:root {
    --primary-color: #4a90e2;
    --secondary-color: #f39c12;
    --background-color: #f0f4f8;
    --text-color: #333;
    --header-bg: #2c3e50;
    --header-text: #ecf0f1;
    --card-bg: #ffffff;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Kanit', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 1rem 0;
    box-shadow: var(--box-shadow);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.5rem;
    margin: 0;
}

nav {
    display: flex;
    align-items: center;
}

nav span {
    margin-right: 1rem;
    font-size: 0.9rem;
}

.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: background-color 0.3s ease, transform 0.2s ease;
    font-size: 0.9rem;
}

.btn:hover {
    background-color: darken(var(--primary-color), 10%);
    transform: translateY(-2px);
}

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

.btn-primary:hover {
    background-color: darken(var(--secondary-color), 10%);
}

main {
    padding: 2rem 0;
}

h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.url-form, .login-form, .register-form {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.input-group {
    display: flex;
    margin-bottom: 1rem;
}

input[type="url"], input[type="text"], input[type="password"], input[type="email"] {
    flex-grow: 1;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
}

button {
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

button:hover {
    background-color: darken(var(--primary-color), 10%);
    transform: translateY(-2px);
}

.result, .message {
    margin-top: 1rem;
    padding: 1rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.short-url {
    color: var(--secondary-color);
    font-weight: 600;
    text-decoration: none;
    word-break: break-all;
}

.copy-btn {
    background-color: var(--secondary-color);
    margin-left: 0.5rem;
    font-size: 0.8rem;
}

.features, .premium-features {
    margin-top: 2rem;
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

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

footer {
    background-color: var(--header-bg);
    color: var(--header-text);
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
    font-size: 0.9rem;
}

.fas, .far {
    margin-right: 0.5rem;
}

.features p, .premium-features p {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
}

.features .fas, .premium-features .fas {
    color: var(--primary-color);
    font-size: 1.2rem;
    width: 1.5rem;
}

.btn .fas, .btn .far {
    margin-right: 0.3rem;
}

.premium-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.premium-features h2, .premium-features .btn {
    grid-column: 1 / -1;
}

@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        text-align: center;
    }

    nav {
        margin-top: 1rem;
    }

    .input-group {
        flex-direction: column;
    }

    input[type="url"], button {
        width: 100%;
        margin-bottom: 0.5rem;
    }

    .result p {
        flex-direction: column;
        align-items: flex-start;
    }

    .copy-btn {
        margin-left: 0;
        margin-top: 0.5rem;
    }

    .premium-features {
        grid-template-columns: 1fr;
    }
}

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

    .container {
        padding: 0 10px;
    }

    h1 {
        font-size: 1.2rem;
    }

    h2 {
        font-size: 1.1rem;
    }

    .btn {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
}

/* เพิ่มหรือแก้ไขส่วนนี้ในไฟล์ CSS ของคุณ */

.user-urls {
    margin-top: 2rem;
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.table-responsive {
    overflow-x: auto;
}

.url-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.url-table th,
.url-table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

.url-table th {
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
}

.url-table .original-url {
    width: 15%;
    text-align: center;
}

.url-table .short-url {
    width: 40%;
}

.url-table .click-count {
    width: 15%;
    text-align: center;
}

.url-table .actions {
    width: 30%;
    text-align: center;
}

.btn-link,
.btn-copy {
    padding: 0.3rem 0.5rem;
    font-size: 0.8rem;
    border-radius: 4px;
    text-decoration: none;
    transition: background-color 0.3s ease;
}

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

.btn-copy {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    cursor: pointer;
}

.btn-link:hover,
.btn-copy:hover {
    opacity: 0.8;
}

@media (max-width: 768px) {
    .url-table, .url-table thead, .url-table tbody, .url-table th, .url-table td, .url-table tr {
        display: block;
    }
    
    .url-table thead tr {
        position: absolute;
        top: -9999px;
        left: -9999px;
    }
    
    .url-table tr {
        border: 1px solid #ccc;
        margin-bottom: 0.5rem;
    }
    
    .url-table td {
        border: none;
        border-bottom: 1px solid #eee;
        position: relative;
        padding-left: 50%;
        text-align: left;
    }
    
    .url-table td:before {
        position: absolute;
        top: 6px;
        left: 6px;
        width: 45%;
        padding-right: 10px;
        white-space: nowrap;
        content: attr(data-label);
        font-weight: bold;
    }
    
    .url-table .original-url,
    .url-table .short-url,
    .url-table .click-count,
    .url-table .actions {
        width: 100%;
    }
}

.user-type {
    padding: 0.3rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-left: 0.5rem;
}

.user-type.regular {
    background-color: #4a90e2;
    color: white;
}

.user-type.premium {
    background-color: #f39c12;
    color: white;
}

/* เพิ่มส่วนนี้ต่อท้ายไฟล์ CSS ที่มีอยู่ */

.premium-features {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-top: 2rem;
    text-align: center;
    box-shadow: var(--box-shadow);
}

.premium-features h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.premium-features p {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.premium-features i {
    margin-right: 0.5rem;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.premium-features .btn-primary {
    margin-top: 1.5rem;
    font-size: 1.1rem;
    padding: 0.75rem 2rem;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.premium-features .btn-primary:hover {
    background-color: darken(var(--secondary-color), 10%);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

/* Media queries สำหรับ responsive design */
@media (max-width: 1200px) {
    .container {
        max-width: 960px;
    }
}

@media (max-width: 992px) {
    .container {
        max-width: 720px;
    }
}

@media (max-width: 768px) {
    .container {
        max-width: 540px;
    }
    .feature-list {
        grid-template-columns: repeat(2, 1fr);
    }
    .premium-features h2 {
        font-size: 1.5rem;
    }
    
    .premium-features p {
        font-size: 1rem;
    }
    
    .premium-features .btn-primary {
        font-size: 1rem;
        padding: 0.6rem 1.5rem;
    }
}

@media (max-width: 576px) {
    .container {
        max-width: none;
        padding: 0 15px;
    }
    .feature-list {
        grid-template-columns: 1fr;
    }
    .premium-features h2 {
        font-size: 1.3rem;
    }
    .feature-item i {
        font-size: 2rem;
    }
    .feature-item span {
        font-size: 0.9rem;
    }
    
    .premium-features h2 {
        font-size: 1.3rem;
    }
    
    .premium-features p {
        font-size: 0.9rem;
    }
    
    .premium-features i {
        font-size: 1rem;
    }
}

/* เพิ่ม CSS สำหรับ notification */
.notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 12px 24px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    gap: 8px;
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.notification.show {
    transform: translateY(0);
    opacity: 1;
}

.notification.success {
    background: #4CAF50;
    color: white;
}

.notification.error {
    background: #f44336;
    color: white;
}

.notification i {
    font-size: 1.2em;
}

@media (max-width: 768px) {
    .notification {
        left: 20px;
        right: 20px;
        text-align: center;
        justify-content: center;
    }
}