:root {
    --color-primary: #1E3C94;
    --color-container: #1E2D4E;
    --color-title: #5AA3FA;
    --color-subtitle: #B1C1DD;
    --color-label: #FFFFFF;
    --color-stock-high: #068F65;
    --color-stock-medium: #D37008;
    --color-stock-low: #D82423;
    --color-secondary: #3498db;
    --color-danger: #e74c3c;
    --color-light: #ecf0f1;
    --border-radius: 8px;
    --box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--color-primary);
    color: var(--color-label);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Auth Container */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--color-primary);
}

.login-box {
    background-color: var(--color-container);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 30px;
    width: 100%;
    max-width: 400px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.login-box h2 {
    color: var(--color-title);
    margin-bottom: 10px;
}

.login-box p {
    color: var(--color-subtitle);
    margin-bottom: 20px;
}

.firebase-status {
    margin: 20px 0;
    padding: 10px;
    border-radius: var(--border-radius);
    background-color: rgba(255, 255, 255, 0.1);
    font-size: 14px;
    color: var(--color-subtitle);
}

.login-btn {
    background-color: var(--color-title);
    color: var(--color-container);
    border: none;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 16px;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: var(--transition);
    font-weight: 600;
}

.login-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.login-btn:hover:not(:disabled) {
    opacity: 0.9;
}

.login-note {
    margin-top: 20px;
    font-size: 12px;
    color: var(--color-subtitle);
}

/* Main Content */
.main-content {
    display: none;
}

/* Header Styles */
.header {
    background-color: var(--color-container);
    box-shadow: var(--box-shadow);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.header-left {
    display: flex;
    align-items: center;
}

.header-right {
    display: flex;
    align-items: center;
}

.system-title {
    color: var(--color-title);
    font-size: 1.5rem;
    margin: 0;
    font-weight: 700;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--color-title);
}

.user-details {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.user-details span {
    font-weight: 500;
    color: var(--color-label);
}

.logout-btn {
    background-color: var(--color-danger);
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.8rem;
    margin-top: 5px;
    width: fit-content;
}

.logout-btn:hover {
    opacity: 0.9;
}

/* Sections Container */
.sections-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

/* Sections */
.section {
    background-color: var(--color-container);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    width: 100%;
}

.section-header {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
    gap: 15px;
}

.section-header .icon {
    font-size: 24px;
    color: var(--color-title);
}

.section-title {
    margin: 0;
    color: var(--color-title);
    font-size: 1.5rem;
}

.section-subtitle {
    margin: 5px 0 0;
    color: var(--color-subtitle);
    font-size: 0.9rem;
}

/* Form Styles */
.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--color-label);
}

.form-control {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: var(--transition);
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-label);
}

.form-control:focus {
    border-color: var(--color-title);
    outline: none;
    box-shadow: 0 0 0 3px rgba(90, 163, 250, 0.2);
}

.register-btn {
    background-color: var(--color-title);
    color: var(--color-container);
    border: none;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 16px;
    width: 100%;
    transition: var(--transition);
    font-weight: 600;
    margin-top: 10px;
}

.register-btn:hover {
    opacity: 0.9;
}

/* Stock Grid */
.stock-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin-top: 20px;
}

.stock-card {
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    transition: var(--transition);
    border-left: 4px solid transparent;
}

/* Stock Status Classes */
.stock-card.high-stock {
    background-color: var(--color-stock-high);
    border-left-color: #056a4d;
}

.stock-card.medium-stock {
    background-color: var(--color-stock-medium);
    border-left-color: #b35e07;
}

.stock-card.low-stock {
    background-color: var(--color-stock-low);
    border-left-color: #b31d1c;
}

.stock-card.out-of-stock {
    background-color: var(--color-stock-low);
    border-left-color: #b31d1c;
    opacity: 0.9;
}

.stock-card h3 {
    margin-top: 0;
    color: var(--color-label);
    font-size: 1.1rem;
}

.stock-amount {
    font-size: 2rem;
    font-weight: bold;
    margin: 15px 0;
    color: var(--color-label);
}

.stock-label {
    display: block;
    color: var(--color-label);
    font-size: 0.9rem;
}

.stock-label a {
    color: var(--color-label);
    text-decoration: underline;
}

/* History Section */
.history-section {
    width: 100%;
}

.history-container {
    margin-top: 20px;
    overflow-x: auto;
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 15px;
    min-width: 600px;
}

.history-table th,
.history-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--color-label);
}

.history-table th {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-title);
    font-weight: 500;
}

.history-table tbody tr:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.delete-btn {
    background-color: var(--color-danger);
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
}

.delete-btn:hover {
    opacity: 0.9;
}

/* Export Button */
.export-btn {
    background-color: var(--color-title);
    color: var(--color-container);
    border: none;
    padding: 10px 15px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
    margin-left: auto;
    font-weight: 500;
}

.export-btn:hover {
    opacity: 0.9;
}

/* Alerts Container */
.alert-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

.alert {
    padding: 15px 20px;
    margin-bottom: 10px;
    border-radius: var(--border-radius);
    color: white;
    box-shadow: var(--box-shadow);
    display: flex;
    align-items: center;
    gap: 10px;
    transition: var(--transition);
    background-color: var(--color-container);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.alert-success {
    border-left: 4px solid var(--color-stock-high);
}

.alert-error {
    border-left: 4px solid var(--color-stock-low);
}

.alert-warning {
    border-left: 4px solid var(--color-stock-medium);
}

/* Responsive Design */
@media screen and (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: 10px;
    }

    .header-left, 
    .header-right {
        width: 100%;
        justify-content: center;
        text-align: center;
    }

    .user-details {
        align-items: center;
    }

    .sections-container {
        grid-template-columns: 1fr;
    }

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

    .container {
        padding: 10px;
    }

    .section {
        padding: 15px;
    }

    .history-table {
        min-width: 100%;
    }
}

/* Responsive adjustments for very small screens */
@media screen and (max-width: 480px) {
    .system-title {
        font-size: 1.2rem;
    }

    .section-title {
        font-size: 1.2rem;
    }

    .stock-card {
        padding: 15px;
    }

    .stock-amount {
        font-size: 1.5rem;
    }
}