/* =========================
   RESET
========================= */

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

body {
    font-family:
        Inter,
        Arial,
        sans-serif;
    background: #08090d;
    color: #f5f5f7;
    min-height: 100vh;
}


/* =========================
   NAVBAR
========================= */

.navbar {
    height: 70px;
    padding: 0 7%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid #1d1f27;
    background: rgba(8, 9, 13, 0.96);
}

.logo {
    font-size: 21px;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.logo span {
    color: #8b5cf6;
    margin-right: 6px;
}

.nav-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: #9ca3af;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #22c55e;
    box-shadow: 0 0 10px #22c55e;
}


/* =========================
   CONTAINER
========================= */

.container {
    width: min(1100px, 90%);
    margin: auto;
}


/* =========================
   HERO
========================= */

.hero {
    text-align: center;
    padding: 75px 0 55px;
}

.badge {
    display: inline-block;
    padding: 7px 13px;
    border: 1px solid #30234f;
    border-radius: 999px;
    color: #a78bfa;
    background: #120d1f;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
    margin-bottom: 22px;
}

.hero h1 {
    font-size: clamp(42px, 6vw, 70px);
    line-height: 1.05;
    letter-spacing: -3px;
}

.hero h1 span {
    color: #8b5cf6;
}

.hero p {
    max-width: 650px;
    margin: 22px auto 0;
    color: #9ca3af;
    font-size: 17px;
    line-height: 1.7;
}


/* =========================
   QUICK CONCEPTS
========================= */

.quick-start {
    margin-bottom: 45px;
}

.quick-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    margin-bottom: 16px;
}

.quick-header h2 {
    font-size: 18px;
    margin-bottom: 5px;
}

.quick-header p {
    color: #666a75;
    font-size: 13px;
}


/* =========================
   ADD CONCEPT BUTTON
========================= */

.add-concept-button {
    flex-shrink: 0;

    border: 1px solid #30234f;
    border-radius: 12px;

    background: #120d1f;
    color: #c4b5fd;

    padding: 10px 16px;

    font-family: inherit;
    font-size: 12px;
    font-weight: 700;

    cursor: pointer;

    transition:
        transform 0.2s ease,
        background 0.2s ease,
        border-color 0.2s ease,
        box-shadow 0.2s ease,
        color 0.2s ease;
}

.add-concept-button:hover {
    transform: translateY(-2px);
    background: #191326;
    border-color: #8b5cf6;
    color: #ffffff;

    box-shadow:
        0 8px 25px rgba(139, 92, 246, 0.18);
}

.add-concept-button:active {
    transform: translateY(0);
}


/* =========================
   TOPIC GRID
========================= */

.topic-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}


/* =========================
   TOPIC CARD
========================= */

.topic-card {
    width: 100%;
    min-height: 135px;

    background: #101116;

    border: 1px solid #242630;
    border-radius: 16px;

    padding: 18px;

    color: #ffffff;

    text-align: left;

    cursor: pointer;

    font-family: inherit;

    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;

    transition:
        transform 0.2s ease,
        border-color 0.2s ease,
        background 0.2s ease,
        box-shadow 0.2s ease;
}

.topic-card:hover {
    transform: translateY(-4px);

    background: #15101f;

    border-color: #8b5cf6;

    box-shadow:
        0 8px 30px rgba(139, 92, 246, 0.15);
}

.topic-card:active {
    transform: translateY(-1px);
}

.topic-icon {
    display: block;
    font-size: 27px;
    margin-bottom: 13px;
}

.topic-card strong {
    display: block;
    color: #ffffff;
    font-size: 14px;
    margin-bottom: 6px;
}

.topic-card small {
    display: block;
    color: #777b86;
    font-size: 11px;
}


/* =========================
   CUSTOM QUICK CONCEPT
========================= */

.custom-topic-wrapper {
    position: relative;
    width: 100%;
    min-width: 0;
}

.custom-topic-card {
    width: 100%;
}


/* =========================
   DELETE CONCEPT BUTTON
========================= */

.delete-concept-button {
    position: absolute;

    top: 10px;
    right: 10px;

    width: 27px;
    height: 27px;

    display: flex;
    align-items: center;
    justify-content: center;

    padding: 0;

    border: 1px solid #30234f;
    border-radius: 50%;

    background: #120d1f;
    color: #777b86;

    font-family: Arial, sans-serif;
    font-size: 18px;
    font-weight: 400;

    line-height: 1;

    cursor: pointer;

    opacity: 0;

    transform: scale(0.8);

    transition:
        opacity 0.2s ease,
        transform 0.2s ease,
        background 0.2s ease,
        border-color 0.2s ease,
        color 0.2s ease;
}

.custom-topic-wrapper:hover .delete-concept-button {
    opacity: 1;
    transform: scale(1);
}

.delete-concept-button:hover {
    background: #21151a;
    border-color: #7f3f49;
    color: #fca5a5;
    transform: scale(1.08);
}

.delete-concept-button:focus {
    opacity: 1;
    outline: none;
    border-color: #8b5cf6;
}


/* =========================
   LEARNING SECTION
========================= */

.learning-section {
    margin-bottom: 22px;
}

.section-heading {
    margin-bottom: 13px;
}

.section-heading h2 {
    font-size: 18px;
    margin-bottom: 5px;
}

.section-heading p {
    color: #666a75;
    font-size: 13px;
}


/* =========================
   LEARNING MODES
========================= */

.mode-selector {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.mode {
    border: 1px solid #242630;
    background: #101116;
    color: white;

    border-radius: 14px;

    padding: 18px;

    display: flex;
    align-items: center;
    gap: 14px;

    text-align: left;

    cursor: pointer;

    font-family: inherit;

    transition: 0.2s;
}

.mode:hover {
    border-color: #4c3b72;
    transform: translateY(-2px);
}

.mode.active {
    border-color: #8b5cf6;
    background: #15101f;
}

.mode-icon {
    font-size: 25px;
}

.mode strong {
    display: block;
    font-size: 14px;
    margin-bottom: 5px;
}

.mode small {
    color: #858894;
}


/* =========================
   WORKSPACE
========================= */

.workspace {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}

.input-card,
.response-card {
    background: #101116;
    border: 1px solid #242630;
    border-radius: 18px;
    padding: 25px;
    min-height: 360px;
}


/* =========================
   INPUT CARD
========================= */

.card-header h2 {
    font-size: 19px;
    margin-bottom: 8px;
}

.card-header p {
    color: #858894;
    font-size: 13px;
    line-height: 1.5;
}

textarea {
    width: 100%;
    height: 190px;

    margin-top: 22px;

    resize: none;

    background: #08090d;

    border: 1px solid #242630;
    border-radius: 12px;

    padding: 16px;

    color: white;

    font-size: 14px;

    outline: none;

    font-family: inherit;
}

textarea:focus {
    border-color: #8b5cf6;
}

textarea::placeholder {
    color: #555863;
}


/* =========================
   BOTTOM BAR
========================= */

.bottom-bar {
    margin-top: 15px;

    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 15px;
}

.example {
    color: #666a75;
    font-size: 11px;
}

.example span {
    color: #8b5cf6;
}

.ask-button {
    border: none;
    border-radius: 10px;

    background: #8b5cf6;

    color: white;

    padding: 12px 18px;

    font-weight: 700;

    cursor: pointer;

    font-family: inherit;

    transition: 0.2s;
}

.ask-button:hover {
    background: #7c3aed;
    transform: translateY(-1px);
}


/* =========================
   RESPONSE CARD
========================= */

.response-header {
    display: flex;
    align-items: center;
    gap: 9px;

    padding-bottom: 18px;

    border-bottom: 1px solid #242630;
}

.response-header span {
    color: #8b5cf6;
}

.empty-state {
    text-align: center;
    margin-top: 80px;
}

.empty-icon {
    width: 55px;
    height: 55px;

    display: flex;
    align-items: center;
    justify-content: center;

    margin: auto;

    border-radius: 15px;

    background: #191326;

    color: #a78bfa;

    font-size: 25px;
}

.empty-state h3 {
    margin-top: 18px;
    font-size: 15px;
}

.empty-state p {
    margin-top: 8px;

    color: #666a75;

    font-size: 13px;

    line-height: 1.5;
}


/* =========================
   AI RESPONSE
========================= */

.ai-response {
    margin-top: 22px;

    color: #d1d5db;

    font-size: 14px;

    line-height: 1.8;
}

.ai-response h3 {
    color: white;
    margin-bottom: 12px;
}

.ai-response .highlight {
    color: #a78bfa;
    font-weight: 700;
}

.concept-box {
    background: #15101f;

    border: 1px solid #30234f;

    border-radius: 12px;

    padding: 15px;

    color: #c4b5fd;

    line-height: 1.7;
}

.mistake-box {
    background: #21151a;

    border: 1px solid #5c3038;

    border-radius: 12px;

    padding: 13px;

    color: #fca5a5;
}


/* =========================
   FUTURE VISION
========================= */

.future-vision {
    margin-top: 24px;

    padding: 22px;

    display: flex;
    align-items: flex-start;

    gap: 18px;

    background: #101116;

    border: 1px solid #242630;

    border-radius: 16px;
}

.future-icon {
    font-size: 25px;
}

.future-vision h2 {
    font-size: 16px;
    margin-bottom: 7px;
}

.future-vision p {
    color: #777b86;

    font-size: 12px;

    line-height: 1.7;

    max-width: 800px;
}


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

footer {
    text-align: center;

    color: #444752;

    font-size: 12px;

    padding: 45px 0 25px;
}

.prototype-label {
    margin-top: 5px;
    color: #30323a;
}


/* =========================
   MOBILE
========================= */

@media (max-width: 750px) {

    .navbar {
        padding: 0 5%;
    }

    .hero {
        padding: 50px 0 40px;
    }

    .hero h1 {
        font-size: 42px;
        letter-spacing: -2px;
    }

    .hero p {
        font-size: 14px;
    }

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

    .mode-selector {
        grid-template-columns: 1fr;
    }

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

    .bottom-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .ask-button {
        width: 100%;
    }

    .future-vision {
        flex-direction: column;
    }

    .delete-concept-button {
        opacity: 1;
        transform: scale(1);
    }
}


/* =========================
   QUICK CONCEPT MOBILE
========================= */

@media (max-width: 700px) {

    .quick-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .add-concept-button {
        width: 100%;
    }
}


/* =========================
   SMALL MOBILE
========================= */

@media (max-width: 480px) {

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

    .hero h1 {
        font-size: 36px;
    }

    .nav-status {
        display: none;
    }

}