/* ========================================
   Global Styles & Reset
   ======================================== */

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
        color: #f0f0f0;
    }
}

/* ========================================
   Header Styles
   ======================================== */

header {
    background: linear-gradient(135deg, #004aad 0%, #0066dd 100%);
    color: white;
    text-align: center;
    padding: 30px 20px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    animation: slideDown 0.6s ease-out;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

header p {
    font-size: 1.1rem;
    opacity: 0.95;
    font-weight: 300;
}

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

/* ========================================
   Container & Main Content
   ======================================== */

.contenedor {
    width: 90%;
    max-width: 1100px;
    margin: 40px auto;
    background: white;
    padding: 40px 30px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    animation: fadeIn 0.8s ease-out;
}

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

.contenedor h2 {
    color: #004aad;
    margin-bottom: 25px;
    font-size: 1.8rem;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

/* ========================================
   Table Styles
   ======================================== */

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 40px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

thead {
    background: linear-gradient(135deg, #004aad 0%, #0066dd 100%);
    color: white;
}

th {
    padding: 16px;
    text-align: center;
    font-weight: 600;
    font-size: 0.95rem;
}

td {
    padding: 14px 16px;
    text-align: center;
    border-bottom: 1px solid #e0e0e0;
}

tbody tr {
    transition: all 0.3s ease;
}

tbody tr:nth-child(even) {
    background-color: #f8f9fa;
}

tbody tr:hover {
    background-color: #e3f2fd;
    transform: scale(1.01);
    box-shadow: inset 0 0 10px rgba(0, 74, 173, 0.1);
}

tbody tr:nth-child(even):hover {
    background-color: #e3f2fd;
}

/* ========================================
   Calculator Section
   ======================================== */

.calculadora {
    margin-top: 50px;
}

.calculadora h2 {
    color: #004aad;
    margin-bottom: 30px;
}

/* Conversion Group */
.conversion-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
    padding: 25px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 15px;
}

/* Input Group */
.input-group {
    display: flex;
    flex-direction: column;
}

.input-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: #004aad;
    font-size: 0.95rem;
}

input[type="number"],
select {
    padding: 12px 15px;
    font-size: 1rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    transition: all 0.3s ease;
    background-color: white;
    color: #333;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: #004aad;
    box-shadow: 0 0 0 4px rgba(0, 74, 173, 0.1);
    transform: scale(1.02);
}

input[type="number"]::placeholder {
    color: #999;
}

/* ========================================
   Buttons
   ======================================== */

button {
    padding: 12px 30px;
    font-size: 1rem;
    background: linear-gradient(135deg, #004aad 0%, #0066dd 100%);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 74, 173, 0.3);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 74, 173, 0.4);
    background: linear-gradient(135deg, #0066dd 0%, #0080ff 100%);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(0, 74, 173, 0.3);
}

button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Grid alignment for buttons */
.conversion-group button {
    grid-column: 1 / -1;
    width: 100%;
}

/* ========================================
   Result Display
   ======================================== */

#resultado {
    margin-top: 25px;
    padding: 20px 25px;
    font-size: 1.2rem;
    font-weight: 600;
    text-align: center;
    border-radius: 10px;
    animation: popIn 0.4s ease-out;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #f0f0f0;
    color: #666;
}

@keyframes popIn {
    0% {
        opacity: 0;
        transform: scale(0.9);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

#resultado.success {
    background: linear-gradient(135deg, #d4edda 0%, #c3e6cb 100%);
    color: #155724;
    border: 2px solid #28a745;
}

#resultado.error {
    background: linear-gradient(135deg, #f8d7da 0%, #f5c6cb 100%);
    color: #721c24;
    border: 2px solid #f5494a;
}

/* ========================================
   Quick Conversions
   ======================================== */

.quick-conversions {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 2px solid #e0e0e0;
}

.quick-conversions h3 {
    color: #004aad;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.button-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
}

.quick-btn {
    padding: 10px 15px;
    font-size: 0.9rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.quick-btn:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

/* ========================================
   Footer
   ======================================== */

footer {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, #004aad 0%, #0066dd 100%);
    color: white;
    margin-top: 60px;
    box-shadow: 0 -4px 15px rgba(0, 0, 0, 0.1);
}

footer p {
    margin: 8px 0;
    font-size: 0.95rem;
}

footer a {
    color: #ffeb3b;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

footer a:hover {
    text-decoration: underline;
    color: #fff;
}

/* ========================================
   Responsive Design
   ======================================== */

/* Tablets */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .contenedor {
        margin: 20px auto;
        padding: 25px 20px;
        width: 95%;
    }

    .conversion-group {
        grid-template-columns: 1fr;
        gap: 15px;
        padding: 20px;
    }

    table {
        font-size: 0.9rem;
    }

    th, td {
        padding: 10px 8px;
    }

    .button-group {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile Phones */
@media (max-width: 480px) {
    body {
        font-size: 14px;
    }

    header {
        padding: 20px 15px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    header p {
        font-size: 0.9rem;
    }

    .contenedor {
        margin: 15px auto;
        padding: 15px;
        width: 98%;
        border-radius: 12px;
    }

    .contenedor h2 {
        font-size: 1.3rem;
        margin-bottom: 15px;
    }

    .conversion-group {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 15px;
        border-radius: 10px;
    }

    input[type="number"],
    select {
        padding: 10px 12px;
        font-size: 16px; /* Prevents zoom on iOS */
    }

    button {
        padding: 11px 20px;
        font-size: 0.95rem;
    }

    .quick-btn {
        padding: 9px 12px;
        font-size: 0.85rem;
    }

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

    table {
        font-size: 0.85rem;
    }

    th, td {
        padding: 8px 6px;
    }

    #resultado {
        font-size: 1rem;
        padding: 15px 20px;
        margin-top: 15px;
    }

    .quick-conversions {
        margin-top: 25px;
        padding-top: 20px;
    }

    .quick-conversions h3 {
        font-size: 1.1rem;
    }

    footer {
        padding: 20px 15px;
    }

    footer p {
        font-size: 0.85rem;
    }
}

/* ========================================
   Accessibility Features
   ======================================== */

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

/* High contrast mode */
@media (prefers-contrast: more) {
    body {
        background: linear-gradient(135deg, #000 0%, #1a1a1a 100%);
    }

    .contenedor {
        background: white;
        border: 3px solid black;
    }

    button {
        border: 2px solid black;
    }

    table {
        border: 2px solid black;
    }
}

/* ========================================
   Print Styles
   ======================================== */

@media print {
    body {
        background: white;
    }

    header,
    footer,
    .calculadora,
    button,
    .quick-conversions {
        display: none;
    }

    .contenedor {
        box-shadow: none;
        border: 1px solid #ccc;
    }

    table {
        page-break-inside: avoid;
    }
}

/* ========================================
   Utility Classes
   ======================================== */

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

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

.hidden {
    display: none;
}

.visible {
    display: block;
}