/* ============================================
   PAKISTAN LAND MEASUREMENT CALCULATOR
   Professional CSS Stylesheet
   ============================================ */

/* Root Variables */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --light-bg: #ecf0f1;
    --white: #ffffff;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --border-color: #bdc3c7;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

/* ============================================
   GLOBAL STYLES
   ============================================ */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-dark);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* ============================================
   HEADER STYLES
   ============================================ */

.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #34495e 100%);
    color: var(--white);
    padding: 40px 20px;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
}

.logo-section {
    margin-bottom: 20px;
}

.logo-section i {
    font-size: 48px;
    margin-bottom: 15px;
    display: block;
    color: var(--secondary-color);
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 5px;
    font-weight: 700;
    letter-spacing: 1px;
}

.subtitle {
    font-size: 1.1em;
    color: #bdc3c7;
    margin-bottom: 20px;
}

.conversion-info {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.info-badge {
    background: rgba(255, 255, 255, 0.2);
    padding: 10px 20px;
    border-radius: 25px;
    font-size: 0.95em;
    border: 1px solid rgba(255, 255, 255, 0.3);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.info-badge i {
    color: var(--secondary-color);
}

/* ============================================
   MAIN CONTENT
   ============================================ */

.main-content {
    background: var(--white);
    margin: 30px 20px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

/* ============================================
   TABS STYLES
   ============================================ */

.tabs-container {
    display: flex;
    flex-wrap: wrap;
    background: var(--light-bg);
    border-bottom: 2px solid var(--border-color);
    overflow-x: auto;
}

.tab-button {
    flex: 1;
    min-width: 150px;
    padding: 18px 15px;
    border: none;
    background: transparent;
    color: var(--text-dark);
    cursor: pointer;
    font-size: 0.95em;
    font-weight: 600;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    border-bottom: 3px solid transparent;
}

.tab-button:hover {
    background: rgba(52, 152, 219, 0.1);
    color: var(--secondary-color);
}

.tab-button.active {
    background: var(--white);
    color: var(--secondary-color);
    border-bottom-color: var(--secondary-color);
}

.tab-button i {
    font-size: 1.1em;
}

/* ============================================
   TAB CONTENT
   ============================================ */

.tabs-content {
    padding: 40px;
    min-height: 600px;
}

.tab-pane {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-pane.active {
    display: block;
}

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

/* ============================================
   FORM STYLES
   ============================================ */

.form-section {
    max-width: 800px;
    margin: 0 auto;
}

.form-section h2 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 1.8em;
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-section h2 i {
    color: var(--secondary-color);
}

.form-description {
    color: var(--text-light);
    margin-bottom: 30px;
    font-size: 1em;
    line-height: 1.6;
}

.calculation-form {
    background: var(--light-bg);
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group:last-child {
    margin-bottom: 0;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-dark);
    font-size: 1em;
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-group label i {
    color: var(--secondary-color);
    font-size: 1.1em;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-size: 1em;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-group small {
    display: block;
    margin-top: 5px;
    color: var(--text-light);
    font-size: 0.9em;
}

.sides-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 768px) {
    .sides-container {
        grid-template-columns: 1fr;
    }
}

.triangles-container {
    display: grid;
    gap: 25px;
    margin-bottom: 25px;
}

.triangle-card {
    background: var(--white);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    position: relative;
}

.triangle-card h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.triangle-card h4 i {
    color: var(--secondary-color);
}

.triangle-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 15px;
    margin-bottom: 15px;
}

@media (max-width: 768px) {
    .triangle-inputs {
        grid-template-columns: 1fr;
    }
}

.triangle-card .form-group {
    margin-bottom: 0;
}

.remove-triangle-btn {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--accent-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    width: 35px;
    height: 35px;
    cursor: pointer;
    font-size: 1.1em;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-triangle-btn:hover {
    background: #c0392b;
    transform: scale(1.1);
}

/* ============================================
   BUTTON STYLES
   ============================================ */

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 6px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%);
    color: var(--white);
    width: 100%;
    padding: 15px;
    font-size: 1.05em;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

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

.btn-secondary {
    background: var(--light-bg);
    color: var(--secondary-color);
    border: 2px solid var(--secondary-color);
}

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

.button-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

@media (max-width: 768px) {
    .button-group {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   RESULT STYLES
   ============================================ */

.result-section {
    margin-top: 30px;
    animation: slideUp 0.4s ease;
}

.result-section.hidden {
    display: none;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-card {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 10px;
    padding: 30px;
    border-left: 5px solid var(--success-color);
}

.result-card h3 {
    color: var(--primary-color);
    margin-bottom: 25px;
    font-size: 1.5em;
    display: flex;
    align-items: center;
    gap: 10px;
}

.result-card h3 i {
    color: var(--success-color);
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
}

.result-item {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
}

.result-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}

.result-item.highlight {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%);
    color: var(--white);
}

.result-label {
    display: block;
    font-size: 0.9em;
    color: var(--text-light);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.result-item.highlight .result-label {
    color: rgba(255, 255, 255, 0.9);
}

.result-value {
    display: block;
    font-size: 2em;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.result-item.highlight .result-value {
    color: var(--white);
}

.result-unit {
    display: block;
    font-size: 0.85em;
    color: var(--text-light);
    font-weight: 500;
}

.result-item.highlight .result-unit {
    color: rgba(255, 255, 255, 0.85);
}

.result-summary {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--secondary-color);
}

.result-summary p {
    color: var(--text-dark);
    font-size: 1.05em;
    margin: 0;
    line-height: 1.8;
}

/* ============================================
   REFERENCE SECTION
   ============================================ */

.reference-section {
    max-width: 900px;
    margin: 0 auto;
}

.reference-section h2 {
    color: var(--primary-color);
    margin-bottom: 30px;
    font-size: 1.8em;
    display: flex;
    align-items: center;
    gap: 10px;
}

.reference-section h2 i {
    color: var(--secondary-color);
}

.reference-card {
    background: var(--light-bg);
    border-radius: 10px;
    padding: 25px;
    margin-bottom: 25px;
    border-left: 5px solid var(--secondary-color);
}

.reference-card h3 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.3em;
    display: flex;
    align-items: center;
    gap: 10px;
}

.reference-card h3 i {
    color: var(--secondary-color);
}

.reference-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
}

.reference-table thead {
    background: var(--primary-color);
    color: var(--white);
}

.reference-table th,
.reference-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.reference-table tbody tr:hover {
    background: var(--light-bg);
}

.reference-table tbody tr:last-child td {
    border-bottom: none;
}

.instruction-item {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 15px;
    border-left: 4px solid var(--secondary-color);
}

.instruction-item h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 1.1em;
    display: flex;
    align-items: center;
    gap: 8px;
}

.instruction-item h4 i {
    color: var(--secondary-color);
}

.instruction-item p {
    color: var(--text-dark);
    line-height: 1.7;
    margin: 0;
}

.tips-list {
    list-style: none;
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
}

.tips-list li {
    padding: 12px 0;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--light-bg);
}

.tips-list li:last-child {
    border-bottom: none;
}

.tips-list i {
    color: var(--success-color);
    font-size: 1.1em;
}

.method-item {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 15px;
}

.method-item h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-weight: 600;
}

.method-item p {
    color: var(--text-dark);
    margin: 8px 0;
    font-family: 'Courier New', monospace;
    background: var(--light-bg);
    padding: 10px;
    border-radius: 4px;
}

/* ============================================
   FOOTER STYLES
   ============================================ */

.footer {
    background: var(--primary-color);
    color: var(--white);
    padding: 30px 20px;
    text-align: center;
    border-top: 3px solid var(--secondary-color);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-content p {
    margin: 8px 0;
    font-size: 0.95em;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.footer-content p:first-child {
    margin-top: 0;
}

.footer-content p:last-child {
    margin-bottom: 0;
    color: #bdc3c7;
    font-size: 0.9em;
}

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

@media (max-width: 768px) {
    .header {
        padding: 30px 15px;
    }

    .header h1 {
        font-size: 1.8em;
    }

    .subtitle {
        font-size: 1em;
    }

    .conversion-info {
        flex-direction: column;
    }

    .info-badge {
        width: 100%;
        justify-content: center;
    }

    .tabs-container {
        flex-wrap: wrap;
    }

    .tab-button {
        min-width: 120px;
        padding: 15px 10px;
        font-size: 0.85em;
    }

    .tab-button i {
        display: none;
    }

    .tabs-content {
        padding: 25px 15px;
        min-height: auto;
    }

    .calculation-form {
        padding: 20px;
    }

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

    .form-section h2 {
        font-size: 1.4em;
    }

    .reference-table {
        font-size: 0.9em;
    }

    .reference-table th,
    .reference-table td {
        padding: 10px;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.5em;
    }

    .tab-button {
        min-width: 100px;
        padding: 12px 8px;
        font-size: 0.75em;
    }

    .tabs-content {
        padding: 15px;
    }

    .calculation-form {
        padding: 15px;
    }

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

    .form-section h2 {
        font-size: 1.2em;
    }

    .btn {
        padding: 10px 15px;
        font-size: 0.9em;
    }

    .button-group {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.hidden {
    display: none !important;
}

.visible {
    display: block !important;
}

.text-center {
    text-align: center;
}

.text-success {
    color: var(--success-color);
}

.text-error {
    color: var(--accent-color);
}

.text-warning {
    color: var(--warning-color);
}

/* ============================================
   SCROLLBAR STYLING
   ============================================ */

::-webkit-scrollbar {
    width: 10px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--secondary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: #2980b9;
}