/* ========== CSS VARIABLES ========== */
:root {
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
    --gradient-hover-start: #5568d3;
    --gradient-hover-end: #6a3d9a;
    
    /* Colors */
    --color-primary: #667eea;
    --color-primary-hover: #5568d3;
    --color-secondary: #48bb78;
    --color-secondary-hover: #38a169;
    --color-danger: #f56565;
    --color-danger-hover: #e53e3e;
    --color-text: #333;
    --color-text-light: #666;
    --color-text-lighter: #999;
    --color-bg: white;
    --color-bg-light: #f7fafc;
    --color-bg-lighter: #f0f4f8;
    --color-border: #e2e8f0;
    
    /* Spacing */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 25px;
    --spacing-xxl: 30px;
    
    /* Border radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 10px;
    --radius-full: 50%;
    
    /* Shadows */
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 8px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.3);
    
    /* Transitions */
    --transition-fast: 0.2s;
    --transition-normal: 0.3s;
    --transition-slow: 0.5s;
}

/* ========== RESET & BASE ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    min-height: 100vh;
    padding: var(--spacing-lg);
}

/* ========== LAYOUT ========== */
.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    background: var(--color-bg);
    padding: var(--spacing-xxl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-xxl);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    color: var(--color-text);
    font-size: 2em;
}

/* ========== BUTTONS ========== */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all var(--transition-normal);
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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

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

.btn-danger {
    background: var(--color-danger);
    color: var(--color-bg);
}

.btn-danger:hover {
    background: var(--color-danger-hover);
}

/* ========== DEVICE LIST ========== */
.device-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xxl);
}

/* ========== LOCATION FOLDERS ========== */
.location-folder {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.location-folder:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.location-folder-header {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: var(--color-bg);
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
    transition: background var(--transition-fast);
}

.location-folder-header:hover {
    background: linear-gradient(135deg, var(--gradient-hover-start) 0%, var(--gradient-hover-end) 100%);
}

.folder-chevron,
.section-chevron {
    font-size: 0.8em;
    transition: transform var(--transition-normal);
    display: inline-block;
}

.location-folder-title {
    margin: 0;
    font-size: 1.5em;
    color: var(--color-bg);
}

.location-device-count {
    background: rgba(255, 255, 255, 0.2);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 20px;
    font-size: 0.9em;
    font-weight: 600;
}

.btn-credit-all {
    background: var(--color-secondary);
    color: white;
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    white-space: nowrap;
}

.btn-credit-all:hover {
    background: var(--color-secondary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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

.location-devices-container,
.settings-section-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal) ease-out;
}

.location-folder.expanded .location-devices-container {
    max-height: 5000px;
    transition: max-height var(--transition-normal) ease-in;
}

.location-devices {
    padding: var(--spacing-lg);
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

/* ========== DEVICE CARDS ========== */
.device-card {
    background: var(--color-bg);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.device-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.device-card h3 {
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    font-size: 1.5em;
}

.device-info {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
}

.device-info strong {
    color: var(--color-text);
}

.device-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.device-actions .btn {
    flex: 1;
    padding: var(--spacing-sm);
    font-size: 14px;
}

/* ========== MODALS ========== */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background-color: var(--color-bg);
    margin: 5% auto;
    padding: var(--spacing-xxl);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.close {
    color: var(--color-text-lighter);
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    right: var(--spacing-lg);
    top: var(--spacing-lg);
    transition: color var(--transition-fast);
}

.close:hover {
    color: var(--color-text);
}

/* ========== FORMS ========== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--color-text);
    font-weight: 600;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 16px;
    transition: border-color var(--transition-normal);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
}

.help-text {
    display: block;
    margin-top: var(--spacing-xs);
    font-size: 12px;
    color: var(--color-text-light);
    font-style: italic;
}

.button-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
}

.button-group .btn {
    flex: 1;
}

/* ========== STATUS & UPLOAD ========== */
.upload-status {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    display: none;
}

.upload-status.success {
    display: block;
    background: #c6f6d5;
    color: #22543d;
    border: 1px solid #9ae6b4;
}

.upload-status.error {
    display: block;
    background: #fed7d7;
    color: #742a2a;
    border: 1px solid #fc8181;
}

.empty-state {
    text-align: center;
    padding: 60px var(--spacing-lg);
    color: var(--color-bg);
    font-size: 1.2em;
}

.empty-state h2 {
    margin-bottom: var(--spacing-md);
}

.device-status {
    background: var(--color-bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
}

.status-section {
    background: var(--color-bg-lighter);
    padding: 12px;
    border-radius: var(--radius-sm);
    margin: var(--spacing-md) 0;
}

.progress-bar-container {
    width: 100%;
    height: 20px;
    background: var(--color-border);
    border-radius: 10px;
    overflow: hidden;
    margin-top: var(--spacing-sm);
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    transition: width var(--transition-slow) linear;
    border-radius: 10px;
}

.countdown-text {
    font-weight: 600;
    color: var(--color-primary);
    font-size: 14px;
}

.online-status {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: var(--radius-full);
    background: #cbd5e0;
}

/* ========== ANIMATIONS ========== */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== HAMBURGER MENU ========== */
.hamburger-menu-container {
    position: relative;
}

.hamburger-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
    cursor: pointer;
}

.hamburger-btn:hover {
    background: var(--color-primary-hover) !important;
}

.hamburger-menu {
    position: absolute;
    top: calc(100% + var(--spacing-sm));
    right: 0;
    background: var(--color-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    min-width: 220px;
    z-index: 1000;
    overflow: hidden;
    animation: slideDown var(--transition-fast) ease-out;
}

.hamburger-menu .menu-item {
    display: block;
    width: 100%;
    padding: 12px var(--spacing-lg);
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-text);
    font-size: 16px;
    transition: background var(--transition-fast);
    border-bottom: 1px solid var(--color-border);
}

.hamburger-menu .menu-item:last-child {
    border-bottom: none;
}

.hamburger-menu .menu-item:hover {
    background: var(--color-bg-lighter);
}

.hamburger-menu .menu-item span {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* ========== SETTINGS SECTIONS ========== */
.settings-section {
    margin-bottom: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--color-bg);
}

.settings-section-header {
    background: var(--color-bg-lighter);
    padding: var(--spacing-md) var(--spacing-lg);
    cursor: pointer;
    user-select: none;
    transition: background var(--transition-fast);
    border-bottom: 1px solid var(--color-border);
}

.settings-section-header:hover {
    background: var(--color-border);
}

.section-chevron {
    color: var(--color-primary);
}

.settings-section.expanded .section-chevron {
    transform: rotate(90deg);
}

.settings-section.expanded .settings-section-content {
    max-height: 2000px;
    padding: var(--spacing-lg);
    transition: max-height var(--transition-normal) ease-in;
}