/* ============================================
   POS MOBILE-FIRST STYLESHEET WITH THEME SYSTEM
   ============================================ */

/* ========== CSS VARIABLES FOR THEMING ========== */
:root {
    /* Light Theme (Default) */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    --gradient-start: var(--primary-color);
    --gradient-end: var(--secondary-color);
    
    --transition-speed: 0.3s;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
}

/* Dark Theme */
[data-theme="dark"] {
    --primary-color: #818cf8;
    --primary-dark: #6366f1;
    --primary-light: #a5b4fc;
    --secondary-color: #f472b6;
    
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-tertiary: #9ca3af;
    
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

/* Blue Theme */
[data-theme="blue"] {
    --primary-color: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #38bdf8;
    --secondary-color: #06b6d4;
    --gradient-start: #0ea5e9;
    --gradient-end: #06b6d4;
    
    --bg-primary: #f0f9ff;
    --bg-secondary: #e0f2fe;
    --bg-tertiary: #bae6fd;
}

/* Green Theme */
[data-theme="green"] {
    --primary-color: #10b981;
    --primary-dark: #059669;
    --primary-light: #34d399;
    --secondary-color: #14b8a6;
    --gradient-start: #10b981;
    --gradient-end: #14b8a6;
    
    --bg-primary: #f0fdf4;
    --bg-secondary: #dcfce7;
    --bg-tertiary: #bbf7d0;
}

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background var(--transition-speed) ease, color var(--transition-speed) ease;
}

/* ========== LOGIN SCREEN STYLES ========== */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    position: relative;
}

.theme-switcher {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    gap: 0.5rem;
    z-index: 100;
}

.theme-btn {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    color: white;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.theme-btn:active {
    transform: scale(0.95);
}

.theme-btn.active {
    background: white;
    color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.login-card {
    width: 100%;
    max-width: 400px;
    background: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    padding: 2rem;
    animation: slideUp 0.5s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.logo-container {
    width: 80px;
    height: 80px;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
}

.logo-container i {
    font-size: 2.5rem;
    color: white;
}

.login-header h1 {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error-color);
    color: var(--error-color);
    padding: 1rem;
    border-radius: var(--border-radius-sm);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.error-message i {
    font-size: 1.25rem;
}

.login-form {
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.form-group label i {
    color: var(--primary-color);
}

.form-group input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: all var(--transition-speed) ease;
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.password-input {
    position: relative;
    display: flex;
    align-items: center;
}

.password-input input {
    padding-right: 3rem;
}

.toggle-password {
    position: absolute;
    right: 0.5rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-speed) ease;
}

.toggle-password:hover {
    color: var(--primary-color);
    background: var(--bg-tertiary);
}

.btn-login {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all var(--transition-speed) ease;
    box-shadow: var(--shadow-md);
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.login-footer {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.login-footer strong {
    color: var(--primary-color);
}

/* ========== UTILITY CLASSES ========== */
.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-success { color: var(--success-color); }
.text-warning { color: var(--warning-color); }
.text-error { color: var(--error-color); }

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

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

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

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

/* ========== RESPONSIVE DESIGN ========== */

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    .login-card {
        padding: 2.5rem;
    }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    html {
        font-size: 18px;
    }
    
    .theme-switcher {
        top: 2rem;
        right: 2rem;
        gap: 0.75rem;
    }
    
    .theme-btn {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .login-card {
        max-width: 450px;
    }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .login-container {
        padding: 2rem;
    }
}

/* ========== PRINT STYLES ========== */
@media print {
    body {
        background: white;
    }
    
    .theme-switcher {
        display: none;
    }
}

/* ========== ACCESSIBILITY ========== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus visible for keyboard navigation */
*:focus-visible {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}