/* ========================================
   ElanjaiTecH QR Code Generator
   Design System & Styles
   ======================================== */

/* ---------- CSS Custom Properties ---------- */
:root {
    /* Color Palette */
    --color-primary: #6366f1;
    --color-primary-hover: #4f46e5;
    --color-primary-light: rgba(99, 102, 241, 0.12);
    --color-primary-glow: rgba(99, 102, 241, 0.25);

    --color-accent: #06b6d4;
    --color-accent-hover: #0891b2;

    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;

    /* Surfaces */
    --bg-body: #f0f2f7;
    --bg-panel: rgba(255, 255, 255, 0.82);
    --bg-panel-solid: #ffffff;
    --bg-input: #f8f9fc;
    --bg-input-focus: #ffffff;
    --bg-hover: rgba(99, 102, 241, 0.06);
    --bg-preview: #ffffff;

    /* Text */
    --text-primary: #1a1a2e;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --text-on-primary: #ffffff;

    /* Borders */
    --border-color: rgba(0, 0, 0, 0.08);
    --border-color-strong: rgba(0, 0, 0, 0.14);
    --border-focus: var(--color-primary);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.10);
    --shadow-glow: 0 0 24px var(--color-primary-glow);

    /* Radii */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Backdrop */
    --backdrop-blur: blur(20px);

    /* Header */
    --header-height: 64px;
}

/* ---------- Dark Theme ---------- */
[data-theme="dark"] {
    --bg-body: #0f1117;
    --bg-panel: rgba(30, 32, 44, 0.82);
    --bg-panel-solid: #1e202c;
    --bg-input: #262836;
    --bg-input-focus: #2e3040;
    --bg-hover: rgba(99, 102, 241, 0.10);
    --bg-preview: #1a1c28;

    --text-primary: #e8eaf0;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;

    --border-color: rgba(255, 255, 255, 0.07);
    --border-color-strong: rgba(255, 255, 255, 0.12);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.20);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.30);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.35);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.40);
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color var(--transition-slow), color var(--transition-slow);
}

/* Animated background gradient */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 50% at 20% 20%, rgba(99, 102, 241, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse 60% 40% at 80% 80%, rgba(6, 182, 212, 0.06) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

[data-theme="dark"] body::before {
    background:
        radial-gradient(ellipse 80% 50% at 20% 20%, rgba(99, 102, 241, 0.12) 0%, transparent 60%),
        radial-gradient(ellipse 60% 40% at 80% 80%, rgba(6, 182, 212, 0.08) 0%, transparent 60%);
}

/* ---------- Header ---------- */
#app-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-panel);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border-bottom: 1px solid var(--border-color);
    height: var(--header-height);
    transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.brand {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.brand-icon {
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: white;
    border-radius: var(--radius-md);
    display: grid;
    place-items: center;
    flex-shrink: 0;
}

.brand-name {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    line-height: 1.2;
}

.brand-tagline {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    font-weight: 500;
    letter-spacing: 0.02em;
}

/* Icon Button (theme toggle) */
.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    border: 1px solid var(--border-color);
    background: var(--bg-input);
    color: var(--text-secondary);
    cursor: pointer;
    display: grid;
    place-items: center;
    transition: all var(--transition-fast);
}

.icon-btn:hover {
    background: var(--bg-hover);
    color: var(--color-primary);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
}

/* Theme toggle icon visibility */
[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }

/* ---------- Main Layout ---------- */
#app-main {
    position: relative;
    z-index: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-lg);
}

.app-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    align-items: start;
}

/* ---------- Panel (glassmorphism) ---------- */
.panel {
    background: var(--bg-panel);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    box-shadow: var(--shadow-lg);
    transition: background-color var(--transition-slow), border-color var(--transition-slow), box-shadow var(--transition-slow);
}

.controls-panel {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    max-height: calc(100vh - var(--header-height) - var(--space-lg) * 2);
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color-strong) transparent;
}

.controls-panel::-webkit-scrollbar { width: 6px; }
.controls-panel::-webkit-scrollbar-track { background: transparent; }
.controls-panel::-webkit-scrollbar-thumb { background: var(--border-color-strong); border-radius: 3px; }

.preview-panel {
    position: sticky;
    top: calc(var(--header-height) + var(--space-lg));
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

/* ---------- Section Blocks ---------- */
.section-block {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.section-title {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.section-subtitle {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

/* ---------- QR Type Tabs ---------- */
.type-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.type-tab {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border-radius: var(--radius-full);
    border: 1px solid var(--border-color);
    background: var(--bg-input);
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

.type-tab.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--text-on-primary);
    box-shadow: 0 2px 8px var(--color-primary-glow);
}

/* ---------- Form Elements ---------- */
.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.form-group label {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.input-fields {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.text-input,
.select-input {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 1.5px solid var(--border-color);
    background: var(--bg-input);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
    outline: none;
}

.text-input:focus,
.select-input:focus {
    border-color: var(--border-focus);
    background: var(--bg-input-focus);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.text-input::placeholder {
    color: var(--text-tertiary);
}

textarea.text-input {
    resize: vertical;
    min-height: 80px;
}

.select-input {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2364748b' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 14px center;
    padding-right: 40px;
    cursor: pointer;
}

/* WiFi Encryption select */
.input-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

/* ---------- Style Options (dot, corner) ---------- */
.style-options {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.style-option {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    border: 2px solid var(--border-color);
    background: var(--bg-input);
    color: var(--text-secondary);
    cursor: pointer;
    display: grid;
    place-items: center;
    transition: all var(--transition-fast);
}

.style-option:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: var(--bg-hover);
}

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

/* ---------- Color Inputs ---------- */
.color-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

.color-input-wrap {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 6px 10px;
    border-radius: var(--radius-md);
    border: 1.5px solid var(--border-color);
    background: var(--bg-input);
    transition: all var(--transition-fast);
}

.color-input-wrap:focus-within {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

input[type="color"] {
    width: 32px;
    height: 32px;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    padding: 0;
    background: none;
}

input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch { border: 1px solid var(--border-color-strong); border-radius: 6px; }

.color-hex {
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--text-tertiary);
    font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ---------- Logo Upload ---------- */
.logo-upload-area {
    border: 2px dashed var(--border-color-strong);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    min-height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-upload-area:hover,
.logo-upload-area.drag-over {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}

.logo-upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    color: var(--text-tertiary);
    font-size: 0.85rem;
    pointer-events: none;
}

.upload-hint {
    font-size: 0.72rem;
    opacity: 0.6;
}

.logo-preview-wrap {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-preview-wrap img {
    max-width: 80px;
    max-height: 80px;
    border-radius: var(--radius-sm);
    object-fit: contain;
}

.remove-logo-btn {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 24px;
    height: 24px;
    border-radius: var(--radius-full);
    border: none;
    background: var(--color-error);
    color: white;
    font-size: 1rem;
    line-height: 1;
    cursor: pointer;
    display: grid;
    place-items: center;
    transition: transform var(--transition-fast);
    pointer-events: auto;
}

.remove-logo-btn:hover {
    transform: scale(1.15);
}

/* ---------- Range Slider ---------- */
.range-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color-strong);
    outline: none;
    transition: background var(--transition-fast);
}

.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    box-shadow: 0 2px 6px var(--color-primary-glow);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.range-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 2px 12px var(--color-primary-glow);
}

.range-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px var(--color-primary-glow);
}

/* ---------- Preview Panel ---------- */
.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.preview-actions-top {
    display: flex;
    gap: var(--space-sm);
}

.preview-canvas-area {
    background: var(--bg-preview);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    padding: var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 320px;
    transition: background-color var(--transition-slow);
}

[data-theme="dark"] .preview-canvas-area {
    background: #1a1c28;
    background-image:
        linear-gradient(45deg, rgba(255,255,255,0.02) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(255,255,255,0.02) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, rgba(255,255,255,0.02) 75%),
        linear-gradient(-45deg, transparent 75%, rgba(255,255,255,0.02) 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

.qr-preview-container {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 100%;
}

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

.qr-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
    color: var(--text-tertiary);
    font-size: 0.9rem;
    padding: var(--space-xl);
}

/* ---------- Action Buttons ---------- */
.action-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
}

.action-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 12px 16px;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1.5px solid transparent;
    white-space: nowrap;
}

.action-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.primary-btn {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
    color: var(--text-on-primary);
    border-color: var(--color-primary);
    box-shadow: 0 2px 8px var(--color-primary-glow);
}

.primary-btn:not(:disabled):hover {
    box-shadow: 0 4px 16px var(--color-primary-glow);
    transform: translateY(-1px);
}

.primary-btn:not(:disabled):active {
    transform: translateY(0);
}

.secondary-btn {
    background: var(--bg-input);
    color: var(--text-secondary);
    border-color: var(--border-color);
}

.secondary-btn:hover {
    background: var(--bg-hover);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.outline-btn {
    background: transparent;
    color: var(--text-secondary);
    border-color: var(--border-color);
}

.outline-btn:not(:disabled):hover {
    background: var(--bg-hover);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.text-btn {
    background: none;
    border: none;
    color: var(--text-tertiary);
    font-family: inherit;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.text-btn:hover {
    color: var(--color-error);
    background: rgba(239, 68, 68, 0.08);
}

/* ---------- History Panel ---------- */
.history-section {
    border-top: 1px solid var(--border-color);
    padding-top: var(--space-md);
}

.history-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-sm);
}

.history-list {
    display: flex;
    gap: var(--space-sm);
    overflow-x: auto;
    padding: var(--space-sm) 0;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color-strong) transparent;
}

.history-list::-webkit-scrollbar { height: 4px; }
.history-list::-webkit-scrollbar-track { background: transparent; }
.history-list::-webkit-scrollbar-thumb { background: var(--border-color-strong); border-radius: 2px; }

.history-item {
    flex-shrink: 0;
    width: 72px;
    height: 72px;
    border-radius: var(--radius-md);
    border: 2px solid var(--border-color);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition-fast);
    background: var(--bg-input);
    display: grid;
    place-items: center;
}

.history-item:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
    transform: scale(1.05);
}

.history-item canvas {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.history-item img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.history-empty {
    color: var(--text-tertiary);
    font-size: 0.8rem;
    padding: var(--space-sm);
}

/* ---------- Toast ---------- */
.toast {
    position: fixed;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%) translateY(120%);
    background: var(--bg-panel-solid);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    z-index: 1000;
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
    white-space: nowrap;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    border-color: var(--color-success);
    box-shadow: 0 4px 20px rgba(16, 185, 129, 0.15);
}

.toast.error {
    border-color: var(--color-error);
    box-shadow: 0 4px 20px rgba(239, 68, 68, 0.15);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
    .app-grid {
        grid-template-columns: 1fr;
    }

    .controls-panel {
        max-height: none;
        overflow-y: visible;
    }

    .preview-panel {
        position: static;
    }
}

@media (max-width: 640px) {
    #app-main {
        padding: var(--space-md);
    }

    .panel {
        padding: var(--space-lg);
        border-radius: var(--radius-lg);
    }

    .header-inner {
        padding: 0 var(--space-md);
    }

    .brand-name {
        font-size: 1rem;
    }

    .type-tabs {
        gap: 6px;
    }

    .type-tab {
        padding: 6px 10px;
        font-size: 0.72rem;
    }

    .type-tab svg {
        width: 14px;
        height: 14px;
    }

    .action-buttons {
        grid-template-columns: 1fr;
    }

    .color-grid {
        grid-template-columns: 1fr;
    }

    .input-row {
        grid-template-columns: 1fr;
    }

    .style-option {
        width: 42px;
        height: 42px;
    }
}

/* ---------- Animations ---------- */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.panel {
    animation: fadeIn 0.5s ease-out both;
}

.controls-panel {
    animation-delay: 0.1s;
}

.preview-panel {
    animation-delay: 0.2s;
}

/* Generating state */
.qr-preview-container.generating {
    animation: pulse 1.2s ease-in-out infinite;
}

/* Focus-visible for keyboard navigation */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

button:focus:not(:focus-visible),
input:focus:not(:focus-visible),
select:focus:not(:focus-visible) {
    outline: none;
}