
}

.size-number-input {
    width: 80px;
    padding: 8px 10px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: .88rem;
    font-family: var(--font);
    color: var(--text);
    text-align: center;
    background: var(--card-bg);
    transition: all var(--transition);
}

.size-number-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}


/* Style Grid (Nét vẽ, Đánh dấu, Trung tâm) */
.style-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
    padding: 4px 0;
}

.style-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    aspect-ratio: 1;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    cursor: pointer;
    transition: all var(--transition);
    padding: 5px;
}

.style-btn svg {
    width: 100%;
    height: 100%;
    fill: var(--text-secondary);
    stroke: var(--text-secondary);
}

.style-btn:hover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.style-btn:hover svg {
    fill: var(--primary);
    stroke: var(--primary);
}

.style-btn.active {
    border-color: var(--primary);
    background: var(--primary-light);
    box-shadow: 0 0 0 2px var(--primary-glow);
}

.style-btn.active svg {
    fill: var(--primary);
    stroke: var(--primary);
}

/* Logo */

.logo-upload {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

.logo-upload-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1.5px dashed var(--border);
    border-radius: var(--radius-md);
    font-size: .85rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition);
    background: var(--bg);
}

.logo-upload-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.btn-remove-logo {
    padding: 8px 14px;
    border: 1px solid #e74c3c;
    background: transparent;
    border-radius: var(--radius-sm);
    font-size: .8rem;
    color: #e74c3c;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
}

.btn-remove-logo:hover {
    background: #e74c3c;
    color: #fff;
}

/* ===========================
   FEATURES SECTION
   =========================== */
.features {
    padding: 80px 0;
    background: var(--card-bg);
}

.section-title {
    font-size: 1.75rem;
    font-weight: 800;
    text-align: center;
    color: var(--text);
    margin-bottom: 8px;
    line-height: 1.3;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: .95rem;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    text-align: center;
    padding: 36px 28px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    transition: all var(--transition);
    background: var(--card-bg);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.feature-icon-speed {
    background: linear-gradient(135deg, #e8f7f1, #d4f1e4);
    color: var(--primary);
}

.feature-icon-speed svg { stroke: var(--primary); }

.feature-icon-custom {
    background: linear-gradient(135deg, #e8f0fd, #dce6fa);
    color: #3b82f6;
}

.feature-icon-custom svg { stroke: #3b82f6; }

.feature-icon-free {
    background: linear-gradient(135deg, #fce8f0, #fad6e3);
    color: #e74c8b;
}

.feature-icon-free svg { stroke: #e74c8b; }

.feature-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text);
}

.feature-card p {
    font-size: .88rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* ===========================
   GUIDE SECTION
   =========================== */
.guide {
    padding: 80px 0;
    background: var(--bg);
}

.steps {
    max-width: 650px;
    margin: 0 auto;
    position: relative;
}

.steps::before {
    content: '';
    position: absolute;
    left: 32px;
    top: 60px;
    bottom: 60px;
    width: 2px;
    background: linear-gradient(180deg, var(--primary), rgba(15,161,113,.1));
    border-radius: 2px;
}

.step {
    display: flex;
    gap: 28px;
    align-items: flex-start;
    position: relative;
    margin-bottom: 48px;
}

.step:last-child {
    margin-bottom: 0;
}

.step-number {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    font-weight: 800;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
    box-shadow: 0 4px 16px var(--primary-glow);
}

.step-content {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 28px;
    border: 1px solid var(--border-light);
    flex: 1;
    transition: all var(--transition);
}

.step-content:hover {
    box-shadow: var(--shadow-md);
    border-color: transparent;
}

.step-icon-wrap {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    background: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 14px;
}

.step-icon-wrap svg {
    stroke: var(--primary);
}

.step-content h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.step-content p {
    font-size: .88rem;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 14px;
}

.step-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.step-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 12px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 20px;
    font-size: .76rem;
    font-weight: 600;
}

.step-tag::before {
    content: '✓';
    font-size: .7rem;
}

/* ===========================
   FOOTER SIMPLE
   =========================== */
.footer-simple {
    text-align: center;
    padding: 24px 0;
    color: var(--text-muted);
    font-size: .85rem;
    border-top: 1px solid var(--border-light);
    background: var(--card-bg);
}

.footer-simple p {
    margin: 0;
}

.footer-simple a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: color var(--transition);
}

.footer-simple a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* ===========================
   FLOATING BUTTONS
   =========================== */
.floating-buttons {
    position: fixed;
    bottom: 28px;
    right: 28px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 900;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    transition: all 0.35s ease;
}

.floating-buttons.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: all;
}

.fab {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition);
    box-shadow: var(--shadow-lg);
}

.fab-generate {
    background: linear-gradient(135deg, var(--accent), #ff4500);
    color: #fff;
}

.fab-top {
    background: var(--card-bg);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.fab:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: var(--shadow-xl);
}

/* ===========================
   MODAL
   =========================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.5);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 24px;
    animation: fadeIn 0.3s ease;
}

.modal-overlay.show {
    display: flex;
}

.modal {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 800px;
    max-height: 85vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
    animation: modalIn 0.35s ease;
}

@keyframes modalIn {
    from { opacity: 0; transform: scale(.95) translateY(10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-light);
}

.modal-header h3 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.1rem;
    font-weight: 700;
}

.modal-close {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    background: var(--bg);
    color: var(--text-secondary);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: #fde8e8;
    color: #e74c3c;
}

.modal-body {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 16px;
}

.modal-qr-item {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 16px;
    text-align: center;
    transition: all var(--transition);
    background: var(--card-bg);
}

.modal-qr-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.modal-qr-item canvas {
    max-width: 100%;
    height: auto;
    margin-bottom: 8px;
    border-radius: 4px;
}

.modal-qr-item .qr-item-text {
    font-size: .75rem;
    color: var(--text-muted);
    word-break: break-all;
    line-height: 1.4;
}

.modal-footer {
    display: flex;
    gap: 10px;
    padding: 16px 24px;
    border-top: 1px solid var(--border-light);
    justify-content: flex-end;
}

/* ===========================
   TOAST
   =========================== */
.toast {
    position: fixed;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text);
    color: #fff;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: .88rem;
    font-weight: 500;
    z-index: 3000;
    transition: transform 0.4s cubic-bezier(.4,0,.2,1);
    box-shadow: var(--shadow-xl);
    pointer-events: none;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
}

/* ===========================
   RESPONSIVE
   =========================== */
@media (max-width: 900px) {
    .tool-card {
        grid-template-columns: 1fr;
    }

    .tool-right {
        border-left: none;
        border-top: 1px solid var(--border-light);
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .steps::before {
        display: none;
    }

    .step {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .step-tags {
        justify-content: center;
    }
}

@media (max-width: 600px) {
    .header-container {
        height: 56px;
    }

    .nav {
        display: none;
    }

    .hero {
        padding: 80px 0 40px;
    }

    .tool-left,
    .tool-right {
        padding: 20px;
    }

    .tabs {
        gap: 4px;
    }

    .tab {
        padding: 6px 10px;
        font-size: .78rem;
    }

    .section-title {
        font-size: 1.35rem;
    }

    .features,
    .guide {
        padding: 48px 0;
    }

    .modal-body {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    }

    .download-actions {
        flex-direction: column;
    }
}

/* ===========================
   SCROLLBAR
   =========================== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ===========================
   LOADING ANIMATION
   =========================== */
.loading-spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Print styles */
@media print {
    .header, .floating-buttons, .footer, .features, .guide, .tool-left, .advanced-toggle, .advanced-panel, .download-actions {
        display: none !important;
    }

    .hero {
        padding: 0;
        background: none;
    }

    .tool-card {
        box-shadow: none;
        border: none;
        grid-template-columns: 1fr;
    }

    .tool-right {
        border: none;
        background: none;
    }

    .modal-overlay {
        position: static;
        background: none;
        backdrop-filter: none;
    }

    .modal {
        box-shadow: none;
        max-height: none;
    }

    .modal-header, .modal-footer {
        display: none !important;
    }

    .modal-body {
        padding: 0;
    }

    .modal-qr-item {
        break-inside: avoid;
        border: 1px solid #ccc;
    }
}