:root {
    --petroleum-900: #001d23;
    --petroleum-800: #002f38;
    --petroleum-700: #083e48;
    --petroleum-600: #245660;
    --petroleum-500: #406e77;
    --petroleum-400: #5d868e;
    --petroleum-300: #7aa0a8;
    --petroleum-200: #99b5ba;
    --petroleum-100: #b8cbcf;
    --petroleum-50: #d6e2e4;
    --petroleum-25: #f5f8f8;
    --aqua-500: #28a1ad;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

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

body {
    font-family: 'IBM Plex Sans', sans-serif;
    padding: 20px;
    background-color: var(--petroleum-25);
    color: var(--petroleum-700);
}

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

@media (min-width: 1440px) {
    .container {
        display: flex;
        flex-direction: row;
        align-items: flex-start;
        gap: 30px;
        max-width: 1400px;
    }

    .form-section {
        flex: 0 1 470px;
        min-width: 470px;
        margin-bottom: 0;
    }

    .diploma-section {
        flex: 1 1 auto;
        min-width: 0;
    }
}

h1 {
    text-align: center;
    margin-bottom: 30px;
}

h2 {
    margin-bottom: 20px;
}

.form-section {
    background-color: white;
    padding: 24px;
    margin-bottom: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 29, 35, 0.1);
}

.form-group {
    margin-bottom: 20px;
}

.form-group-section {
    margin-bottom: 30px;
    padding-bottom: 25px;
    border-bottom: 1px solid var(--petroleum-100);
}

.form-group-section:first-of-type {
    padding-bottom: 0;
}

.form-group-section:last-of-type {
    border-bottom: none;
    margin-bottom: 10px;
}

.instructors-form-group {
    display: flex;
    gap: 20px;
    margin-bottom: 0;
}

.instructor-form-column {
    flex: 1;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    color: var(--petroleum-600);
    font-size: 14px;
}

input[type="text"],
input[type="password"],
input[type="date"],
textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--petroleum-100);
    border-radius: 6px;
    font-size: 14px;
    font-family: 'IBM Plex Sans', sans-serif;
    color: var(--petroleum-700);
    background-color: white;
}

input::placeholder,
textarea::placeholder {
    color: var(--petroleum-300);
}

input::-webkit-input-placeholder,
textarea::-webkit-input-placeholder {
    color: var(--petroleum-300);
}

select {
    width: 100%;
    padding: 10px 12px;
    padding-right: 40px;
    border: 1px solid var(--petroleum-100);
    border-radius: 6px;
    font-size: 14px;
    font-family: 'IBM Plex Sans', sans-serif;
    color: var(--petroleum-600);
    background-color: white;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6' fill='none'%3E%3Cpath d='M1 1L5 5L9 1' stroke='%237aa0a8' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    cursor: pointer;
}

input[type="text"]:hover,
input[type="password"]:hover,
input[type="date"]:hover,
textarea:hover {
    border-color: var(--petroleum-300);
}

select:hover {
    border-color: var(--petroleum-300);
}

input[type="text"]:focus,
input[type="password"]:focus,
input[type="date"]:focus,
textarea:focus {
    outline: 2px solid var(--aqua-500);
    outline-offset: 2px;
    border: 1px solid var(--petroleum-100);
}

select:focus {
    outline: 2px solid var(--aqua-500);
    outline-offset: 2px;
    border: 1px solid var(--petroleum-100);
}

textarea {
    resize: vertical;
}

.required-mark {
    font-weight: normal;
    color: var(--petroleum-300);
}

.char-count {
    display: block;
    margin-top: 4px;
    font-size: 12px;
    color: var(--petroleum-500);
}

.update-notice {
    display: none;
    margin-top: 16px;
    font-size: 14px;
    color: var(--petroleum-600);
}

.update-notice.show {
    display: block;
}

button {
    min-width: 120px;
    padding: 12px 24px;
    background-color: var(--petroleum-700);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    font-family: 'IBM Plex Sans', sans-serif;
    transition: background-color 0.2s;
    text-align: center;
    display: block;
}

button:hover {
    background-color: var(--petroleum-800);
}

button:active {
    background-color: var(--petroleum-900);
}

.diploma-section {
    background-color: white;
    padding: 24px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 29, 35, 0.1);
}

.diploma-preview {
    border: 3px solid var(--petroleum-500);
    padding: 40px;
    min-height: 200px;
    background-color: #fff;
    margin-bottom: 20px;
    position: relative;
    display: flex;
    flex-direction: column;
    text-align: center;
}

.diploma-preview > p {
    margin: auto;
    color: var(--petroleum-700);
}

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

.diploma-logo {
    max-width: 120px;
    height: auto;
    margin-bottom: 35px;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.diploma-content h1 {
    color: var(--petroleum-700);
    font-size: 24px;
    font-weight: bold;
    margin-bottom: 20px;
}

.diploma-content .certifies-text {
    color: var(--petroleum-500);
    font-size: 12px;
    margin-bottom: 10px;
}

.diploma-content .student-name {
    color: var(--petroleum-700);
    font-size: 16px;
    font-weight: bold;
    margin-bottom: 8px;
}

.diploma-content .student-title {
    color: var(--petroleum-700);
    font-size: 10px;
    font-style: italic;
    margin-bottom: 6px;
}

.diploma-content .completed-text {
    color: var(--petroleum-500);
    font-size: 12px;
    margin-bottom: 10px;
}

.diploma-content .course-name {
    color: var(--petroleum-700);
    font-size: 16px;
    font-weight: bold;
    margin-bottom: 8px;
}

.diploma-content .course-desc {
    color: var(--petroleum-500);
    font-size: 12px;
    margin-bottom: 30px;
    line-height: 1.5;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
    white-space: pre-line;
}

.diploma-content .diploma-details {
    text-align: center;
    margin-top: 10px;
    padding-top: 0;
    border-top: none;
}

.diploma-content .diploma-details p {
    color: var(--petroleum-700);
    margin-bottom: 7px;
    font-size: 11px;
}

.diploma-content .diploma-details strong {
    color: var(--petroleum-700);
}

.diploma-content .issued-date {
    color: var(--petroleum-500);
    font-size: 12px;
    margin-top: 30px;
    font-style: italic;
}

.instructors-section {
    display: flex;
    justify-content: space-between;
    margin-top: 50px;
    padding-top: 30px;
    border-top: 2px solid var(--petroleum-200);
}

.instructor-column {
    flex: 1;
    text-align: center;
}

.instructor-column:first-child {
    padding-right: 20px;
}

.instructor-column:last-child {
    padding-left: 20px;
}

.instructor-name {
    color: var(--petroleum-700);
    font-size: 11px;
    margin-bottom: 6px;
}

.instructor-title {
    color: var(--petroleum-700);
    font-size: 9px;
    font-style: italic;
    margin-top: 0;
}


.login-container {
    max-width: 400px;
    margin: 100px auto;
    background-color: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 2px 10px rgba(0, 29, 35, 0.15);
}

.login-container h1 {
    text-align: left;
    margin-bottom: 30px;
    color: var(--petroleum-700);
}

.error-message {
    color: #d32f2f;
    margin-top: 10px;
    margin-bottom: 16px;
    display: none;
    font-size: 14px;
}

.error-message.show {
    display: block;
}