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

body {
    font-family: Arial, sans-serif;
    background: #f7f8f5;
    color: #1f2933;
    min-height: 100vh;
}

.app {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.card {
    width: 100%;
    max-width: 420px;
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

h1 {
    font-size: 48px;
    text-align: center;
    margin-bottom: 8px;
}

.subtitle {
    text-align: center;
    color: #667085;
    margin-bottom: 32px;
}

h2 {
    font-size: 24px;
    margin-bottom: 8px;
}

.description {
    color: #667085;
    margin-bottom: 24px;
}

form {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

input {
    width: 100%;
    padding: 13px 14px;
    border: 1px solid #d0d5dd;
    border-radius: 10px;
    font-size: 15px;
}

input:focus {
    outline: none;
    border-color: #4f7d5a;
}

button {
    border: none;
    border-radius: 10px;
    padding: 14px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    background: #4f7d5a;
    color: white;
}

button:hover {
    opacity: 0.9;
}

#message {
    margin-top: 18px;
    text-align: center;
    line-height: 1.6;
}

textarea,
select {
    width: 100%;
    padding: 13px 14px;
    border: 1px solid #d0d5dd;
    border-radius: 10px;
    font-size: 15px;
    font-family: inherit;
    margin-bottom: 14px;
}

textarea {
    resize: vertical;
}

label {
    display: block;
    text-align: left;
    margin-bottom: 8px;
    font-weight: 600;
}

.chat-card {
    max-width: 600px;
}

.chat-messages {
    height: 420px;
    overflow-y: auto;
    padding: 16px;
    margin-bottom: 16px;
    border: 1px solid #e4e7ec;
    border-radius: 14px;
    background: #f9fafb;
}

.chat-message {
    max-width: 80%;
    padding: 12px 14px;
    margin-bottom: 10px;
    border-radius: 12px;
    line-height: 1.5;
    white-space: pre-wrap;
}

.student-message {
    margin-left: auto;
    background: #4f7d5a;
    color: white;
}

.assistant-message {
    margin-right: auto;
    background: white;
    border: 1px solid #e4e7ec;
}

.chat-input-area {
    display: flex;
    flex-direction: column;
}

.chat-input-area textarea {
    margin-bottom: 10px;
}